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.50 Caliber Browning Guns

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pictsidhe

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Most Merlin engined planes don't whistle. Some of them have a bit of supercharger whine, if coming straight at you.
 

scramjetter

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Mar 2, 2020
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Speaking of whistling airplanes, I always thought it'd be cool to mount something like the Jericho Trumpet found on Stuka dive bombers.
 

pictsidhe

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My PSRU has a loud, high pitched whine. It is very similar to the whine of a super-charger.
I have a supercharged BMW Mini with a roots type blower. It sounds uncannily like an Austin-Morris Mini with noisy gears 😁 Centrifugal superchargers, as used by RR, sound a little different. I haven't compared them, but I'd guess a different ratio of harmonics.
 

Yellowhammer

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Born In Alabama, reside: Louisiana (unfortunately)
It's my understanding that they taped the barrels so the ground crew would know if the guns had been fired, after returning to base.

The main reason for the tape, was to prevent any debris or dust getting inside the barrels during run up and take off. If even a little speck of a rock happens to gets inside, it could blow the barrel upon firing.

Yes, it also served as a way for the ground crew to tell if the pilot had used his gun on a particular mission.
 

Yellowhammer

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Born In Alabama, reside: Louisiana (unfortunately)
Yes, in the case of our Mustang and a few other Mustang owned by friends.

Our Mustang with no gun ports is used guide often by the owner to do an airshow routine. We started noticing that in hight "G" maneuvers the plane was starting to whistle just like in the video. We traced it to the gear doors sagging under "G" load. Re-rigging the gear fixed the problem.

This is my own opinion based off my experience.

Brandon

Thanks for the clarification sir. Makes perfect sense. I have noticed the method of attachment on the gear doors on Mustang. There is the primary hinge located at the top (when gear is extended) and there is a ring or U-bolt type fastener around the strut that holds it in place.

I can definitely see how they would sag in high G maneuvers.

Thanks again for the clarification. You are a gentleman sir!
 

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TXFlyGuy

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Apr 25, 2012
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Republic of Texas
Thanks for the clarification sir. Makes perfect sense. I have noticed the method of attachment on the gear doors on Mustang. There is the primary hinge located at the top (when gear is extended) and there is a ring or U-bolt type fastener around the strut that holds it in place.

I can definitely see how they would sag in high G maneuvers.

Thanks again for the clarification. You are a gentleman sir!
Hard for me to grasp this, as my hydraulic system will keep the inner gear doors closed flush at all times, even during high G maneuvers. The pump will run any time it senses the doors are open when commanded to be closed, or if a slight drop in pressure is detected.

Did North American not design the P-51 gear doors like this?
 

Deuelly

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Nov 6, 2012
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Location
Marshall, MN
Hard for me to grasp this, as my hydraulic system will keep the inner gear doors closed flush at all times, even during high G maneuvers. The pump will run any time it senses the doors are open when commanded to be closed, or if a slight drop in pressure is detected.

Did North American not design the P-51 gear doors like this?
They actually have mechanical unlocks that need to be checked every 50 hours to make sure they're holding tight.

Brandon
Screenshot_20201102-184903_Chrome.jpgScreenshot_20201102-185012_Chrome.jpg
 
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