Webmaster's Note: This group of questions is from "Mild Bill" Dahlgren. If you have any answers for or comments on these questions, please email Mild Bill at , and also please "copy" your email to this site at
I'm interested in the XF-84H as a (flying) model project and have been trying to track down (particularly) [three] details. First, a small point -- do I presume correctly that the forward section of the "spinner" is fixed? Second, the biggie, the powerplant. Every reference I have says Allison T-40, which I do not believe. My guess is Allison T-38 or something else. Also, some articles refer to an afterburner. On a turboprop this seems unlikely but photos suggest a variable outlet tailpipe which seems equally unreasonable -- maybe they DID try an afterburner. Finally, a tiny question about that "torque fin/vortex generator." Judging from its location in reference to other F-84 models and its dark color I'd guess it to be an antenna of some sort.
My thoughts on the "fixed" spinner and doubts about the T-40 derive from the Douglas Skyshark and the two Pogo projects. On all three aircraft the forward part of the "spinner" WAS fixed. On the XFV-1 and the 'Shark the "spinner" was to be the location of the gun aiming radar and the XFY-1 made its tethered flights with the tether attached where the forward "spinner" section would have been mounted. As for the engine, the T-40 was essentially two T-38s together driving a contra-rotating gearbox. Converting that to drive a single propellor and finding room for two side by side power units in the "H" fuselage seem unlikely. A single-unit T-38 seems more likely, though it'd be a lot less powerful, of course. I believe that the mixed power XF-88 test plane did use a T-38 to spin the prop so that might be a vote in its favor. True, the '88 had a standard spinner but it was strictly a propellor test-bed from the beginning. The '84H at least had pretentions of developing into an operational aircraft and would need someplace to stash the radar.
Good info on the "H" does seem hard to come by. I get the impression from the material I've accumulated that everybody has been copying other peoples' information -- all going back to an erronious original that started the chain. All these questions could be settled by a good look at the Kern County Pylon "H." I just wish it wasn't 2000 miles away!
Many Thanx, Wm Dahlgren,