New whif project.............Operational F-108 Rapier

[KJ_Lesnick]

The thing that's really amazing about the F-108 is that even though it was designed for high speed, it probably would have had much better energy maneuverability qualities in a dogfight than one would expect.

It's wing area is huge (1,865 square feet), it's engines and consequently thrust to weight ratio were more powerful than listed*.  Granted the wing is very thin (averaging 3.5%), but I wouldn't be surprised if it would still get a L/D ratio better than the F-4's wing at high subsonic-speeds at altitudes above 20,000 to 25,000 feet.    

I wouldn't be surprised if it's instantaneous agility was pretty nice too.  It was a big design, but it was a delta and they generally had good instantaneous-g figures, the outboard wing's anhedral would probably make for a nice rate of roll.  It was stated to be capable of 5.33G's (which means it could probably pull 50% more = 7.995 G's)


KJ Lesnick

* Officially the maximum afterburning thrust of the J-93 was listed between 27,000 and 31,000 lbf.  However it was stated that the J-58 could produce 26,500 lbf dry, other statements about the J-58 being 50% more powerful than the J-75 (17,500 x 1.5 = 26,250) seem to support this.  In at least one, possibly two books about the A-12/YF-12A/SR-71/M-21, it was stated that the afterburning thrust would be on the order of 45,000 (that was the early J-58 prior to it being modified for the SR-71).  The J-93 was rated in the same thrust class as the J-58 (maybe a small touch more powerful) which probably means it could produce 27,000 lbf to 31,000 lbf dry depending on model and extrapolating on that, afterburning would probably be at least 45,000 lbf.  That means with dry power 54,000 lbf is generated, and with full power at least 90,000 lbf.  The F-108A just before it was cancelled was around 104,320 lbs (That source is from the book XB-70:  North American's Mach-3 Superbomber, by Dennis R. Jenkins and Tony R. Landis).  That isn't a bad fully loaded T/W ratio.  When you consider how much weight is fuel (combat weight is based on a 50% fuel-load) that would exceed 1:1 at combat weight with afterburning.

[General Melchet]

Thanks fellas,

Mossie, Yep it should work well with the T4's intakes..I've a strong suspicion that it has a lot better moulding quality than the Rapier, the wing surfaces are, (were) atrocious and needed a LOT of work on my sample.
Any of the schemes you mention would suit it down to the ground !!

Nev...that one did cross my mind as did  74  Tiger squadron... .....not too sure I'd fancy an NMF on this surface though !!!

KJ....That is exactly the same thought that crossed my mind on viewing the model from different angles!!!...it just looks like it should pull high G in tight corners ala F-15, certainly as well as an F4....the wing loading was offset somewhat by the 4 big fences mounted under the fuselage and 2/3rds span, the Mach 3 speed possible by use of intake pressure ( as in the XB-70  and F-12) and the wings anhedral dropping to dihedral 2/3 rds the way outboard, creating a stable pressure wave at altitude.

Unbelievable to think it was cancelled back in 1959!!!

Andy

[KJ_Lesnick]

General Melchet,

KJ....That is exactly the same thought that crossed my mind on viewing the model from different angles!!!...it just looks like it should pull high G in tight corners ala F-15, certainly as well as an F4....the wing loading was offset somewhat by the 4 big fences mounted under the fuselage and 2/3rds span

How do the wing-fences adversely affect wing-loading?  To the best of my knowledge they were for providing directional control

the Mach 3 speed possible by use of intake pressure ( as in the XB-70  and F-12) and the wings anhedral dropping to dihedral 2/3 rds the way outboard, creating a stable pressure wave at altitude.

I don't think the F-108 utilizes compression lift, or at least to the same degree as the B-70.

[tigercat2]

I have read all I can find on the F-108, and remember seeing somewhere that one of the features of this aircraft was the ability to destroy an incoming hostile aircraft 1000 miles away from home base in 30 minutes after scramble!!  That might be stretching things a bit, but proably not too much; 2 - 3 minutes from klaxon horn to airborne, 6 - 10 minutes or so to get up to Mach 3 and 75000 feet, target acquisition 200 miles or so away and missile launch at Mach 3 while still heading towards the target (away from land). 

Not bad performance for an aircraft today, how about 50(!) years ago.


Wes W.

[GTX]

Can't wait to see the finished product.

Regards,

Greg

[General Melchet]

Thanks chaps, it was certainly an ambitious project Wes, way ahead of it's time..at least some of the tech made it into other aircraft so all was not wasted...

Cheers Greg, hope to set about it post Telford...


Andy....

[Ian the Kiwi Herder]

F-108 = Sex with wings...... IMHO 

Ian

[batmancustoms]

Great idea!  Well done!

[General Melchet]

Thanks chaps, I agree it's one gorgeous design, looking forward to getting on with it .as is usual with early Anigrand's , it's endless sanding, sanding dry fit, sanding, etc, etc..............................................

Andy

[bearmatt]

Hello General!

Still sanding? 
Or did I miss the Roll-Out 
(I know you were busy with the SR-75...)

Cheers

bearmatt

[ysi_maniac]

Just top notch

[General Melchet]

Thanks fellas, Bearmat, I'm afraid it's on hold for a while as I've a few' real life 'projects to finish in time for Telford, however this and the Vought F-8U-3 Crusader 3 will be running again early September ready for SMW10, hopefully on display with the B-70 and SR-75..

Thanks for the interest,

Andy....

[wolfik]

looks interesting...and yes...like Ian saed...sex with wings  
we can see the good old time when air force was a manfolk domain...
only a tom cruise-sized pilot was able to place his donkey in such a cockpit...
any size of boobs would be pressed to an unsightly head cheese

by the way...is it finished already?

[CAO 700]

Excellent job! I think we want more pictures!

[KJ_Lesnick]

General Melchet,

Not a big deal, we all have various responsibilities in our daily lives.