XP-65/F7F Development

[wuzak]

Mosquitos could stay in the air on one engine.
many large twin bombers (especially British ones) could not, but the Mosquito was not one of them.

And, if lightly loaded, could do aerobatics on one engine.

Geoffrey de Havilland Jnr famously did so when demonstrating the prototype.

 

[XBe02Drvr]

Mosquitos could stay in the air on one engine.
many large twin bombers (especially British ones) could not, but the Mosquito was not one of them.

I challenge you to get your single engine Mosquito onto a pitching carrier deck at night and walk away from it! Zipper's right this time.
Cheers,
Wes

 

[XBe02Drvr]

The AA/AT/tank gun round used a LOT more propellant than the 37mm aircraft gun. firing it out of short barrel would have resulted in a LOT of muzzle flash and a considerably lower muzzle velocity compared to the full length barrel, even if better than the short round.

Ye gads! Can you imagine stuffing an M3 and what, maybe 12-15 M63 rounds into a fighter plane? The breech would be practically in the pilot's lap, and where would you stuff the ammo? But you might wind up with a trajectory that would nearly match your .50s.
Cheers
Wes

 

[Shortround6]

I challenge you to get your single engine Mosquito onto a pitching carrier deck at night and walk away from it! Zipper's right this time.
Cheers,
Wes

USN nightfighter squadrons used single engine planes during WW II. Loose the engine and you don't even make it back to the carrier to ditch alongside (or by destroyer.)
Any twins used (Marines used some Venturas) as night fighters were land based.

 

[Shortround6]

There was an enlarged 37mm aircraft gun using the big 37mm ammo. Most sources say it was used only on PT boats.

While the barrel was only about 15in longer it weighed twice as much and the Breech mechanism also weighed almost double what the small 37 did. (405lbs for the complete gun). It may have been planned for the P-63 but if any were fitted it was for testing only.

 

[tomo pauk]

Ye gads! Can you imagine stuffing an M3 and what, maybe 12-15 M63 rounds into a fighter plane? The breech would be practically in the pilot's lap, and where would you stuff the ammo? But you might wind up with a trajectory that would nearly match your .50s.
Cheers
Wes

Soviets did it.
Their NS-37 cannon fired ammo that was more powerful than the ammo the US anti-tank guns. Used both against aerial and ground targets, rate of fire 250 rds/min (almost twice the M4 from P-39s was capable for). The LaGG-3-37 and Yak-9K used the cannon.
NS-37 37mm cannon
American M9 cannons was of similar properties, but I don't think that it was ever used in combat.

 

[tyrodtom]

The magazine certainly looks similar ( maybe enlarged) to the 37 mm magazine used on the P-39.

 

[*SkyChimp*]

I believe the M-16 rifle was one of the few modern weapons to be built in multiple factories (although the M-14 was also),
strange as politics and government contracts are the Government (army) wanted more than one source during the vietnam war, which is understandable.
However Colt had to turn over not only blueprints of the rifle but information on tools, jigs, manufacturing procedures/techniques and so on. The two other companies that built the M-16 at the time (everybody with lathe in the garage seems to be building them now) both charged more per rifle than Colt. One company charged almost double what Colt was getting per rifle in contract at the same time.
The strange part (and politics) comes in when at least one senator wanted to investigate Colt for excessive profits but not the other companies.

At the risk of bringing this topic further off topic, the other companies probably would have to charge more for copies of the M16 than Colt. Colt owns the Technical Data Package (TDP) for both the M16 and M4 carbine. The US Govt may share the TDP with other producers, but those producers must pay Colt a royalty for every gun they manufacture using Colt's TDP. Presently, Colt doesn't have a contract with the US Govt to produce the rifle or carbine. I believe the present contract is with FN in South Carolina. Yet, Colt makes money off that contract in the form of royalties.

 

[XBe02Drvr]

Loose the engine and you don't even make it back to the carrier to ditch alongside (or by destroyer.)

Statistically the same engine installed in a twin has nearly twice the inflight failure rate as it does in single engine applications. Don't ask me why. Carrier aviators of the time all took their chances with a single engine.
Cheers,
Wes

 

[wuzak]

Statistically the same engine installed in a twin has nearly twice the inflight failure rate as it does in single engine applications. Don't ask me why. Carrier aviators of the time all took their chances with a single engine.
Cheers,
Wes

Wasn't that more to do with the size of the aircraft and the size of the aircraft carrier?

 

[XBe02Drvr]

Wasn't that more to do with the size of the aircraft and the size of the aircraft carrier?

Well, that's definitely a concern, but in the case of the Mossie, it's a tail dragger, not especially known for it's low speed handling and even worse with assymetric thrust. Its ability to execute a waveoff on one engine in dirty configuration from carrier approach speeds would have been dubious at best. The alternate scenarios are: 1, a crash on deck (heavy, fast, combustible, UGLY SCENE), or 2, a VMC roll into the drink alongside, likely hitting the water nose down inverted and rolling. There's a reason why pretty much all carrier based large twins have historically been trike gear machines, operated from angle decks, and attempted engine out landings only in the most dire emergencies. The protocol in case of an engine failure is bingo ashore.
Cheers,
Wes

 

[BiffF15]

A nice long piece of pavement is so nice... And a hotel with a bar... And per diem... And AF guys are such p---ies...

 

[XBe02Drvr]

A nice long piece of pavement is so nice... And a hotel with a bar... And per diem... And AF guys are such p---ies...

We had the East Coast F4J RAG squadron ACM training detachment on base, while nearby McDill AFB had the F4E Replacement Training Squadron. They used to visit us from time to time for "short field practice" on our 8500 foot runways. They would always send a truckload of mechanics and wheel, tire and brake assemblies to wait in the hot brake area for every landing.
Their landings were entertaining to watch, often floating a third of the way down the runway before greasing on at about Navy/Marine approach speed. We always had a crew out there to do quick resets of the overrun arrestor gear. It's hard to imagine that hunk of iron as a floater, but the AF managed to do it.
Once on the ground, they clustered together in their immaculate flight suits under the supervision of their training cadre and stared about them like Parisian sophisticates suddenly transported to a peasant village in India. They refused all offers of hospitality or sustenance as if they feared contamination or infestation, got back in their jets and went home. A true intercultural exchange!
Cheers,
Wes

 

[pbehn]

Even as a Brit I have heard of the perils of landing at a rival force's airfield by misfortune or worse, by accident, aircraft covered in graffiti and the butt of everyones jokes.

 

[XBe02Drvr]

Even as a Brit I have heard of the perils of landing at a rival force's airfield by misfortune or worse, by accident, aircraft covered in graffiti and the butt of everyones jokes.

This was no accident or misfortune, but a deliberate training exercise. And forget graffiti, along with the mechanics came Air Police who quickly established a perimeter around the aircraft and crews while they conducted their debrief. Woe betide the poor sailor or officer who might try to approach. "Untermenschen need not apply!"
Cheers,
Wes

 

[soulezoo]

A nice long piece of pavement is so nice... And a hotel with a bar... And per diem... And AF guys are such p---ies...

Hey now! I didn't complain! And besides, it's expensive down under!

 

[GregP]

The Mossie was one of the worst twins on one engine ever conceived. Vmc is 175 knots! Doesn't mean it was bad; it means it needed two engines or else land straight ahead when an engine fails if you are slower than Vmc.

It had a lot of really good qualities, but single-engine operations weren't one of them.

 

[XBe02Drvr]

The Mossie was one of the worst twins on one engine ever conceived. Vmc is 175 knots! Doesn't mean it was bad; it means it needed two engines or else land straight ahead when an engine fails if you are slower than Vmc.

It had a lot of really good qualities, but single-engine operations weren't one of them.

The function of the second engine is to deliver you to the scene of the accident.
Cheers,
Wes

 

[pbehn]

The function of the second engine is to deliver you to the scene of the accident.
Cheers,
Wes

If it got me close enough to the carrier to parachute out I wouldn't mind.

 

[Zipper730]

Regarding the F7F

I'm curious about the R-2600/R-2800 thing: If the R-2800 first was available in 1940 what was the issue with procuring them? The USN was okay with buying them for the XF4U and the program started back in 1938 right? Were they buying the R-2800 back then or were they to use a different engine?

Regarding the 37mm cannon

There was an enlarged 37mm aircraft gun using the big 37mm ammo.

If I recall it was the M9

It may have been planned for the P-63 but if any were fitted it was for testing only.

It was proposed for the XA-41 as well interestingly. Though it was quite heavy, it had a faster muzzle velocity and delivered a heavier projectile which would be useful.

Their NS-37 cannon fired ammo that was more powerful than the ammo the US anti-tank guns.

How did they get it down to such a light weight. These figures indicate around 330 pounds vs 405