R-i-i-i-i-g-g-g-g-h-h-h-h-t.....

[oboe]

From p.237 of Bill Yenne's book, "Aces High", subtitled "The Heroic Saga of the Two Top-Scoring Aces of World War II", presented for your entertainment, analysis and comments:

"Bong next took a few shots at another Japanese fighter, but was hit in the radiator of his left engine.  When he returned to Tacloban, Bong's crew chief discovered the round that punctured the Lightning's engine was not a 12.7 mm Japanese slug but an American .50-caliber round.  Since no Americans had been shooting at Dick, he had apparently been flying so fast and maneuvering so much that he had overtaken and collided with one of his own bullets!"

Not sure I can imagine any real-world scenario where physics could make this possible.  The rounds exit the muzzle traveling at the velocity of the aircraft + the muzzle velocity of the Browning machine gun, and the radiators on a P-38 are mounted well behind the gun muzzles, on the sides of the twin booms.   

So no, just no.

 

[Vraciu]

From p.237 of Bill Yenne's book, "Aces High", subtitled "The Heroic Saga of the Two Top-Scoring Aces of World War II", presented for your entertainment, analysis and comments:

Not sure I can imagine any real-world scenario where physics could make this possible.  The rounds exit the muzzle traveling at the velocity of the aircraft + the muzzle velocity of the Browning machine gun, and the radiators on a P-38 are mounted well behind the gun muzzles, on the sides of the twin booms.   

So no, just no.

Vertically. 

[Oldman731]

Vertically.

This.  Happened to a Grumman Tiger in the 1950s:

"With that 0.5-G dive, Attridge had flown below the trajectory of his bullets and, 11 seconds later, flew through them as their flight paths met.."

http://www.aerofiles.com/tiger-tail.html

- oldman

[oboe]

I think I need a diagram.   I still can't picture it, given where the nose guns are on the centerline, and the radiators outboard in the booms?

[Vraciu]

Bullets veer....  Planes maneuver...

[colmbo]

I can't see how this could of happened.  Other Americans might not have been shooting AT Bong but that doesn't mean someone didn't hit him.  We've all seen gun camera footage from WWII showing friendlies flying in front of friendlies that were shooting.

How do they know it was a .50 cal and not an enemy round.  Did they recover the projectile?

The P-38 is subsonic, just can't see it overtaking his own supersonic bullet.

[oboe]

Thanks for the link, Oldman, that helps me picture what might've happened.   How unlikely though!   And the P-38 had to have taken much longer to catch up to its own bullets, but it doesn't sound so impossible now.

The cynic in me assumed it must've been a cover story for a friendly fire incident they didn't want to deal with, especially involving their top ace.

<S> guys

EDIT: Colmbo the book said the crew chief recovered the round, but I don't know how they tell the difference between US and Japanese ammo.  Color of the slug or shape maybe?

The .50-caliber bullets are supersonic after exiting the muzzle but like any ballistic projectiles start slowing from drag and dropping due to gravity immediately, so while still far fetched maybe its not as impossible as I first thought.     

[Puma44]

Perhaps a “Golden BB” occurance.

[Vraciu]

Perhaps a “Golden BB” occurance.

Yeah or a semi-squib round, etc..

The author’s description/implication leaves much to be desired, but...

[Vulcan]

This.  Happened to a Grumman Tiger in the 1950s:

"With that 0.5-G dive, Attridge had flown below the trajectory of his bullets and, 11 seconds later, flew through them as their flight paths met.."

http://www.aerofiles.com/tiger-tail.html

- oldman

BS, the bullets muzzle velocity is relative to that of the aircraft. The muzzle velocity of 50 cal is around 3000fps - roughly 2000 miles per hour. So the aircraft firing the bullet would have to exceed 2000 mph to get past the bullet it fired.

IF you fired almost vertically, then got your nose down and managed to intercept your bullets they would be falling at terminal velocity, around 300fps or less depending on the bullet. Unlikely to do anything to an engine.

[Vraciu]

BS, the bullets muzzle velocity is relative to that of the aircraft. The muzzle velocity of 50 cal is around 3000fps - roughly 2000 miles per hour. So the aircraft firing the bullet would have to exceed 2000 mph to get past the bullet it fired.

IF you fired almost vertically, then got your nose down and managed to intercept your bullets they would be falling at terminal velocity, around 300fps or less depending on the bullet. Unlikely to do anything to an engine.

The instant that round leaves the barrel it is decelerating. 

[Oldman731]

The instant that round leaves the barrel it is decelerating.

And falling.  While the aeroplane (for purposes of this exercise!) is maintaining a constant speed.

To my surprise, I couldn't readily locate a good ballistics chart for .50 BMG.

Might be easier to visualize if you think of the plane firing while climbing.  Plane then levels off, while bullets travel in an arc above it.  Given the right combination of angles, course and velocities, the bullets will come down on the plane.

- oldman

[bustr]

Does this help?

[Oldman731]

Does this help?

Not quite what I was looking for.  I was hoping to find the bullet's velocity at different ranges, to show how much it slows down.  There are quite a few online ballistics calculators that will do that now, but I'm too lazy to calculate enough examples to illustrate the point.  Plus I don't know the ballistic coefficient of the M2 ball round.

- oldman

[Guppy35]

Since no matter how good a fighter jock he was, he couldn't see everything going on in the airspace around him, i'd suggest some other Allied fighter driver had a round go astray.

Douglas Bader's story was he collided with a 109 when he went down.  Turns out he was shot down by a squadron mate who chopped off his tail with 20mm.

Johnny Godfrey in watching gun camera footage after he returned from his stint as a POW learned that it was his wingman who shot him down while strafing.   

Friendly bullets don't exist