xrearl 27 Posted January 11, 2017 https://tacairnet.com/2015/06/18/redeveloping-the-f-4-phantom-ii-into-a-mach-3-fighterspy-plane/ 3 Share this post Link to post Share on other sites
Fubar512 1,350 Posted January 11, 2017 Wow. Thanks for sharing this. Share this post Link to post Share on other sites
Stratos 3,192 Posted January 11, 2017 Amazing history! Thanks for sharing!! Share this post Link to post Share on other sites
RUSTYMORLEY 162 Posted January 11, 2017 Wow. Thanks for sharing this. Same for me, a very unusual tale indeed !!! Share this post Link to post Share on other sites
JediMaster 451 Posted January 13, 2017 I remember reading that in one of my books about the F-4. As it never got very far it's not widely known, but it's an interesting "what if" up there with the F-108, TSR2, and YF-12. Share this post Link to post Share on other sites
Stratos 3,192 Posted January 14, 2017 I just printed it and will add to my Phantom reference book, such development planes are always cool. Share this post Link to post Share on other sites
Toryu 156 Posted January 16, 2017 You can't build a Mach 3 capable airframe by just bolting on water-tankss, tweaking the inlet-system and modifying the flight-controls of a Mach 2 airframe. The most critical problem north of Mach 2 is shock-heating. You can go Mach 2.5 for a very short time in an aluminium-airframe (as actually demonstrated by F-4s during Project Skyburner), but that's about it. Aluminium will weaken a lot above 120°C, which is about the leading-edge temperature at Mach 2*. If you want to go faster (even just on a dash), you'll need different materials: stainless steel (heavy) or titanium (a dog to work with - especially machining - thus gold-dust expensive). The US had their strategic bird at this time (SR-71), and giving funds to Israel for tweaking a Mach 2 bird into a low-volume Mach 3 retrofit-program wasn't a politically and fiscally sane idea. ___ * Depends on a couple of factors, but generally Mach 2 is an upper-bound for aluminium-airframes for this very reason 2 Share this post Link to post Share on other sites
Fubar512 1,350 Posted January 17, 2017 You can't build a Mach 3 capable airframe by just bolting on water-tankss, tweaking the inlet-system and modifying the flight-controls of a Mach 2 airframe. The most critical problem north of Mach 2 is shock-heating. You can go Mach 2.5 for a very short time in an aluminium-airframe (as actually demonstrated by F-4s during Project Skyburner), but that's about it. Aluminium will weaken a lot above 120°C, which is about the leading-edge temperature at Mach 2*. The F-104's Vmax was also limited due to thermal issues, it could attain a Mach number high enough to melt its windscreen (which if I recall correctly, occurred between Mach 2.25 and 2.5). I am sure a similar issue existed with the F-4. Share this post Link to post Share on other sites
Toryu 156 Posted January 17, 2017 There was a flight by an operational F-104C, using tweaked inlet-cones (similar to those on the NF-104) and the larger tail of the twin-seaters/ G-model. They went out to about Mach 2.5 with acceleration still ongoing, when the pilot (Tom Delashaw) RTBed. http://www.i-f-s.nl/f-104-records/ There used to be a pilot's account of Delashaw, but I can't find it now. The F-104G has three limits concerning speed: M 2.0 (mainly a stability limit) 750 KIAS (q-limit) 121°C Compressor Inlet Temperature The windscreen-thing was probably an issue on all fightes back then. Luckily, the fuel wouldn't last too long anyway. Share this post Link to post Share on other sites
