Factors Controlling Aircraft Design And Combat Performance

By Nathaniel F Silsbee
Major, US Army Air Forces

An authoritative analysis of American, British and German warplanes shows why record of United States craft is good and reveals fallacies in arguments of self-appointed critics of AAF planes — hitherto unrevealed glimpses of the future give sound reason for continued faith in our designers and builders.

The airplane was not always a military weapon. Orville Wright has more than once expressed his sorrow that the machine which he and his brother made a practical reality should have been used for such frightful purposes. Quite early in the history of heavier-than-air craft alert military men realized the latent potentialities of the airplane to bring new speed, new vision and new range in warfare.

As the airplane was applied to various uses in actual battle a few well defined types were developed. Models change with a breath-taking rapidity, but types remain fairly static. B-17E is a model, heavy bomber is a type.

Each desirable quality in airplane performance calls for a certain property, and the various properties conflict with each other to a remarkable degree. The aeronautical engineer's knowledge of his subject tells him what properties are necessary to produce the particular qualities he desires, and his skill or creative genius guides him in so adjusting the mixture as to obtain the most while sacrificing the least.

Thus it is practically impossible to get a high top speed without increasing landing speed — sometimes beyond the safety point — particularly in combat areas where modern airfields are not available. This may produce what is popularly known as a "hot" ship, though it should be pointed out that the phrase really means a speedy high performance plane which, if mastered by the pilot, may prove to be actually safer to handle, both in the air and in landing. An example of the danger is the original German Heinkel He-113, a beautiful and cleanly designed fighter, but which landed so fast it proved to be a pilot-killer. It has since been redesigned, and has become a successful fighter, second only to the Messerschmitt Me-109F and Focke-Wulf FW-190.

The best known current example of the fact that "you can't have your cake and eat it, too" in a military airplane is the Jap's Mitsubishi-00 Navy fighter, or Zero. To secure maneuverability, rapid climb and high ceiling not only were all pilot safety factors such as protective armor and self-sealing gas tanks sacrificed, but durability as well. Aluminum sheeting is very light, and the general construction far from rugged. Evidently both planes and pilots are classed as "expendables," like bombs, guns, etc.

To gain the air superiority we need to win this war, America must have a sufficient quantity of high quality airplanes. We must have hundreds of thousands of well-trained airmen — and that means aircrews, as well as ground crews to "keep 'em flying." We must have air bases at strategic points, including landing fields, storage and maintenance facilities, housing and technical installations, and all that goes to enable a modern air force to carry on. We must have an air supply system to maintain American Air Forces offensive actions on the far-flung battle fronts. Our training programs, under the Flying Training Command and the Technical Training Command, have been expanding at an amazing rate, and well trained air and ground crews are coming out by the thousands every month. Our engineers and construction crews have been busy for well over a year establishing the necessary air bases for action in the main theaters of combat. In this paper we are concerned principally with the airplanes, but don't forget the other three elements in making up a balanced and powerful striking air force. Some of the following points will appear elementary to many readers, but in estimating our progress in the race for air supremacy and in order to properly evaluate much of the current discussions of our airplanes, it is important to get down to brass tacks.

In discussing airplanes it is important to remember that mere numbers, such as 50,000 or 100,000 per year, mean very little. The questions to ask are, "What exactly are these planes to be used for? What type do we need? How many of each?"

The basic functions of air power include:

  1. Attack,
  2. fighting,
  3. observation, and
  4. transport.
Out of experience in the use to which airplanes are put certain general specifications have emerged. Military airplanes are designed to meet certain specifications as to exactly what that airplane is expected to do. Each model is a tailor-made job. It would be very convenient, and far less expensive, if a single type of airplane could be designed and produced which would perform all functions, but that simply is not in the cards.

It is true that certain of our aircraft have in actual use proved surprisingly versatile, and with minor modifications are performing three or four different chores better than anyone had a right to expect. The best example of this is the Douglas A-20 light bomber, used by the RAF as the Boston III for raids in occupied France and the Low Countries and by American units in the new role of dive bomber. It just about completes the circuit when we note that some of the new models have been equipped to carry torpedoes. Here is versatility plus, but the reason is that specifications for this attack bomber type (as distinctly an American development as the long-range heavy bomber) are far less contradictory than for other more standardized types, in addition to which the exigencies of warfare have a way of prodding human ingenuity in no uncertain terms.

The main combat types are fighters and bombers, and the service types are observation planes, cargo and transport, and trainers, including primary, basic, advanced single-engine (for fighter pilot training), and advanced twin-engine (for training of bomber pilots, bombardiers, navigators, aerial gunners, etc.) For the most part we shall consider only the combat types. Each has definite design specifications to meet certain performance requirements.

Of the four functions of air power attack is fundamental, and air power should be regarded not primarily concerned with airplanes fighting in the air, but as attacks on vital ground objectives from the air. That means bombers, backbone of any air force.

Primarily the bomber must be a good weight carrier, with sufficient range to reach distant targets and still get back, with allowance for adverse conditions. The yardstick for both heavy bombers and cargo planes is power-loading — the gross weight divided by the total horsepower, and the fewer pounds per horsepower the better. A good average is between 12 and 13 lb — the B-17E and C-47 are both about 12.5. From a design standpoint that means a large airplane with high lift wings, which limits maneuverability. To secure greater range, larger fuel capacity may be provided, but bomb load is thus reduced. This is one of the important differences between the British heavies, such as the Stirling and Lancaster and our long-range B-17s and B-24s. The former were designed to carry loads of six to eight tons to targets within 600 to 800 mi at altitudes of 12,000 to 18,000 ft. American heavies were developed for high level daylight precision bombing at long range.

These characteristics are fundamental for a bomber, but hardly less important are the factors of speed so that enemy fighter planes will not be able to fly rings around it, and ability to carry its heavy load to high altitudes to escape the worst anti-aircraft fire which has been developed by practically all the belligerent nations, now effective up to approximately 25,000 ft. Superior horsepower and gear-driven or turbo-supercharging are the answers to these problems. From a military standpoint a correlative to high altitude performance is the precision bombsight.

An excellent example of the need of highly specialized design to meet specific performance requirements is the dive bomber. For more than 20 years dive bombing has been a specialty of our Navy and Marine Corps and, as is well known, the idea was seized by the Luftwaffe in the early thirties and developed in the Spanish Civil War. The Junkers Ju-87 Stuka (from sturz kampf or "diving fighter") was used with devastating effect in the Nazi campaigns of 1940. Meanwhile, the Army Air Forces continued development of attack aviation (now included in light bombardment), using fast, low-flying planes for ground strafing troops, ammunition dumps, machine gun emplacements, etc. The Stukas proved extremely vulnerable without local air superiority, as was proved not only in the Battle of Britain, but in recent action in the desert, where Rommel lost Ju-87s by the score, with the RAF losing practically none of its Douglas Bostons. However, under certain conditions on land — and definitely at sea — the dive bomber may fill an important place as a specialized type.

Although there are still large numbers of the 5-year-old Ju-87s in service, the real dive bombing threat of the Luftwaffe is the twin-engine Junkers Ju-88b, which came out in 1939. Also used as a level bomber for short-range bombing and long-range reconnaissance, this "all-purpose" bomber, with the Heinkel He-111K and the Dornier Do-217Z constitute the backbone of the Luftwaffe striking force, as four-engine heavy bomber types have not yet been extensively developed in Germany, the Focke-Wulf 200K Kurier and the Heinkel 177 being the principal models in this class.

Our Navy and Marines use the Douglas SBD Dauntless, and the Army Air Forces have a similar version known as the A-24. The Vultee A-31 Vengeance is a newer model, built for the British. The Army equivalent of the Curtiss SB2C, the Navy's Helldiver II, is the A-25 which is expected to be the most powerful dive bomber in any service. A dive bomber version of the North American P-51 Mustang ins now in production for the Army Air Forces.

Air fighting, hardly less important than air attack, has two main purposes: First, defensive — the interception of hostile bombers — and second, offensive — gaining air superiority during an attack. For this two-fold purpose modern fighter planes have been developed by different countries which, on the whole, have proved to have similar characteristics and performance.

Design Problems

The conflicting requirements for a single-seat fighter plane constitute an aeronautical engineer's nightmare. First of all is speed, speed sufficient to exceed that of enemy bombers and fighters at any and all altitudes. This problem of superior speed at any altitude is one of the most difficult of all. Owing to the fact that engine power falls off as the airplane goes higher and higher, every military plane has a critical altitude at which it performs best, depending on the supercharger.

An excellent illustration of this is found on the engine data card found in the cockpit of a German Focke-Wulf FW-190A3 shot down by the RAF. Its rate of climb showed "3,050 ft per min at 4,000 ft with supercharger in M gear, and 3,280 ft per min at 17,500 ft supercharger in S gear."

Compared with the 2- or 3-ratio gear-driven supercharger the turbine-driven supercharger is more flexible and provides a greater range of altitude at which maximum power can be obtained. The design compromise on the matter of high speeds at all altitudes has not yet gone beyond the stage of practically two types of fighter planes for our Army Air Forces, those of critical altitudes about 13,000 ft with a service ceiling up to 25,000, and the distinctively high altitude jobs which operate effectively up to 38,000 or 40,000 ft with turbo-superchargers. (We don't know yet if these or any other planes can fight effectively up that high.)

In the first class we have the Curtiss P-40 series, the Bell P-39 Airacobra and the North American P-51 Mustang. In the high altitude class we have the Lockheed P-38 Lightning with two Allison supercharged engines, and the Republic P-47 Thunderbolt, powered by a 2,000-hp Double Wasp. The British use the Hurricane for low and medium levels, and the newest Spitfire for high altitude work. The Hawker Typhoon, with Napier Sabre 2,200-hp engine is reported in production, and from all indications will be faster and more effective at high altitude.

The Germans have three first-line fighters, all with fairly high ceiling. Fastest is the Heinkel He-113, powered by a Daimler-Benz 603 inverted V-engine of 1,300 hp, but the other two, the Focke-Wulf FW-190, and especially the Messerschmitt Me-109F, are more effective at high altitudes.

Second only in performance to speed in relation to altitude is climb. Enemy bombers approaching at 20,000 ft at 300 mph, penetrate 5 mi every minute. If the fighter planes require 6 or 7 min to reach that altitude, the bombers will have progressed between 30 and 35 mi during that time. A high rate of climb insures ability to intercept the enemy more quickly, a feature very prominent in German design. It is also of interest to note that the Jap Navy Zero has this as its leading characteristic.

The conflict of design features between high speed and fast climb resolves itself to this: speed requires high power and low drag, small wing area and highly streamlined contour. Climb demands high power and large wing area compared with total weight. Net result, as usual, a compromise.

These characteristics have to do with fighters as airplanes, but airplanes are also weapons. Chief military feature of a fighter plane is fire power, for in the last analysis no combat ship is better than its armament. It was the edge which eight .30-calibre guns on the Spitfires and Hurricanes, plus slightly higher speed than the Messerschmitts and Heinkels, which was in large part responsible for winning the air Battle of Britain.

Today eight .300-calibre machine guns is an absolute minimum, and most modern fighters have combinations of two to four 20-mm cannon with two to four or more .30- or even .50-calibre machine guns. Instead of these mixed mountings, some fighters have four 20-mm cannon — Hurricane IIc, Spitfire Vc — or six .50-caliber machine guns — Warhawk, Thunderbolt. This additional fire power is necessary owing to the greatly decreased vulnerability of modern bombing planes, with their higher speed, rugged construction, leak-proof gasoline tanks and armor protection. The heavier .50-caliber machine guns firing 800 rounds per min are much more effective, and at a greater distance, than the rifle-calibre .30s which fire at a rate of 1,200 per min.

American armament experts on the whole favor the .50-calibre gun, while most of the British, German and other foreign military aircraft use combinations of the 20-mm cannon and .303-calibre or 7.7-mm machine guns. This insistent demand for more fire power increases the weight, and thus reduces speed, especially the rate of climb.

Besides these three fundamental characteristics of speed, climb and fire power, fighter planes must have other performance features. Prominent is maneuverability, both for offense — to get the plane into firing position — or as the principal means of defense in combat.

A good fighter must have clear visibility to enable the pilot to scan the skies in all directions to discover his opponents and avoid being surprised. It must have good handling qualities for landing and taking off from small fields. It must be of simple, rugged construction for easy maintenance in the field, a very important feature, as time is at a premium in war, and grounded fighter planes may be worse than none at all.

These qualities have largely to do with what has hitherto been called the interceptor fighter, used defensively to intercept enemy aircraft. For protection of friendly aircraft in short-range operations by destroying the enemy's fighters, or providing an umbrella for task force operations fighter planes are used. (It should be noted that although the "P" designation remains, the term "pursuit" ship has been superseded by "fighter" as more generally suitable.) Another function of the fighter plane, however, is to escort bombers on long-range missions. As yet no country has been able to satisfactorily solve the problem of providing a fighter plane with sufficient gasoline capacity to give a range of, say, 2,000 mi (and this means a radius of bomber action not more than 800 mi, or 40 percent of range), without sacrificing such primary fighter characteristics as speed, climb and maneuverability.

It will be recalled that on the first raids over occupied France by our Boeing B-17Es, they were escorted by RAF and AAF pilots in Spitfires. These raids, such eye-openers to the British to the possibilities of daylight precision bombing, were all short run affairs. In a longer raid over the North Sea a few days later, as soon as the fighter escort turned back to England the last five of the eleven Fortresses were attacked by a swarm of Focke-Wulf and Messerschmitt high-altitude fighters. Net result, one Fortress severely damaged, but all returned safely to base after dropping bombs on their targets; three Nazi planes down in flames and nine others destroyed or damaged. More spectacular results have since been achieved by both B-17s and B-24s.

All of which illustrates two things. At present long-range bombers cannot have fighter interference all the way. It is when the escort fighters leave that trouble begins and is likely to increase as the mission flies farther into enemy territory; in other words, at the very time when the fighter protection is most needed it is not available.

The other point is likely to make history. This incident, backed by scores of similar examples of B-17s in the Pacific area and an increasing number of instances of British Stirlings and Lancasters, proves that substantial progress has been made in the last year or so toward the ideal of a heavy bomber able to look after itself independent of fighter escort. Over and over again these bombers, and our two-engine Douglas A-20s, Martin B-26s and North American B-25s in every important theater of operations have demonstrated that their speed, heavy fire power and sturdy construction are more than a match for enemy anti-aircraft and fighter opposition. The pay-off to date is a B-17E which returned with two engines out of operation, tail surfaces almost shot away, riddled by nearly 1,500 bullet holes. In their first six weeks of action over Europe, Fortress gunners shot down 40 German fighter planes. Only two B-17s were lost.

The average tactical range of British and German single-seat fighters is 600-700 mi, with a radius of action of 200 to 250 mi, or 35 percent. In heavy action, as a practical matter, it is considerably less than this maximum figure. According to The Aeroplane, clear-cut air supremacy can hardly be achieved with present equipment (Hurricanes and Spitfires) beyond a radius of 75,180[sic] mi. Most American fighters and the Jap Zero have a maximum range of about 900 mi, the P-38 traveling considerably further. To increase the range for ferrying or strategical purposes jettisonable belly tanks have recently been provided. Until the difficulties of a genuine long-range fighter are resolved, and there are obvious advantages in having a fighter plane with sufficient gasoline to stay in the air several hours, a partial solution will continue to be found in the use of fast, heavily armed two-engine bomber fighters, like the formidable Messerschmitt Me-110, tough, speedy Douglas A-20 or the powerful British Beaufighter. The latter two incidentally, are far and away the best night fighters now in operation, a highly specialized job in itself.

Thus the fighter, with all the conflicting qualities of speed, climb, firepower, maneuverability, visibility, ease of handling and maintenance added up, and with range thrown in for good measure, becomes more of a compromise than any other airplane type. The Army Air Forces award the design of a new type to manufacturers as a result of a competition based on several announced specifications. Merit is measured in terms of:

  1. Performance, including speed, range and ceiling, 350 points;
  2. engineering features, including structure, armament, powerplant and equipment installations, and maintenance, 350 points; and
  3. military features, including general suitability, landing and takeoffs, arrangement of guns, etc, 300 points.

Too few people realize that many of today's first-line military airplanes are the result of tried and proved designs brought out six years or more ago, vastly improved as to speed, ceiling and firepower, but still essentially the same craft.

In the fighter class the best examples are the Hurricanes and Spitfires. In 1934 the British Air Ministry issued a specification for an eight-gun fighter with 1¾-hr range at full throttle. (the knock-down, drag-out fight to get the eight .303 guns into the specifications was something else again. Such heavy armament was unheard of in those days, but the concentrated shotgun firepower thus provided saved England in 1940.) Using the Rolls-Royce Merlin, both fighters were test-flown in 1936, came into limited production in 1937, and the first squadrons were outfitted in the summer of 1938. The Hurricane had a top speed of 335 mph, and the Spitfire 365. Improved versions of the Merlin and design refinements have more than kept pace with the demands for more protective armor and increased fire power, as the newest models are five to ten mi faster than the originals and, in the case of the Spitfire Mark V the critical altitude has been boosted.

The German Messerschmitt Me-109 was brought out in 1936 and came into full production in 1937, its final design having been largely influenced by real combat experience gained in the Spanish Civil War. The same is true of the newer Russian fighter planes. This conflict set the seal on the monoplane with retractable landing gear as the fighter type of the immediate future. The Me-109 was originally designed for an engine of 650 hp and was the first fighter to use a 23-mm shell cannon firing through the propeller hub. Without material change of design the power plant has been successively stepped up to 850, 1,050, and now 1,150 hp, in the Me-109F. These successive rejuvenations brought the original speed of 265 mph to 365 or better. Armament has remained the same, but after the failure of the Luftwaffe to smash the Soviet Air Force during the summer of 1941 — an operation in which the Me-109E model was counted on heavily — this fighter began to appear with protective armor plate. Recent reports from Russia indicate that the still newer Me-109G is in action, as a high-altitude, partly armored fighter with a Daimler-Benz 603 liquid-cooled engine of 1,600-1,700 hp, armed with three cannon and two machine guns. The Me-109 has probably reached the limit in this newest model, but it still packs plenty of punch.

The year 1936 saw the advent of another famous fighter which was to make history, the Curtiss Hawk 75 which carried the Army Air Corps designation P-36. Powered by a Wright Cyclone or Pratt & Whitney Twin Wasp 850-hp radial aircooled engine it had a speed of slightly over 300 mph, somewhat faster than the Me-109 but slower than the Hurricane or Spitfire of the same vintage. All but the P-36 used V-type liquid-cooled engines. The decided edge in speed which this engine produced, accentuated by racing records by souped-up models, helped swing Air Corps procurement policy toward it for the fighter planes. The highly successful P-36 was slightly redesigned to take the new Allison V-1710 (then turning up 950 hp) as the YP-37, which was developed int the P-40, A, B, C, (British Tomahawk), and the P-40D and E (Kittyhawk) with much heavier fire power, self-sealing gasoline tanks and increased armor. The newest model P-40F or Warhawk has the Packard-built Rolls-Royce Merlin XX engine and has a higher critical altitude and service ceiling than the earlier models, and according to reports from the various fighting fronts is already showing up in favorable actions, although no details are releasable.

The one Army fighter which uses a radial air-cooled engine, the Republic P-47 designed by Alexander Kartveli, can also trace a lineage back through the smaller P-43, and more indirectly to the P-35. Improved cowling, external streamlining, a highly efficient system of ducts for air cooling and turbo-supercharger, have combined to make the P-47 a speedy, powerful high altitude fighter.

The German Focke-Wulf 190, designed by Kurt Tank, draws many features from an early ancestor, the FW-159, first brought out in 1934-35. The FW-190 is powered with a BMW 801 14-cylinder, two-row air-cooled radial engine of about 1,600 hp, and has a top speed of about 375 mph, with a good rate of climb. A newer version, powered by a BMW 802 engine of 2,000 hp is coming into production and should prove to be a very tough customer. The Jap Zero also uses a 14-cylinder radial of about 1,000 hp, with a top speed of about 340 mph.

Heavy Bomber Development

So much for fighters and their engines. The story on bombers is substantially the same. An outstanding example is the Boeing Model 299, Air Corps B-17. This was designed in 1934 as the world's first long-range four-engine heavy bomber to be the keystone of an American striking air force. It was test-flown in 1936 and its development by adding supercharging for high altitude operations, leak-proof gasoline tanks, heavy defensive fire power from .50-calibre machine guns firing from all angles — many from power-operated turrets — is a story full of examples of pioneering ingenuity. Its European vindication, after years of criticism, and equally amazing performance in the Pacific area, as a tough customer both offensively and defensively, speak for themselves. The original engines were 850-hp Wright Cyclones, which have been successively stepped up to 1,250 hp, or a total of 5,000 hp. The B-17E in production by Boeing, Douglas and Vega has a top speed of over 315 mph and weighs more than 30 tons, 10 tons of which is fuel and bombs.

Another interesting case history is that of the Heinkel He-111K,one of the most widely used bombers of the Luftwaffe. In late 1935 a fast, nicely streamlined twelve-place "commercial" airliner known as the Heinkel 111 was placed in service with Lufthansa. Soon, however, a faster version came out, equipped with two Daimler-Benz 600 engines of 650 hp, the same engine as the original Me-109. With a speed of about 235 mph, it went into service with the Luftwaffe and was used in Spain. It was further stepped up with 800 hp Jumo 211s, then 1,000 hp Daimler-Benz 601s and finally, as the Heinkel 111K5 with DB-601As of 1,150 hp. With these modifications and other improvements, top speed went from around 200 to about 275 mph, the original armament of three 7.7-mm machine guns was doubled and a 23-mm shell cannon added, all manually operated. (In fact, the Germans have been very backward in their use of power-operated turrets.) Still widely used, the He-111K has a service ceiling of 24,000 ft and a range of 2,000 mi with a light bomb load.

Up to the advent of the British four-engine heavies, one of the most consistently successful long-range bombers was the Vickers Wellington, "Wimpy" for short, and familiar in this country as the plane in the motion picture "Target for Tonight." The prototype appeared in 1936, the first production job in late 1938, and by the middle of 1939, just before the kick-off of World War II, an RAF Bomber Command squadron received its equipment of Wellingtons, powered by Bristol Pegasus nine-cylinder air-cooled radials of 965 hp, with a speed of 235 mph at 15,000 ft, its critical altitude. Wicked looking gun turrets with two .303s in the tail and nose and one from cabin windows on each side provided good defensive armament. Range was about 1,500 mi with a ton and a half of bombs. Its unique geodetic construction made for slow production but was exceptionally sturdy. Wellington Mark II came out in early 1941 with two Rolls-Royce Merlin Xs of 1,150 hp, which improved speed, ceiling, range and bomb load. The Mark III and Mark IV are now in service, powered respectively by Bristol Hercules and Pratt & Whitney Twin Wasps, both 14-cylinder air-cooled radial engines of 1,300 to 1,400 hp.

No Substitute for Time

These examples of fighter and bomber development in Britain, the United States and Germany are far from exhaustive, but illustrate the immense value of having well established designs ready before the shooting starts. Many other example could be given to show the time required before a brand new design is ready to be put into full scale production and combat operation, but two or three will suffice. The Bell P-39 Airacobra was designed in 1937-38, the prototype test flown in the spring of 1940, good production was reached in the autumn of 1941, and it was thrown into action on various fronts during spring of 1942. The twin-engine Lockheed P-38 was test-flown across the country in February, 1939, in about 7½ hr, hitting over 400 mph. It had an official NACA rating of 404 mph at 16,600 ft. However, it was thought to be too heavy — around seven tons — and in all nearly 2,000 changes were made down to the model P-38E, which was in good production from late 1941, and in action by late spring of 1942.

The Republic P-47 is the first American fighter designed since the outbreak of war to see action. Based somewhat on the Republic P-43, the only Army Air Forces fighter type using a radial air-cooled engine, the turbosupercharged P-47 design was completed in September, 1940, the prototype was test-flown in May, 1941, improvements made and limited production achieved by the spring of 1942. The advanced model coming off the lines at the parent factory and two other plants are now going into large-scale production.

These three fighters as well as the Curtiss Hawk series, went through the usual sequence of design award, prototype, exhaustive tests, award of contract for production in quantity, then tooling-up at factory. The Martin B-26, fastest and most powerful of its type in the air, broke this tradition by tooling up for quantity production first on the chance of success and a resulting large contract. When the first B-26 flew in late November, 1940, it was a production model and several others were nearly ready. It is now well known that it landed too fast, and there were the usual bugs to be ironed out. This has been done, at least two full years were saved, and now the plane is doing its deadly damnedest on a dozen fronts, doubling in brass as the world's fastest land based torpedo bomber in the actions at Midway and the Aleutians.

Other planes are now coming along on this telescoped plan, as our greatest battle has been against time. Some of these have already been test-flown and will be in production by next spring and, speaking generally, the speeds, bomb loads, fire power, ceilings, and ranges of these new bombers will be breath-taking. A principal factor in this stepped-up performance will be improved engines, with or without the use of higher-octane gasoline.

Looking at the Record

When all is said and done, however, the acid test of a military airplane is its record in combat. Do fighters knock off enemy fighters and bombers, or do they get knocked off? Do bombers get through to their targets, drop their loads accurately, and get back to do it again, despite enemy fighter and anti-aircraft opposition? On the whole, so far in this war, the combat record of American planes has been good, and it is getting better fast. Our heavy bombers have turned in amazing performances, and the new B-17Fs and B-24Es in large-scale pooled production have been further improved with far greater bomb loads and flexibility between range and load. Our medium bombers are highly praised for their speed, striking power, and high degree of invulnerability. The A-20s and B-25s are powered by Wright 14-cylinder Cyclones of 1,700 hp and the B-26 by Pratt & Whitney Double Wasps of 2,000 hp. As a matter of fact, except the practically untried Dornier Do-217E2, powered by two BMW 802 18-cylinder 2,000 hp radials, there are no medium bombers anywhere to match them.

In the fighter class it is admitted that for high-altitude work we have not yet been able to match the best fighters of Britain, Germany and Japan,but the high-flying P-38 and P-47 will soon be in wide-scale service, and on the basis of tests and operational reports to date should amply take care of things "upstairs." Accounts of the performance of the P-38s in the Aleutians and the southwest Pacific indicate that their speed, rapid climb, high ceiling and terrific fire power are just what the doctor ordered to rub the rim off the Jap Zero, and this combination of qualities, together with a much longer operational range than the Spitfire, should prove equally effective against the Focke-Wulf 190 in the European area. In the lower levels, where much of the fighting still takes place, our fast, well armed and well protected P-39s and P-40s are shooting down enemy planes on all fronts, in some areas on a better than 4-to-1 basis. The British are immensely pleased with the North American P-51, which not only handles beautifully and is easy to service, but is said to outrun the speedy Spitfire at levels below 20,000 ft.

In the widely scattered theaters of operation, supply and service is a vital consideration, and our rapidly expanding world-wide air line under the Air Transport Command, and maintenance set-up of the Air Service Command's overseas division have become as important as any of the fighting outfits.

The ability to eliminate bugs, and work in really essential battle-proven changes is a test for our American system of flexible-quantity production, avoiding the danger of Germany's original over-confident freezing of designs. There are indications that the Nazis have corrected this to some extent in that the FW-190 fighter and Do-217E1 bomber have been in operation about a year with 1,600-hp engines. These two airplanes, designated FW-290 and Do-217E2, may well prove to be serious contenders for a place in any list of the world's "best" planes. However, new American designs hinted at above, and British models should be in operation as soon as these Luftwaffe planes, and there is little doubt that the qualitative edge of United Nations' military aircraft will continue to be maintained. Already we are ahead on a monthly production basis and this advantage will be further increased. Incidentally, in any selection of the "best" planes, the main point of this article should be kept in mind — a particular airplane is "best" suited for its designed purpose. Without a common yardstick, comparisons between planes are frequently unfair. To cite one example, in the heavy bomber category it may be freely granted that the British Lancaster is "best" at the moment for very heavy night bombing of Germany, but any list that fails to take account of the amazing 'round the world record of the Boeing B-17 and Consolidated B-24 will hardly gain acceptance by a majority of aviation authorities.

No country has a corner on aeronautical developments, and the race for quality calls for research and still more research. Air power is today proving a decisive factor on many of the fighting fronts, and will eventually lead the way to victory. But victory alone is not enough. Peace and goodwill are the only worth goals, and here again air power can show the way.

This article was originally published in the November, 1942, issue of Aviation magazine, vol 41, no 11, pp 97-99, 307-308, 312, 315-316, 319-320.
The PDF of this article [ PDF, 10.2 MiB ] includes photos of Heinkel 111s on the production line, an early Heinkel airliner, and a Zero in US markings, and diagrams of the armament of an Me-110 and the bombing equipment of a Stuka.
Photos are not credited.