Spitfire mk VB/Seafire vs Zero

[kool kitty89]

The arrangement of the cooling system, radiator, and oil cooler on the P-40 (seen above) is one of the best on liquid cooled-engined fighter designs in the war with the entire group packed under the engine making a very small target, the entire vulnerable engine area is limited to the immidiate vicinity of the engine, unlike other designs with long cooling kines running to spread out (wing or belly mounted) radiators.
(and similarly the P-39.P-63, albeit inside the rear fusalage allong with the engine, but in a similarly compact layout)

THe ultimate of this bing the Il-2 with the radiator mounted directly behind the engine within the nose and heavily armored. (strangely the oil cooler was mounted in a very vulnerably position on the belly, something finally corrected in the Il-10)

 

[renrich]

Interesting that all this discussion of vulnerability of engines leaves out the german BMW radials versus the liquid cooled DBs. JD, you make some excellent observations. However, earlier you intimated that the FAA solved the problems of operating the Corsair off of carriers before the USN. Perhaps you did not mean it exactly as I have stated but that is a myth. If one examines the chronology of the Corsair history, the FAA did not even get any Corsairs to familiarise with at Quonset Point, RI, much less deploy on carriers, until after the USN had identified and pretty much rectified the various factors which hampered the early Corsairs. By the time that was done the preparations to deploy Hellcats on carriers were already well underway so the Corsair with it's superior performance was delayed in use on carriers for about a year. As far as radials being less apt to succumb to battle damage because of the absence of the liquid cooling system. I have been a homebuilder since 1962. I don't need statistical evidence for me to know that a single family or multi family residence is more likely to burn down because of external causes if it has a wood shingle roof than if it has a fire resistant composition roof. To me, that is a direct analogy. As far as Mustang losses in Korea, I have read that somewhere but won't bother to try to find the exact source. I have a golf course to explore. Pinon Hills in Farmington, NM. Supposed to be one of the best public courses in the US.

 

[JoeB]

see next

 

[JoeB]

As far as radials being less apt to succumb to battle damage because of the absence of the liquid cooling system.

As far as Mustang losses in Korea, I have read that somewhere but won't bother to try to find the exact source.

It is intuitive that liquid cooled planes would generally have higher loss rates, the question is how much.

On F-51 and F4U in Korea, suprisingly there isn't AFAIK an accurate complete tally of F4U sorties. The standard stat of F-51 is 341 combat losses (almost all to AA or unknown/flying into terrain counted as 'combat') in 62,607 combat sorties, .54%, quoted in McLaren "Mustangs over Korea", among other places.

But here's a more micro comparison adding up sorties and losses from the monthly and semi-annual reprots of the 4 Marine F4U sdns in Korea early in the war, using August and September 1950, the most intense period of combat in the first phase of the war. They lost 10 F4U's in action in 3,170 total combat sorties, .32%. In same two months 36 F-51's were lost to AA and 4 to 'enemy action unk' in 9,688 'effective' sorties (FEAF Monthly Summary Dec 1950), .41%. It's higher but not dramatically so. The total war F-51 loss rate was higher than early war rate because enemy AA became more formidable in the static phase of the war later on. Different statistic keeping (which sorties and losses to count as combat) might affect the above comparison somewhat.

The big discrepancy in loss rates in Korea was between jets and props. The F-80's total combat loss rate was only .15%, and even excluding air superiority missions early in the war, still a lot less. That was also the comparison that F-80 pilots were accurately predicting when forced to convert back to F-51's early in the war, their reluctance often quoted. The same thing was seen in F9F v naval props, perhaps they were more rugged than piston planes, but most obviously they simply moved faster and were therefore harder to hit for the AA typically encountered.

Another thing to remember though is that the F4U had a significantly higher loss rate to AA than the F6F in apples v apples carrier operations in 1945 as has been discussed before, it wasn't the best example of rugged radial plane.

Another set of stats to put air v liquid cooled in some context is a USN loss survey for Sept '44-Aug 45, single engine radial losses (not all fighters). Overall 501 a/c were hit and 193 of them lost. 23 of 37 hit in the engine were lost, of course air cooled in all cases ("WWII Fighter Conflict" by Price, p.59). So, even an increase to 37 out of 37 wouldn't have affected the overall losses much in that sample. Of course a plane like the P-51 had a cooling system which substantially increased the area of the 'engine incl cooling system' compared to a radial, so the 37 could also have gone up, but still the impact on overall losses might not be dramatic.

On F4F 'pin cushion' tactic, that's mentioned in enough places, sourced back to quotes and reports of the time, to be more than an 'anecdote'. OTOH in that case like most there isn't a set of rigorous scientific statistics establishing the exact effect of such a tactic, or how much such a tactic explains of the substantial superiority in realworld (w/ everything as it was, not 'woulda shoulda coulda') combat effectiveness F4F's displayed over P-40's, v Zeroes, in 1942.

Joe

 

[renrich]

JB, Good stuff in your post. other factors that might affect the stats are, did Marine and Navy pilots press their attacks lower and longer because their operations were more dedicated or trained for ground support than AF pilots and did prop plane pilots do likewise because of having more fuel endurance and because of slower speeds and maneuverability issues? I was under the impression that Marine and Navy pilots flew the majority of ground support missions in the early going in Korea.

 

[JoeB]

JB, Good stuff in your post. other factors that might affect the stats are, did Marine and Navy pilots press their attacks lower and longer because their operations were more dedicated or trained for ground support than AF pilots and did prop plane pilots do likewise because of having more fuel endurance and because of slower speeds and maneuverability issues? I was under the impression that Marine and Navy pilots flew the majority of ground support missions in the early going in Korea.

Strike altitude and tactics (especially whether planes went back for multiple runs on the *same target*, a proven good way to get shot down) is a potential issue in comparing ground strike loss rates between any different air arms, I agree. The same would potentially be true comparing Typhoon and P-47 loss rates as someone suggested.

But, non-rigorously but reading a lot of original combat reports I don't see evidence of a big difference there between naval services and AF early in the Korean War. Both tended to raise altitudes later in the war to keep losses under control against proliferating Communist AA. The same was actually true in 9th AF in WWII, too high losses resulted in more closely enforced instructions to stay higher. Very low altitude strafing wasn't viable day after day against field forces well equipped with AAA.

Marine air in Korea was always on a smaller scale than AF. I'm not comparing Navy air because their mission profiles tended to be different on average, whereas Marine F4U and F-51 tasking was pretty similar (in fact later on 1st Marine Air Wing was under the operational control of 5th AF and F4U and F-51tasking was pretty much identical). Early on, the Marine task organization for close support was superior (and well publicized in the press, as Marine successes often are); in terms of coordination but what F4U's and F-51's were trying to do was pretty similar. Also as you suggested early criticism (ca. July 1950) of AF close support was also because it was mainly performed by F-80's which had limited payload and little endurance over the battlefield, being based in Japan. By August-September the 5th AF had converted more sdns back to F-51's, based in Korea. However later on F-80's were based in Korea, carried similar payloads to F-51's, and F-80 losses were still a lot lower. Also, at least some Communist POW's voiced the opinion F-80's were more effective because there was less warning of their approach.

Joe

 

[John Davies]

Renrich, thanks for your comments. A comparison between the surviveability of inline and radial-engined German fighters would be interesting. The reason I suggested comparing the attrition rates of the P-47 and the Typhoon in Northern France in 1944 is that it is as close as one can get to an "other things being equal" test; similar duties, same enemy, different type of power plant. If anyone has the figures, I'd be very interested.

I agree with you that a liquid-cooled power plant intuitively ought to be more vulnerable; all those radiators and pipes just waiting for something to cut them. My suspicion (and I confess it is no more than that) is that this was much more of a factor in ground attack than fighter-vs-fighter combat.

There is probably a simple reason for this. In fighter-vs-fighter combat, the vast majority of rounds fired missed. Johnnie Johnson, in his autobiography "Wing Leader", expressed a low opinion of Fighter Command gunnery. He considered the average pilot was capable of bringing off a no-deflection shot from dead astern at medium range, but could not be relied upon to achieve anything more demanding. In his opinion, except in the case of a few good marksmen, deflection shooting was largely a waste of time.

This may be the reason why there were so few aces. Admittedly, Johnson raises this in the context of a conversation with Beurling, who was an exceptional marksman, but it does give pause for thought. In typical English country style, Johnson suggests shooting for the pot with a twelve-bore was excellent training for a fighter pilot. He says that someone who could "bring down a curling widgeon in the dusk" would have no trouble hitting an enemy aircraft!

I suppose the reasons are pretty simple. A fighter pilot had to concentrate on a lot more than just shooting. He also had to fly his own aircraft, (a fairly high workload in itself) and most important of all, pay attention to not getting shot down himself. In contrast, a ground-based gunner simply had to lay off his deflection and let fly. Even if the relative speeds were much faster, so he did not have long to aim at a small, fast-moving target, it still looks like an easier task. Also, there were often an awful lot of them. Bob Stanford Tuck hated flying against light flak. He considered that a lone fighter had a fair chance against one light flak emplacement, little against two, and this was how he was shot down in 1942. I do not know what he would have thought of the massed batteries both the Germans and Japanese used to defend airfields late in the war.

Turning to the Corsair, I admit I do not know its full development history, so your comments are very interesting. Thanks.

I do recommend "Carrier Fighter" by Norman Hanson, if you can get hold of a copy. It is a quite splendid book. Hanson flew with one of the FAA Corsair squadrons. Although much of their work was appallingly dangerous, it is clear he was an aggressive optimist, and coped well. Mind, if you were not an aggressive optimist, I suppose you would not be a fighter pilot. He absolutely loved flying this big powerful brute of an aircraft.

At the end of the war he and his fellow-pilots were planning to take their carrier's entire air wing of Corsairs in formation under the Sydney harbour bridge. They reckoned that compared with the sort of thing they had been doing on a daily basis on operations, this would be dead easy. Senior brass got wind of it, and threatened mass court-martials, so they never did. Pity about that.

Hanson mentions two problems with the early Corsairs; a low canopy which unduly restricted vision, later replaced by something much better, (and the FAA certainly had some of those early canopied aircraft, I've seen pictures), and an undercarriage with too much bounce in it, necessitating a modification to the oleos. My impression from Hanson is that neither problem was fully solved by the time the FAA took its first Corsairs into action, but they were sorted shortly afterwards.

I'm quite prepared to accept that the USN had solved most of the Corsair's problems fairly early on, but delayed taking them to sea. But there is a whole world of difference between solving problems under test conditions, and trying the beast out under operational conditions and finding out how it works in such an environment.

I don't think the FAA deserves especial credit for commissioning the Corsair for carrier operations before the USN. The FAA had a very powerful incentive. Desperation. The FAA had a very urgent need for adequate numbers of high-performance aircraft, and would basically take anything and everything that would fly and fight.

Desperation was also the reason for the Seafire. The Merlin 32 powered LIIC, and the FIII and LIII, both powered by versions of the Merlin 55, were very effective aircraft in the air. Combat reports show they were more than a match for most of their opponents, both Japanese and German, and were even just about a match for the Fw190. But it was an absolutely horrible carrier aircraft. Take the difficulties of deck landing it, making accidents more likely than with aircraft properly designed for carrier operations. (Which I've covered in detail in another post). Add the fact that when an accident did occur, the Seafire's comparatively fragile structure was much more likely to sustain severe damage than, for instance, one of the products of the Grumman Ironworks. It was basically an aircraft that should never have been taken to sea, and would not have been, if British industry had produced a credible alternative in adequate numbers. For that we had to wait for the Sea Fury.

And that, as everyone knows, is because the FAA entered WW2 with some good carriers, more building, and no high-performance naval aircraft whatsoever. As a piece of purely mutton-headed thick-witted "planning", that takes some beating!

 

[renrich]

JD, good stuff in your post, again. What you are saying about poor marksmanship by fighter pilots is, I suspect, the rule rather than the exception. The USN pilots were exposed to a lot more gunnery training, especially full deflection shooting, than probably any other flyers. Just like with wing shooting, though, some have the aptitude for it and many don't. That poor marksmanship is the very reason, I believe, that a radial engined airplane was somewhat less likely to sustain crippling damage than the other liquid cooled engine AC. During the BOB, I would bet that the HE111s brought down, especially because of the rifle caliber weapons used by the Brits, succumbed often to damage to the cooling systems of the inline engines. If the British pilot got lucky, one 303 ball round, in the right place could put an engine out of use, even if the pilot was a poor shot and could not hit the enemy with the prescribed number of bullets that statistics dictated. Re, Corsair, the fifth production Corsair, in Nov. 42, has the seat raised and a new canopy fitted. Those changes are implemented on the 689th production AC. Sep 25, 42, initial carrier tests are performed by the 7th production AC with 4 landings made on CVE26, USS Sangamon. Problems noted are: cowl flap actuators leak, engine oil leaks from valve push rods, forward view is poor, AC bounces on landing and swings because low tail wheel puts flaps close to deck. June 1, 1943, RN squadron #1830 is formed at Quonset Pt RI using Corsair Is. July 15, 1943, VF17 is aboard the new carrier, Bunker Hill with F4U1s, for it's shakedown cruise, they are promised the new raised cockpit F4Us upon return to Norfolk. As you can see the USN already had a full squadron operating off a carrier only 45 days after the RN began familiarising it self with F4Us off a land base. The problem was that even though a fix for the problems was found in short order, it took a while for that fix to become incorporated into the production line. As you said, the RN and the USN were desperate to get the airplanes into the fight and they had to make do with early production AC and with field modifications. How would it have been to have been the pilot of that first F4U with it's deck landing problems lining up for that first landing on that tiny CVE flight deck? I bet his A-hole was puckered up so tight you couldn't drive a hat pin up it with a sledge hammer!

 

[HoHun]

Hi Glider,

>I think the difference is that the frontal area of a large proportion of the in lines is similar to the Radial when you include the frontal area of the cooling system.

Good point, and interesting picture! I have actually toyed with the thought of measuring out areas of comparable fighters' systems in threeviews, but I'm afraid I don't really have sufficiently detailed threeviews.

>The cooling systesm was very vulnerable to any small piece of flak, debris or small calibre bullet.

That small calibre bullets were generally considered ineffective shows that this was not a significant vulnerability in air-to-air-combat at least.

I'd agree with John that air-to-ground actions might have a different threat profile. However, bomber defensive guns would tend to face the attacker at similar aspects as ground-based guns, and small-calibre bullets were considered ineffective in that role, too.

Regards,

Henning (HoHun)

 

[HoHun]

Hi Renrich,

>I don't need statistical evidence for me to know that a single family or multi family residence is more likely to burn down because of external causes if it has a wood shingle roof than if it has a fire resistant composition roof. To me, that is a direct analogy.

I don't doubt the cause-effect relationship between a piercing hit by a rifle-calibre bullet on the cooling system and the resultant loss of the engine

However, the question really is how likely it was to achieve such a piercing hit with a rifle-calibre bullet. The historical answer is: so unlikely that the warring parties gave up on trying, and replaced the rifle-calibre guns with heavy machine guns or even cannon wherever possible.

It's possible that the heavier guns used had a higher chance of achieving that critical piercing hit so that the cooling system was indeed a significant area of vulnerability again, but lacking data, we can't tell for sure. (I just point this out to avoid the impression I consider the cooling system invulnerable - it most definitely was not

Regards,

Henning (HoHun)

 

[HoHun]

Hi Joeb,

>They lost 10 F4U's in action in 3,170 total combat sorties, .32%. In same two months 36 F-51's were lost to AA and 4 to 'enemy action unk' in 9,688 'effective' sorties (FEAF Monthly Summary Dec 1950), .41%. It's higher but not dramatically so.

Thanks for the data! Food for thought there

>Another thing to remember though is that the F4U had a significantly higher loss rate to AA than the F6F in apples v apples carrier operations in 1945 as has been discussed before, it wasn't the best example of rugged radial plane.

I didn't follow all the details of the earlier discussion, but if we'd conclude that different aircraft types of generally similar layout and technology could have significantly different survivability, that would make our task of data analysis quite a bit harder ...

>Another set of stats to put air v liquid cooled in some context is a USN loss survey for Sept '44-Aug 45, single engine radial losses (not all fighters). Overall 501 a/c were hit and 193 of them lost. 23 of 37 hit in the engine were lost, of course air cooled in all cases ("WWII Fighter Conflict" by Price, p.59).

Ah, that's interesting - while liquid engines are not mentioned, the statistics seem to illustrate (my conclusion) that the majority of losses were caused by damage to vulnerable systems shared by liquid-cooled and air-cooled engines. With Price' table in front of you, would you say this conclusion is justified?

>On F4F 'pin cushion' tactic, that's mentioned in enough places, sourced back to quotes and reports of the time, to be more than an 'anecdote'.

The anecdotal nature is due to the pilots who did not survive flying in the sights of a Zero for a prolonged time did not come back to have the 7.7 mm holes counted. (It would be interesting to know the number of holes in the machines that made it back, though.)

>how much such a tactic explains of the substantial superiority in realworld

Flying straight and allowing yourself to be shot at? I'd be delighted to see the cause-and-effect relationship of that move to a general "substantial" combat superiority explained

Regards,

Henning (HoHun)

 

[HoHun]

Hi Renrich,

>The USN pilots were exposed to a lot more gunnery training, especially full deflection shooting, than probably any other flyers. Just like with wing shooting, though, some have the aptitude for it and many don't.

From Clay Tice and MF Kirby, who flew USAAF P-40 and P-400 (P-39) respectively early in the war, I heard that they gunnery training was almost non-existent, with one of the two mentioning that his only training consisted in strafing a raft anchored off-shore - while flying in close formation with the wing leader, wich almost precluded aimed fire.

If that's typical for USAAF training early in the war, the better combat results achieved by the US Navy with rigorous gunnery training would seem to come as no surprise ...

Regards,

Henning (HoHun)

 

[renrich]

Henning, I have quoted Lundstrom, "The First Team," on several occasions. You owe it to yourself to try to get a copy. I am positive you would get much out of it. He goes into much detail about the USN pilot and gunnery training. As far as I know, that book is the best researched and most authoritative one on that particular subject(USN fighters, first six months of the war) available. Example: he makes a real attempt to match the kills by both sides to the extent of naming the IJN and USN pilot. I never really understood the implications of full deflection shooting until I read his book(the second time.)

 

[HoHun]

Hi Renrich,

>Henning, I have quoted Lundstrom, "The First Team," on several occasions. You owe it to yourself to try to get a copy.

Is the exact title "First Team: Pacific Naval Air Combat from Pearl Harbor to Midway"? Seems it is out of print, but I'll keep my eyes peeled! (I just closed another gap in my collection when I purchased a copy of Brown's "Wings of the Navy" last Friday ...)

>I never really understood the implications of full deflection shooting until I read his book(the second time.)

Well, what are the implications? Now you've roused my curiosity!

Regards,

Henning (HoHun)

 

[renrich]

That is the correct title. There is a second volume entitled. "The First Team and the Guadalcanal Campaign," that pretty much finishes the year 1942. He was supposed to be working on a third book which would be a continuation but it has not been published. The implications of full deflection shooting which he says was only taught in any detail by the USN of all the airforces were many. He also points out that some ETO pilots mastered deflection shooting on their own and used it to good effect. Full deflection shooting was mainly used against enemy bombers because it gave the defensive gunners almost impossible firing solutions. However once it was mastered it gave the pilot a lot of confidence in any type of firing run. It was time consuming to learn which is one reason it was not taught in detail by other air forces and it required a certain amount of visibility over the nose which most European and USAAF fighters did not have. In following his diagrams I had my wrists all twisted up trying to understand the maneuvers of a full deflection firing run(which means that at the moment of opening fire your nose is pointed at 90 degrees to the flight path of the target) He also goes into detail about the training of the USN pilot before and during the war as well as the IJN pilot. Both books are a good read, very detailed and authenticated. Some on this forum are familiar with the books. I wish that all the members who are biased toward the point of view that the ETO was the "only war" could read them.

 

[John Davies]

Slightly away from the main course of the discussion, but worth mentioning....

Welcome to the official web site for the Fleet Air Arm Museum

 

[renrich]

JD, if memory serves the RN in WW1 had one of the better fighters in the war, the Sopwith Triplane.

 

[John Davies]

Renrich yes, we did. And in WW1 we also had all sorts of interesting innovations coming in at an enormous rate. Like flying-off platforms on the turrets of capital ships, short flying-off platforms on lighters towed by destroyers (head into 15 knots of wind at about 30 knots giving a total of 45 and with an aircraft with a low stalling speed you just wind it up and go!), plus a great deal more besides.

Then after the war the RN was run by admirals who were mostly interested in developing new and better battleships, and naval aviation was put in the hands of the RAF, who for different reasons also saw it very much as a sideline, so as a result we went into WW2 with NO high-performance naval aircraft at all.

I can't help thinking you organised things better in the USA!

 

[John Davies]

Coming back to the inline vs radial debate, it's surely important to remember that this was only ONE factor. It's easy to concentrate on it, because it is tangible and obvious. But other factors, including intangible ones, may be more important. Precisely because they are intangible, and therefore hard to put numbers to, they may be ignored. But they could still be overwhelmingly important.

Training, tactics, good leadership, even high morale, can all make a huge difference to casualty rates. And above all adaptability and the ability to learn FAST, because tactics as taught in training sometimes proved to be either ineffective or even suicidal in real combat. This means not being hidebound, and being prepared to throw the rule-book away if it wasn't working. Some leaders had the courage of their convictions, and did what worked, whether it was "authorised procedure" or not. Others did not, and stuck to the book.

For instance, in "Carrier Fighter", Hanson describes the standard ground-attack with guns doctrine as they were taught. Approach in a shallow dive, pull out into a low firing pass, then pull up slightly and depart the area. As he says, against the very heavy light AA defences of many Japanese airfields, this would have been suicide, for two reasons. Firstly, Japanese light AA was very effective and aggressive. Secondly, it is hard to judge the pull-out with enough accuracy. When a high-performance monoplane pulls out, for a brief distance it will "mush"; i.e its attitude may be level or even slightly nose-up, but its trajectory will briefly continue downwards. Pull out too high and you make a lovely target; pull out too low and you mush into the ground. Either way you are probably dead.

So they developed a new technique, of taking their Corsairs in fast and very very low indeed, and this seemed to work. And don't ever go back for a second pass. Typhoons in Northern France seem to have developed similar techniques. There were many accounts of them coming back with quite large bits of foliage embedded in the leading edges. That thick wing may have been draggy, but it was very strong!

By the way, I've seen a video clip of a Spitfire "mushing" into the ground at a display. It is very distressing to watch, so I will not give the URL.

Now of course there were attempts made to feed back the lessons of combat into operational training. Pilots were sometimes "rested" by being posted to an operational training unit to educate the next generation. But the system was not perfect.

For instance, I've read the autobiography of an FAA pilot who flew Swordfish under extremely demanding conditions, until he was basically burned out. (Hunting U-Boats off very small escort carriers in the north Atlantic winter, usually in appalling weather conditions, out of sight of the convoy, with primitive and unreliable homing aids). He was posted to head an OTU equipped with Barracudas, a very different type of aircraft indeed. As he was the first to admit, he did not do a very good job there.

For myself, I'd rather have flown an inline-engined aircraft in a squadron that was well led and used effective tactics, than a radial engined aircraft in a squadron which was not.

 

[drgondog]

That is the correct title. There is a second volume entitled. "The First Team and the Guadalcanal Campaign," that pretty much finishes the year 1942. He was supposed to be working on a third book which would be a continuation but it has not been published. The implications of full deflection shooting which he says was only taught in any detail by the USN of all the airforces were many. He also points out that some ETO pilots mastered deflection shooting on their own and used it to good effect. Full deflection shooting was mainly used against enemy bombers because it gave the defensive gunners almost impossible firing solutions. However once it was mastered it gave the pilot a lot of confidence in any type of firing run. It was time consuming to learn which is one reason it was not taught in detail by other air forces and it required a certain amount of visibility over the nose which most European and USAAF fighters did not have. In following his diagrams I had my wrists all twisted up trying to understand the maneuvers of a full deflection firing run(which means that at the moment of opening fire your nose is pointed at 90 degrees to the flight path of the target) He also goes into detail about the training of the USN pilot before and during the war as well as the IJN pilot. Both books are a good read, very detailed and authenticated. Some on this forum are familiar with the books. I wish that all the members who are biased toward the point of view that the ETO was the "only war" could read them.

Rich - the USN probably was better organized for aerial gunnery training pre-WWII. Having said that the USAAF realized that they needed to start doing so and formed the first training propgrams in June 1941.

The initial training ranged from shooting skeet to movie projections - both distinctly lacking in stick and rudder co-ordination. It wasn't until early 1942 that Advanced training on tow targets for both fighter pilots and gunners were a standard part of the training and only in mid 1942 did the USAAF integrate RAF training into Operational theatres - especially for 8th AF.

Nobody graduated from Advanced as a Fighter pilot by mid 1943 w/o passing the aerial Gunnery program. IIRC correctly ~10% was the minimum passing grade for the high deflection tests.

In early 1944 the frangible bullet technology for ballistics and safety made it feasible to shoot at modified 'real a/c' starting with the A-20 and then by August 1944 - the TP-63 - but the K-14 was also being installed along with computing gunsights in the B-29 and those technologies were almost good enough to replace the actual airplane as a target in gunnery practice up to about a 45 degree deflection shot.