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PikeBishop
03-30-2004, 03:25 AM
Dear All,

Firstly I would like to say that personally I am more interested in the balance of requirements inherent in different machines regardless of their country of origin.
There seem to be many people in the forums who fixate on one factor such as maximum speed or even hearsay evidence about how a particular machine performed. This is not very helpful to Oleg.
What factors should one look at?
Well, one of the best examples is the A6M Zero.
It is important to understand that depending on what criteria are worked towards governs what comes out of the melting pot. The final product will have a formulae with both strengths and weaknesses.
Now the Zero had a very low power loading. Each HP of the engine was required to pull only 4.5lbs. This means that acceleration and climb rate would be good. (The P51 figure was 6.5lbs)
The Zero had a very low Wing Loading - each square foot of wing had to support 20lb or so of weight (The P40E had a loading of 30lb/sq ft). This in turn would mean a very low stall speed, therefore good lift at low speed and so a low best climb speed. (steep climbing angle).
This augments the effect of the climb rate.
Low stall speed = tight turning abililty PROVIDED you have the power available to sustain it, which the Zero, as we have seen certainly had.
In combat the maximum speed has little relevance and only comes into play when chasing or running away. Once one is mixing it speeds fall into an equilibrium within the respective flight envelopes. More relevent is whether your enemy can out-climb you. If your enemy does then he can gain more energy from the height gain and negate your e.g. greater maximum speed.
Now, if we look at control response, the aircraft that opposed the Zero in the early days of WWII had comparable flight envelopes with the mid-speed range at around 200-225mph....the best point on the envelope combining good turn roll and climb.
Ceiling was good for the time. Roll rate was a problem at higher speeds but this was improved from the A6M3 model onwards. Dive speed was not that good but light construction limits this (low weight and tolerance limits), but acceleration is still there in the initial dive.
So as we all know the Zero was light in construction which was the only weakness in the formulae.
However I am sure that the Japanese view was that if the Zero pilot started an encounter on equal terms the Zero pilot would quickly gain the advantage and keep it.....even if his adversary could out-dive him he would still have the height advantage.
Now if we return to the importance of excess power and combine the two forces of turning (drag) and climbing (loss of speed going 'uphill') the Zero could pull a 2g turn and still climb at 500ft/min enabling the pilot to either keep his guns bearing on a climbing enemy or evading when being fired upon by an enemy with much less excess power (just about all opposition at the time).
As regards to the dive and zoom attack, this can only be carried out from a position of advantage and suprise. Without the suprise element the Zero pilot would have a better chance than most of regaining the initiative.
If we now turn to the KI84....this is basically the Zero's formulae without the shortcomings of the Zero. It could not turn with the Zero but it was far far stronger whilst retaining the Zero's power loading acceleration and climb characteristics.
Heavy firepower and the ability to dive at 500mph made it a very dangerous opponent. It's roll rate was not far short or the FW190 although the ailerons became a little heavy beyond 300mph but this was comparable with the best American types.
It is the formulae to which the aircraft is built that makes it what it is and the Japanese had a very good formulae. The Raiden Shiden and KI100 had similar formulae.
The U.S.A. adopted different criteria which from the dogfight point of view. Their formulae was based on ruggedness speed and lots of guns and bombs. Such aircraft could not hope to compete with the agility acceleration and climbing power of the Japanese types but had and advantage in ceiling and dive rate and often speed (except for perhaps the KI84).
It should be noted here that the Japanese opted for radial engines because of their ability to absorb much more damage than the inline engines, but they could not generate the power at altitude. But then the Japanese aircraft were lighter anyway negating this advantage.
With the abovementioned later Japanese fighters they were always slightly slower and did not have the ceiling but they matched or bettered their Americsn adversaries in every other way. They were just vastly outnumbered but never outclassed and deserve better recognition by many here who perhaps do not recognise which factors are the important ones as regards performance figures, combined the to much emphasis on hearsay evidence about performance.
The Spitfire was built to another great formulae but its weakness was acceleration and range. The P51 was a good all-rounder and performed well in all area's but did not really excel anywhere except perhaps in range.
The 109 and FW190 were other good alrounders but I think that the Japanese were able to draw every last ounce of 'edge' from their designs.

regards,

SLP

PikeBishop
03-30-2004, 03:25 AM
Dear All,

Firstly I would like to say that personally I am more interested in the balance of requirements inherent in different machines regardless of their country of origin.
There seem to be many people in the forums who fixate on one factor such as maximum speed or even hearsay evidence about how a particular machine performed. This is not very helpful to Oleg.
What factors should one look at?
Well, one of the best examples is the A6M Zero.
It is important to understand that depending on what criteria are worked towards governs what comes out of the melting pot. The final product will have a formulae with both strengths and weaknesses.
Now the Zero had a very low power loading. Each HP of the engine was required to pull only 4.5lbs. This means that acceleration and climb rate would be good. (The P51 figure was 6.5lbs)
The Zero had a very low Wing Loading - each square foot of wing had to support 20lb or so of weight (The P40E had a loading of 30lb/sq ft). This in turn would mean a very low stall speed, therefore good lift at low speed and so a low best climb speed. (steep climbing angle).
This augments the effect of the climb rate.
Low stall speed = tight turning abililty PROVIDED you have the power available to sustain it, which the Zero, as we have seen certainly had.
In combat the maximum speed has little relevance and only comes into play when chasing or running away. Once one is mixing it speeds fall into an equilibrium within the respective flight envelopes. More relevent is whether your enemy can out-climb you. If your enemy does then he can gain more energy from the height gain and negate your e.g. greater maximum speed.
Now, if we look at control response, the aircraft that opposed the Zero in the early days of WWII had comparable flight envelopes with the mid-speed range at around 200-225mph....the best point on the envelope combining good turn roll and climb.
Ceiling was good for the time. Roll rate was a problem at higher speeds but this was improved from the A6M3 model onwards. Dive speed was not that good but light construction limits this (low weight and tolerance limits), but acceleration is still there in the initial dive.
So as we all know the Zero was light in construction which was the only weakness in the formulae.
However I am sure that the Japanese view was that if the Zero pilot started an encounter on equal terms the Zero pilot would quickly gain the advantage and keep it.....even if his adversary could out-dive him he would still have the height advantage.
Now if we return to the importance of excess power and combine the two forces of turning (drag) and climbing (loss of speed going 'uphill') the Zero could pull a 2g turn and still climb at 500ft/min enabling the pilot to either keep his guns bearing on a climbing enemy or evading when being fired upon by an enemy with much less excess power (just about all opposition at the time).
As regards to the dive and zoom attack, this can only be carried out from a position of advantage and suprise. Without the suprise element the Zero pilot would have a better chance than most of regaining the initiative.
If we now turn to the KI84....this is basically the Zero's formulae without the shortcomings of the Zero. It could not turn with the Zero but it was far far stronger whilst retaining the Zero's power loading acceleration and climb characteristics.
Heavy firepower and the ability to dive at 500mph made it a very dangerous opponent. It's roll rate was not far short or the FW190 although the ailerons became a little heavy beyond 300mph but this was comparable with the best American types.
It is the formulae to which the aircraft is built that makes it what it is and the Japanese had a very good formulae. The Raiden Shiden and KI100 had similar formulae.
The U.S.A. adopted different criteria which from the dogfight point of view. Their formulae was based on ruggedness speed and lots of guns and bombs. Such aircraft could not hope to compete with the agility acceleration and climbing power of the Japanese types but had and advantage in ceiling and dive rate and often speed (except for perhaps the KI84).
It should be noted here that the Japanese opted for radial engines because of their ability to absorb much more damage than the inline engines, but they could not generate the power at altitude. But then the Japanese aircraft were lighter anyway negating this advantage.
With the abovementioned later Japanese fighters they were always slightly slower and did not have the ceiling but they matched or bettered their Americsn adversaries in every other way. They were just vastly outnumbered but never outclassed and deserve better recognition by many here who perhaps do not recognise which factors are the important ones as regards performance figures, combined the to much emphasis on hearsay evidence about performance.
The Spitfire was built to another great formulae but its weakness was acceleration and range. The P51 was a good all-rounder and performed well in all area's but did not really excel anywhere except perhaps in range.
The 109 and FW190 were other good alrounders but I think that the Japanese were able to draw every last ounce of 'edge' from their designs.

regards,

SLP