AH-64 Apache

[Jeff D. Welker]

BLADES OF GLORY - A couple of Boeing Apaches doing a quick gas-n-burger-n-go at Willie/KIWA yesterday afternoon.

[Chetan]

I could not help but notice the difference in the engine exhaust system between the two Apaches. Could some one explain what the role of the deflectors are. Are they incorporated so that the exhaust mixes with the rotor downwash so that it is cooler, resulting in a relatively lower IR signature?

[Jay Beckman]

Yup, IR Suppression...

[Joe Copalman]

For what it's worth, this is the first time I've seen this mod as well.  The flight crew in both birds were civilians from Boeing, so my hunch is that they're testing a new bolt-on IR-suppression kit.

[Jeff D. Welker]

I'm not sure it is that easy to see; however, the heat/IR signature below the tail boom in the first Apache appears to be more evident that in the second bird with the different exhaust system. I apologize for the different angles but the first Apache dusted off the second and I had to wait for it to clear the dirt cloud.

[jslugman]

I could not help but notice the difference in the engine exhaust system between the two Apaches. Could some one explain what the role of the deflectors are. Are they incorporated so that the exhaust mixes with the rotor downwash so that it is cooler, resulting in a relatively lower IR signature?

There might be some mixing but I'd hazard a guess that it's to shield the exhaust from the lower-rear aspect and some ner-do-well with a MANPAD

[Jeff D. Welker]

WHAT U LOOKIN AT? - I've been on an Apache jag lately - they're just too cool.

[Chris Kennedy]

Very nice!

Good thing he doesn't have the gun slaved to his helmet.

[Chetan]

I'm not sure it is that easy to see; however, the heat/IR signature below the tail boom in the first Apache appears to be more evident that in the second bird with the different exhaust system. I apologize for the different angles but the first Apache dusted off the second and I had to wait for it to clear the dirt cloud.

Nice pictures Jeff. They seem to answer the question of the role played by the upturned exhaust deflectors. The rotor downwash seems to disperse the hot exhaust gases more thoroughly and onto a wider area, thereby reducing the possibility of a lock-on by any MANPAD's (as mentioned by James). This would be a good mod especially for the Apache's with uprated engines (hotter exhaust), if any. Thanks

[jslugman]

I wonder what (if any) effect it has blowing the exhaust air up into the rotors flight-wise.

[Jay Beckman]

My gut tells me that while it may not hurt, it can't help.

The exhaust gases are thinner (in terms of air density) which has to impact lift to some degree.

[Joe Copalman]

Less talk, more rock:

[Chris V]

Nice shots Jeff!

[Bubak]

[Jeff D. Welker]

AH-64D