This popular question is not only legitimate, but it spawns a good deal of passion among aviation and military buffs. And when emotion takes over, rational analysis goes out of the window.

Some frustrated aviation historians say that when deeply technical and scientific topics, like aircraft performance, are reduced to enthusiastic debate, the matter falls predictably into favoritism, propaganda, ideology, and other (less constructive) atmospheres that prevent us from getting closer to the truth. Cold and logical assessment should reign instead.

There is a dictum that states “you do not know, what you do not know”. Aviation is so wide-ranging that even experts in one area often lack familiarity with others. You may recognize some of the things where your expertise is limited but you are blind to others even to the point of not knowing they exist.

Nevertheless, the topic is approachable. After all, the technical offices of the air forces relayed to the engineers what the air forces thought was important in a specification. And once fighters started to face each other in combat, and enemy fighters were captured, it became possible to revise this understanding and update specifications (not to mention combat methods or doctrines).

The first thing that should be understood when answering the question of the “best fighter” is that from the beginning to the end of WW II there was a continuous drive to improve each fighter. Let’s see an example: the Spitfire Mk Ia deployed in May 1940 (just before the Battle of Britain) and the Spitfire Mk XIVe that saw broad use with the squadrons from mid-1944 to the end of the war were drastically different machines.

The table below is an eye-opener:

If you asked an RAF squadron commander to choose between the Spitfire Mk I and the Spitfire Mk XIV for his squadron, he would surely select the latest model. In general, the latest version of any fighter model enjoyed superior performance over earlier versions.

One approach to answering the question of the “best fighter” is to compare only the latest fighters, but this approach has important limitations. The variants that faced each other during the bitterest engagement in WWII, like the Battle of Britain, Barbarossa, Midway, the Dieppe Raid, the battles over Germany, etc., were not the latest models, but earlier types that appeared at identifiable periods of the war.

Meaningful comparisons consider the fighters who faced each other in combat during specific battles, as this is the best way to detect why one side or the other did better. Fortunately, this does not prevent us from comparing the latest versions if we wish to learn how a design evolved.

Therefore, the question “What fighter was better, the Spitfire of the Bf 109?” is meaningless. But the following two questions are valid: “Was the Spitfire Mk I better than the Bf 109E-4?”, “Is the Spitfire Mk XIV superior to the Mk I?”.

The next thing we need to clarify is what a better fighter means.

A fighter aircraft is an operational tool that an air force uses to crack specific problems. One of the problems that an air force comes across is how to shoot down an enemy aircraft in the air. This problem can be solved using different methods, like using anti-aircraft guns, but one practical approach is to use another aircraft to destroy them. The fighter exists for a reason: to shoot down enemy aircraft. Its design reflects this imperative.

During WW II, fighter pilots found they had to shoot down different classes of enemy aircraft: fighters, transport aircraft, reconnaissance aircraft, and light, medium, and heavy bombers. And they had to accomplish this during both day and night.

Engineers and tacticians found that the day and night environments differed so much that specialized fighter aircraft with vastly different characteristics had to be designed and deployed.

Even if we narrow our analysis to daylight combat, a fighter could excel at shooting down fast, highly maneuverable but relatively frail fighters and at the same time, it could be inadequate to tackle relatively slow and unwieldy bombers that were rather sturdy and heavily defended with flexible guns.

For the purposes of this article, we will narrow the topic of the “best fighter” to fighters who had the mission of destroying other fighters in air combat during daylight.

The last factor that we must address is, whose perspective we will use to answer the question. The fighter pilot’s perspective (who is doing the fighting) or the supreme fighter commander’s (who seeks to attain air superiority)?

A fighter may have been ideal for the pilot, but if it was too difficult to manufacture, maintain in operation, or fly by green pilots, air commanders would not be satisfied. The supreme fighter commander needs a fighter aircraft that is competent or excels at five different operational environments that we will call “arenas”:

1. Factory Arena

When comparing WW II tanks, B. Kavalerchik wrote: “The worst tank in the world which manages to show up at the right time and in the right place is immeasurably superior to the best tank in the world which fails to arrive when and where it is needed”. Similarly, an aircraft must be produced in large quantities and delivered to the Air Force when required. Manufacturing costs and man-hours to build it are key factors. Strategic raw materials and tooling restrictions must be considered. The lack of Aluminum forced the Soviets to use wood in their fighter’s airframes. Fuel octane placed limits on German engines. Technological limitations prevented the use of gyro-gunsights by the Luftwaffe and VVS. To shine in this realm, a fighter should be economical, easy to manufacture in great numbers, and it should have great performance with the materials and technology at hand.

2. Military Base Arena

Once the fighter was manufactured and delivered to the squadrons, it should be easy to maintain by recently trained personnel, (a serviceability rate of 80% is acceptable during war operations), it should be reliable (10% of sorties in the USAAF returned early for mechanical reasons. The lower the abort rate the better), and it should be durable: it should last a long time as a first-line aircraft. When the aircraft was not suitable for operations due to age or obsolescence, the aircraft was deemed a second-line aircraft (the USAAF lost 17% of aircraft for this reason. This loss is in addition to the losses suffered in combat & accidents!). Hastily trained pilots should find the aircraft easy to fly (for instance the Luftwaffe found that it could train pilots faster in a Fw 190 than in a Bf 109 because of the BMW 801’s Kommandogerat system).

3. Transit Arena

To shoot down an enemy, the fighter must be able to reach the battle area first. And after combat, it must return to the ground safely. The engineers must design the aircraft to meet requirements in at least three flight regimes: high-speed regime (combat), medium-speed regime (cruise flight, to reach the battle area and return to base), and low-speed regime (for take-offs and landings). The Transit Arena includes the last two, while the high-speed regime is covered in the Combat Arena.

Factors like range & endurance are critical in the Transit Arena. For practical reasons, the engineers designed the fighters to excel in the high-speed regime, at the expense of the behavior at low speeds. Short wings are good for high speed but dangerous for landings. Consequently, many pilots died in training and landing accidents (27% of all USAAF aircrews that died in WWII did so in training crashes), and numerous aircraft were destroyed during training (the USAAF lost 12,000 fighters in operations in Europe while 6,000 were lost in training mishaps in the USA).

4. Combat Arena

Pilots in combat readily noticed that not all fighters were the same. Some were superior. They noticed that some performance parameters are more relevant for combat, like speed, climb rate, firepower, and maneuverability. Engineers saw that several of these factors could be quantified, while others were qualitative in nature (for instance, visibility and durability to damage). We will cover these in more detail in the next section.

5. Development Arena

Fighter pilots and commanders realized that performance advantages were difficult to sustain. Both adversaries continuously improved their aircraft. A good fighter should have room for improvement to avoid early obsolescence. The Spitfire and the Bf 109 saw continuous improvements from the beginning to the end of the war, while the Hurricane had a shorter career.

Comparing Fighters: The Combat Arena

The perspective of fighter commanders-in-chief can also be thought-provoking, but we will focus exclusively on the perspective of fighter pilots to keep the comparisons manageable and prevent this article from becoming too long. Consequently, we will concentrate in the Combat Arena and will exclude all others.

Fighter comparisons are intricate because air combat is a fluid action where numerous factors intervene, many of them interconnected. We can approach this with objectivity by selecting the performance attributes that are most relevant during the combat phase.

The fighter’s mission is to destroy other airplanes and to accomplish this the aircraft must maneuver in the airspace to attain the same plane where the enemy is moving until the weapons are in range and it has the appropriate lead. Then it must fire to achieve hits and keep firing until the target is wrecked.

Against an unwary target achieving a firing solution requires minimum steering while attacking a rival that is fully aware and flying an agile aircraft requires hard maneuvering to attain a firing opportunity that lasts only seconds or less.

Hard maneuvering reduces situational awareness (SA), and this endangers the attacker, so the most fundamental tactic is to achieve surprise. The best aces applied ambush tactics and shunned dogfighting as a low-payoff activity.

According to most test and combat pilots, including Royal Navy’s Eric Brown, the major attributes that a day-fighter needs to be effective are:

• All-around visibility to detect the enemy first and avoid being surprised (day fighters lacked radar in WWII).
• Transceiver (radio) to broadcast sightings quickly by any pilot in the unit and for the leaders to direct the action of the formation.
• High speed to catch up with the enemy rapidly or to escape from him.
• Superior climb rate to attain an advantageous position for attack or to reduce exposure using vertical maneuvering.
• Swift dive acceleration to overtake the enemy or to break off the action.
• Heavy firepower to maximize the short-lived openings during combat.
• Exceptional maneuverability to attain a good firing position or to negate one to the enemy (this can be subdivided into tight turn radius, fast roll rate, rapid acceleration, and a high power-to-weight ratio for agility).
• High ceiling that furnishes altitude advantage.
• Durability, to absorb damage and return to the base.
• Long-range to penetrate the enemy airspace.

Dive acceleration, although critically important, will be omitted from our comparisons because reliable quantitative or qualitative information is absent for most fighters (dive acceleration depends on dive angle and diving time, and fighters lacked instrumentation to measure it).

Range is also a key attribute that we have omitted because it is included in the Transit Arena. Once the adversarial airplanes were in sight, range played a relatively minor part.

A comment is pertinent, however. For fighter commanders-in-chief, range was one of the most important characteristics because it defined the practical depth of the incursion. Bombers suffered serious casualties without fighter escort, so longer range allowed better protection, and this in turn helped to attain air superiority. The P-51 was chosen over the P-47 to equip most USAAF Fighter Groups mainly because of its larger operational radius. For fighter pilots too, range was always a cause of concern since most fighters had short endurance. Pilot training schools highlighted the importance of fuel management. This was even more important for aircraft carrier-based fighters. So, when making your own assessments, bear this in mind.

 The previous image shows the attributes that will be considered in the comparison (in black) and those that have been excluded (in blue).

It must be stressed that the results of a dogfight depended not only on fighter performance; pilot quality (training and experience), and the tactical conditions at the time of the engagement were just as important. Having said that, we will assume that pilot quality is identical, and the tactical condition is neutral.

There were other important but secondary attributes that will be excluded from the comparison because pilot evaluations usually do not include them except as an observation and therefore, dependable data is often scarce.

The most important secondary attributes are mentioned for completeness:

1. Handling. It is the ease with which a pilot can achieve the task he is demanding the aircraft to perform.
2. Ergonomics. An umbrella term describing many factors that contribute to the pilot focusing outside the cockpit rather than on the systems in the cabin. Comfort (part of ergonomics) allows him to fight in any weather without impairment. If the windshield fogs at altitude and he cannot see the enemy, the aircraft is worthless. There are recorded instances where squadrons were forced to descend because the pilots were too cold to be attentive.
3. Airframe Stressing (rugged airframe). Since hard maneuvering imparts positive and negative G's, the airframe must be tough enough to withstand those loads. The more rugged the heavier the airframe. For instance, FAA part 23 defines airworthiness standards for civilian aircraft under 12,500 pounds of weight (all single-engine WW2 fighters, except the P47, were this light). A normal category plane is stressed to +2.1/-0.84 G and an acrobatic aircraft to +6.0/-3.0 G. The airframe of an acrobatic airplane may be more than 30% heavier than a normal category. G is a measure of acceleration. 1G is the acceleration we feel due to gravity. FAA part 23 did not apply to WWII fighters (of course), but every air force had its own (similar) regulations.
4. The engine must operate over a wide range of G's. Early in the war, the Rolls Royce engine of the Spitfire could not withstand negative G’s.
5. Ammo Load. More ammunition helps during long-drawn-out dog-fighting clashes.
6. Gunsight. Ring-and-bead sights became obsolete a few years before WW2 and optical gunsights were used most of the war, but by the end of the conflict, lead computing sights appeared helping the pilot to achieve hits at high-deflection angles and longer ranges. This helped the average pilot.

Cyberboardz Fighter Evaluation Cards

Eric Brown, a superlative Royal Navy Test Pilot, evaluated dozens of different fighters from many nations. He came up not only with a list of the most vital traits (which have been stated above) but he recognized that some of them were more important than others. He ranked them in order of importance and using his list we assigned a weight to each of them.

The Fighter Evaluation Card developed by Cyberboardz arrives at a score using the following method:

1.  We incorporated eleven major attributes relevant for combat.
2. Each one has a weight depending on its importance, as shown in the next image.

3. The Messerschmitt Bf 109 F-2 is the benchmark. All other fighters will be compared against it.
4. By default, we gave a 10 to each trait of the benchmark aircraft (a 10 does not mean perfect but it facilitates comparisons. Values higher and lower than 10 are possible).
5. The fighter that we want to compare is selected (in this case the Bf 109E-4 in the blue row).
6. Each trait is compared against the benchmark individually. A value higher or lower than 10 will be given depending on the actual performance difference between the model in question and the benchmark fighter. For example, the Bf  109E-4 maximum speed was slower than the Bf 109F-2’s so a value of 9 is assigned. Its firepower was heavier, however, so an 11 is given.

          How much higher (or lower) than 10 (sometimes called the spread) requires thoughtful consideration, so we designed an algorithm to calculate the values consistently.

7. The totals are added (considering the weight), and the Bf 109E-4 ends up with a score of 96, which is identical to the Spitfire Mk Ia (see next picture) but inferior to the F-2 which appeared later in the war. Historians have debated for a long time which fighter was better, the Spit Mk I or the Bf 109E-4. The scorecard shows they both enjoyed practically the same performance.

       The advantage of this method is that it requires no initial selection of "perfect 10" attributes. A set of fighters can be compared, and later others with better characteristics can be added without changing the algorithm.

Comparisons of WW2 Fighters that Fought in 1940-41

The following table captures how the most famous day fighters of the 1940-1941 period on the Western Front compared. From this list of twelve fighters, the best was the Focke Wulf 190A-2, and the worst was the Boulton Paul Defiant Mk I.

The Bf 109E-4 and Spitfire Mk I were on equal terms in 1940. Both surpassed the Hurricane Mk I. Later the Germans introduced the E-7, F-2, and F-4 and each one was better than its predecessor. The British similarly deployed the Spitfire Mk IIa (1940) and the Mk Vb (1941). The latter was somewhat better than the F-4 thanks to its awesome firepower and better maneuverability, although the F-4 was superior in the vertical plane. In 1941, the Luftwaffe achieved technical superiority with the Fw 190A-2, while the Hurricane Mk II began to lag behind.

 Remember that these comparisons apply to WW II fighters engaged in daylight combat with other fighters from the perspective of the fighter pilot. This is an objective comparison, using well-researched data and employing an impartial methodology.

Room for debate still exists, of course. We considered the eleven major traits in the Combat Arena but skimmed over dive acceleration because reliable data is scarce. The secondary traits have similarly been omitted because of a lack of dependable records (i.e., ergonomics, handling, and a few others). It needs to be mentioned that firepower has a limit of 15 which was ample enough to destroy another fighter with a brief burst of fire. Heavier firepower was excessive against fighters but vital against heavy bombers (which are not part of this comparison). Also, as previously mentioned, the Fighter Commander’s perspective, which includes additional categories (classified as “arenas”) is not incorporated.

Furthermore, the weights depend on the tactics employed. There were two basic dogfighting tactics: energy tactics (fighting using the vertical plane, also known as Dive-and-Zoom) and angles tactics (fighting using the horizontal plane, also known as Turning or Angles fight). The most successful fighter pilots preferred energy tactics and the weights are skewed to favor the attributes that facilitated this tactic the most (max. speed and initial climb have more weight than maneuverability).

Another important consideration is that fighter tacticians realized that the performance of their aircraft changed with altitude. The speed increased roughly linearly with altitude. At sea level, the engine usually develops its greatest power (not always), because the air density is at its maximum, but this in turn creates much more drag reducing the maximum speed. As altitude increases, air density decreases so drag is reduced. However, lower air density means less engine power, so superchargers or turbochargers are used to limit this loss of power. Up to a certain altitude they succeed, and the net result is increased speed with altitude. When these air compressors reach their maximum capacity, the engine starts to lose power, and the aircraft speed decreases greatly. The supercharger/turbocharger max. rated capacity is adjusted to different altitudes depending on the aircraft model, so the altitude at which fighters developed max speed is different. This is the reason the Cyberboardz cards include the maximum speed at sea level and at best altitude. Climb performance behaves similarly and this is incorporated into the card.

The table below shows the effect of altitude on maximum speed for Soviet and German fighters of the Barbarossa (1941) period.

 The chart tells us that the MiG-3 was the fastest and reached maximum speed at about 7.000 m, after that, its supercharger could not compensate for the thin air density and power as well as speed decreased. Below 5.900 m the Bf 109F-1 was faster. Since German and Soviet bombers operated at 4.800 m or below most air combat on the Eastern Front was fought at those altitudes giving the F-1 an edge. The Yak-1 surpassed the MiG-3 at low altitudes (below 3.000 m) thanks to its two-stage supercharger. Once the second stage kicked in, however, the Yak-1 was inferior. This shows that the pilots had to carefully select its tactics so they could face the enemy on their terms.

The scorecard and the performance section of our cards give you enough information so you can conduct tests if you wish. You can assign different weights and recalculate the results if you feel like experimenting!

If on the other hand, you want objective comparisons based on dependable data, and you do not want to spend long hours researching and calculating, the Fighter Evaluation Cards deliver.

Enjoy!