Maneuverability vs Speed

[BarnOwlLover]

If it hits. The problem was aiming them, which didn't help with the low ammo capacities of the versions on the aircraft I mentioned (60 rpg). You have to compensate for drop and time of flight.

 

[Shortround6]

I don't disagree. But another advantage of those 20mm is that they had greater range. Would you want to go head to head with a Zero in a Hurricane?

Depends, If the Zero had already used up his cannon ammo on somebody else?
Hurricane has about 10 seconds more firing time than the Zero's 20mm guns,
Zero is firing about 17 shells a sec from the two guns.
The 20mm gun on the Zero is about 4 1/2 times as destructive as the .303 Browning.

which one is easier to hit with may be different. The Japanese 20mm shell may not have the same time of flight over a given distance as the 7.7 mm ammo but it may be close. The Japanese 20mm shell is slower than the German MGFF/L shells but the 7.7 mm is slower than the German 7.9mm.

 

[Wild_Bill_Kelso]

I guess there is only one way to settle this debate


View: https://www.youtube.com/watch?v=JkAukrEGUCM

 

[ThomasP]

re thickness of the wing skinning contributing to the 'weakness' of the A6M

The idea that the wing skin was only .032" thick is incorrect - or at least partially/mostly incorrect. The main wing structure was designed as monococque, with the skin contributing to the overall strength of the 'box' formed by the front spar and the rear spar, and to lesser degree to the wing structure ahead of the front spar and behind the rear spar.

On the bottom surfaces - in between the front and rear spars - the skin varied from .118" near the wing root to .031" near the tip. On the upper surfaces - in between the front and rear spars - the skin was .062" thick near the root, decreasing to .031" at the tip.

To design the main monocoque load bearing structure with a constant skin thickness of .031" for the main load bearing box would be incompetent at best. Horikoshi was not incompetent.

Skin thickness was thinner overall on the wing ahead of the main spar, with .062" on the bottom surface near the root and tapering to .028" at the tip. (I do not have the thickness for the upper surfaces ahead of the main spar - assuming they were different?)

The skin thickness on the bottom surfaces behind the rear spar was .022". (I do not have the thickness for the upper surfaces behind the rear spar.)

These measurements were taken by ATIU (later known as DTIC I think) from an A6M3 captured at Buna.

 

[GregP]

From what I understand 93% loss was from that one strike, same as the 6 Betty's that all went down, lets get real, losing 25% of your A6M's, 52% of Vals and 50% of Kates is simply unsustainable in anyone's language,

Just to clarify, but it's very sustainable for one or two or even several missions. It's NOT sustainable as an average for many missions.

 

[GregP]

Quick context and historical check. An aircraft going into service in 1941 WASN'T an early war bomber, WAS it? Let alone a 'very early war' one!

As much as I'm also keen not to see Japanese aircraft and engineering unfairly 'done down' by old tropes and assumptions that contain more than a whiff of racism, its also true that part of the allied response to being trounced early on in the PTO was the false idea that they were facing oriental 'wunderwaffen'. The latter is a bit of mythologizing pedalled rather too hard to offset the basic fact that the allies had grossly underestimated the Japanese, had been complacent, were caught by surprise, lacked esprit de corps and had poor initial morale and strategy. Britain, facing enemies on two fronts had under-deployed units largely fielding equipment that by 1941 was down-right obsolete, semi-obsolete or unsuitable for the European theatre of operation because of the rapid advances being made in the previous two and a bit years of conflict. The Dutch in the East Indies had lost their home nation. The Australians were a small nation by population and slowly re-arming and the Americans had yet to throw their industrial and design might at the war.

The G4M first flew in October 1939. It was adopted into service from 1941. Basic performance figure as follows taken from wiki, so not canon, but at least indicative. If it *is* wildly inaccurate, hopefully the experten here will go and correct the entry? I'm sure greater performance could be attained by stripping airframes etc (but that's equally possible for all aircraft)

• Maximum speed: 428 km/h (266 mph, 231 kn) at 4,200 m (13,780 ft)
• Cruise speed: 315 km/h (196 mph, 170 kn) at 3,000 m (9,843 ft)
• Range: 2,852 km (1,772 mi, / 1,540 nmi - I'm guessing dependent on model / weapon load?)
• Ferry range: 5,040 km (3,130 mi, 2,720 nmi)
• Rate of climb: 9.166 m/s (1,804.3 ft/min)
• Service ceiling circa 28,000ft
• Bombload: circa 2000lbs

So lets have a look at what other contemporary aircraft and compare like with like as far as we can with some twin-engined aircraft designed and put into service around a similar timeframe (1941). Are they not broadly comparable?

De Havilland Mosquito: First flight - November 1940. Adopted into service 15 November 1941 (source, Owen Thetford - Mosquito BIV - first variant in service)

Maximum speed: 380mph at 17000 ft
Cruise speed: 300mph at 22000ft
Range: 1,370 mi with maximum bombload, 1795 mi with reduced bombload (
(ferry range not listed)
Initial rate of climb 1,700 ft/min
Service ceiling: 28,800ft
Bombload: 2000lbs

The Mosquito was clearly used in many of the same roles as the Betty - low level strike, anti shipping, level bombing, and of course, went on to do many more besides

Mosquito too spicy and unfair comparison because it flew a year later than the G4M, even though its design and conception started around the same time and it went into service the same year? OK, lets consider some another relevant comparative:

Bristol Beaufighter: First flight, 17 July 1939. Adopted into service 27 July 1940

maximum speed: 335 mph (540 km/h) at 16,800 ft (5,000 m). (strike varients, 303 mph at 1, 500ft)
Cruise speed: (couldnt find one listed so far - but reading Bingham, the implication seems to be that this was 250ish)
Range: circa 1480mi
Initial Climb: circa 1,850 ft/min (564 m/min
Service ceiling: 15,000ft
Bombload: 1500lbs of bombs, alternatively 8 x 60lb rockets or 1 x 2,127lb torpedo

... and thats not even getting into the territory of 4 x belt fed 20mm cannon vs 2 x 15 round mag fed swivel guns.


Obviously, the sources for all are guilty of blending and mixing ferry range with combat radius, but whilst it clearly has an excellent range, there's nothing which appears to be superlative about the G4M and much which shows it at a disadvantage in terms of clunky/ ineffective defensive armament, propensity to burn, lightweight structure etc. It remains a good looking machine and without doubt, striking at long range and with surprise, it was a very effective weapon. But you don't keep surprising people with the same tactics. And there's a world of difference between lightning first strikes or making unmolested bombing raids on Chinese cities and the attrition of a long and opposed campaign.

As an actual design, its dated in some respects - for fun I looked up the UKs other twin engine torpedo bombers. The Beaufort? First flew a year before and introduced into service a year before the Betty. Listed top speed is about the same as the G4M at 271mph, lower combat range by a hundred miles. Bomb load of torpedo carriage - same at circa 2000lbs. Similarly inadequate defensive armament. But undoubtedly much stronger structure.

The closest comparison to the 1941 Betty in service is probably the venerable Hampden, an aircraft that flew a full five years before and entered service in 1938. No, no canon armament - but equally deficient defensively. However, its only 19mph slower at rated altitude, but can manage 1720mi with a 2000lb bombload (or cash that for a lower range for up to a 4000lb load). Famously, it also operated as a torpedo bomber and was known for its manoeuvrability.

We shouldn't be mythologizing the aircraft too much. We should be a bit more interested in the skill of the aircrew (especially their peerless long range navigation) and the the initial strategy to understand what made the Betty such an effective weapon in my opinion.

None of which has much if anything to do with speed versus manoeuvrability. But that dog rolled over and died about four weeks ago!

To be fair, the Mosquito was both a fighter as well as a fast bomber and the Beaufighter was .... a fighter. The G4M was a medium bombers, not a small, fast bomber.

If you want to compare it with something, compare it to Whitleys, Wellingtons, Bostons, B-25s, and B-26s.

G4M: 266 mph. 1941. 2200 pounds bombs. 21000 pound airplane. 1770 mile range. 3130 mile ferry. Cruise 196 mph.
Whitley: 230 mph. 1937. 7000 pounds bombs. 33500 pounds airplane. 1650 mile range. 2400 mile ferry. Cruise 210 mph.
Wellington: 235 mph. 1938. 4500 pounds bombs. 28500 pound airplane. 2550 mile range. Cruise 195 mph.
Boston: 317 mph. 1941. 4000 pounds bombs. 24000 pound airplane. 945 mile range. 2300 mile ferry. Cruise 280 mph.
B-25: 272 mph. 1941. 3000 pounds bombs. 35000 pound airplane. 1350 mile range. Cruise 230 mph.
B-26: 278 mph. 1941. 4000 pounds bombs. 37000 pound airplane. 1150 mile range. 2850 mile ferry. Cruise 216 mph.

I seriously doubt any could haul the max bomb load and also go the max range. In any airplane, you trade payload for fuel.

So, as far as speed goes, the G4M is faster than a Whitely or a Wellington, about the same as a B-25 and the B-26 has a small speed advantage, but not enough to matter. NONE of them cruised at maximum speed, so I'm not sure why comparing maximum speeds is even relevant. The G4M cruised about like the bottom of the class, which wasn't all THAT much slower than the middle of the class. Only the B-25 and A-20 were significantly faster at cruise.

It serves to highlight the A-20, which is the fastest in the list and hauls a good payload.

The G4M doesn't seem to carry as much weight as the others, but it has a better standard range than all but the Wellington. They seem to have used it mostly as an attack airplane and not a medium bomber, going for specific tactical targets. All in all, the G4M is not especially impressive, but it also isn't too far behind the field if you are using it for tactical purposes. It is easily the lightest of the medium bombers above by a ton and a half.

 

[PAT303]

I stand corrected. 20mm cannon still does a lot more damage though right?

As I have already stated no, in the early years fuzes were unreliable to the point British testing found training ammunition to be just as effective as real ammunition because the HE API quite often didn't work meaning it acted no different to the basic machined practice slug, the Luftwaffe found their fuzes either worked too early bursting on the skin or too late exploding after passing through or not at all.

 

[PAT303]

The Japanese called this "Hineri Komi"

It must have been nice to find Allied pilots who flew straight and level as the A6M pilot did his Hineri Komi maneuver all around him.

 

[Greg Boeser]

To be fair, the Mosquito was both a fighter as well as a fast bomber and the Beaufighter was .... a fighter. The G4M was a medium bombers, not a small, fast bomber.

If you want to compare it with something, compare it to Whitleys, Wellingtons, Bostons, B-25s, and B-26s.

G4M: 266 mph. 1941. 2200 pounds bombs. 21000 pound airplane. 1770 mile range. 3130 mile ferry. Cruise 196 mph.
Whitley: 230 mph. 1937. 7000 pounds bombs. 33500 pounds airplane. 1650 mile range. 2400 mile ferry. Cruise 210 mph.
Wellington: 235 mph. 1938. 4500 pounds bombs. 28500 pound airplane. 2550 mile range. Cruise 195 mph.
Boston: 317 mph. 1941. 4000 pounds bombs. 24000 pound airplane. 945 mile range. 2300 mile ferry. Cruise 280 mph.
B-25: 272 mph. 1941. 3000 pounds bombs. 35000 pound airplane. 1350 mile range. Cruise 230 mph.
B-26: 278 mph. 1941. 4000 pounds bombs. 37000 pound airplane. 1150 mile range. 2850 mile ferry. Cruise 216 mph.

I seriously doubt any could haul the max bomb load and also go the max range. In any airplane, you trade payload for fuel.

So, as far as speed goes, the G4M is faster than a Whitely or a Wellington, about the same as a B-25 and the B-26 has a small speed advantage, but not enough to matter. NONE of them cruised at maximum speed, so I'm not sure why comparing maximum speeds is even relevant. The G4M cruised about like the bottom of the class, which wasn't all THAT much slower than the middle of the class. Only the B-25 and A-20 were significantly faster at cruise.

It serves to highlight the A-20, which is the fastest in the list and hauls a good payload.

The G4M doesn't seem to carry as much weight as the others, but it has a better standard range than all but the Wellington. They seem to have used it mostly as an attack airplane and not a medium bomber, going for specific tactical targets. All in all, the G4M is not especially impressive, but it also isn't too far behind the field if you are using it for tactical purposes. It is easily the lightest of the medium bombers above by a ton and a half.

The B-26 numbers you used are for the long wing B-26B/C.
The early, short wing B-26 used in the Pacific had a top speed over 300 mph, routinely carried up to 3000 lbs., or a torpedo, and could extend its range with a 250 US gallon bomb bay tank.

 

[GregP]

I wasn't going to cover all models of all families, but the early B-26 did carry less and go faster. Almost all aircraft families seem to get heavier and slower as they "develop." In fact, I can't think of a single one that got lighter and faster until they went from the P-51D to the P-51H. And then it didn't very much lighter. It DID get faster. After that, I can't think of another one that got lighter and faster.

 

[Wild_Bill_Kelso]

It must have been nice to find Allied pilots who flew straight and level as the A6M pilot did his Hineri Komi maneuver all around him.

I guess you think it's made up?

The maneuver is not for an enemy pilot flying strait and level, it was for an enemy pilot that follows the Japanese fighter into a loop. Anyway, believe whatever you like. I heard the earth is flat too.

 

[Wild_Bill_Kelso]

As I have already stated no, in the early years fuzes were unreliable to the point British testing found training ammunition to be just as effective as real ammunition because the HE API quite often didn't work meaning it acted no different to the basic machined practice slug, the Luftwaffe found their fuzes either worked too early bursting on the skin or too late exploding after passing through or not at all.

Sorry, don't buy the idea that the cannons weren't working.

 

[Wild_Bill_Kelso]

It serves to highlight the A-20, which is the fastest in the list and hauls a good payload.

Except, as I already noted upthread with the stats by A-20 type, the A-20s being used in the Pacific had considerably less range than that. The A-20A had a little over 500 miles range.

 

[Greg Boeser]

I wasn't going to cover all models of all families, but the early B-26 did carry less and go faster. Almost all aircraft families seem to get heavier and slower as they "develop." In fact, I can't think of a single one that got lighter and faster until they went from the P-51D to the P-51H. And then it didn't very much lighter. It DID get faster. After thgat, I can't think of another one that got lighter and faster.

P-40L, got a little lighter, not much faster.
Maybe the P-40N-1. But many of these were upgunned back to 6 gun standard in the field.

 

[PAT303]

I guess you think it's made up?

The maneuver is not for an enemy pilot flying strait and level, it was for an enemy pilot that follows the Japanese fighter into a loop. Anyway, believe whatever you like. I heard the earth is flat too.

No I don't think you made it up but at all, every nation had their trick maneuvers but thinking it'll work after a few times is fantasy, it's no different to not dogfighting at low speeds against the Zero, pilots will soon learn and counter the move, lastly your Zero pilot is shooting at 90 degree's deflection so if he shoots as shown in the diagram he will miss, he won't be aiming at the engine radiators pilot or anything else but open air 3-6 lengths in front of the target depending on distance and speed.

 

[Wild_Bill_Kelso]

No I don't think you made it up but at all, every nation had their trick maneuvers but thinking it'll work after a few times is fantasy, it's no different to not dogfighting at low speeds against the Zero, pilots will soon learn and counter the move.

I never said they did it every time. The original context of this little mini-dispute is whether radiators were really vulnerable. I think they were.

Frankly, I think people in each country tend to remember the propaganda told to their people during the war, it gets repeated again and again. US and British planes got armor before Japanese planes did, so we tend to emphasize that as decisive. But it's really a little bit around the margins. Assuming they haven't run out of 20mm ammunition yet, it only takes a handful of shells to tear the wing off of a fighter plane. Or shred the cockpit, with or without armor, if you are attacking from above as the Japanese often did. And a little .30 cal gun can shoot holes in the radiator too, especially if it has plumbing going down into the wings.

The Japanese themselves emphasized the radiator being a vulnerable target, and told their pilots to aim for it.

Whether their cannon worked, or whether they could shoot holes in radiators with cannons or machine guns, the evidence is in the hundreds of Allied fighters sitting on the bottom of the Pacific. They sure didn't seem to have trouble shooting down Hurricanes and Fulmars at Ceylon either in the Indian Ocean. Or Spitfires and Darwin.

All the details are interesting, but I don't think they amount to the A6M being at any disadvantage here in a given air battle.

 

[PAT303]

Sorry, don't buy the idea that the cannons weren't working.

Sorry but its the truth, just to make it even more difficult aircraft were both stressed skin and fabric, fuzes that worked on alloy didn't work on fabric, fuzes that worked on fabric pre-ignited on stressed alloy. Later Mine shells got graze fuses that were instantaneous and the Hispano HE fuzes initiated after approximately two thirds of their length passed through the outer skin, or not at all.

 

[PAT303]

I never said they did it every time. The original context of this little mini-dispute is whether radiators were really vulnerable. I think they were.

Vulnerable compared to what?, if we are talking about vulnerability and thinking one bullet through the radiator makes a plane vulnerable what about the A6M,with no seat armour, no frontal armoured screen, nil engine protection or self sealing fuel tanks what part of it is not vulnerable?.

 

[Wild_Bill_Kelso]

Sorry but its the truth, just to make it even more difficult aircraft were both stressed skin and fabric, fuzes that worked on alloy didn't work on fabric, fuzes that worked on fabric pre-ignited on stressed alloy. Later Mine shells got graze fuses that were instantaneous and the Hispano HE fuzes initiated after approximately two thirds of their length passed through the outer skin, or not at all.

I know they had some trouble with the cannon, but i also know the cannon worked, which is why basically every nation except the US switched over to 20mm cannon on every fighter. As 'superlative' as the eight (lmg) gun armament was supposed to be, it didn't last too long in the world of fighter design

 

[Wild_Bill_Kelso]

Vulnerable compared to what?, if we are talking about vulnerability and thinking one bullet through the radiator makes a plane vulnerable what about the A6M,with no seat armour, no frontal armoured screen, nil engine protection or self sealing fuel tanks what part of it is not vulnerable?.

My point is that the Allied planes were vulnerable too. The pilot armor also didn't always work, the rubber lined fuel tanks didn't always prevent fires. The Hurricane and Spitfire still had an unprotected (except for aluminum 'armor') fuel tank in front of the pilot as late as 1943.

Pilot armor and self sealing fuel tanks were good to have, but their importance is sometimes exaggerated. Read the operational histories. Zeros didn't burst into flames every time they were hit. Hurricanes and P-40s and P-39s were not immune to 20mm cannon fire. Their radiators did get punctured, yes sometimes by a single small caliber bullet, and that did result in planes going down. These are just facts.