Cool vid of an F-14 breaking wind, and Su-30 crashing

[ThaGrandCow]

<< Great post Fandu. I generally agree with what you mentioned, but the following was a little unclear for me.



<< So when your flying, the speed of the waves extending in front of you is less than the speed of sound (340m/sec). >>




When you say the speed of the wave is less than the speed of sound, is that relative to the aircraft in flight? >>



exactly

 

[Fandu]

Yea, that's relative to the aircraft. When a sound wave is emitted, it's emitted from a stationary point. It doesn't matter how fast your traveling, the wave still acts as if it's emitted from a stationary point. So as your approach the barrier, the speed of the waves in front of the plane, relative to it becomes less and less. Until when you hit 340m/sec when your traveling the same speed as the waves and they start stacking up infront of the aircraft. If you try out that link, start with a speed less than mach 1, say .7. Then watch the waves in front of, and the 2 mach lines that begin to form behind the plane as you approach the 1.0. Higher than 1.0, you still have a mach cone, it's just that it forms behind the plane instead of around it. The edges of the mach cone where the waves superimpose is the sonic boom.
Hope that helped

 

[BeauJangles]

<< i always thought those pictures were fake!

what exactly is going on there? are we seeing the atmosphere turn opaque? or is that some kind of exhaust? >>



When you break the sound barrier the air behind you becomes rarefied (expanded). This happens behind a wall of condensed air. As the air rapidly expands the water in the condenses, thus leaving a 'cloud' of water. It happens every time you break the sound barrier, though sometimes it's more visible then others.

 

[crab]

Got a reply:



<< ========================================================================
As far as I can determine, someone was very creative with PhotoShop editor or some other program.
But it did make for an interesting photo. Below is from a friend who worked on original B-52H program.
----------------------------------------------------------------------------------------------------------------------------------------------
Thanks ***** but the 52H I picked up at Boeing Wichita in 1960 was tested for

breaking the sound barrier that far back! We were very good back then and I

said "tested", not that it happened. >>

 

[BrunoPuntzJones]

Good on the reply crab, could have been several weeks before I got mine

Well there goes my idea

 

[swayinOtis]

<< SonicBUFF

No idea on the validity of this, but I do know I got it from somebody in the Air Force >>



The B-52 is subsonic. If in doubt, read the fact sheet.

 

[swayinOtis]

i found a link that talks about the crazy ass pilot in that b-52 crash. it's unreal. the guy was the officer in charge of standards and evaluation, yet he broke every rule in the book. half the wing was afraid to fly with him. they talk about some of his scarier moments. you won't believe what this idiot would do.

read it here

 

[duke]

Here's a website that can better explain how a subsonic aircraft can create a normal shockwave on it's wings.