We aren't comparing performance, we are comparing design philosophies. Lets say for an argument the RAF gave Supermarine a design brief saying they want the Spitfire to have range and maneuverability as the primary considerations like the A6M was, Supermarine would have made what is accentually an armed PR model but that's not what the RAF wanted. The A6M was designed for a very different war than what the Spit Hurri 109 and later the 190 P51 Tempest P47 fought
The Zero's Maneuverability (1 Viewer)
- Thread starter MIflyer
- Start date
R Leonard
Staff Sergeant
Paraphrasing a very early 2000's dinner table conversation I once had with my father, an F4F driver, indeed, a career naval aviator, on the subject landing and ground loops.
Ground loops . . . easy to do in an F4F. The structure and positioning of the landing gear gave the inexperienced pilot the opportunity to bring a landing roll-out to a grinding halt. The structure of the landing gear allowed for some lateral play. You could walk up to a parked F4F's wingtip, grab it with both hands and chin yourself. In the process, the shock absorber on the side you were on would depress and that wing would go down and the opposite wing would go up. When you let go, all would return to an even keel. The positioning of the gear was close to the fuselage and allowed, even accentuated, this tipping effect.
Now picture an F4F coming in for a landing . . . anything, like a sudden cross wind, that might tend to push the plane to the left, or worse, to the right due to engine torque, would have the same effect on the landing gear. A push to a given side causes the landing gear to depress on that side with the resulting raising of the wing on the opposite side. If the push is hard enough, it can even cause the wheel on the off side to lose contact with the ground. This is especially likely if the push occurs early in the roll-out when the speed of the airplane is still high enough to generate lift and thus create a vicious circle of events. The wing on the off side starts to go up, creating more lift on that side due to change in attitude, causing the wing to go higher still, causing the off side wheel to break contact with the ground.
A pilot without any practice in dealing with this problem tends to want to do something about it as soon as it starts to occur . . . the problem is that the instinctive reaction is to hit the brakes . . . except by then lift has taken over and the brake you want to hit is on a wheel that is up in the air. If the pilot hits both brakes (gotta slow this damn thing down so there's no more lift) then he winds up braking on the downside wheel only with a result that increases the forces pushing that side down causing the wingtip to contact with the ground which in most cases results in a great cloud of dust and screeching of unhappy metal as the plane pivots around on it's wing tip and come to the above mentioned grinding halt . . . a ground loop. "I was thoroughly scared the one time it happened to me," he said.
There are ways to avoid this. The first way is not to do anything. When a wing starts to go up don't respond. Let nature take its course and eventually the plane will lose enough speed to lose lift and the off side wing will come down of it's own accord. Takes a lot of willpower, but can be done. The second way is to avoid the problem by making the plane work for you. Remember that the F4F, and 99.44% of its contemporaries, were tail draggers. If your landing gear is out under the wing somewhere, like the SBD or the A6M2, for examples, the ground loop is not a common, indeed a rare, problem. But for planes like the F4F and, say, the Me-109 or Spitfire, the landing gear placed very close to the fuselage presents the problem. The natural tendency is to strive for the "3 point" landing, with all wheels contacting the ground at the same time. This type of landing finesse contributes to the problem . . . with the tail wheel contacting the ground at near to the same time as the main gear, the wings are at an attitude that still provides lift. (Put your arm out your car window with you hand out flat, fingers together, parallel with the ground. Now, rotate your hand at the wrist so that the leading edge of the flattened surface is angled up about 5 degrees . . . Viola! Lift.) If you land the F4F in a tail high position (move your hand back to where it is parallel to the ground) lift goes away. The solution then was to land tail high and then as the plane slowed to where its speed was no longer sufficient to provide lift, the tail would come down of its own accord and you have a nice smooth landing with no (or little, anyway) possibility of a ground loop.
The reverse of this landing method worked just as well for take offs. As you start the take off run, you get your tail up as soon as you can by gently applying forward pressure on the stick. This causes the tail to come up while keeping the wings parallel to the ground as speed builds up. At the proper speed you only need center the stick, the tail starts to go down, the main wings start to rotate up, and it feels like you're jumping off the runway. This take off method became a handy habit to have when the tail draggers started to go away as tricycle gear came in to more and more use in the late 40's and into the 50s'. With tricycle gear, you were already in a tail high position, so you merely needed to exert enough pressure to keep the plane down on the runway until the desired speed was acquired, then off the pressure and off you go.
Dad said he got in the habit of using the tail high landing and take off methods with all the tail draggers. It has the added bonus of providing adequate visibility over the nose in either evolution, something that went away as soon as the tail went down on landing or that didn't appear until the tail came up on takeoff. It worked remarkably well in the F4U-1 with its well-known, near legendary, landing bounce. Most of the landing bounce problem was cause by folks attempting the "3-point" landing and succeeding. Dad said he never had a landing bounce in an F4U because he used the tail-high method. Couldn't understand what everyone was upset about when there was a simple solution to the problem.
Of course, all of the F4F ground loop issue is a landing field problem. The problem goes away on carrier landings because of the arrestor hook. He said he knew pilots at whose land landings he would just cringe and wait for the loop, but when they came in on a carrier it was like the easiest thing in the world.
This sort of conversation we'd have after dinner and the girls had left the table. God knows how they started, but afterwards I'd go off and write it down. I think somewhere in the boxes of papers there may even be a draft of a missive he wrote to one of his correspondents on the subject of F4F landings, but where and in which box? I dunno.
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GregP
Major
Never said to directly compare performance. YOU said flying the opposition was pointless.
That reeks of arrogance, militarily at least. It isn't pointless ... your pilots will be flying against it and everything you KNOW about it makes you better able to decide what tactics to use to fight it. You may also discover things you WANT in your next aircraft design or that you want to incorporate into your existing design.
There are MANY reason to fly the opposition, especially using a test pilot who has combat experience, and almost none to NOT flying it other than military arrogance.
It is tantamount to saying, "we didn't build this thing, so it can't be any good and there is nothing we can learn from it!"
That kind of thinking has been conclusively proven to be wrong. Ask the RAF when the Fw 190 came out in numbers, the Germans when the Yak-3/9 came out in numbers or the Japanese when the Hellcat got into the fray. You can add the Corsair because they had already been surprised by the Hellcat by that time, and another great airplane was not much of a surprise to them when they encountered the Corsair. That still didn't make them feel any better about facing it.
We never had to face fighting the Spitfire, but we still flew it and acquired some for operational use. Several things stood out in that design, and we added some into the design of the Bearcat, which wasn't as heavily-built as the Hellcat was or as long-raged either.
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- Thread starter
- #104
MIflyer
Major
I have a book by one WW2 F6F pilot said that he trained on the F6F and did not fly the F4F until he got to the Pacific, at a base where they needed pilots to test F4F's and presumably FM-1's and FM-2's that had come out of depot maintenance. He said that compared to the F6F, the F4F was like going from a family sedan to a sports car. Since he had a lot of experience by then he loved flying the Wildcat, just for fun, although I have no doubt he would vastly prefer the F6F in combat. Of course the FM-2, lighter and with more HP at lower altitudes than the F4F was pretty peppy in its own right.
Back in the mid-80's I was thinking about buying an airplane and wondered about taildraggers. I had only 4 hours in a Champ years before and took an hour of instruction in a Citabria., flying from the airfield where they filmed The Rocketeer a few years later. I have never yelled so much in an airplane in my life. All would be going just fine and I would touch down and then give it the power to take off again - whereby the airplane would hop into the air and turn sideways. YEEOOOWWWW!
In the words of Wolfgang Langswhich, "The conventional gear is a good take off gear but it is a poor landing gear." So I bought an airplane that is the easiest to land around.
But the interesting thing about the Zero is that not only was it a superb dogfighter under optimum conditions, it was also easy to fly.
Yes, that is the way you do it with a taildragger. Not only does it allow he aircraft to accelerate more quickly, but it generally puts the rudder and fin in a better position to provide better control authority. And oddly enough, pushing forward on the stick sounds like an invitation to disaster, given that you have no nosewheel, but it is the proper thing to do and that goes for landing as well.
Back in the mid-80's I was thinking about buying an airplane and wondered about taildraggers. I had only 4 hours in a Champ years before and took an hour of instruction in a Citabria., flying from the airfield where they filmed The Rocketeer a few years later. I have never yelled so much in an airplane in my life. All would be going just fine and I would touch down and then give it the power to take off again - whereby the airplane would hop into the air and turn sideways. YEEOOOWWWW!
In the words of Wolfgang Langswhich, "The conventional gear is a good take off gear but it is a poor landing gear." So I bought an airplane that is the easiest to land around.
But the interesting thing about the Zero is that not only was it a superb dogfighter under optimum conditions, it was also easy to fly.
MiTasol
Major
That depends on the aircraft. Tail draggers are like women - what one likes another hates and a third does not care. Some tail draggers like to three point and some must always be flown onto the ground tail high.
If I'm arrogant and wrong why did no one else build their aircraft to the same standard as the A6M, and if the A6M design was so good why did they change it to be like everyone else?. The A6M was successful and able to reach out over vast area's of the Pacific because of the situation it fought not because it was a revolutionary aircraft.
MiTasol
Major
Why you should always pay attention to what the enemy is doing technology wise - from a British publication 1939..
Air services request proposals for designs for the missions they anticipate they will need to fly. The other air services wanted aircraft more suited to the kinds of missions they anticipated flying. The extraordinary range of the A6M was a primary requirement of the design along with performance that they thought would match contemporary land-based fighters. It was a difficult enough set of requirements that Nakajima did not propose an entry because they did not believe such an aircraft was possible with then current technology.
As for why later models of the A6M were different, the tactical and strategic situation changed as the war progressed. Technology improved to a slight extent as well, but the A6M2 (Type 0 Mk.I) was still seen as the superior fighter to the later Type 0 Mk.II (A6M3 and A6M5) at lower altitudes (under about 15,000 Feet) as was plainly stated in their manuals.
There is no doubt that the requirements for the design were met. The question is whether the choices that were made to meet these requirements were optimal. They certainly limited the development potential for the design. While other countries seemed to have follow on designs ready in two or three years, the Japanese never had a replacement for A6M.
Keep in mind that even with something so common as an automotive cylinder head bolts, the common pracrice today is to tighten them to PLASTIC deformity: Tighten to a specified torque reading and then give it ANOTHER FULL TURN. (!) Been a while since I installed a cylinder head, but this is what I remember. Used head bolts look fine but are basically paper weights after one use.
There was some discussion earlier in this thread about the diving speed limitations of the Type 0 Fighter.
There is of course the listed maximum diving speeds listed in the aircraft manual.
No matter what the source, there is no question that of all the variants, the A6M2 such as the one captured in the Aleutians and rebuilt certainly had the lowest limits. What is interesting is that when the Allies were evaluating Koga's A6M2, no one bothered to tell them the maximum diving speed was so low and the aircraft seemed to compare quite favorably against contemporary USN and Army types.
There is of course the listed maximum diving speeds listed in the aircraft manual.
No matter what the source, there is no question that of all the variants, the A6M2 such as the one captured in the Aleutians and rebuilt certainly had the lowest limits. What is interesting is that when the Allies were evaluating Koga's A6M2, no one bothered to tell them the maximum diving speed was so low and the aircraft seemed to compare quite favorably against contemporary USN and Army types.
GregP
Major
You don't fly the enemy's airplanes to compare design philosophies. You fly them to see what they have that you don't have and what their weaknesses are ... to compare performance. If you want to compare philosophies, you can LOOK and at and analyze it on the ground.
Anything in the air is a performance-based evaluation.
Philosophers don't win air wars, pilots and weapons and tactics do. That's why you FLY them.
ThomasP
Chief Master Sergeant
re
Good point. This appears to be true of some other contemporary aircraft as well.
In the thread "Hurricane Dive Speeds" I asked if anyone had info on the true VNE of the Hurricane, as I had often run across mention of the Hurricane pilots reporting dive speeds of 450 mph IAS (and as high as 470 mph IAS a few times). But in the Pilot's Notes the VNE is listed as 380 mph IAS (early) or 390 mph IAS (post-metal wing mod). German Bf 109 pilots also reported the Hurricane being able to stay with them longer in a dive than they were supposed to be able to.
slaterat kindly provided a link "Comparison of Pacific, Indian Ocean, Mediterranean, and North Atlantic naval combat" to a few actual after-action combat reports that verified the Hurricane using 450 mph IAS dive speeds.
From after-action reports it seems that US P-39 pilots reported that the Zero was able to keep up with them in dives, to the point that some of the pilots decided they had been lied to by the higher-ups - as they had been told that the Zero's could not keep up with them in a dive. The P-39 "maximum permissible diving speed" is listed as 523 mph in the Jun'43 revision of the P-39D-1/-2 PFOI. In the P-39N-1 and Q-1 PFOI it repeats the "maximum permissible diving speed" of 523 mph, but states that the "475 mph is the maximum recommended indicated air speed".
This phenomena would seem to indicate that the VNE for both the Zero and the Hurricane are more of a suggestion than a hard line that must not be crossed and/or the max diving speeds of some of the US aircraft were not correct.
?
Good point. This appears to be true of some other contemporary aircraft as well.
In the thread "Hurricane Dive Speeds" I asked if anyone had info on the true VNE of the Hurricane, as I had often run across mention of the Hurricane pilots reporting dive speeds of 450 mph IAS (and as high as 470 mph IAS a few times). But in the Pilot's Notes the VNE is listed as 380 mph IAS (early) or 390 mph IAS (post-metal wing mod). German Bf 109 pilots also reported the Hurricane being able to stay with them longer in a dive than they were supposed to be able to.
slaterat kindly provided a link "Comparison of Pacific, Indian Ocean, Mediterranean, and North Atlantic naval combat" to a few actual after-action combat reports that verified the Hurricane using 450 mph IAS dive speeds.
From after-action reports it seems that US P-39 pilots reported that the Zero was able to keep up with them in dives, to the point that some of the pilots decided they had been lied to by the higher-ups - as they had been told that the Zero's could not keep up with them in a dive. The P-39 "maximum permissible diving speed" is listed as 523 mph in the Jun'43 revision of the P-39D-1/-2 PFOI. In the P-39N-1 and Q-1 PFOI it repeats the "maximum permissible diving speed" of 523 mph, but states that the "475 mph is the maximum recommended indicated air speed".
This phenomena would seem to indicate that the VNE for both the Zero and the Hurricane are more of a suggestion than a hard line that must not be crossed and/or the max diving speeds of some of the US aircraft were not correct.
?
MiTasol
Major
That article is about aviation hardware and the industry used bolt stretch for a long while in certain applications and then came up with special washers that indicated that the bolt had reached the point of plastic deformity. Such hardware is always single use.
Was F8F-1 very robust? Especially the outer wings? And when compared to the earlier Grumman fighters.
It is perhaps a "cultural issue", at least in the UK and probably elsewhere in Europe, the vast majority of fighter fields were smallish, roughly square-shaped grass fields still at least in 1940 and three-point landing was the norm for the fighter pilots at that time. Wheelers could even be looked down on a bit.
Admiral Beez
Major
IDK, you tell us.
GregP
Major
Hey Pat303. No intention to snark here. Just observation that we fly the enemy's aircraft whenever we can, to see what they fly like.
We've always done that, as do other air forces. I'm pretty sure the design philosophy stuff gets done as you suggest, but flying them seems to be paramount for the pilots who must face them. Just seems to be the way it is in practice.
No intent to start anything here, and I am reluctant to continue further discussion as there seems to be no point. I doubt we'll capture any 5th-gen stealth plane in operational condition to test fly, anyway.
Cheers.
We've always done that, as do other air forces. I'm pretty sure the design philosophy stuff gets done as you suggest, but flying them seems to be paramount for the pilots who must face them. Just seems to be the way it is in practice.
No intent to start anything here, and I am reluctant to continue further discussion as there seems to be no point. I doubt we'll capture any 5th-gen stealth plane in operational condition to test fly, anyway.
Cheers.
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Admiral Beez
Major
I wouldn't be surprised if some sanctuary-seeking pilot flew their Chengdu J-20, Shenyang FC-31 or Sukhoi Su-57 into NATO or Western territory, where it would be studied.
It's happened before, see Cold War pilot defections; including with the MiG-15 under Operation Moolah, and later with the MiG-25, see the defection of Viktor Belenko. And once Pakistan and/or Egypt acquire their J-31s I'd give it good odds that one will fall into Western hands.
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special ed
1st Lieutenant
- 7,092
- May 13, 2018
The Germans felt confident enough to fly several P-51Ds, a P-47 and a B-17s in the combat arena. The Japanese formed a squadron of P-40Es and used them in combat. Our enemies evaluated our aircraft they captured, learned what they could, and flew them against us. The Germans used French, Czech and Italian aircraft after evaluation.
Greg Boeser
1st Lieutenant
We could send Clint Eastwood to steal one.
