,,smithsonian ,,annals ,,of ,,flight ,,volume #a ,,number #b ,the ,first ,airplane ,diesel ,engine3 ,packard ,model ,,dr-#ihj of #aibh ,robert ,b4 ,meyer ,,smithsonian ,,institution ,,national ,,air ,,museum ,,washington1 ,d4,c4 ,illustration3 ,frontispiece--,president ,herbert ,hoover 7in front of microphones7 presenting the ,collier ,trophy to ,alvan ,macauley 7nearest engine71 ,president of the ,packard ,motor ,car ,co41 on ,march #ca1 #aicb 7although the award was for #aica74 ,also present were ,hiram ,bingham1 ,u4,s4 ,senator from ,connecticut 7nearest pillar71 ,clarence ,m4 ,young1 ,director of ,aeronautics1 ,u4,s4 ,department of ,commerce 7between ,macauley and ,hoover71 and ,amelia ,earhart1 first woman to fly across the ,atlantic ,ocean 7between ,macauley and the engine74 ,in the foreground is a cutaway ,packard diesel aeronautical engine and directly in front of ,senator ,bingham is the ,collier ,trophy1 ,america's highest aviation award4 7,smithsonian photo ,a#dhhbe47 ,,smithsonian ,,annals ,,of ,,flight ,,volume #a ,,number #b ,the ,first ,airplane ,diesel ,engine3 ,packard ,model ,,dr-#ihj of #aibh ,,robert ,b4 ,,meyer ,curator of ,flight ,propulsion ,,smithsonian ,,institution ,,national ,,air ,,museum ,,washington1 ,d4,c4 #aifd ,the following microfilm prints are available at the ,smithsonian ,institution3 ,the ,packard ,diesel ,aircraft ,engine--,a ,new ,chapter in ,transportation ,progress4 ,an advertising brochure produced by the ,packard ,motor ,car ,company in #aicj1 illustrated1 #ag pages4 ,fifty-,hour ,test of the ,engine by the ,packard ,company1 #aicj4 ,text and charts1 #ad pages4 ,fifty-,hour ,test of the ,engine by the ,u4,s4 ,navy in #aica3 ,text and charts1 #bf pages4 ,packard ,instructional ,manual1 #aica4 ,illustrated1 #gd pages4 ,the ,packard ,diesel ,engine1 ,aviation ,institute of ,u4,s4,a4 ,pamphlet ,no4 #ba-;,a1 #aicj4 ,illustrated1 #cb pages4 ,for sale by the ,superintendent of ,documents1 ,u4,s4 ,government ,printing ,office ,washington1 ,d4,c41 #bjdjb--,price #fj cents ,contents ,page ,,acknowledgments vi ,,foreword vii ,,introduction #a ,history #b ,,description #aa ,specifications #aa ,operating ,cycles #ac ,weight-,saving ,features #ae ,diesel ,cycle ,features #bj ,development #bc ,,comments #bg ,,analysis #cc ,advantages #cc ,disadvantages #ce ,,appendix #a4 ,agreement ,between ,hermann ,i4 ,a4 ,dorner and ,packard ,motor ,car ,company #dc #b4 ,packard to ,begin ,building ,diesel ,plane ,engines ,soon #df #c4 ,effect of ,oxygen ,boosting on ,power and ,weight #dg ,acknowledgments ,it is difficult to acknowledge fully the assistance given by persons and museums for the preparation of this book4 ,however1 ,i wish especially to thank ,hugo ,t4 ,byttebier1 engine historian1 ,buenos ,aires1 ,argentina2 ,dipl4 ,ing4 ,hermann ,i4 ,a4 ,dorner1 diesel designer1 ,hanover1 ,germany2 ,harold ,e4 ,morehouse1 and ,c4 ,h4 ,wiegman1 ,lycoming ,engines1 ,williamsport1 ,pennsylvania2 ,barry ,tully1 ,goodyear ,aircraft1 ,akron1 ,ohio2 ,richard ,s4 ,allen1 aviation author1 ,round ,lake1 ,new ,york2 ,william ,h4 ,cramer1 brother of ,parker ,d4 ,cramer1 ,wantagh1 ,new ,york2 ,erik ,hildes-,heim1 ,early ,bird and aviation historian1 ,fairfield1 ,connecticut4 ,i am particularly grateful to curators of the following museums who have been so generous in their assistance3 ,deutsches ,museum1 ,munich1 ,germany 7,dipl4 ,ing4 ,w4 ,jackle72 ,henry ,ford ,museum1 ,dearborn1 ,michigan 7,leslie1 ,r4 ,henry72 ,u4,s4 ,air ,force ,museum1 ,wright-,patterson ,air ,force ,base1 ,dayton1 ,ohio 7,maj4 ,robert ,l4 ,bryant1 ,jr41 director72 ,science ,museum1 ,london1 ,england 7,lt4 ,comdr4 7,e7 ,w4 ,j4 ,tuck1 ,royal ,navy74 ,the preparation of this paper could not have been accomplished without the aid of the ,national ,air ,museum of the ,smithsonian ,institution and the help of ,philip ,s4 ,hopkins1 director1 and ,paul ,e4 ,garber1 head curator and historian4 ,foreword ,in this second number of the ,smithsonian ,annals of ,flight1 ,robert ,b4 ,meyer ,jr41 curator and head of the flight propulsion division1 tells the story of the first oil-burning engine to power an airplane1 the ,packard diesel engine of #aibh1 now in the collections of the ,national ,air ,museum4 ,the author's narrative1 well illustrated with drawings and photographs1 provides a historical background for the development of the engine1 and a technical description that includes specifications and details of performance4 ,it also contains comments from men and women who flew planes powered by the ,packard diesel4 ,the author concludes with an analysis of the engine's advantages and disadvantages4 ,,philip ,s4 ,,hopkins ,director1 ,national ,air ,museum #cj ,july #aifd ,introduction ,on display in the ,national ,air ,museum1 ,smithsonian ,institution1 is the first oil-burning engine to power an airplane4 ,its label reads3 ,packard ,diesel ,engine--#aibh--,this first compression-ignition engine to power an airplane developed #bbe hp at #aiej revolutions per minute4 ,it was designed under the direction of ,l4 ,m4 ,woolson4 ,in #aica1 a production example of this engine powered a ,bellanca airplane to an #hd hour and #cc minute nonrefueled duration record which has never been equalled4--,weight_/power ratio3 #b4bf lb per hp--,gift of ,packard ,motor ,car ,co4 ,illustration3 ,figure #a 7left74--,front view of first ,packard diesel1 #aibh4 ,note hoop holding cylinders in place and absence of venturi throttles4 ,this engine was equipped with an air pressure starting system4 7,smithsonian photo ,a#bchh47 ,illustration3 ,figure #b 7right74--,left side view of first ,packard diesel1 #aibh4 ,heywood starter 7air7 fitting shown on the head of the next to lowest cylinder4 7,smithsonian photo ,a#bchh;,c47 ,this revolutionary engine was created in the short time of one year4 ,within two years of its introduction in #aibh1 airplane diesel engines were being tested in ,england by ,rolls-,royce1 in ,france by ,panhard1 in ,germany by ,junkers1 in ,italy by ,fiat1 and in the ,united ,states by ,guiberson4 ,packard had demonstrated to the world the remarkable economy and safety of the airplane diesel engine1 and the response was immediate and favorable4 ,the novelty and performance of the ,packard diesel assured it a large and attentive audience wherever it was exhibited4 ,yet in spite of its performance record the engine was doomed to failure by reason of its design1 and it was further handicapped by having been rushed into production before it could be thoroughly tested4 ,history ,the official beginning of the ,packard diesel engine can be traced to a license agreement dated ,august #ah1 #aibg1 between ,alvan ,macauley1 president of the ,packard ,motor ,car ,company of ,detroit1 ,michigan1 and ,dipl4 ,ing4 ,hermann ,i4 ,a4 ,dorner1 a diesel engine inventor of ,hanover1 ,germany4#a ,before the agreement was drawn up1 ,capt4 ,lionel ,m4 ,woolson1 chief aeronautical engineer for ,packard1 tested an air-cooled and a water-cooled diesel that ,dorner had designed and built in ,germany4#b ,both engines attained the then high revolutions per minute of #bjjj and proved efficient and durable4 ,they demonstrated the practicability of ,dorner's patented solid type of fuel injection which formed the basis of the ,packard diesel's design4#c ,using elements from ,dorner's engines1 ,woolson and ,dorner designed the ,packard diesel with the help of ,packard engineers and ,dorner's assistant1 ,adolph ,widmann4 ,woolson was responsible for the weight-saving features1 and ,dorner for the combustion system4 ,the historic first flight took place on ,september #ai1 #aibh1 at the ,packard proving grounds in ,utica1 ,michigan1 just a year and a month from the day ,dorner agreed to join the ,packard team4 ,woolson and ,walter ,e4 ,lees1 ,packard's chief test pilot1 used a ,stinson ,,sm-#a;,,dx ,detroiter4 ,the flight was so successful1 and later tests were so encouraging1 that ,packard built a #fej1jjj plant during the first half of #aibi solely for the production of its diesel engine4 ,the factory was designed to employ more than #fjj men1 and #ejj engines a month were to have been manufactured by ,july #aibi4d ,illustration3 ,figure #c4--;,alvan ,macauley 7left71 ,president of the ,packard ,motor ,car ,co4 and ,col4 ,charles ,a4 ,lindbergh with the original ,packard diesel-powered ,stinson ,detroiter in the background1 #aibi4 7,smithsonian photo ,a#dhcai;,d47 ,the engine's first cross-country flight was accomplished on ,may #ac1 #aibi1 when ,lees flew the ,stinson ,,sm-#a;,,dx ,detroiter from ,detroit1 ,michigan1 to ,norfolk1 ,virginia1 carrying ,woolson to the annual field day of the ,national ,advisory ,committee for ,aeronautics at ,langley ,field4 ,the #gjj-mile trip was flown in #f-a_/b hours1 and the cost of the fuel consumed was #d4fh4 ,had the airplane been powered with a comparable gasoline engine1 the fuel cost would have been about #e times as great4#e ,on ,march #i1 #aicj1 using the same airplane and engine1 ,lees and ,woolson flew from ,detroit1 ,michigan1 to ,miami1 ,florida1 a distance of #aajj miles in #aj hours and #ae minutes with a fuel cost of #h4ej4 ,the production engine1 slightly refined from the original1 received the first approved type certificate issued for any diesel aircraft engine on ,march #f1 #aicj4 ,the ,department of ,commerce granted certificate no4 #dc after the ,packard ,company had ground- and flight-tested this type of engine for approximately #cch1jjj hp hr1 or about #aejj hr of operation4#f ,illustration3 ,figure #d4--;,dipl4 ,ing4 ,hermann ,i4 ,a4 ,dorner1 #aicj4 ,german diesel engine designer1 was responsible for the ,packard ,,dr-#ihj aircraft engine4 7,smithsonian photo ,a#dhfde47 ,illustration3 ,figure #e4--;,capt4 ,lionel ,m4 ,woolson1 #aica4 ,chief ,aeronautical ,engineer1 ,packard ,motor ,car ,co4 ,designer of ,packard ,,dr-#ihj diesel engine4 7,smithsonian photo ,a#dhfde;,a47 ,one of the early production versions powered a ,bellanca ,pacemaker which was piloted by ,lees and his assistant ,frederic ,a4 ,brossy to a world's nonrefueling heavier-than-air duration record4 ,the flight lasted for #hd hours1 #cc minutes from ,may #be through #bh1 #aica1 over ,jacksonville1 ,florida4 ,this event was so important that it was the basis of the following editorial1 published in the ,july #aica issue of ,aviation1#g which summarizes so well the progress made by the diesel engine over a #c-year period and the hope held for its future3 ,a ,,record ,,crosses ,,the ,,atlantic--,the ,diesel engine took its first step toward acceptance as a powerplant for heavier-than-air craft when1 in the summer of #aibh1 a diesel-powered machine first flew4 ,the second step was made at the #aicj ,detroit show1 when the engine went on commercial sale4 ,the third was accomplished last month1 when a plane with a compression-ignition engine using furnace oil as a fuel circled over the beaches around ,jacksonville for #hd hours and inscribed its performance upon the books as a world's record--the longest flight ever made without intermediate refueling4 ,with the passing of the refueling-duration excitement1 and with the apparent decision to allow that record to stand permanently at its present level1 trials for straight time in the air without replenishment of supplies begin to regain a proper degree of appreciation4 ,no other record1 unless it be some of those for speed with substantial dead loads1 is of such importance as the non-stop distance and duration marks4 ,no other has such bearing upon precisely those qualities of aerodynamic efficiency1 fuel economy1 and reliability of airplane and powerplant that most affect commercial usefulness4 ,it is more than three years since the duration record left ,american shores1 and it has been more than doubled in that time4 ,its return is very welcome4 ,it is doubly welcome for being made with a fundamentally new type of engine4 ,the diesel principle is not a commercial monopoly4 ,it is open to anyone4 ,already two different designs in ,america1 and one or two in ,europe1 have been in the air4 ,for certain purposes1 at least1 it seems reasonable to expect that its special advantages will bring it into widespread use4 ,every practical demonstration of the progress of the diesel toward realizing its theoretical possibilities in the air as it has realized them on the land and at sea is a bit of progress toward better and more economical commercial flying1 and so benefits the whole industry4 ,the fourth1 and next1 main element in the demonstration will be provided when diesels go into regular service on some well-known transport line as standard equipment1 and the accumulation of data on performance under normal service conditions begins4 ,we believe that that will happen before the end of #aicb4 ,many men1 from ,dr4 ,rudolf ,diesel to ,walter ,lees and ,frederic ,brossy1 have had direct or indirect hands in the making of this record4 ,the greatest of all contributions was that of ,lionel ,m4 ,woolson1 who created the engine and flew with it in every test and brought it through its early troubles to the point of readiness for the commercial market4 ,the flight that lasted four days and three nights is his memorial1 quite as much as is the bronze plaque unveiled last ,april in the ,detroit show hangar4 ,illustration3 ,figure #f4--,stinson ,,sm-#a;,,dx ,detroiter4 ,this airplane1 powered with original ,packard ,,dr-#ihj diesel engine1 made the world's first diesel-powered flight on ,september #ai1 #aibh4 7,photo courtesy of ,henry ,ford ,museum1 ,dearborn1 ,michigan47 ,illustration3 ,figure #g4--,packard-,bellanca ,pacemaker4 ,this airplane1 powered by a ,packard ,,dr-#ihj diesel1 holds the world's record for nonrefueling1 heavier-than-air aircraft duration flight4 ,the flight lasted #hd hours1 #cc minutes1 #a-a_/d seconds1 and was completed on ,may #bh1 #aica1 ,jacksonville1 ,florida4 7,smithsonian photo ,a#dhddf;,b47 ,illustration3 ,figure #h4--,verville ,air ,coach1 ,october #aicj4 7,smithsonian photo ,a#dhhdd47 ,illustration3 ,figure #i4--,packard-,bellanca ,pacemaker owned by ,transamerican ,airlines ,corporation and used by ,parker ,d4 ,cramer1 pilot1 and ,oliver ,l4 ,paquette1 radio operator1 in their flight from ,detroit1 ,michigan1 to ,lerwick1 ,shetland ,islands1 summer #aica4 7,smithsonian photo ,a#bjj47 ,illustration3 ,figure #aj4--;,ford #aa-;,,at-#a ,trimotor1 #aicj1 with #c ,packard #bbe-;hp ,,dr-#ihj diesel engines4 ,note special bracing for the outboard nacelles4 7,smithsonian photo ,a#dhcaa;,b47 ,illustration3 ,figure #aa4--,towle ,,ta-#c ,flying ,boat1 #aicj1 with #b ,packard #bbe-;hp ,,dr-#ihj diesel engines4 7,smithsonian photo ,a#dhcai47 ,illustration3 ,figure #ab4--,stewart ,m-#b ,monoplane1 #aicj1 with #b ,packard #bbe-;hp ,,dr-#ihj diesel engines4 7,smithsonian photo ,a#dhcai;,c47 ,illustration3 ,figure #ac4--;,consolidated ,,xpt-#h;,a1 #aicj4 ,this is a ,consolidated ,,pt-#c;,a powered by a ,,dr-#ihj ,packard diesel4 7,smithsonian photo ,a#dhcai;,e47 ,the ,robert ,j4 ,collier ,trophy1 ,america's highest aviation award1 was won by the ,packard ,motor ,car ,company in #aica for its development of the diesel engine4 ,the formal presentation was made at the ,white ,house1 ,march #ca1 #aicb1 by ,president ,hoover on behalf of the ,national ,aeronautic ,association4 ,alvan ,macauley1 president of the ,packard ,motor ,car ,company1 accepted the trophy1 saying3 ,we do not claim1 ,mr4 ,president1 that we have reached the final development even though our diesel aircraft engine is an accomplished fact and we have the pioneer's joy of knowing that we have successfully accomplished what had not been done before4444#h ,the amazing early success of the ,packard diesel is illustrated by the following chronological summary3 #aibg--,license agreement signed between ,alvan ,macauley and ,hermann ,i4 ,a4 ,dorner to permit designing of the engine4 #aibh--;,first flight of a diesel-powered airplane accomplished4 #aibi--;,first cross-country flights accomplished4 #aicj--,packard diesels were sold on the commercial market and were used to power airplanes manufactured by a dozen different ,american companies4 #aica--,world's official duration record for nonrefueled heavier-than-air flight4 ,first flight across the ,atlantic by a diesel-powered airplane4 #aicb--,packard diesels tested successfully in the ,goodyear nonrigid airship ,defender4#i ,official ,american altitude record for diesel-powered airplanes established 7this record still stands74 ,in spite of this promising record1 the project died in #aicc4 ,the ,december #aiej issue of ,pegasus gave two reasons for the failure of the engine3 ,one blow had already been dealt the program through the accidental death of ,capt4 ,l4 ,m4 ,woolson1 ,packard's chief engineer in charge of the ,diesel development1 on ,april #bc1 #aicj4 ,then the ,big ,depression took its toll in research work everywhere and ,packard was not excepted4 ,illustration3 ,figure #ad4--,walter ,e4 ,lees1 ,packard chief test pilot 7in cabin7 and ,frederic ,a4 ,brossy1 ,packard test pilot1 before taking off on their world's record1 nonrefueling1 heavier-than-air aircraft duration flight1 which lasted #hd hours1 #cc minutes1 and #a-a_/d seconds4 7,smithsonian photo ,a#dhddf;,e47 ,illustration3 ,figure #ae4--,walter ,e4 ,lees1 official timer1 and ,ray ,collins1 manager1 #aicj ,national ,air ,tour1 with their official airplane1 a ,packard diesel ,waco ,taper ,wing1 at ,packard proving grounds near ,detroit4 7,smithsonian photo ,a#diddi47 ,illustration3 ,figure #af4--;,capt4 ,karl ,fickes1 acting head of ,goodyear's airship operations1 pointing out features on one of the ,defender's ,packard diesel engines to ,roland ,j4 ,blair1 ,goodyear airship pilot1 ,akron1 ,ohio4 ,from ,aero ,digest1 ,february #aicb4 7,smithsonian photo ,a#difgd47 ,the engine did not fail for the above mentioned reasons4 ,capt4 ,woolson's death was indeed unfortunate1 but there were others connected with the project who carried on his work for three years after he passed away4 ,the big depression was also unfortunate1 but it did not stop aeronautical engine development4 ,it was a time when such an engine would have been most welcome if it had been produced in large enough numbers to bring the price down to compare favorably pricewise with gas engines of the same horsepower class4#aj ,the ,packard diesel failed because it was not a good engine4 ,it was an ingenious engine1 and two of the several features it pioneered 7the use of magnesium and of a dynamically balanced crankshaft7 survive in modern reciprocating engine designs4 ,in addition1 when it was first introduced1 no other engine could match it for economical fuel consumption and fuel safety4 ,it also had other less important advantages1 but its disadvantages outweighed all these advantages1 as will be seen4 ,description ,specifications ,the following specifications are for the production engine and its prototypes1 known as the model ,,dr-#ihj3aa ,type #d-stroke cycle diesel ,cylinders #i--static radial configuration ,cooling ,air ,fuel injection ,directly into cylinders at a pressure of #fjjj psi ,valves ,poppet type1 one per cylinder ,ignition ,compression--glow plugs for starting--air compression #ejj psi at #ajjj ,f4 ,fuel ,distillate or furnace oil ,horsepower #bbe at #aiej rpm ,bore and stroke #d-ac_/af in4 #f in4 ,compression ratio #af3a--maximum combustion pressure #aejj psi ,displacement #ihb cu in4 ,weight #eaj lb without propeller hub ,weight-horsepower ratio #b4bf lb hp ,where manufactured ,u4,s4,a4 ,fuel consumption 4#df lb per hp_/hr at full power ,fuel consumption 4#dj lb per hp_/hr at cruising ,oil consumption 4#jd lb per hp_/hr ,outside diameter #de-aa_/af in4 ,overall length #cf-c_/d in4 ,optional accessories ,starter--,eclipse electric inertia2 #f volts4 ,special series no4 #g ,generator--,eclipse type ,g-#a2 #f volts ,illustration3 ,figure #ag4--,longitudinal cross section1 ,packard diesel engine ,,dr-#ihj4 7,smithsonian photo ,a#dhhde47 ,illustration3 ,figure #ah4--,transverse cross section1 ,packard diesel engine ,,dr-#ihj4 7,smithsonian photo ,a#dhhdg47 ,illustration3 ,figure #ai4--,right side view of engine1 showing accessories2 ,packard ,motor ,car ,co4 #ej-;hour test1 #aicj4 ,a1 starter2 ,b1 oil filter4 7,smithsonian photo ,a#dhcbc47 ,illustration3 ,figure #bj4--,rear left view of engine1 showing accessories1 ,u4,s4 ,navy #ej-;hour test1 #aica4 ,barrel valve type venturi throttles4 ,a1 starter2 ,b1 oil filter2 ,c1 fuel circulating pump2 ,d1 generator4 7,smithsonian photo ,a#dhcbd;,c47 ,operating ,cycles ,the sequences of operation of a ,packard diesel engine compared with those of a #d-stroke cycle gasoline engine are illustrated in figure #ba4 ,illustration3 ,brief ,analysis of ,action in a ,four-,cycle ,gasoline ,engine ,mixture of air and gasoline enters cylinder from carburetor4 ,mixture is compressed into smaller volume by piston moving upward4 ,an electric spark ignites the compressed mixture causing it to explode4 ,combustion heat increases the cylinder pressure forcing piston downward4 ,momentum carries piston upward which pushes burnt gases out through the exhaust valve4 ,similar ,action in the ,packard-,diesel ,aircraft ,engine ,atmospheric air only1 enters cylinder through single valve4 ,air is so greatly compressed by upward moving piston that it reaches temperature of #ajjj ,f4 ,just before piston is at dead center fuel oil is sprayed into cylinder and spontaneously ignited4 ,power of this explosion is passed to crankshaft in conventional manner4 ,piston forces out burnt gases through same single valve which is cooled by inrush of new air as cycle repeats4 ,figure #ba4--,operating cycles4 7,smithsonian photo ,a#dhhdf47 ,although the size1 weight1 and general arrangement of the ,packard diesel did not differ radically from conventional gasoline engines of a similar type1 there were definite differences caused by the diesel cycle4 ,in the words of ,capt4 ,woolson3#ab ,as this engine operates on an entirely different principle than the gasoline engines used heretofore in aircraft1 it is desirable before launching into a mechanical description to consider first in a general way the principles of operation of the ,diesel cycle as opposed to the ,otto cycle principle on which nearly all gasoline engines operate4 ,the real point of departure between the two systems of operation is the ignition system involved4 ,in the gasoline engine an electric spark is depended upon to fire a combustible mixture of gasoline vapor and air which mixture ratio must be maintained within rather narrow limits to be fired by this method4444 ,in the ,diesel engine1 air alone is introduced into the cylinders1 instead of a mixture of air and fuel as in the gasoline engine1 and this air is compressed into much smaller space than is possible when using a mixture of gasoline and air1 which would spontaneously and prematurely detonate if compressed to this degree4 ,the temperature of the air in the cylinder at the end of the compression stroke of a ,diesel engine operating with a compression ratio of about #af3a is approximately #ajjj degrees ,fahr41 which is far above the spontaneous-ignition temperature of the fuel used4 ,accordingly1 when the fuel is injected in a highly atomized condition at some time previous to the piston reaching the end of its stroke1 the fuel burns as it comes in contact with the highly heated air1 and the greatly increased pressures resulting from the tremendous increase in temperature brought about by this combustion1 acting on the pistons1 drive the engine1 as in the case of the gasoline engine4 ,summing up1 the differences between the ,diesel and gasoline engines start with the fact that the gasoline engine requires a complicated electrical ignition system in order to fire the combustible mixture1 whereas the ,diesel engine generates its own heat to start combustion by means of highly compressed air4 ,this brings about the necessity for injecting the fuel in a well-atomized condition at the time that combustion is desired and the quantities of fuel injected at this time control the amount of heat generated2 that is1 an infinitesimally small quantity of fuel will be burned just as efficiently in the ,diesel engine as a full charge of fuel1 whereas in the gasoline engine the mixture ratio must be kept reasonably constant and1 if the supply of fuel is to be cut down for throttling purposes1 the supply of air must be correspondingly reduced4 ,it is this requirement in a gasoline engine that necessitates an accurate and sensitive fuel-and-air metering device known as the carburetor4 ,the fact that the air supply of a ,diesel engine is compressed and its temperature raised to such a high degree permits the use of liquid fuels with a high ignition temperature4 ,these fuels correspond more nearly to the crude petroleum oil as it issues from the wells and this fact accounts for the much lower cost of ,diesel fuel as compared to the highly refined gasoline needed for aircraft engines4 ,weight-,saving ,features ,in order to be successful in aviation use1 the modern lightweight diesel of the time had to have its weight reduced from #be lb_/hp to #b4e lb_/hp4 ,this required unusual design and construction methods1 as follows3 ,crankcase3 ,it weighed only #cd lb because of three factors3 ,magnesium alloy was used extensively in its construction1 thus saving weight as compared with aluminum alloy1 which was the conventional material at this time4 ,it was a single casting4 ,this saved weight because heavy flanges1 nuts1 and bolts were dispensed with4 ,the cylinders1 instead of being bolted to the crankcase1 as was normal practice1 were held in position by two circular hoops of alloy steel passing over the cylinder flanges4 ,they were tightened to such an extent that at no time did the cylinders transfer any tension loads to the crankcase4 ,this type of fastening actually strengthened the crankcase in contrast to the usual method4 ,for this reason it could be built lighter4 ,the hoops did not always function well4 ,the first job ,i ever did on the ,towle was to patch the holes in the top and bottom of the hull when a cylinder blew off during run-up and nearly beheaded the pilot4#ac ,illustration3 ,figure #bb4--,rear view of engine with rear crankcase cover removed1 showing valve and injector rocker levers and injector control ring mounted on crankcase diaphram4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbc;,d47 ,illustration3 ,figure #bc4--,main crankcase4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbe;,b47 ,illustration3 ,figure #bd4--,rear crankcase cover and gear train3 crankshaft gear drives ,b1 which drives oil pump at ,f4 ,a1 integral with ,b1 drives internal cam gear4 ,b also drives ,c on fuel-circulating pump4 ,d1 driven by crankshaft gear1 drives ,e on generator shaft4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbe;,c47 ,illustration3 ,figure #be4--,master and link connecting rods4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbc;,a47 ,illustration3 ,figure #bf4--;,crankshaft with automatic-timing retarding device on rear end of pivoted- and spring-mounted counterweights4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbc;,b47 ,illustration3 ,figure #bg4--,propeller hub and vibration damper4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbe;,a47 ,crankshaft3 ,since this engine developed the high maximum cylinder pressure of #aejj psi1 it was necessary to protect the crankshaft from the resulting heavy stresses4 ,without such protection the crankshaft would be too large and heavy for practical aeronautical applications4 ,although the maximum cylinder pressures were #aj times as great as the average ones1 they were of short duration4 ,the method of protecting the crankshaft took full advantage of this fact4 ,it consisted of having the counterweights flexibly mounted instead of being rigidly bolted1 as was common practice4 ,the counterweights were pivoted on the crank cheeks4 ,powerful compression springs absorbed the maximum impulses by permitting the counterweights to lag slightly1 yet forced them to travel precisely with the crank cheeks at all other times4 ,propeller ,hub3 ,the propeller is1 of course1 subject to the same stresses as the crankshaft4 ,instead of being rigidly bolted to the shaft as was common practice1 it was further protected from excessive acceleration forces by being mounted in a rubber-cushioned hub4 ,this permitted the use of a lighter propeller and hub4 ,valves3 ,a further weight saving resulted from the use of a single valve for each cylinder instead of two as in the case of conventional gasoline aircraft engines4 7,a diesel engine designed in this manner loses less efficiency than a gasoline one because only air is drawn in during the intake stroke47 ,in addition to the weight saving brought about by having fewer parts in the valve mechanism1 there was an additional advantage since the cylinder heads could be made considerably lighter4 ,illustration3 ,figure #bh4--;,cylinder disassembly1 showing valve and fuel injector4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbd;,d47 ,diesel ,cycle ,features ,although ,woolson designed the ingenious weight-saving features1 ,dorner was responsible for the engine's diesel cycle which employed the solid type of fuel injection4 ,in order to understand ,dorner's contribution1 a brief description of the type of diesel injection pioneered by ,dr4 ,rudolf ,diesel is necessary4 ,his system injected the fuel into the cylinder head with a blast of air supplied by a special air reservoir at a pressure of #ajjj psi or more4 ,known as the air blast type of injection it produced good turbulence1 with the fuel and air thoroughly mixed before being ignited4 ,such mixing increases engine efficiency1 but it involves the provision of bulky and costly air-compressing apparatus which can absorb more than #e percent of the engine's power4 ,naturally the compressor also adds considerably to the engine's weight4 ,in contrast to this1 a solid type of fuel injection may be employed to eliminate the complications of the air blast system4 ,it consists of injecting only fuel at a pressure of #ajjj psi or more4 ,air is admitted by intake stroke1 as with a gasoline engine4 ,turbulence is induced by designing the combustion chamber and piston so as to give a whirling motion to the air during the intake stroke4 ,the following quotation from ,dorner now becomes readily understandable4 ,since #aibb my invention consisted in eliminating the highly complicated compressor and in injecting directly such a highly diffused fuel spray so that a quick first ignition could be depended upon4 ,by means of rotating the air column around the cylinder axis1 fresh air was constantly led along the fuel spray to achieve completely sootless burning-up4444 ,in #aicj ,i sold my ,u4,s4,a4 patents to ,packard4#ad ,valve ,ports3 ,the inlet port 7which was also the exhaust port7 was arranged tangentially to the cylinder4 ,this design imparted a very rapid whirling motion to the incoming air1 thereby aiding the combustion process4 ,engine efficiency and rpm were both increased4 ,fuel ,injector ,pumps3 ,a combination fuel pump and nozzle was provided for each cylinder in contrast to the usual system of having a multiple pump unit remotely placed with regard to the nozzles4 ,the former system was adopted after frequent fuel-line failures were experienced due to the engine's vibration4 ,woolson stated that his system prevented pressure waves1 which interfered with the correct timing of the fuel injection1 from forming in the tubing4 ,leigh ,m4 ,griffith1 vice president of ,emsco ,aero1 writing in the ,september #aicj1 ,s4,a4,e4 ,journal stated3 ,regarding the superiority claim for the simple combination of fuel pump and injection valve into one unit1 without connecting piping1 the author entirely overlooks the fact that the elasticity of a pipe and its contained fuel can be important aids in securing that extremely abrupt beginning and ending of injection which is so desirable4 ,illustration3 ,figure #bi4--;,fuel-injector disassembly4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbc;,c47 ,a major advantage obtained from combining the fuel pump and injection valve is the ability of an engine so equipped to burn a wide variety of fuels4 ,the elimination of the above-mentioned type of high-pressure tubing reduces the possibility of a vapor lock occurring1 thereby permitting more volatile fuels to be burned4 ,this increases the range of hydrocarbon fuels the engine can utilize4 ,it could run on any type of hydrocarbon from gasoline to melted butter4#ae ,another reason for combining the fuel pump and injection valve is given by ,p4 ,e4 ,biggar in ,diesel ,engines 7published in #aicf by the ,macmillan ,company of ,canada ,ltd41 ,toronto73 ,in the ,dorner pump1 for example1 the stroke of the plunger is changed by using a lever-type lifter and moving the push-rod along the lever to vary its movement4 ,unfortunately1 in all arrangements of this sort1 the plunger comes to a reluctant and weary stop1 as the roller of the lifter rounds the nose of the cam4 ,when the movement does finally end1 the injection does not necessarily stop1 as the compressed fuel in the injection pipe is still left to dribble miserably into the combustion chamber4 ,to minimize this defect1 the designer has placed the pump and injector together in a single unit4 ,illustration3 ,figure #cj4--,mechanism for retarding valve and fuel-injection timing during starting 7see also fig4 #bf74 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbd;,e47 ,illustration3 ,figure #ca4--,upper--valve and fuel injector cam2 lower--fuel-injector cam used for starting4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbe47 ,starting ,system3 ,on ,november #a1 #aifa1 ,c4 ,h4 ,wiegman1 vice president of engineering of the ,lycoming ,division of ,avco ,corporation wrote to the ,museum in part as follows3 ,early in the development it became quite evident that cold starting was a problem4 ,this was finally worked out by ,packard through the use of glow plugs and speeding up the injectors during the cranking period4 ,it had been felt that during the slow cranking process we were not vaporizing the fuel through the nozzles and that if we could speed up the injection pumps during this period of cranking a better vaporization could be obtained4 ,our tests showed that we were right1 and that the engine could be started quite easily at minus #aj ,f through the use of glow plugs4 ,the method used for speeding up the injection pumps was accomplished by utilizing a crankshaft cam during the cranking period4 ,the starter would shift the running cam out of position allowing the crankshaft cam to take over4 ,after the engine fired1 the starter was disengaged and the running injector pump cam would assume its original position4 ,the starting cam would be run at engine speed during cranking1 and the running cam at #a_/h reverse engine speed during engine operation4 ,the shifting was accomplished by a pin-in-slot and spring arrangement to change the indexing of the cams to starting position and return4 ,an ,eclipse electric starter with an oversized flywheel was used4444 ,this was powered by a double-sized battery4 ,development ,air ,shutters3 ,the first engines had no provision for throttling the intake air4 ,this allowed the engine to run on its own lubricating oil when the throttle was in idle position4 ,as a result the engine idled too fast1 thereby causing either excessive taxiing speeds or rapid brake wear4 ,this inability to idle slowly also caused high landing speeds since the propeller did not turn slowly enough to act as an airbrake4 ,figure #a shows the first model4 ,note that the tubular air intakes on top of the cylinders have no valves4 ,figure #cb shows a later model4 ,note the butterfly valves in the ,u-shaped air intakes4 ,here they are shown fully opened4 ,when the throttle was placed in idle position these valves automatically closed and prevented air from flowing past them4 ,air could then only enter from the back of the intakes4 ,since less air could flow into the cylinders1 the force of their explosions was reduced1 which1 in turn1 lowered the idling revolutions per minute4 ,figure #bh shows a cylinder from a more advanced model4 ,note the circular opening between the air intake and the intake_/exhaust housing4 ,a barrel type of valve fitted into this opening4 ,one of these valves can be seen just below and to the left of the cylinder4 ,when the throttle was placed in idle position this valve rotated to a position which cut off almost all of the airflow into its cylinder4 ,this increased the vacuum formed toward the end of the intake stroke1 thereby causing more resistance1 which reduced the idling rpm to that of a gasoline engine4#af ,illustration3 ,figure #cb4--;,front left view of engine from ,packard ,motor ,car ,co4 #ej-;hour test1 #aicj1 showing butterfly valve type venturi throttles4 7,smithsonian photo ,a#dhcbe;,e47 ,illustration3 ,figure #cc4--;,front left view of engine from ,u4,s4 ,navy test1 #aica1 showing spiral oil cooler4 7,smithsonian photo ,a#dhcbd;,a47 ,crankcase3 ,it was strengthened by having external ribs added4 ,note the contrast between the first engine1 figure #b1 and a later model1 figure #cb4 ,oil ,cooler3 ,the drum-shaped honeycombed cooler was replaced by a spiral pipe type located between the engine cowl and the crankcase4 ,figure #c shows an example of the former type of cooler located at the top of the engine between two of the cylinders4 ,figure #cc illustrates the latter type located between the cowling and the crankcase4 ,cylinder ,fastening3 ,early models had their cylinders strapped and bolted to the crankcase4 ,later ones had them only strapped4 ,figure #b shows a bolt-fastened clamp between two of the cylinders on the first engine4 ,figure #ai shows a later model without any bolts holding down the cylinders4 ,pistons3 ,the pistons used in the #aibi engine had one compression ring and one oil scraper ring above the piston pin1 and one oil scraper ring below it4 ,there were three grooves1 two above the piston pin1 and one below it4#ag ,pistons used in #aicj had two compression rings1 one oil scraper ring above the piston pin1 and one oil scraper ring below it4 ,there were four grooves1 three above the piston pin1 and one below it4#ah ,the #aica pistons had one compression ring above the piston pin1 and one compression ring and four oil scraper rings below it4 ,there were four grooves1 one above the piston pin1 and three below it4#ai ,illustration3 ,figure #cd4--,modified pistons after endurance run4 ,u4,s4 ,navy test1 #aica4 7,smithsonian photo ,a#dhcbe;,d47 ,combustion ,chamber3 ,in #aica the contour of the cylinder head was changed slightly4 ,this improved the combustion efficiency to the extent that the stroke of the fuel pumps could be decreased about #ae percent4 ,the specific fuel consumption then decreased about #aj percent4 ,in addition the compression ratio was reduced from #af3a to #ad3a4bj ,these changes were designed to eliminate smoke from the exhaust at cruising speed1 and to reduce it at wide-open throttle4 ,valves3 ,a two-valve-per-cylinder model was built1 but not put into production4 ,it featured more horsepower 7#cjj71 a higher rate of revolutions per minute 7#bjjj71 and a better specific fuel consumption 7about 4#ce lb_/hp_/hr74#ba ,capt4 ,woolson designed the production model with a single large valve for each cylinder4 ,this was done in order to shorten the development period1 for it is easier to design a single valve which serves both the intake and exhaust functions than one valve for each function4 ,not only are there fewer parts1 but more important1 there are no heat-dissipating problems4 ,although the single valve is heated when it releases the exhaust gases1 it is immediately cooled by the incoming air of the next cycle4 ,this cooling advantage is not shared by a valve which only passes exhaust gases4#bb ,cylinder ,head3 ,ribs were added to increase its rigidity 7compare fig4 #cb with fig4 #cc74 ,engine ,size3 ,a #djj-;hp model was developed in #aicj4 ,it was not put into production4#bc ,comments ,comments of ,aeronautical ,engineers3 ,these comments appeared in ,aviation for ,february #ae1 #aicj1 just a month before the ,packard diesel received its approved-type certificate4 ,they were in answer to the question1 ,what is your opinion of the probable early future of the compression ignition type of engine in aircraft powerplants8 ,most of the engineers were enthusiastic about the diesel engine's future in aviation2 however1 neither ,george ,j4 ,mead nor ,c4 ,fayette ,taylor shared their colleagues' opinions4 ,mead's prophesy was accurate except for his discounting the diesel's role in lighter-than-air craft4 ,taylor was correct in implying that there was a future for the diesel in powering airships4 ,george ,j4 ,mead 7vice president and technical director1 ,pratt ,whitney ,aircraft ,company73 ,compared with the present ,otto cycle engine1 the ,diesel powerplant weight1 including fuel for a long-distance flight1 would apparently be less4 ,it is doubtful whether there would be any saving if the orthodox engine were operated on a more suitable fuel4 ,inherently the ,diesel engine must stand higher pressures and therefore is heavier per horsepower4 ,a partial solution of this difficulty is the two-cycle operation1 which seems almost a requirement if the ,diesel cycle is to be considered at all for aircraft4 ,for any normal commercial operation in the ,united ,states there seems to be little or no improvement to be had from the ,diesel4 ,after all1 it is not entirely a question of fuel cost but payloads carried for a given horsepower4 ,it seemed at one time as though the ,diesel was particularly desirable for ,zeppelin work4 ,now that blau gas has been introduced1 which obviates the need of valving precious lifting gas1 the ,diesel cycle seems much less interesting for this purpose4 ,there may be a reduction in fire hazard and radio interference with the ,diesel cycle1 but it is doubtful whether it will be used in view of these considerations alone4 ,c4 ,fayette ,taylor 7professor of aeronautical engineering1 ,massachusetts ,institute of ,technology73 ,i believe that the compression ignition engine will continue to remain in the experimental stage during the year #aicj4 ,i should expect its first really practical installation to be in lighter-than-air craft4 ,p4 ,b4 ,taylor 7acting chief engineer1 ,wright ,aeronautical ,corporation73 ,i believe the compression ignition engine is probably the type which will eventually supersede the present electric ignition units4 ,this development will come slowly and will not be a solid injection engine4 ,henry ,m4 ,mullinnix 7former chief of powerplant section1 ,navy ,bureau of ,aeronautics73 ,the advantages of compression-ignition1 including reduced fire hazard1 more efficient cycle1 elimination of electrical apparatus and hence of radio interference1 elimination of carburetion problems1 and other benefits less evident1 would seem to outweigh the difficulties encountered in metering and injecting minute quantities of fuel at the proper instant4 ,although the ,diesel engine suffers upon comparison with the ,otto cycle engine in flexibility there seems to be a definite field for employment of ,diesels and a gradual extension of their use may be predicted4 ,john ,h4 ,geisse 7chief engineer1 ,comet ,engine ,corporation73 ,i am firmly convinced that the ,diesel engine in the future will not only maintain the advantages of ,diesel engines as they are now known1 but will also be lighter in pounds per horsepower than the present ,otto engines4 ,lt4 ,cdr4 ,c4 ,g4 ,mc,cord 7,u4,s4 ,navy1 ,naval ,aircraft ,factory73 ,the use of compression ignition in due time appears to be assured2 but increase in weights above those of present ,otto cycle engines1 to insure reliability1 must be expected4 ,l4 ,m4 ,woolson 7aeronautical engineer1 ,packard ,motor ,car ,company73 ,there is no question that the compression ignition aircraft engine will in time offer severe competition to the gasoline engine4 ,there are1 however1 many basic problems to be solved for the solution of which there exists no precedent4 ,n4 ,n4 ,tilley 7chief engineer1 ,kinner ,airplane and ,motor ,corp473 ,considerable development of the compression ignition type of engine for aircraft will be required before it is commonly available4 ,it is believed that the weight per horsepower must be equal to1 or less than1 that of the present type of engines1 in order to interest the public1 since rapid take-off1 rate of climb1 and speed are desired1 rather than low fuel consumption or high mileage4 ,most flights are of few hours duration4 ,it is believed that flights must be of over five or six hours duration in order to show any advantage of ,diesel engines 7with low fuel consumption7 if appreciably heavier than present engines4 ,also the difference between ,otto cycle and ,diesel becomes slight as the compression ratios come closer together4 ,comments of ,flight ,crews3 ,the preceding comments were made by engineers thinking primarily of the commercial possibilities of the diesel4 ,following are comments by flight crewmembers about the operating characteristics of the ,packard diesel4 ,the former were largely optimistic4 ,most of them were only familiar with the aeronautical diesel as a design project and therefore did not have the practical experience necessary to understand all of its limitations4 ,the latter were pessimistic1 as they knew firsthand various shortcomings of the engine which only became apparent when it was operated4 ,clarence ,d4 ,chamberlin1 pioneer pilot3 ,my only experience with the ,packard diesel was in a ,lockheed ,vega which ,i owned back about #aicb4 ,the ,wright ,j-#e had been replaced with the #bbe hp ,packard ,diesel4 ,my main complaint was the excessive fumes4 ,when ,i would come home at night my wife would greet me with1 ,you have been flying that oil burner again4 ,it was so bad that passengers' clothing would smell like a smoky oil stove for hours after a flight4 ,looking backward1 it is my guess that the ,diesel would have had only a limited period of acceptance even if all mistakes had been avoided4 ,it is easier and cheaper to get performance with lighter and more powerful engines and longer runways than by refining the airplane4 ,fuel economy of an engine has ceased to be the deciding factor4 ,higher utilization of a high speed ,jet at least in part offsets the inefficient use of fuel4 ,the only time the ,diesel had a chance was from the middle #bj's perhaps on thru ,,ww-#b for certain things due to gasoline shortage4 ,to sum it up1 the thing that licked them worst was the use of a single valve for inlet and exhaust making it impossible to collect and keep the fumes out of the fuselage4#bd ,ruth ,nichols1 prominent aviatrix3 ,i was flying ,chamberlin's diesel-powered ,lockheed1 in which a month before ,i had made an official altitude record for both men and women in aircraft powered by an engine of that type4 ,the record1 ,i believe1 still holds4 ,it was a rugged1 dependable plane whose experimental oil-burning engine nevertheless had a number of bugs4 ,for one thing1 it was constantly blowing out glow-plugs used for warming the fuel mixture1 and when that happened long white plumes of smoke would stream out1 giving spectators the impression that the ship was on fire4 ,for another1 the vibration was so bad that out of #aj standard instruments on the plane1 #g were broken from the jarring before my return4 ,the diesel fuel also produced a strong odor in the cockpit1 the fumes so permeating my luggage and clothes that my public appearances during the tour always were highly and not very agreeably aromatic4 ,having a strong stomach1 ,i soon became accustomed to the fumes1 but another pilot who ferried the plane between cities for me on one occasion 444 was almost overcome4 ,on arrival he said1 ,i wouldn't fly that oil burner another mile4#be ,illustration3 ,figure #ce4--;,ford #aa-;,,at-#a ,trimotor1 #aicj1 with #c ,packard #bbe-;hp ,,dr-#ihj diesel engines1 right side view of right engine nacelle4 7,smithsonian photo ,a#dhcaa47 ,richard ,totten1#bf airplane mechanic3 ,the ,ford ,trimotor was the poorest of the lot4 ,it was inherently noisy and slow1 and with the ,packards installed it was on the point of being underpowered4 ,it was almost impossible to synchronize the three engines1 and the beat was almost unbearable4 ,it was not flown much but it made a fine conversation piece standing on the airport apron4444 ,the ,waco taperwing developed the unnerving habit of breaking flying and landing wires from the vibration1 and most of the time sat on the hangar floor with its wings drooping like a sick pigeon4 ,in flight the open cockpit filled with exhaust smoke and unburned fuel and the pilot would land after an hour's flight looking like an ,indianapolis #ejj ,mile ,race driver4444 ,the ,stinson ,detroiter1 the ,bellanca ,pacemaker and the ,buhl-,verville ,airsedan were the most successful ships and were the most used4 ,the ,airsedan1 in which ,woolson was killed1 was his favorite ship1 and the one ,i believe that was the most flown4 ,the ,towle ,,ta-#c amphibian flew beautifully1 but not for long4 ,it never got a chance to do much as it was a victim of the depression4 ,the ,towle was powered by #b ,packard diesels on loan from the ,packard ,motor ,car ,company4 ,it was built of corrugated aluminum exactly like the ,ford ,trimotor4 ,as a matter of fact1 ,towle had been employed by ,ford until ,ford cancelled airplane building4 ,towle got his airplane built at the hangar on ,grosse ,isle in ,detroit1 and ran out of money during the flight testing program4 ,he now looked for money to continue with and found a backer in the person of one ,doctor ,adams1 a widely advertised ,painless ,dentist of ,detroit4 ,adams wanted a quicker return on his money than the average backer and he insisted that ,towle put the airplane in service so it could start earning some money4 ,at this time the amphibian was beginning to become popular for intercity flying1 especially around the ,great ,lakes region as all of the major cities were located on the waterfront4 ,what was more natural than an airline flying passengers right into the downtown area of a city8 ,thompson was doing it between ,detroit and ,cleveland1 ,marquette was doing it between ,detroit and ,milwaukee1 so ,adams applied for permission to operate an airplane between ,detroit and ,cleveland and other cities on the lakes4 ,in those days it was necessary to prove an airplane's reliability by flying a certain number of trips over the proposed route with a simulated payload4 ,this payload was supposed to consist of sand bags1 but usually consisted of any mechanic or pilot who happened to be loose at the moment1 and who had nerve enough to go along4 ,mechanics were easier to load and unload than sand bags4 ,the ,towle was in the middle of the qualification flights1 and the publicity began to appear about the new airline4 ,much newsprint was devoted to the fact that the ,towle was powered by the new ,packard diesel engine1 and this1 of course1 made it the only safe airline since all its competitors were using the old-fashioned dangerous gasoline4 ,on the last payload trip of the ,towle the pilot asked me if ,i wanted to go along1 and of course ,i was delighted4 ,i neglected to mention that ,i had been hired by the ,adams airline as a mechanic because of my experience in repairing the corrugated skin of the ,ford ,trimotor owned by my employer1 the ,knowles ,flying ,service4 ,the mere fact that ,i did many repairs to the airframe did not preclude me from getting my share of the engine work too1 and since ,i was already familiar with the ,packard diesel1 ,i was quickly hired by ,dr4 ,adams4 ,the last flight was indeed the last flight4 ,we took off from the ,detroit ,city ,airport and when we crossed the ,detroit river the pilot decided to land at the ,solvay ,coal ,company docks and fuel up for the opening of the airline the next day4 ,the ,solvay ,coal ,company was the only place in ,detroit where diesel fuel was obtainable at the time and all of the diesel powered yachts got fuel there4 ,the pilot was not too experienced in the operation of amphibians1 and he put the wheels down as we approached the river4 ,when we hit the water the airplane went over on its back and sunk to the bottom4 ,it came up to the surface again1 and we all climbed out onto the keel1 and waited for rescue4 ,a police boat came over and took us to the dock4 ,the police sent us to the hospital and then went back and towed the airplane over to the shipyard next door to ,solvay4 ,while we were at the hospital1 the crane man hooked onto the ,towle and lifted it out of the water and gently set it down on the dock4 ,he was only trying to help1 but he inadvertently set it down on its back instead of its wheels4 ,that was the end of the ,adams airline4 ,the ,packard ,company took back their engines4 ,i helped remove them the next day4 ,we dismantled the airplane and trucked it back to the airport where it sat in a state of neglect for some time4 ,the pilot was fired1 ,i lost my job1 and ,towle lost his airplane4 ,analysis ,advantages ,a ,packard diesel advertisement which appeared in ,aero ,digest for ,june #aicj stated that this engine had three major advantages over its gasoline rivals3 ,greater reliability because of extreme simplicity of design2 greater economy because of lower fuel cost plus lower fuel consumption1 permitting greater payloads with longer range of flight2 and greater safety because of removal of the fire hazard through the use of fire-safe fuel and absence of electrical ignition equipment4 ,these were the engine's principal advantages4 ,others are analyzed here by the author in order of their importance4 ,at low altitudes the diesel uses an excess of air to eliminate a smoking exhaust2 consequently at high altitudes1 where the air is less dense1 the diesel is still able to maintain much of its power4 ,in contrast1 the carburetored gasoline engine is sensitive to the fuel-air ratio and thus has no surplus air available at higher altitudes4 ,a malfunctioning carburetor could cause a gasoline engine to cease operating1 but an inoperative fuel injector would cause the ,packard diesel to lose one ninth of its power1 since each cylinder had its own independently operating injector4 ,in practice1 however1 because of the excessive vibration1 the engine was generally shut off immediately after a cylinder cut out4#bg ,shielding was unnecessary because the diesel had no electrical ignition system4 ,carburetor icing was an impossibility because there was no carburetor4 ,any excess lubricating oil in a diesel engine's cylinder is consumed cleanly to produce power4 ,by contrast1 such oil in a gasoline engine's cylinder is only partly burned4 ,as a result carbon deposits form that eventually cause malfunctioning of the spark plugs1 valves1 and combustion chambers4 ,this advantage accrued to the diesel because it utilized an excess of air1 and in addition its cylinder walls were hotter4 ,the engine was very clean-running from the standpoint of oil leakage4 ,this was a safety factor since it eliminated the possibility of a fire starting on the outside surfaces of the engine1 and in addition it saved the time and money that was normally spent cleaning engines4#bh ,since the diesel utilized its heat of combustion more efficiently than the gasoline engine1 its cooling fin area could be reduced by #ce percent4 ,this permitted better streamlining4 ,having less cooling fin area1 it warmed up more rapidly than a gasoline engine4 ,illustration3 ,the ,,packard-,,diesel ,,aircraft ,,engine ,fire-,safe ,fuel ,furnaces in many a home burn similar oil ,a lighted match cannot ignite or explode it ,saturated cloth can burn only like a wick ,and the oil itself will quench this fire ,but only when property atomized the spray may be ignited ,graphic ,proof of fuel safety in the ,packard-,diesel ,aircraft ,engine ,figure #cf4--;,advertisement emphasizing the advantages of fire-safe fuel4 7,smithsonian photo ,a#dhhdh47 ,due to the greater simplicity1 it was more practical to build a large diesel than a large gasoline engine4 ,large airplanes would therefore need fewer engines if diesel powered4 ,smaller fuel tanks could be used because of the greater fuel economy of the diesel1 and also because of the high specific gravity of fuel oil as compared to gasoline4 ,furthermore1 these smaller tanks could be placed in more convenient locations4 ,not having a carburetor the engine could not backfire1 further reducing the fire hazard4 ,the exhaust note was lower because of the diesel's higher expansion ratio4 ,the absence of an ignition system permitted the diesel to operate in the heaviest types of precipitation4 ,such conditions might cause the ignition system of a gasoline engine to malfunction4 ,the ,packard diesel was flown at times without exhaust stacks or manifolds2 this was practical from a safety standpoint because of the diesel's lower exhaust temperature due to its higher expansion ratio4 ,elimination of these parts reduced the weight and cost of the engine installation4 ,finally1 the engine was ideal for aerobatics1 since the injectors1 unlike carburetors1 would work equally well whether right side up or upside down4 ,an advantage peculiar to the ,packard among aeronautical diesels was its light weight4 ,the ,english ,beardmore ,tornado ,,iii weighed #f4i lb_/hp1 and the ,german ,junkers ,,sl-#a 7,,fo-#d7 weighed #c4a lb_/hp1 while the ,packard weighed but #b4c lb_/hp4 ,in fairness to the ,beardmore1 it was the only one of the three engines designed for airship use1 and part of its heaviness was due to the special requirements of lighter-than-air craft4 ,a contemporary and comparable ,american gasoline engine1 the ,lycoming ,r-#fhj1 weighed #b4b lb_/hp4 ,to have designed a diesel aircraft engine as light as a gasoline one was a remarkable achievement4 ,disadvantages ,there are four main reasons why the ,packard diesel was not successful4 ,first the ,packard ,motor ,car ,company put the engine into production a brief three years after it was created4 ,the only successful airplane diesel1 the ,german ,junkers ,jumo1 was in development more than three times as long 7#aiab-aibi74 ,the following tests indicate that the ,packard diesel was not ready for production1 and hence was unreliable4 ,packard ,motor ,car ,company #ej-;,hour ,test 7,feb4 #ae-ah1 #aicj73 ,this test was identical to the standard ,army #ej-;hour test which was used for the granting of the ,approved ,type ,certificate4 ,the engine tested was numbered #ajj1 and was the first to be made with production tools 7approximately half a dozen engines had been handmade previously74 ,it had to be stopped three times1 twice due to failure of the fuel pump plunger springs and once due to the loosening of the oil connection ring4 ,these failures were attributed to manufacturing discrepancies4 ,in addition1 #d out of a total of #ajc valve springs broke4#bi ,u4,s4 ,navy #ej-;,hour ,test 7,jan4 #bb1 #aica1 to ,march #ae1 #aica73 ,the engine used in the ,navy test was numbered #abj4 7,apparently only #bj production engines had been built during the preceding #ab months2 ,dorner in a letter of ,march #c1 #aifb1 states that the total number of ,packard diesels produced was approximately #be47 ,the engine had to be stopped three times1 twice due to valve-spring collar failures and once due to a valve head breaking4 ,because of these failures this test was not completed4 ,the following significant quotations have been extracted from the test3 ,the engine is not recommended for service use4444 ,flight tests1 until the durability of the engine is improved1 be limited to a determination of the critical engine speeds1 and to short hops in seaplanes4444 ,it is believed that this size engine should be made suitable for service use before this type in a larger class is attempted4 ,this latter statement probably refers to the #djj-;hp model4 ,a year had passed between the making of engine #ajj and #abj1 yet the reliability had not improved4 ,although unreliability was the immediate cause of failure1 there were two design defects which would have doomed the engine even if it had been reliable4 ,all the ,packard diesels were of the #d-stroke cycle unblown type1 yet the most successful airplane diesels were of the #b-stroke cycle blown type4#cj ,the advantages of the latter type for aeronautical use are that it is of a more compact engine1 of lower weight and greater efficiency4#ca ,the engine was therefore built around the wrong cycle4 ,the ,packard diesel of #aibh was designed to compete with the ,wright ,j-#e ,whirlwind which powered ,lindbergh's ,spirit of ,st4 ,louis in #aibg4cb ,the specifications were within two percent of each other4 ,the diesel engine's fuel consumption was far less although its price was considerably higher4 ,packard ,diesel ,wright ,j-#e ,,dr-#ihj ,whirlwind ,diameter 7in47 #de-aa_/af #de ,horsepower #bbe #bbe ,weight 7lb7 #eaj #eaj ,weight-horsepower ratio #b4bf #b4bf ,fuel consumption 7lb per hp_/hr at #j4dj #j4fj cruising74 ,cost #djbe #cjjj ,the advantages of lower fuel cost and greater cruising range offered by the diesel engine would be relatively unimportant to a private pilot flying for pleasure1 but would be vital to the commercial operator using airplanes powered by engines having several times the horsepower of the ,packard diesel4 ,its size1 moreover1 was too small for the technology of fuel injectors4#cc ,the ,packard ,company realized that the production engine was too small4#cd ,in #aicj a #djj-;hp version was built but was not put into production1 probably because of the unreliability of the #bbe-;hp model4 ,the fourth principal reason why the engine failed is explained by the following quotation from ,the ,propulsion of ,aircraft1 by ,m4 ,j4 ,b4 ,davy 7published in #aicf by ,his ,majesty's ,stationery ,office1 ,london73 ,although the development and adoption for transport purposes of the relatively high-speed compression ignition engine has been rapid during the last few years1 there has been no corresponding advance in its adoption for aircraft propulsion4 ,a reason for this is the recent great advance in take-off power in the petrol 7gasoline7 engine due to the introduction of #hg octane fuel 7which permits higher compression ratios7 and the strong probability of #ajj octane fuels in the near future1 still further increasing this power4 ,the need for increased take-off power results from the higher wing loading necessitated by the modern demand for commercial aircraft with higher cruising speeds with reasonable power expenditure4 ,production of the ,packard diesel ceased in #aicc4 ,during that same year the ,pratt ,whitney ,aircraft ,company and the ,wright ,aeronautical ,corporation specified #hg-octane fuel for certain of their engines4 ,less than #aj years later octane ratings had increased to over #ajj1 putting the diesel at a further disadvantage4#ce ,although the above disadvantages sealed the ,packard diesel's fate1 there were other minor reasons for its failure4 ,the ,packard diesel had the highest maximum cylinder pressure 7up to #aejj psi at peak rpm7 of any proven contemporary aircraft diesel engine4 ,leigh ,m4 ,griffith1 vice president and general manager1 ,emsco ,aero ,engine ,company1 had this to say about the ,packard diesel's high maximum cylinder pressure in the ,september #aicj ,s4,a4,e4 ,journal3 ,the designers considered it necessary to adopt unusual but admittedly clever expedients to counteract the great torque irregularity caused by the excessive maximum pressure4 ,the adoption of the lower pressure of #hjj lbs4 would have eliminated the necessity for the pivoted spring-mounted counterweights and the shock-absorbing rubber propeller-drive4444 ,the use of such high pressures is in reality the quick and easy way to secure high-speed operation and can be justified only from this standpoint1 although the resulting increased difficulty in keeping the engine light enough was a strong offsetting factor4#cf ,insofar as the engine life was concerned it is true that #a1ejj-psi peak pressures were observed but the engine was so developed to withstand these pressures4444 ,one of the most severe problems connected with the development of this engine was the piston ring sealing4 ,special compression rings were made with no gaps and further work in this respect could have been used to advantage had the engine been kept in production4#cg ,it is significant that in #aicj the ,packard diesel had a compression ratio of #af3a1 whereas in #aica it has been reduced to #ad3a4 ,this was probably done to reduce vibration and the problem of piston-ring sealing4#ch ,the exhaust products had an unpleasant odor which was particularly objectionable during taxiing4 ,professor ,c4 ,fayette ,taylor1 writing in the ,january #aica issue of ,aviation1 remarked about this fault3 ,one is inclined to question whether the disagreeable escaping of exhaust gas from the intake ports can be overcome1 while still retaining the obvious advantages in weight and simplicity of the single valve4 ,the engine exhaust deposited a black oily film4 ,in fact some airplanes fitted with the ,packard diesel engine were painted black1 so that soot deposits from the exhaust would not be noticed4#ci ,since the passengers' and pilots' compartments were generally located behind the engines1 and were not airtight1 damage to clothing resulted4 ,this fault could have been eliminated by the use of separate valves for the intake and exhaust systems4 ,it was not possible to start the engine when the temperature dropped much below #cb ,f unless glow plugs were used4 ,these spark-plug-like devices1 which were only used for starting1 had resistance windings which glowed continuously when turned on4 ,the additional heat glow plugs provided made starting an easy matter in the coldest weather2 however1 they complicated the design of an engine noted for its simplicity1 and they used so much electricity that only a long flight would allow the generator to fully recharge the battery4 ,h4 ,r4 ,ricardo1 writing in the ,june #d1 #aicj1 issue of ,the ,aeroplane said3 ,referring to the very fine achievement of the ,packard ,company of ,america in producing a small radial air-cooled heavy-oil engine1 a petrol engine of similar design and with the same margin of safety would weigh less than #a-a_/b lbs4 per hp4 ,the important point made is that a gasoline engine designed along the same lines as the ,packard diesel would weigh considerably less1 but would then suffer from the ,packard's reduced structural safety factor4 ,it is significant that as the ,packard developed1 it became heavier4#dj ,like other diesels1 the ,packard cost more to build than a comparable gasoline engine1 because of the type of construction required for the diesel's higher maximum cylinder pressures and the difficulty of machining the fuel injectors4 ,having fuel injectors1 the engine was more sensitive to dirt in the fuel system than a carburetor-equipped gasoline engine4#da ,the fuel injectors were a crude and deficient mechanism subject to rapid wear1 and often these injectors caused smoking exhausts and high fuel consumptions4#db ,in the event of battery or starter failure1 a comparable gasoline engine could be started by swinging the propeller4 ,because of the engine's high compression1 it would have been impossible to have hand-started a ,packard diesel this way4 ,in a letter to the ,air ,museum1 ,january #ae1 #aifb1 ,dorner commented3 ,during my first demonstration 7of high-speed diesel engines7 in #aibf in ,california and later in ,detroit ,i learned from ,capt4 ,woolson that the large transport airlines were controlled by oil companies which were not interested in 7supplying7 two different kinds of aircraft fuel1 and in savings of fuel4 ,the ,may issue of ,aero ,digest had a full-page illustrated advertisement titled ,announcing ,national ,distribution for ,texaco ,aerodiesel ,fuel4 ,although distribution was limited1 the ,american oil industry did not prevent the airplane diesel from becoming a success in the civil market4 ,however1 it is significant that the advertisement was placed by ,frank ,hawks of the ,texas ,company largely as a gesture of friendship to ,woolson4#dc ,the situation in the military market was different1 however1 as testified by this quotation from the same letter4 ,the military administration1 having paid all of the expenses for the testing period to that date 7#aica71 came after the tests to the conclusion that the advantages of the diesel as compared to its disadvantages did not justify the great risk to procure and distribute two different kinds of fuel in case of war4 ,two accidents1 which received wide publicity and no doubt did considerable harm to the entire project1 occurred to ,packard diesel-powered airplanes4 ,the following quotation is from the ,herald ,tribune for ,april #bc1 #aicj3 ,attica1 ,new ,york--,losing their bearings in a blinding snowstorm and mistaking the side of a snow-covered hill for a suitable landing place1 three men1 one of them ,capt4 ,lionel ,m4 ,woolson1 aeronautical engineer for the ,packard ,motor ,company and adapter of the diesel engine to airplanes1 were killed here today4 ,illustration3 ,figure #cg4--;,interior of ,bellanca1 showing ,parker ,d4 ,cramer1 pilot 7left71 and ,oliver ,l4 ,paquette1 radio operator1 just before taking off from ,detroit1 ,michigan1 on ,july #bh1 #aica4 7,smithsonian photo ,a#bjb47 ,the second of these accidents is described in the ,september #aica issue of ,u4,s4 ,air ,services3 ,columbus wanted to sail west beyond the limits set by the learned navigators of his time1 and in much the same consuming fashion ,parker ,d4 ,cramer wanted to show his generation and posterity that a subarctic air route to ,europe via ,canada1 ,greenland1 ,iceland1 ,norway1 and ,denmark was feasible4444 ,on ,july #bg1 without any preliminary announcement1 ,cramer left ,detroit in a ,diesel-engined ,bellanca1 and following the course he took with ,bert ,hassel three years ago1 he flew first to ,cochrane1 on ,hudson ,bay4 ,his next stop was ,great ,whales and then ,wakeham ,bay4 ,from there he flew to ,pangnirtum1 ,baffin ,land1 and across the ,hudson ,straits to ,holsteinborg1 ,greenland4 ,he crossed the icecap at a point farther north than the routes that have been discussed heretofore1 but almost on the most direct or ,great ,circle route from ,detroit to ,copenhagen4 ,he was accompanied by ,oliver ,paquette1 radio operator4 ,they were on their way more than a week before they were discovered4 ,to ,iceland1 to the ,faroe ,islands1 to the ,shetlands4 ,they were taxiing across the little harbor of ,lerwick1 ,shetland ,islands1 when a messenger from the bank waved a yellow paper4 ,it was a warning of gales on the coast east to ,copenhagen4 ,cramer apparently thought it was an enthusiastic bon voyage1 and1 after circling the town1 flew away4 ,a ,swedish radio station reported a faint ,hello1 ,hello1 ,hello in ,english1 but the plane was not seen again4 ,as the result of a personal conversation with his brother1 ,william ,a4 ,cramer1 in #aifd1 the author learned that the fuselage and floats of the airplane were found six weeks later4 ,since there was no indication of a heavy impact 7not a single glass dial on the instrument panel was broken71 a successful landing must have been made4 ,several weeks later1 a package was found wrapped in a torn oilskin containing instruments1 maps1 and a personal letter1 all substantiating the evidence that the landing was successful4 ,it can only be surmised that there was engine failure1 probably due to a clogged oil filter4#dd ,once before during the trip a forced landing had been made due to engine malfunctioning1 and a successful takeoff was accomplished in spite of a moderately rough sea4 ,this time1 however1 storm conditions probably made the takeoff impossible4 ,as a final summary of the author's analysis of the ,packard diesel engine1 it must be emphasized that although the engine burned a much cheaper and safer fuel more efficiently than any of its gasoline rivals1 it was too unreliable to compete with them4 ,even if it had been reliable1 it was too small to be useful to the large transport operators1 to whom its fuel economy would have appealed4 ,in addition1 this mechanism operated on the wrong cycle3 #d-stroke1 rather than the lighter1 more compact1 and more efficient blown #b-stroke cycle4 ,lastly1 it was doomed by the advent of high octane gasolines1 first used while it was still in the development stage4 ,these new fuels reduced the diesel's advantage resulting from low fuel consumption1 and1 in addition1 gave the gasoline engine a definite advantage from the standpoint of performance4 ,the ,packard diesel was a daring design but1 for the reasons analyzed in this chapter1 it could not meet this competition1 and therefore failed to survive4 ,appendix #a4 ,agreement between ,hermann ,i4 ,a4 ,dorner and ,packard ,motor ,car ,company ,,this ,,agreement made this #ahth day of ,august #aibg1 by and between ,,hermann ,,dorner1 of ,hanover1 ,germany1 hereinafter referred to as ,licensor1 and ,,packard ,,motor ,,car ,,company1 a ,corporation of the ,state of ,michigan1 ,united ,states of ,america1 of ,detroit1 ,michigan1 hereinafter referred to as ,licensee2 ,,witnesseth1 that ,,whereas1 ,licensor owns certain ,letters ,patent of the ,united ,states and other countries relating to oil burning engines under which he desires to license the ,licensee2 ,,whereas1 ,licensee desires rights under said ,letters ,patent2 ,,now1 ,,therefore1 for the mutual considerations hereinafter set forth1 the parties have agreed as follows3 #a4 ,licensor warrants that he is the inventor of an oil burning engine1 is the sole owner of ,united ,states patent ,number #a1fbh1feg1 dated ,may #ag1 #aibg1 and ,united ,states patent applications1 ,serial ,numbers #df1chc filed ,july #bg1 #aibe1 and #hh1dji and #hh1daa1 filed ,february #ae1 #aibf1 relating to such engines and is joint or sole owner of patents or patent rights relating to said engines in ,england1 ,germany and ,sweden4 #b4 ,licensor agrees to furnish the ,licensee at cost price but not exceeding ,thirty ,dollars 7#cj4jj7 cash1 as many pump and nozzle units as are needed for use in building one or more experimental engines4 #c4 ,licensor hereby gives and grants unto ,licensee an exclusive license for the manufacture1 within the ,united ,states and its dependencies1 and a non-exclusive license for the use and sale1 of engines for aircraft1 and a non-exclusive license for the manufacture1 use1 and sale of engines for motor vehicles and motor boats1 under said ,united ,states patent ,number #a1fbh1feg1 under all after-acquired patents and under all patents that may result from said patent applications1 and from all other patent applications pertaining to his present oil burning engine or reasonable variations thereof1 such licenses to extend for the full life and term of all such patents1 provided however1 that there is specially excepted from this grant--stationary engines1 tractor engines1 and engines for agricultural purposes4 #d4 ,licensor further hereby permits said ,licensee to export to all other countries and sell and use there1 without further royalty1 all engines made by ,licensee in the ,united ,states under this license4 #e4 ,licensor acknowledges receipt of ,one ,thousand ,dollars 7#a1jjj4jj7 in payment of a portion of the expenses heretofore incurred by him and as one of the considerations for this agreement4 #f4 ,licensor agrees to devote all time necessary from this date to ,november #a1 #aibh to supervision of the design of an engine and construction thereof at the plant of the ,licensee and will in his absence furnish the services of a competent assistant1 the expenses of ,licensor and assistant to be paid for by ,licensee at the rate of ,one ,thousand ,dollars 7#a1jjj4jj7 per month for the first three 7#c7 months1 and ,five ,hundred ,dollars 7#ejj4jj7 per month thereafter until the decision in paragraph eight has been made by ,licensee4 #g4 ,licensee agrees to build and test at least one experimental aircraft engine with special ,dorner features1 and to take all reasonable measures to reach the stage of final test4 ,all ,dorner feature engines made by ,licensee will be marked ,licensed ,under ,dorner ,patents4 #h4 ,within one year after the completion of tests of the aircraft engine built by ,licensee hereunder1 or in any event not later than ,november #a1 #aibh1 ,licensee will decide whether it will proceed with the manufacture of engines hereunder1 or not4 ,if ,licensee decides in the affirmative then it will pay ,licensor forthwith the sum of ,five ,thousand ,dollars 7#e1jjj4jj7 as advance on royalties and as minimum royalty for the first production year4 ,if ,licensee decides in the negative for reasons which are under the influence of ,licensor1 then ,licensee will give ,licensor notice and sufficient time to try to correct possible imperfections1 and the time for final decision will be correspondingly extended4 ,if the reasons for the negative decision are under the influence of ,licensee1 then ,licensee will grant to ,licensor an oral conference at ,detroit and explain the reasons in detail4 ,in event a negative decision is finally rendered by ,licensee this agreement may be terminated at any time thereafter upon sixty 7#fj7 days' notice in writing to ,licensee and both parties released from all further obligations hereunder4 #i4 ,licensee agrees that if after three 7#c7 years from the date hereof ,licensee is not manufacturing and does not contemplate the manufacture of1 a certain size and type of aircraft engine which ,licensor would like to grant another manufacturer the right to build and which would not reasonably compete with anything manufactured by ,licensee1 ,licensee will release such size and type aircraft engine from the exclusiveness of this license and thereby permit ,licensor to grant a license to such other manufacturer to make1 use and sell such engine and such engine only4 #aj4 ,licensee agrees to pay royalty on all engines manufactured and sold or used under this agreement1 based on effective brake horsepower under normal load1 as follows3 ,on each of the first ,five ,thousand 7#e1jjj7 such engines produced and sold in any one calendar year1 the royalty shall be at the rate of ,twenty-five ,cents 74#be7 per horsepower2 and on all over ,five ,thousand 7#e1jjj7 in such calendar year1 at the rate of ,ten ,cents 74#aj7 per horsepower2 provided that1 after a total of ,fifty ,thousand ,dollars 7#ej1jjj4jj7 has been paid in royalties the royalties shall be reduced one-half 7#a_/b74 #aa4 ,after the beginning of the second year of production1 ,licensee agrees that if the royalties under the above schedule amount to less than ,ten ,thousand ,dollars 7#aj1jjj4jj7 per year then the royalty shall be ,ten ,thousand ,dollars 7#aj1jjj4jj7 per year payable in quarterly instalments of ,two ,thousand ,five ,hundred ,dollars 7#b1ejj4jj7 each1 or in other words1 the minimum royalty payable shall be ,ten ,thousand ,dollars 7#aj1jjj4jj7 per year4 #ab4 ,royalties shall continue only during the life of said patent ,number #a1fbh1feg1 and when a total of ,two ,hundred ,fifty ,thousand ,dollars 7#bej1jjj4jj7 has been paid by ,licensee to ,licensor1 all royalties shall cease and the license hereunder shall be free thereafter4 #ac4 ,licensor agrees that ,licensee shall have the benefit of any more favorable royalty rates that may be hereafter granted to or enjoyed by any other manufacturer of engines other than aircraft engines4 #ad4 ,licensee agrees to keep proper books of account showing the number of engines manufactured and sold or used under this agreement and to report quarterly to ,licensor4 #ae4 ,in case of suit against the ,licensee for infringement of patents by any of the ,dorner features built under this license ,licensor agrees to assist in the defense of any such suit and pay the expenses thereof up to an amount equal to ,ten ,percent 7#aj7 of all royalties paid by ,licensee to ,licensor hereunder4 #af4 ,in event of default of the ,licensee in the payment of any of the sums herein provided for1 ,licensor may terminate this license agreement by serving upon the ,licensee ,sixty 7#fj7 days' notice in writing of its desire and determination so to do and stating the default upon which the notice is based1 and at the expiration of such ,sixty 7#fj7 days this license shall thereupon be terminated1 provided however that such termination shall not release the ,licensee from obligations already accrued hereunder and not performed1 and provided further that if1 during said ,sixty 7#fj7 days' notice period1 the default named in said notice shall have been made good then this license to continue as if no default and notice had been made or given4 #ag4 ,at the expiration of any one year from ,november #a1 #aibi1 ,licensee may terminate this agreement upon ,sixty 7#fj7 days' notice in writing to ,licensor of its desire and determination so to do1 provided however1 that such termination shall not release the ,licensee from obligations already accrued hereunder and not performed4 #ah4 ,in case of differences of opinion regarding any of the terms of this agreement1 the dispute shall be submitted to arbitration4 ,each party shall select one arbitrator and if they1 after five days1 fail to agree upon a third1 the ,united ,states ,court for the ,detroit ,district shall be asked to appoint such a third arbitrator1 and the decision of a majority of the arbitrators shall be binding upon both parties4 ,in witness whereof1 we have hereto set our hands and seals at ,detroit1 ,michigan1 on the day and year first above written4 ,witnesses--7,signatures73 ,hermann ,dorner ,l4 ,a4 ,wright ,adolf ,widmann ,,packard ,,motor ,,car ,,company ,alvan ,macauley ,president 7,seal7 ,attest3 ,milton ,tibbetts ,assistant ,secretary #b4 ,packard to ,begin ,building ,diesel ,plane ,engines ,soon ,will ,start ,construction at ,once on ,new ,three ,story ,factory to ,handle ,work ,from ,aviation1 ,march #b1 #aibi1 vol4 #bf1 no4 #aj ,,detroit1 ,,mich4--,indications that the ,diesel type airplane engine1 recently developed by ,capt4 ,l4 ,m4 ,woolson1 chief aeronautical engineer of the ,packard ,motor ,car ,co41 will become a commercial reality and possibly a revolutionary factor in airplane engine design1 is seen here in the announcement of the concern that it will begin construction immediately of a #fej1jjj plant to produce the engines in large quantity for the commercial market4 ,the new plant1 according to the announcement by ,hugh ,j4 ,ferry1 treasurer of the ,packard firm1 will be completed and in operation within five weeks4 ,between #fjj and #gjj men will be employed and1 according to expectations1 production will be carried on at the rate of about #ejj ,diesel engines per month by ,july4 ,the ,packard ,diesel was announced first in ,october1 following experiments covering several years4 ,the original engine was placed in a ,stinson-,detroiter1 which was flown successfully by ,captain ,woolson and ,walter ,lees1 ,packard pilot4 ,since that time ,captain ,woolson has built four of the engines1 all of #bjj hp4 capacity1 developing #a hp4 for every #b lb4 of weight4 ,the ,diesel1 installed on the ,stinson-,detroiter1 it was said1 now has had #bjj hr4 flying time1 and gives not the slightest indication that it will need an overhauling for some time4 ,the other three engines have been tested on the block in the company's research plant4 ,it is claimed by the builders that the ,packard ,diesel will produce a saving of about #bj per cent4 in fuel consumption as compared with engines using gasoline4 ,it is claimed further that the ,diesel will prove far more reliable in construction than any airplane engine yet developed4 ,evidence of this1 it was pointed out1 is seen in the performance of the initial ,diesel4 ,,details ,,not ,,announced ,although neither ,mr4 ,ferry1 nor ,captain ,woolson1 would disclose any technical details as to the engine's construction in making it applicable to airplane use1 the secret of its success was reported to be an especially designed pumping device creating high compression necessary for ,diesel firing4 ,since announcement of the engine1 the ,packard factory has been literally a ,mecca for engineers from many parts of the world wishing to see the engine4 ,the ,crown ,prince of ,spain1 in ,detroit last fall1 was given a flight in the ,diesel powered ,stinson4 ,none of the construction secrets1 however1 have been divulged1 it was said4 ,the ,packard announcement set at rest rumors that the company planned construction of a plant costing several million dollars1 as well as reports that the company was going into the production of airplanes4 ,our efforts1 ,mr4 ,ferry said1 will be confined to the engine1 or power plant end of the aircraft industry4 ,we will continue to build the water-cooled type we have been producing for years4 ,the new ,diesel plant will be primarily an assembly plant1 although some machine work will be done there4 ,the bulk of the machine work1 however1 will be done in the present ,packard machine shops4 ,although no approximation of selling price on the new ,diesel was divulged1 it was intimated that the engine will retail at a price competitive with or slightly under the price of present gasoline consuming air-cooled engines of that horsepower range4 ,captain ,woolson will have complete charge of the ,diesel plant1 it was announced4 #c4 ,effect of ,oxygen ,boosting on ,power and ,weight ,from ,p4 ,h4 ,,schweitzer and ,e4 ,r4 ,,klinge1 ,oxygen-,boosting of ,diesel ,engines for ,take-,off1 ,the ,pennsylvania ,state ,college ,bulletin 7,april #a1 #aida71 vol4 #ce1 no4 #ad1 p4 #be4 ,practical ,conclusions ,airplanes require about one third more power during the take-off than in flight4 ,in diesel-engined airplanes the size of the engine could be reduced by #be percent by feeding oxygen into the intake air during the takeoff4 ,applying the results of the experiments to a transport plane1 ,fig4 #ca shows the possible weight saving with various oxygen boosts4 ,the curves are based on #fjjj cruising horsepower and an estimated engine weight of #b lb per hp4 ,for the take-off #hjjj hp are necessary4 ,to supply the additional #bjjj hp1 #bjj lb of oxygen are fed into the intake air during the take-off4 ,the volume of #bjj lb of liquid oxygen is approximately #bj gal4 ,standard liquid air containers of #ee litre capacity weigh #ge lb4 ,therefore the weight of the oxygen and container is #cej lb while the possible saving in engine weight is #djjj lb4 ,the weight per take-off horsepower is thereby reduced from #b to #a4ed lb4 ,the calculation is shown in ,table #a4 ,illustration3 ,figure #ch4--;,effect of ,oxygen ,boost on ,power and ,weight4 7,cruising horsepower #fjjj1 takeoff horsepower #hjjj47 ,oxygen addition may be used for starting diesel engines4 ,the raising of the oxygen concentration from the normal #ba per cent to #de per cent was found to be equivalent to a raise of approximately #aj cetane numbers as far as starting is concerned4 ,five per cent increase in oxygen concentration eliminated exhaust smoke completely4 ,,table #a ,normal horsepower #fjjj ,take-off horsepower #hjjj ,normal fuel consumption #j4d lb per hp-hr1 or #ec4e lb per min ,normal air consumption #ijj lb per min ,normal oxygen consumption1 #ba per cent oxygen #ahi lb per min concentration ,boosted oxygen consumption1 #cb per cent oxygen #bhi lb per min concentration ,oxygen to be supplied #ajj lb per min ,weight of #hjjj-;hp engine #af1jjj lb ,weight of boosted #fjjj-;hp engine #ab1jjj lb ,weight of oxygen for #b-min boost #bjj lb ,weight of container for #bi lb of liquid oxygen #aej lb ,net weight saving by oxygen boost #cfej lb ,weight per horsepower1 nonboosted engine #b lb ,weight per horsepower1 boosted engine #a4ed lb ,footnotes3 #a ,appendix1 p4 #dc4 #b ,letter1 ,hermann ,i4 ,a4 ,dorner to ,national ,air ,museum1 ,march #c1 #aifb4 #c ,see p4 #bj ff4 #d ,appendix1 p4 #df4 #e ,aeronautics 7,october #aibi71 vol4 #e1 no4 #d1 p4 #cb4 #f ,the ,packard ,diesel ,aircraft ,engine--,a ,new ,chapter in ,transportation ,progress 7,detroit3 ,packard ,motor ,car ,co41 #aicj71 p4 #e4 #g ,a memorial to ,woolson who was killed in the crash of a ,packard diesel-powered ,verville ,air ,sedan on ,april #bc1 #aicj4 #h ,packard ,inner ,circle 7,april #ah1 #aicb71 vol4 #ag1 no4 #f1 p4 #a4 #i ,aero ,digest 7,february #aicb71 vol4 #bj1 no4 #b1 p4 #ed4 #aj ,letter1 ,richard ,totten to ,national ,air ,museum1 ,january #bh1 #aifd4 #aa ,instruction ,book for the ,packard-,diesel ,aircraft ,engine 7,detroit3 ,packard ,motor ,car ,company1 #aica71 p4 #c4 #ab ,s4,a4,e4 ,journal 7,april #aicj71 vol4 #bd1 no4 #d1 pp4 #dca and #dcb4 #ac ,letter1 ,richard ,totten to ,national ,air ,museum1 ,january #bh1 #aifd4 #ad ,letter1 ,hermann ,i4 ,a4 ,dorner to ,national ,air ,museum1 ,december #af1 #aifa4 #ae ,the ,national ,aeronautic ,magazine 7,april #aicb71 vol4 #aj1 no4 #d4 p4 #ah4 #af ,aviation 7,may #aica71 vol4 #cj1 no4 #e1 p4 #bha4 #ag ,the ,packard ,diesel ,aircraft ,engine1 p4 #e4 #ah ,instruction ,book for the ,packard-,diesel ,aircraft ,engine1 p4 #c4 #ai ,test of ,packard-,diesel radial air-cooled engine1 ,navy ,department1 ,bureau of ,aeronautics1 ,report ,,ael-#cce1 ,july #ac1 #aica1 ,bu4 ,aer4 ,proj4 #bbfe4 #bj ,aviation 7,may #aica71 vol4 #cj1 no4 #e1 p4 #bha4 #ba ,letter1 ,clarence ,h4 ,wiegman to ,national ,air ,museum1 ,november #a1 #aifa4 #bb ,letter1 ,dorner to ,national ,air ,museum1 ,january #ae1 #aifb4 #bc ,letter1 ,hugo ,t4 ,byttebier to ,national ,air ,museum1 ,october #bj1 #aifa4 #bd ,letter1 ,clarence ,d4 ,chamberlin to ,national ,air ,museum1 ,february #h1 #aifd4 #be ,,ruth ,,nichols1 ,wings ,for ,life 7,philadelphia and ,new ,york3 ,j4 ,b4 ,lippincott ,co41 #aieg71 p4 #bje4 #bf ,letter1 ,richard ,totten to ,national ,air ,museum1 ,january #bh1 #aifd4 #bg ,letter1 ,richard ,totten to ,national ,air ,museum1 ,january #bh1 #aifa4 #bh ,aero ,digest 7,february #aica71 vol4 #ah1 no4 #b1 p4 #eh4 #bi #ej-;,hour ,test of ,packard ,diesel ,aircraft ,engine1 ,packard ,motor ,car ,company1 ,detroit1 ,michigan1 serial no4 #dbf1 test no4 #bcd-gc1 ,february #ai1 #aicj4 #cj ,blower in this sense refers to a low-pressure air pump 7supercharger7 designed to increase cylinder scavenging efficiency by blowing out exhaust gasses4 ,in doing this it also increases somewhat the amount of fresh air introduced into the cylinders4 ,woolson invented a #b-stroke cycle blown engine2 the patent was issued in #aicb 7patent #ahecgad7 with rights assigned to the ,packard ,motor ,car ,company4 7,woolson himself died in #aicj47 #ca ,a #b-stroke cycle engine completes #cfj of crankshaft rotation in what it takes a #d-stroke cycle engine #gbj to accomplish4 ,a #c-;cylinder two-stroke cycle engine therefore has the same capacity to do work as a #f-;cylinder four-stroke cycle engine4 ,for this reason the former type of engine is both more compact and lighter than the latter type4 ,the above advantages1 plus the increased efficiency of the blown #b-;cycle diesel1 are discussed in ,flight--,the ,aeronautical ,engineer ,supplement 7,december #bf1 #aidj71 vol4 #ai1 no4 #aa1 pp4 #ede and #eeb4 #cb ,packard advertisement--,aero ,digest 7,june #aicj71 vol4 #af1 no4 #f1 p4 #bc4 #cc ,aviation 7,march #ae1 #aicj71 vol4 #bh1 no4 #aa1 p4 #eca4 #cd ,the ,national ,aeronautic ,magazine 7,april #aicb71 vol4 #aj1 no4 #d41 p4 #ah4 #ce ,appendix1 p4 #dg4 #cf ,see ,woolson's patent #agidjdg1 issued in #aica and assigned to the ,packard ,motor ,car ,company4 ,an object of my invention is to automatically regulate the compression ratio in an engine inversely to the speed4444 ,see also his patent #ahiacba1 issued in #aicb and assigned to the ,packard ,motor ,car ,company4 ,it describes a similar but nonautomatic system4 ,woolson therefore fully realized the disadvantages of the high cylinder pressures his engine developed at high rpm's4 #cg ,letter1 ,clarence ,h4 ,wiegman to ,national ,air ,museum1 ,november #a1 #aifa4 #ch ,ibid4 #ci ,major ,george ,e4 ,a4 ,hallet1 ,u4,s4 ,air ,service1 former director of engineering division1 ,mc,cook ,field1 ,dayton1 ,ohio4 #dj ,test of ,packard-,diesel radial air-cooled engine1 ,navy ,department1 ,bureau of ,aeronautics1 ,report ,,ael-#cce1 ,july #ac1 #aica1 ,bu,aer ,proj4 #bbfe4 #da ,aviation ,week and ,space ,technology 7,february #ai1 #aifb71 vol4 #gf1 no4 #h1 p4 #aja4 #db ,aeronautics 7,october #aibi71 vol4 #e1 no4 #d1 p4 #ca4 #dc ,letter1 ,richard ,totten to ,national ,air ,museum1 ,january #bh1 #aifd4 #dd ,according to ,frederic ,e4 ,hatch of the ,national ,air ,museum1 it is possible that the engine failed because the fuel injectors became clogged4 ,he notes that the airplane refueled at several fishing ports1 and therefore must have used diesel oil set aside for fishing boats4 ,this oil was generally quite dirty4 ,as a result it was routine for the fishermen to have to clean engine oil filters frequently enroute4 ,the oil filters of the ,packard diesel could not be cleaned in flight4 ,transcriber's ,notes3 ,passages in italics are indicated by underscore4 ,passages in bold are indicated by bold4 ,the following misprints have been corrected3 crackcase corrected to crankcase 7page #af7 is is corrected to it is 7page #cf7 ,other than the corrections listed above1 printer's inconsistencies in spelling1 punctuation1 and hyphenation usage have been retained4