YFM-1 Airacuda

[Shortround6]

16x 60-round drums (info from the Weight and CG Diagram page of the Beaufighter Mk I manual)

Another reason for the guy in the back. He was part of the loading system

Trying to keep four cannons running while maneuvering 60lb drums of ammo in back of a dark and sometimes violently maneuvering (even a 2 G turn means a 60 degree bank) aircraft was not an easy task, in fact after the first four drums (ones on the guns at take-off) it was rare to have even 3 guns ready to fire unless the plane flew straight and level for a while.
Hispano could empty a drum in about 6 seconds.

 

[Zipper730]

16x 60-round drums (info from the Weight and CG Diagram page of the Beaufighter Mk I manual)

With 4 per gun? Could this have been done with the YFM-1's 37mm system -- use a servo assisted motor to switch from drum to drum and load the rounds?

 

[XBe02Drvr]

With 4 per gun? Could this have been done with the YFM-1's 37mm system -- use a servo assisted motor to switch from drum to drum and load the rounds?

In late depression America, with manpower cheap and engineering and machinery expensive, not likely, IMHO. Such a system would be complicated, expensive, and error prone.
You might find it enlightening to research the development of the Navy's 5 inch 54 cal automated multipurpose deck gun. It was a system similar to what you're suggesting that was supposed to fire full auto at surface and air targets. They started appearing on ships in the 1950s and were supposed to be the greatest thing since sliced bread, but were a continual source of mechanical troubles. When I joined the Navy in 1970, they still weren't properly sorted out. My company commanders in both boot camp and "A" school were gunners mate chiefs who had been 5"54 specialists aboard ship, and if you wanted to drive either of them to apoplexy all you had to do was say "5 inch 54" and stand back! You would get a full volume tirade on "that FU POS excuse for a weapons system" they felt they were wasting their careers on. The only unprofessional behavior I ever saw from either one of them.
Apparently the ammo feed system on these guns was prone to jamming due to failure of sensors and interlocks, freezing the gun in the middle of a firing sequence and wreaking havoc on the machinery inside the turret and sometimes injuring personnel. Officially the weapons system was a tremendous success and any failures the result of operator and maintainer error, not any shortcoming in the system. It reportedly got so bad that supervisors were being disciplined for documenting material failures in the system.
"Any resemblance to the torpedo scandals of 1942-43 is entirely coincidental and of no significance whatsoever."

 

[SaparotRob]

In late depression America, with manpower cheap and engineering and machinery expensive, not likely, IMHO. Such a system would be complicated, expensive, and error prone.
You might find it enlightening to research the development of the Navy's 5 inch 54 cal automated multipurpose deck gun. It was a system similar to what you're suggesting that was supposed to fire full auto at surface and air targets. They started appearing on ships in the 1950s and were supposed to be the greatest thing since sliced bread, but were a continual source of mechanical troubles. When I joined the Navy in 1970, they still weren't properly sorted out. My company commanders in both boot camp and "A" school were gunners mate chiefs who had been 5"54 specialists aboard ship, and if you wanted to drive either of them to apoplexy all you had to do was say "5 inch 54" and stand back! You would get a full volume tirade on "that FU POS excuse for a weapons system" they felt they were wasting their careers on. The only unprofessional behavior I ever saw from either one of them.
Apparently the ammo feed system on these guns was prone to jamming due to failure of sensors and interlocks, freezing the gun in the middle of a firing sequence and wreaking havoc on the machinery inside the turret and sometimes injuring personnel. Officially the weapons system was a tremendous success and any failures the result of operator and maintainer error, not any shortcoming in the system. It reportedly got so bad that supervisors were being disciplined for documenting material failures in the system.
"Any resemblance to the torpedo scandals of 1942-43 is entirely coincidental and of no significance whatsoever."

Incredible. Where's Rear Admiral Lockwood when you need him?

 

[MiTasol]

Well, unless you used a Curtiss Electric prop I don't think you could have a gun firing through the prop hub. There may be other technical reasons why electric props are better for some applications.

View attachment 632442

several models of P-39 had Aeroprops and they were hydraulic

 

[MiTasol]

The F-16 has a fly by wire flight control system, so if you lose the engine or just the IGD you are going to lose everything. So it has an Emergency Power Unit powered by hydrazine to enable them to get it on the ground before the pilot ends up being like a guy in lawn chair at 20,000 ft with only a Nintendo game for company.

The F-86 had hydraulic controls that would lock if you lost hydraulics. If my memory is correct one of the race engine builders (Zuchel?) was killed in the 70's when his engine driven pump failed and so did the electric backup. He was caught in a turn that lead to the ground

 

[ThomasP]

Hey Zipper730,

What XBe02Drvr said, with the caveat that the 37mm rounds are much lighter and the recoil much less, so it would probably be easier to produce a reliable feed than for the 5"/54 Mk 42 and Mk 45 naval guns.

Also, what Shortround6 said about the weight of such a drum magazine if you were going to try to reload in the air.

If you assume the 37mm drum magazine weighs the same loaded as the 20mm drum, you would only have about 18 rounds per drum, so 36 rounds total for the dual drum feed before you have to reload. Obviously this is better than 5-round clips, if you can-not/do-not-have-to reload in flight. But if you have to reload in flight, a 5-round clip might be better due to simplicity and ease of handling.

Also, the mounts on the FM-1 were trainable for off direction-of-flight aiming, so whatever feed system is applied will have to move with the gun. If you add the weight of 2x 60 lb drums and the servo/cam driven feed mechanism (say 140-150 lbs total at a minimum) to the gun, you will have to significantly redesign the mounting - probably for strength and clearance, and certainly for balance. This would also maybe require strengthening the airframe structure to which the gun system is attached.

 

[Zipper730]

Another reason for the guy in the back. He was part of the loading system

How did this system exactly work? Did the guy hit a button that basically moved the ammo-drum into position and indicate it was in place, then hit another button or move a lever that basically extracted the ammo from the gun and fed it into the breach with an in-transit light indicating everything was moving, and a light that indicated it was locked, cocked, and ready to rock?

You might find it enlightening to research the development of the Navy's 5 inch 54 cal automated multipurpose deck gun. It was a system similar to what you're suggesting that was supposed to fire full auto at surface and air targets. They started appearing on ships in the 1950s and were supposed to be the greatest thing since sliced bread, but were a continual source of mechanical troubles.

I can't seem to find much on google, but my guess is that the configuration could not properly extract the ammo belt from the drum and reliably feed it into the breech properly?

 

[XBe02Drvr]

I can't seem to find much on google, but my guess is that the configuration could not properly extract the ammo belt from the drum and reliably feed it into the breech properly?

http://www.navweaps.com/Weapons/WNUS_5-54_mk42_sketch.jpg

Take a look at this complicated system. Every stage in the assembling, handling, and loading of the ammunition depends on micro- switches, relays, and interlocks to make things happen in sequence and keep moving parts from crashing into each other. Now keep this mechanical masterpiece in a saltwater environment for years on end with corrosion and contamination setting in, and what do you think is going to happen?

 

[Zipper730]

Take a look at this complicated system. Every stage in the assembling, handling, and loading of the ammunition depends on micro- switches, relays, and interlocks to make things happen in sequence and keep moving parts from crashing into each other.

It seems the biggest area would be the the loading from the drums into the breech, particularly as the barrels were being swung 'round and 'round and pitched up and down.

Now keep this mechanical masterpiece in a saltwater environment for years on end with corrosion and contamination setting in, and what do you think is going to happen?

I assume you'd have corrosion, stuff jamming up, possibly some of the electrical equipment shorting out now and then. I'm not an engineering type, but those are known effects of corrosion and salt-water (which happens to be a decent conductor of electricity -- ironically pure water is not a good conductor).

 

[keithwwalker]

So I always thought the Airacuda had development potential, and by that I mean rationalization.
Why didn't they just use the P-39 system of a tractor propeller for each nacelle and then the cannon's could be operated by the pilot. You lose two crewmembers as they are now redundant.
Rationalize even more, two tractor engines and two 37mm cannon under the wing root where it can be reloaded by the rear gunner and now you have a bomber/tank killer. Of course the P-38 was very close to that concept and was much more brilliant.
Did Bell ever have any proposals of a rationalized Airacuda on the drawing board that never were developed?

 

[XBe02Drvr]

So I always thought the Airacuda had development potential, and by that I mean rationalization.
Why didn't they just use the P-39 system of a tractor propeller for each nacelle and then the cannon's could be operated by the pilot. You lose two crewmembers as they are now redundant.
Rationalize even more, two tractor engines and two 37mm cannon under the wing root where it can be reloaded by the rear gunner and now you have a bomber/tank killer. Of course the P-38 was very close to that concept and was much more brilliant.
Did Bell ever have any proposals of a rationalized Airacuda on the drawing board that never were developed?

The Airacuda was designed to a concept popular in the thirties, the "heavy" bomber destroyer, which turned out to be not survivable in the presence of single seat fighters once the war got going. Witness the BF110 in the BoB. By that time large magazine autoloading 37MM cannons and more powerful engines were available that would have given the 'cuda more performance, but its very concept was starting to prove untenable. In a sky full of MEs, FWs, and A6Ms, clay pigeons comes to mind.

 

[Shortround6]

To further XBe02Drvr's comments. The 37mm cannon originally had a 5 round magazine. You needed gunners to reload. Wiki claims there were 110 rounds in each nacelle which is way beyond what any p-39 or P-63 carried per gun. On the YFM-1 the guns were not aimed by the gunner unless in back up mode. The 37mm guns were aimed by a central gunner and could be aimed off axis to the line of flight.

It could be possible to build a twin engine fighter with a gun firing through the props like the P-39 but the resulting air craft would have been considerably smaller than the YFM-1.
YFM-1 used a bigger wing than an early B-26 bomber. Span and area were actually quite close to the Martin B-10 bomber.

You aren't going to 'save' anything from the YFM-1 except the general layout.

 

[swampyankee]

So I always thought the Airacuda had development potential, and by that I mean rationalization.
Why didn't they just use the P-39 system of a tractor propeller for each nacelle and then the cannon's could be operated by the pilot. You lose two crewmembers as they are now redundant.
Rationalize even more, two tractor engines and two 37mm cannon under the wing root where it can be reloaded by the rear gunner and now you have a bomber/tank killer. Of course the P-38 was very close to that concept and was much more brilliant.
Did Bell ever have any proposals of a rationalized Airacuda on the drawing board that never were developed?

The Airacuda was built to an intrinsically flawed concept, and it was badly executed at that. The errors in execution resulted in an aircraft that was slower than contemporary bombers, had a critical, single-point failure mode, poor flight characteristics, and absent emergency in-flight exit routes for nearly half the crew. Even without retrospect, these problems were, in my opinion, sufficient to make the aircraft unsuitable for service. The conceptual flaw was the idea that a heavily armed aircraft, with roughly the same crew as a bomber would be capable of intercepting an attacking bomber without sensor technologies that did not exist in the mid-1930s. What would be needed for that would be an aircraft with a significant performance advantage over the bombers; this is not going to be possible with an aircraft that's not much, if any, smaller than a bomber (and the Airacuda didn't even manage that).

 

[special ed]

When Bell responded to the proposal, the perceived bomber threat would coming to the US from the sea with no conceivable, possible fighter cover provided. It was basically a "make work" project to enable Bell to advance from a sub component builder to an aircraft factory.

 

[swampyankee]

When Bell responded to the proposal, the perceived bomber threat would coming to the US from the sea with no conceivable, possible fighter cover provided. It was basically a "make work" project to enable Bell to advance from a sub component builder to an aircraft factory.

A trans-Atlantic bomber wasn't really possible, either, so make work does seem most likely, but why? There was not a dearth of airframe companies

 

[XBe02Drvr]

A trans-Atlantic bomber wasn't really possible, either, so make work does seem most likely, but why? There was not a dearth of airframe companies

Wasn't there some cockamanie theory of a European power conquering Iceland and bombing us from there? "Red Storm Rising" four decades early.

 

[Shortround6]

A trans-Atlantic bomber wasn't really possible, either, so make work does seem most likely, but why? There was not a dearth of airframe companies

Maybe not quite trans-Atlantic but certainly very long range.

 

[Zipper730]

When Bell responded to the proposal, the perceived bomber threat would coming to the US from the sea with no conceivable, possible fighter cover provided. It was basically a "make work" project to enable Bell to advance from a sub component builder to an aircraft factory.

Technically, it was kind of a strange mix of aircraft designs: X XBe02Drvr was kind of right that it was inspired to an extent by the idea of a bomber-destroyer concept. The French had a bunch of oddball designs to this concept.

The were built apparently designed often for extended range standing patrols (and standing patrols were the norm prior to the point-defense interceptor, reliable radar and voice-radio), as well as other considerations such as an air-to-ground capability and possibly heavy firepower: These aircraft influenced the YFM-1, as well as the Bristol Beaufighter, the German Henschel 124, the Fw 187 and Bf 110, as well as the Kawasaki Ki 45 and Kawanishi N1K (though the Me 110 wasn't designed for the use as a defensive plane, so much as an offensive fighter-bomber).

The YFM-1 was basically built around a variety of concepts in one: Long-ranged standing patrols (hence the idea for long range), heavy firepower (hence the 37x145mm cannon), the ability to drop bombs on bombers (an idea that was popular at the time), ground-attack (since there wasn't much of an interest in single-engined attack planes, and an idea of being able to drop large numbers of small blast-fragmentation munitions), and the ability to be an escort fighter, which is why it had a turret/waist-gunner (there was a fixation of using fighters as a gun-boat/gunship to augment the defensive firepower of the bombers primarily, with the ability to go out and hunt-down fighters as a secondary).

 

[ThomasP]

Although not in any official original documents, I remember reading (a long time ago) about the idea behind the Airacuda. Whatever article or book I read it in stated that the Airacuda was not originally intended to defend the continental US from foreign bombers, but to be a long range escort for the B-17. The soon-to-be B-17 was thought to be capable of attacking out to 1000 miles away, and a suitable escort was needed.

A secondary idea arose for the defense of places such as Alaska, Hawaii, the Philippines, and other off-shore real estate of interest to the US.
Since it was in vogue to think that the bombers would always get through (at least to a large enough extent that it would be a serious problem) early detection with interception by standing patrols was one option that was kicked around by the higher-ups for a brief period. It was intended to be part of a layered defense.

As I said above this was not from original source documents so I can not vouch for the accuracy.