Favorites and their achilles heels!

[drgondog]

The Mustang B/C/D had a couple of serious issues - namely vicious high G stall/spin characteristics, more vulnerable to 'golden B-B' with underslung radiator/oil cooler and glycol lines, some structural issues in High G diving roll, and for the B/C gun jamming from both high G stresses as well as marginal gun heater.

It can be a beast in a severe cross wind landing - and do NOT ditch the airplane.

 

[herman1rg]

( but then they drink warm beer) .

Not all of us do!!

 

[parsifal]

For the Spitfire, maybe we should add "poor choice of prop and supercharger for the earlier marks".

Design choices are design choices. For the Spit, like anything else, compromises had to be made. For me, and i admit this is open to interpretation, the Spuit was thje best all round fighter in 1938-40. but a price had to be paid for that, and that eventually had an effect on operations for the aircraft and indeed the RAF as a whole. Because the Spit (and all the other RAF SE fighters of the time) could not fly all the way to Germany, the RAF had to fly its bombers at night . Later, when the FC swung opver to the offensive, Spits could not really operate in the FB role very well.

 

[Shortround6]

There are all kinds of 'official requirements" in the 1930s that disappeared real quick when the actual shooting started that affected aircraft designs. The British even had a limitation on maximum tire pressure to avoid causing ruts in the grass air fields. It was the same maximum for all aircraft types so it is rarely, if ever mentioned in individual requirements. It may be a small thing but several small things add up, the landing field requirement was a big thing in the 30s too. Even the Blenheim bomber was practically a STOL machine.
You have to also look at what was possible at the time. The power to weight ratios of the available engines in 1938-40 simple didn't allow a single engine fighter to carry enough fuel to fly long distances and still perform well enough to handle a short ranged fighter. The Zero was the only fighter to pull that trick off and it required some sacrifices and an element of luck. Luck in the form of well trained, experienced pilots going up against mostly Green pilots and often a rather disorganized defense. Imagine Zeros trying to fly from England to Points in Germany (even if not Berlin) in the Spring of 1942 and think how well they would have done?

many people do not really appreciate the changes that better fuel ( and engines ) made. Every body (mostly ) knows about 100 octane fuel but the timing and what it meant to engine operations and aircraft performance is remarkable. Considering the time it takes to get an aircraft from design to large scale service use, just about ALL aircraft (basic airframe)used up until 1942 were designed with 87 octane fuel in mind. granted many of them used 100 and 100/130 fuel to great advantage.

The octane scale is not linear. The performance number scale is much closer to being linear and indicates what an engine could expect to do for internal horsepower, that is the power developed in the cylinders before subtracting friction, pumps and supercharger drive requirements. 100PN = 100 octane. 100/130 should allow for about a 30% increase in power (not all engines responded the same and the range could be from 20-40% increase). 150 PN means a 50% increase over 100PN.
Now going the other way, to see where the late 1930s aircraft designs came from with the expected available power you have 91 octane fuel having a PN of 75.68, while 87 octane has a PN of 68.29 and 80 octane fuel has a PN of 58.33.
With an engine running on 87 octane instead of 100 the engine might see a drop of around 30% in power. (it will be less difference at the crankshaft because to make full use of the 100PN fuel more boost needs to be used which means more power used in the supercharger). Obviously such changes in engine power for little differences in weight mean big changes in aircraft performance including lifting more fuel for longer range.

 

[buffnut453]

P-51 limitation would be jams to the ammunition feeds. Same-same for the F4F.

 

[Jabberwocky]

FW-190A series: Poor altitude performance, poor engine reliability in initial marks

Hawker Typhoon: Poor engine reliability, buckling/loss of tailplane (26 known incidents), leakage of Co2 into cockpit forcing pilots to permanently wear oxygen masks, thick wing harming altitude performance and leading to high-altitude problems with compressibility

Spitfire I/II/early V Hurricane I/early Mk IIs: Problems with Merlin float carburetor lead to cut-out in negative G

de Havilland Mosquito: Wing shedding problems (occurred in 1944 and fixed later that year). NOT due to warping or delamination due to heat/humidity - as oft repeated - but actually due to a manufacturing defect at one of the factories, relating to how the wing skin was attached to the main spar. European Mosquitos suffered more wing failures than Far Eastern Mossies did.

P-51B/C: Problems with gun jamming, rectified with introduction of P-51D

Seafire: Poor arrestor frame arrangement leading to high crash/write off levels during carrier ops;

Bf-109: Narrow track and camber of landing gear;

Me-110: Slow rate of roll, particularly at low speeds

A6M: Slow rate of roll, particularly at higher speeds. Control forces at high speeds were very high (also affected early Spitfires, Hurricanes, Bf-109s and many other fighters with fabric skinned ailerons). Japanese pilots often removed radios, particularly on long-range missions. Lack of self sealing fuel tanks in early models. Low limiting dive speed, improved incrementally through the war with improvements to wing skinning and other mods.

He-177: Prone to engine fires, a problem gradually fixed throguh the war.

FW-200: Prone to breaking at the spine during landing

 

[MikeGazdik]

So many favorites, but to start. P-39- single stage Allison, 37mm cannon. P-40 - single stage Allison, P-51A - single stage Allison. (theme here?) P-47 range, weight. F4U Corsair, my longest answer. I feel when the cockpit was moved aft, the pilot was then placed in a bad spot in the fuselage. I have seen photos where the rear of the air frame from the pilot seat back twists or breaks away from the wing and forward structure. Bad for a hard crash landing. F6F Hellcat too slow, for all the go under the hood. F4f, landing gear off an Army duece and a half. Me 109-landing gear and weak wing, Fw190-should turn better for its weight. Spitfire- um, uh, its too pretty to talk bad about!!!!

 

[Bernhart]

carburators in early hurricanes and spits

 

[buffnut453]

Spitfire: Its limited range and limited fighter bomber capabilities.

I agree that the Spit's range was limited compared to other fighter aircraft but it must be remembered that, at the time of its creation, there was no requirement for longer-range operations. Also, there was no concept of a "fighter bomber" in the 1930s - that was a tactical evolution that occurred during WWII.

Perhaps we need to tighten the question a little and simply examine achilles heels that were related to the aircraft's initial intended role?

 

[Shortround6]

I agree that the Spit's range was limited compared to other fighter aircraft but it must be remembered that, at the time of its creation, there was no requirement for longer-range operations. Also, there was no concept of a "fighter bomber" in the 1930s - that was a tactical evolution that occurred during WWII.

Actually the fighter bomber dates back to WW I. Many British fighters were given bomb racks for four 20lb bombs. This continued on into the 1920s and a number of American fighters of the late 20s and 30s also had racks under each wing for light bombs. The P-26 could carry four 50lb bombs under the center section. The He 51 could carry six 22lb bombs inside the fuselage. I am sure there were others. Curtiss was advertising a total bomb load of 850lbs for export 75 Hawks, I don't think anybody took them up on it. The basic problem until WW II was the fighter had enough trouble just flying as a fighter without trying to strap a big bomb load to it. With 450-600hp for a late 20s/early 30s fighter and a all up weight of under 4,000lbs trying to carry a 500lb bomb just wasn't going to work without using a really big wing that would kill fighter performance once it was dropped.

Perhaps we need to tighten the question a little and simply examine achilles heels that were related to the aircraft's initial intended role?

I think that is a good idea, perhaps two categories?

Early Spitfires had elevators that were too powerful and were hard to coordinate in maneuvers. Later Spitfires were shorter in range than they could have been given that several schemes for adding fuel tanks had been used in limited numbers. Granted it would never equal the Mustang.

 

[TheMustangRider]

The P-51's CG issues due to the implementation of the aft fuselage 85 gallon fuel tank deserves a mention.
A bothersome tendency that forced its pilots to get rid of some of that fuel en route before engaging the enemy.

 

[Arossihman]

Was the original P-47 designed to be an escort fighter? If not then what is the Problem? Did it have equal or greater range than the P-40? The Initial design for the P-47B was offered to the Army in June of 1940 and the contract for the prototype placed in Sept 1940, during the BoB. What was the original range or endurance requirement? The fact that the ASAAC wanted escort fighters 3 years later doesn't mean that the P-47 failed to meet it's original goals.

I have a book at home that can answer that question but i know it was not designed as an escort fighter....however it still lacked by comparison to some of its competitors in climb rate. Although it did live up to army requirements in airspeed,armament,armor, and self sealing tanks,they came up a few gallons short of the capacity requirements for fuel. Granted it would'nt have made much difference in range i feel it was still a minor shortcoming as it could be the difference between ditching in the channel or making an emergency landing in some guys field! Don't get me wrong here to me the p-47 embodies all that i love in a fighter and to me in good hands it can do no wrong, but the early versions had their shortcomings.

 

[pbfoot]

Lack of de icing equipment on Lancaster and halifax , like how stupid is that sending out heavy bombers at night with no deicing but I guess that extra couple of hundred lbs made the difference, most of the crews wouldn'y even know they were icing as they were hopefully flying in darkness , and using a flashlight to peer out if your icing would be a invite for an attack

 

[davebender]

There's no such thing as a free lunch. If you want the P-51 to have extreme endurance all that internal fuel will degrade flight performance.

The late war P-47D-15 carried 375 gallons of internal fuel. That also must have degraded flight performance to some extent. However the jug was such a heavy monster to begin with that additional fuel weight might not be as noticable.

 

[Milosh]

The P-51's CG issues due to the implementation of the aft fuselage 85 gallon fuel tank deserves a mention.
A bothersome tendency that forced its pilots to get rid of some of that fuel en route before engaging the enemy.

Not just the P-51 had this issue, the Spitfire did also when fitted with the rear fuselage fuel tank.

 

[Shortround6]

The question as to the fuel affecting the performance of the P-47 is different than the how it affected the P-51. The P-47B (none used in combat) and the "C" early "D"s had 305 US gallons. They also started with 2000hp engines and the famous "toothpick" propeller. When the later models went to the 370-375 gallon tank it was an enlarged tank in the same place and affected the center of gravity little if any. The later models also had engines that were good for 2300-2500hp and had the paddle blade props. With the P-51 the extra fuel went behind the cockpit and had a serious affect on the center of gravity. Extra weight can certainly affect a planes performance but changes in the center of gravity can affect handling and or trim and control response.

 

[Readie]

Interesting posts.
'Warm beer'..ummm

The Spitfire had some Achilles heels. carburettors... Mind you Miss Shilling's orifice sorted that out.
Shilling devised a simple, yet ingenious, solution that was officially called the R.A.E. restrictor. This was a small metal disc with a hole in the middle, fitted into the engine's carburettor. Although not a complete solution, it allowed RAF pilots to perform quick negative–g manoeuvres without loss of engine power. By March 1941, she had led a small team on a tour of RAF fighter bases, installing the devices in their Merlin engines. The restrictor was immensely popular with pilots, who affectionately named it 'Miss Shilling's orifice' or simply the 'Tilly orifice.' It continued in use as a stop-gap until the introduction of the pressure carburettor in 1943.

As a combat aircraft, the Spitfire's flying performance against that of its foe was obviously of fundamental importance. Until the autumn of 1941 its main adversary was the Messerschmitt. The two were fairly evenly matched, the Spitfire being more manoeuvrable and faster at low level but the ME 109 better in the climb and slightly faster at a higher altitude.
Their respective engines also behaved differently. The Messerschmitt's fuel-injected Daimler-Benz engine did not have the disadvantage of the Spitfire's float-type carburettor causing the engine to cut out during certain manoeuvres. Another weakness of the Spitfire was the heavy stick force the pilot had to contend with from the ailerons when flying at high speed. Although the plane's design was under constant development throughout the war, this aspect was never properly cured.

The Spitfire had a fuel tank directly in front of the pilot, between the engine and the cockpit. The high-octane fuel used in high intensity air combat put the pilot at high risk. A single enemy bullet could ignite the fuel, filling the cockpit with roaring flame. The pilot's only escape was to pull back the canopy and flip the plane upside down in the hope of a safe escape by parachute, all in the space of about eight seconds. Many suffered horrific burns, their hands and faces completely erased by fire. The injury was given its own name – Airman's Burn – and led to the development of new forms of severe burns treatment by the RAF surgeon Archibald McIndoe at a cottage hospital in East Grinstead. His patients were to form the now celebrated Guinea Pig Club which still exists to this day.

By the time the The Mk V design was introduced early in 1941 the Spitfire had become the full equal of the Messerschmitt Bf-109F, and various modifications were available for different fighting conditions. These included extended or 'clipped' wing tips for high or low altitude performance, sand filters for the North African desert, and various combinations of both cannons and machine guns (some even carried bombs). The carburettor was also improved to prevent engine cut-out under negative 'G'.

I am going to have a lie down in shock as I have had to admit that my much loved Spitfire was not 101% perfect...

John

 

[drgondog]

Spitfire aileron ineffectiveness at high speeds ~ 33% at 400 mph (compared to a Mustang/P-47) - were a problem against the 190's.. but fixed later in the series

 

[krieghund]

The Zero for all the usual well highlight faults...however, not starting with the Kinsei engine instead of the Sakae. Would have progressed to the Kinsei 62 in 1942 instead of 1945

Of course we could what if? all day long.......

 

[TheMustangRider]

Not just the P-51 had this issue, the Spitfire did also when fitted with the rear fuselage fuel tank.

To which Spitfire Mk are you referring to Milosh?
Much has been written (or perhaps I've read) about the Mustang's 85 gallon fuel tank but not much about the Spitfire's as far as I'm aware.