Forum: General F-22A Raptor forum

I'm fortunate to live in the greatest concentration of military bases in the world, Hampton Roads, Virginia. My office is in the flight path of the F-22s from Langley.

There seems to be angle or distance at which an observer on the ground hears a whistle coming from the F-22. This whistle is similar to blowing air over the mouth of a bottle, it's low in frequency and only lasts a few seconds.

It appears the F/A-18E/F at NAS Oceana do not make this same noise. Those are the only two gets I can routinely hear in this area to make a comparison. I've been using the whistle noise to tell people how to differentiate between two by sound alone.

What is making this sound?

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Wow, 233 views on this post and no answer!

I wish there was a way to capture the sound on video, but the flights of the 22s are not predictable.

It's the anti-gravity drive! OOPS shouldn't have said that.

It could be all kinds of things, particularly if the gear's down. My money would be on some kind of aerodynamic noise, like over an open gear bay or around a landing gear door.

I used to notice the raptors making what I would call a "Whooping" sound that appeared to be in sync with the exhaust nozzle narrowing down.

Raptors make this noise when the throttles are advanced. It's the influx of air into the intakes for the first few seconds of throttle up that produces the noise.

Quote:

There seems to be angle or distance at which an observer on the ground hears a whistle coming from the F-22. This whistle is similar to blowing air over the mouth of a bottle, it's low in frequency and only lasts a few seconds.

Bottle huh? Miller Lite or Bud Lite? I kind of miss that area in some ways, was stationed at Fort Useless. Lots of history there and plenty of ALL branches of the military too. I got to drive under and aircraft carrier there, once (tunnel). Watched an F-22 demo back in OCT and didn't hear anything but constant thunder.

I think I know what he means. Listen out around the 2:55 - 3:00 minute mark

http://www.youtube.com/watch?v=MPtM5t81 ... re=related

Is that the what you hear?

After viewing this:

Quote:

I think I know what he means. Listen out around the 2:55 - 3:00 minute mark

http://www.youtube.com/watch?v=MPtM5t81 ... re=related

And reading this:

Quote:

Raptors make this noise when the throttles are advanced. It's the influx of air into the intakes for the first few seconds of throttle up that produces the noise.

...I can officially say BINGO!

You can also clearly hear the throttle increasing at 3:38 on the video, along with the whistle noise. So I feel that's pretty definitive.

Since this seems to be a forum where details like to be nitpicked, what is it about the F-22's intake that makes the noise? Is it the S-shape of the intake ducts?

Also, does anyone know the name of aerodynamic effect that is responsible for this phenomenon. I'll spend some time clicking through Wikipedia and report back I find it.

THANKS

From what I've seen and heard in person, it's just an airflow harmonic phenomenon seen on a few aircraft (The F-104 comes immediately to mind). Similar to the whine of a TF-39 on a C-5 or TF-34 on an A-10.

I can't get enough of that sound! Two F-22s came to Niagara Falls Air Reserve (.5 mi from my house) last summer, the frqz. rattled everything in my room. Still can't beat the sound of an F-4 on downwind...

shabah_cactus wrote:

I can't get enough of that sound! Two F-22s came to Niagara Falls Air Reserve (.5 mi from my house) last summer, the frqz. rattled everything in my room. Still can't beat the sound of an F-4 on downwind...

If you think it's loud a half mile away, you should hear it standing right next to one on taxi out. Another crazy thing is the rumble the F119 makes on spool up. It shakes your guts, literally

I have heard that a 747 gets 40% of its thrust from the lips of its engines on takeoff, of air pulled from the flanks of the turbofans and accelerated around the front rim into the fan.

Perhaps on the ground and at the low speeds on approach a throttle adjustment increases that sideways flow of air into the engine and causes that noise.

I hear that sound plenty of times. I usually notice it mostly from 747 (SE Asia, Canada, Europe) and more so on rainy and breezy days. It seems to happen when thrust is increased.

shabah_cactus wrote:

Still can't beat the sound of an F-4 on downwind

Amen Brother! All kinds of yowls hoots and howls form those birds!

Forum: General F-22A Raptor forum

Whistle noise from F-22