F-4e phantom exhaust nozzles

You might start with the F4 Society. They put out a quarterly Journal, and their website has a number of links to other sites.

I'd use the open ones. In a 45 degree dive, the pilot will be back on the power to keep his airspeed on parameters for the dive. The might be slightly closed, but certainly not "conical" looking. The "parked" nozzle position is actually full open - which is also "correct" for Max AB or Mil power settings.

I'd also suspect the "conical" looking ones are actually for a different engine variant. I'd have to see a picture, though...

It's not an "air-ground" thing, it's power setting. While I don't know what to use for your dio, the nozzles are open at idle, go toward close as power increases, then open back up for afterburner. If you can determine the power setting (low, I would think) you can estimate the setting. There probably is not one answer as power would vary during the dive. Curt

The more conical ones on the Fujimi F-4C/B kits in 1/72 (or the Hasegawa/Monogram/ESCI kits in 1/48) are for earlier J79 engines. The F-4E and J tailpipes are specific to those versions, so a simple swap won't do. I don't recall anyone doing aftermarket tailpipes that represent the exhaust in different positions.

Frank

Thanks for the input fellas; I learn something new everyday. It seems that I can use whatever looks best (the Aires cans) and maintain accuracy. I'll assume that the pilot cut back on the throttle and let gravity take over on this bomb run. The resin Aires parts really do look much better than any of the kit parts - Fujimi, Esci, and Hasegawa . Thanks again - Jack

Actually the nozzles should be full open for idle, not mil, and for AB as was stated. As power is advanced to mil, the nozzles progressively close until they are indeed conical, and as AB is selected the nozzles open back up to fully. The nozzles are also always full open when the engines are off. The long nozzle version of the J79 found on F-4Es, Fs, G,s Js, and Ss become quite conical in shape when mil is selected. The short nozzles found on other versions (F-4B, C, D, RFs, etc) operate somewhat differently. As the throttles are advanced, the smooth metal area adjacent to the fuselage slides forward into the fuselage, and the nozzle flaps contract into a much different shape than those on the long nozzle variants. Scott Wilson Phormer Phantom Phixer F-4C and F-4E

Hmmmnn...I think I stand corrected...I need to go watch some F-4's...

But I'll go out on a limb and offer the rest of the story on AB light-off. They actually open a bit wider than nominal "full open" - called "pre-open" - at AB selection to entrain the flow and then choke back down once the AB is lit. The controller attempts to maintain Mach

I'm thinking of the longer nozzle variant here, which doesn't really appear that "conical" (at least compared to the other variety). I've done some overhaul work on the later J-79's, but not the earlier ones you mention. I have to assume they are convergent only nozzles - being a younger pup, I've only worked with the convergent/divergent variety.

As you point out the two are found on differing dash number J-79's, so swapping the two between kits wouldn't even really be approriate unless the subject called for it, I would think.

Ahh, now you got me... I was merely an avionics tech, all I know about the nozzles I learned from watching engine runs while standing fireguard. It's quite an experience standing a couple of feet from the nozzle with the engine in full AB! You feel the noise more than hear it, though even with both ear plugs and Mickey Mouse hearing protectors it was pretty danged loud! Scott Wilson

I also spent some time turning wrenches as a test technician in the cells at GE - as the newbie on shift, it was one of my jobs to walk into the test cell and look for fuel leaks when we took a newly built engin up to Max AB for the first time...we were working F101 and F110DFE at the time.

If you think standing next to the jet is something, try walking into a closed room with one!