Why the early war Japanese fighters were structurally fragile and unarmored?

[Jenisch]

Hello,

I'm wondering if the Japanese accepted such disadvantages to have more range or agility. I think it was because both, because they were interconnected. And the main reason apparently was the lack of more powerful engines, at least in the Zero, as Jiro Horikoshi tells this in his book of the creation of the Zero.

 

[davebender]

I don't think Japanese aircraft were structurally fragile. They just lacked armor.

 

[Jenisch]

I don't think Japanese aircraft were structurally fragile. They just lacked armor.

The early war Japanese planes certainly were. They could not follow Allied types such as the P-40 in a dive.

 

[Juha]

And they found out rapidly that Ki-43 needed some structural strenghtening.

Juha

 

[Messy1]

Starting out early in the war, the Japanese planes were not as robustly built as many allied planes.

 

[tyrodtom]

In comparision with western opponents, they were fragile, or not as overbuilt. Especially the Oscar, according to a interview on U-Tube with a WW2 Oscar pilot, you had to be careful in manuvers, and it shook at high speed.
A A6M2's never exceed speed was below 400mph, with no armor, no self sealing tanks, and not overbuilt, if not fragile. Self-sealing tanks are heavier, and take up possible fuel volumn. They took every measure possible to give maximum range, manuver, and speed, with the limited engine power they had. Everything worked fine as long as they were on the offensive. But if any aircraft could bring it's guns to bear on a Zero, or Oscar, they were in deep trouble, because they could absorb no damage, with no protection, and no excess strength. Their extreme manuverabilty at low speeds made it hard for their opponents to ever get a gunsight on them, but when we learned not to try to fight them at their best speed, but at ours, it was over quick.

 

[davebender]

Be careful here. Many U.S. built fighter aircraft were rather heavy compared to contemporary fighter aircraft. A flying brick is very robust but you pay a price in aerial performance.

 

[Vincenzo]

someone posted data on Zero that was not structurally fragile. i hope some can remember where is that engineering analysis

 

[FLYBOYJ]

I believe you're looking at these aircraft being capable of taking +6/ -3 Gs. Unless they were starting to fall about from being over stressed, they were not structurally fragile unless they had a volley of .50 calibers pumped into them.

 

[tyrodtom]

I remember reading in Pappy Boyington's book, that most of the Japanese pilots he encountered flew beautifully co-ordinated manuvers, never out of trim. Where he would delibertly fly out of trim, to throw the enemy's aim off, his aircraft would actually be going in a little different direction than what it appeared.

I'm just going by one pilots interview, but according to him, the Oscar might have been a little fragile, and in it's case in trim flight might have been necessary, because it's less stressful on the structure.

And I know when trying to get the best performance from a aircraft, in trim flight is required to get the best.


I'm not saying the Zero, or other Japanese aircraft were fragile, except, maybe the Oscar. But a fighter aircraft at some time in it's service is going to take damage, most Japanese fighters and bombers would not absorb much gunfire, they torched or fell apart.

 

[FLYBOYJ]

I remember reading in Pappy Boyington's book, that most of the Japanese pilots he encountered flew beautifully co-ordinated manuvers, never out of trim. Where he would delibertly fly out of trim, to throw the enemy's aim off, his aircraft would actually be going in a little different direction than what it appeared.

And I know when trying to get the best performance from a aircraft, in trim flight is required to get the best.

Actually you want a fighter to have a degree of instability built into it and I guess this reflects the point.

 

[tyrodtom]

I guess trim was a bad choice of words. What Pappy meant was he was flying in a skid or slip sometimes, and deliberately didn't have the ball centered in turns. Just to make the other guys aiming problems just a little more difficult.

I've read of a similiar approach from another WW2 fighter pilot also, but can't recall who.

What Pappy said for example, they were perfect loops, round, and you could likely guess where the loop wound end. It made it easier to lead them with your fire.

From the interview with the Oscar pilot, it sounded like it had to be flown that way, it wouldn't hold up under rough handling.

 

[FLYBOYJ]

I guess trim was a bad choice of words. What Pappy meant was he was flying in a skid or slip sometimes, and deliberately didn't have the ball centered in turns. Just to make the other guys aiming problems just a little more difficult.

I've read of a similiar approach from another WW2 fighter pilot also, but can't recall who.

Actually you never fly a fighter coordinated, as you quoted Boyington, you always want to be uncoordinated to a point for the reasons stated. But the other point, you don't want a fighter to be too stable.

 

[tomo pauk]

someone posted data on Zero that was not structurally fragile. i hope some can remember where is that engineering analysis

Maybe this one?

 

[drgondog]

One advanced feature for the time was extruded wing spars, even with the splice. More expensive than beam cap/shear web as mostly followed in late 1930-1940 designs - but lighter due to absense of more rivets.

I don't know what the Japanese design structural standards were but suspect no less than preliminary design/prototype 8g limit positive/-3g limit negative. Remember the 51 was an 8g a/c at 8000 pounds and actual limit load capability shrunk to ~ 6.4 g at 10,000 punds gross weight for the D, and less at max Gross Wt.

 

[Jenisch]

Mitsubishi A6M Zero - Wikipedia, the free encyclopedia:

Captain Eric Brown, the Chief Naval Test Pilot of the Royal Navy, recalled being impressed by the Zero during tests of captured aircraft. "I don't think I have ever flown a fighter that could match the rate of turn of the Zero. The Zero had ruled the roost totally and was the finest fighter in the world until mid-1943."

 

[FLYBOYJ]

Mitsubishi A6M Zero - Wikipedia, the free encyclopedia:

Captain Eric Brown, the Chief Naval Test Pilot of the Royal Navy, recalled being impressed by the Zero during tests of captured aircraft. "I don't think I have ever flown a fighter that could match the rate of turn of the Zero. The Zero had ruled the roost totally and was the finest fighter in the world until mid-1943."

Doesn't mention at what speed....

 

[Vincenzo]

Maybe this one?

yes i've read the web version Design Analysis of the Zeke 32 (Hamp - Mitsubishi A6M3)

 

[fastmongrel]

I remember reading in Pappy Boyington's book, that most of the Japanese pilots he encountered flew beautifully co-ordinated manuvers, never out of trim. Where he would delibertly fly out of trim, to throw the enemy's aim off, his aircraft would actually be going in a little different direction than what it appeared.

.

Seems to have been a common trick in one book I have read an experienced BOB pilot said you could always tell the new guys because they flew straight and stiff. The guys who had a few sorties under there belts soon learnt to play with the trim and just accept the fact that you couldnt fly hands and feet off.

 

[ColesAircraft]

I think it may be said that the design and manufacturing philosophy employed by Japan in the '30s and '40s has extended to their modern automobile industry: an emphasis on light weight and efficiency, which in the case of automobiles has made Japan what it is today thanks to oil prices.

I don't think it's fair to say that this philosophy was imposed upon Japan due to an inability of Japanese industry to manufacture powerful aircraft engines. The Nakajima Sakae that powered the Zero possessed an impressive power to weight ratio (much as their modern automotive counterparts do). In fact when restorers of Zeros today replace the Sakae with the best American-made replacement engines they can find, the performance of the aircraft suffers dramatically. There is simply no non-Japanese radial engine in the world capable of replacing the original - anywhere, by any manufacturer or nation.

The Japanese adopted this philosophy in large part as the aviation industries of the world debated the value of light versus heavy fighters (and the British built the Defiant, unfortunately). It was certainly a natural choice for Japan to go the light fighter route for economic reasons, but that wasn't the only factor. The US experimented with light fighters as well, and the idea was behind the original Bf109 in Germany. Unlike the 109, however, the Zero was less able to adapt itself to more powerful engines and heavier equipment as the need for such measures became apparent. But for many months of the war the Zero ruled the Pacific.

The designers of the Zero also created the Raiden (or "Jack"), which was a heavy fighter/interceptor in every respect with impressive performance comparable to Allied designs. Ironically, most Japanese pilots disliked it immensely (Saburo Sakai saying "it flew like a truck"). The Japanese could do it, and do it well. But after 1942 their cause was lost.

Ron Cole

Cole's Aircraft Website:index