GE J79 with Burner....

[charveldan]

[Tripower455]

I need one..... 6 gallons a minute at idle might be a bit expensive though!

[charveldan]

The F-4 Phantom had 2 of those badboys.

Can't figure what these guys are gonna do with this one ?

[Luke Gibson]

Originally Posted by charveldan

The F-4 Phantom had 2 of those badboys.

Can't figure what these guys are gonna do with this one ?

.....my favorite jet engine!

How big of a nerd am I that I have a favorite jet engine? (Don't answer....)

[shakeshakeshake]

So awesome

F4s are bad ass.

[Tele Wacker]

My goodness! All you need is one more of these and an F-4 frame.
Was this down in Florida somewhere?

[RussB]

They didn't close the turkey feathers after they lit the can...maybe they were afraid the engine would break loose from the stand!



I got to watch several P&W F-100-P-229E's being tested. I worked on the dies that made the individual panels of the turkey feathers

[charveldan]

The turkey feathers stay open on an F-4, F-14 & F-15 in full burner.

[RussB]

...but when you close 'em up, thrust increases by a lot!

[RussB]

Originally Posted by Buck Murdock

Thrust isn't increased during AB use by closing the nozzle. The pilot can't control the nozzle opening directly anyway. The AB fuel control won't usually let the nozzle close during AB use. They can malfunction of course, but normally there's a fail-safe that, if something does break, makes the AB shut down, and the nozzle goes to about half-closed. At that point, it's sometimes hard to even get to MIL power.

Is that true of all afterburner engines?

[Stratobuc]

Originally Posted by shakeshakeshake

So awesome

F4s are bad ass.

Steve Ritchie said if he had a MiG 21 instead of a Phantom, he could have shot down an F-4 every day. He should know.


My favorite airframe for that engine:

[charveldan]

Originally Posted by Stratobuc

Steve Ritchie said if he had a MiG 21 instead of a Phantom, he could have shot down an F-4 every day. He should know.


My favorite airframe for that engine:

[Luke Gibson]

Originally Posted by Stratobuc

Steve Ritchie said if he had a MiG 21 instead of a Phantom, he could have shot down an F-4 every day. He should know.


My favorite airframe for that engine:

Missile with a man in it....

[RussB]

Originally Posted by Buck Murdock

Well, I can't say either way for all AB-equipped engines. But for the 79s and similar, even at, say, 75% power, even one broken nozzle leaf will create a high EGT condition (overheating, more or less). A "cocked nozzle" is reason for grounding the aircraft, and that's sometimes when only about 4-5inches (1 leaf) of the entire nozzle is not able to open fully.

If you could override the afterburner fuel control, I suppose you could try to close the nozzle while the AB was lit (I'm sure dudes in the test cell have tried it). But the temp at the turbines would instantly climb, you'd lose a lot (most?) of the cooling air that normally protects the metal that the AB is made from (under normal conditions, the flame never actually touches the metal, since there's a cushion of cooler air between the two). There's also the fact that the AB is meant to function as a ramjet: the more air/fuel you add, the faster you go. Closing the nozzle dramatically restricts the airflow, which is useful at MIL power, but sort of defeating the purpose at AB.

Again, though, I can't speak for all designs. I'm no expert. I'm not even an internet-level expert

Thanks for posting this. I believe I just learned something!



In my days at P&W, the department that manufactured and re-furbished afterburner cans was right down the aisle from my department.

They would strip and re-coat the AB's with that white coating...not sure exactly what it was but it was sprayed on, similar to a spray welding process.

[dc_jcm800]

My dad worked at the GE for 30 years. He tested f404's and t700 helicopter engines.
Such a badass job!!!
I remember one family day that he worked running an f404 as a demo.
My hero!