Vought (LTV) V-517 and V-520 Sea Control Ship (SCS) fighters

[Dsadow]

Hi,
Looking for information on the LTV V-517 V/STOL fighter proposed for the Sea Control Ship.

 

[overscan (PaulMM)]

Tony Buttler published a 3 view of the V-517, a perspective drawing of the V-517 and a front view of the related V-520 design plus information on it in American Secret Projects: Fighters and Interceptors 1945-1978.

I highly recommend you pick up a copy

 

[Mark Nankivil]

Here are some drawings for the V517 courtesy of the Vought Archives.

Enjoy the Day! Mark

 

[Mark Nankivil]

...and the V520, again from the Vought Archives.

Enjoy the Day! Mark

 

[AeroFranz]

You brought back good stuff - thanks Mark!

 

[Stargazer]

Awesome!

 

[Steve Pace]

Loving Snoopy as the pilot of V-517 (bottom drawing)!

 

[OM]

Loving Snoopy as the pilot of V-517 (bottom drawing)!

...Agreed! It begs for more examples of subtle humor in blueprints, much as the "Easter Eggs" found in the Star Trek TNG Enterprise blueprints.

 

[elmayerle]

Loving Snoopy as the pilot of V-517 (bottom drawing)!

...Agreed! It begs for more examples of subtle humor in blueprints, much as the "Easter Eggs" found in the Star Trek TNG Enterprise blueprints.

Heh, or the "Goodstone" tire logo that appears on the B-2 GA drawings (though you really have to enlarge them in CADAM to see that).

 

[Stargazer]

The difference between the V-517 and V-520 models seems to reside only in the fact that the former had a "fixed" engine. What does that mean exactly here?

 

[Mark Nankivil]

Variations on a theme. Seems the fold out lift engines were a design fashion of sorts in that general time frame when you look at some of the other designs coming out of Republic, Fairchild and the like though you can say the same for the lift engines in the fuselage along the center line. It would be interesting to read what the Navy was thinking and if they had preferences that the two designs were trying to cater to.

I would think that the fold out engine version has better roll control in slow flight/hover and possibly a more stable hover than the lift engines mounted in the fuselage aft of the cockpit. I would also think that general maintenance would be easier with the fold out engines though you pay a price with a bit more complexity in the mechanics of the set up. Either way though, that's not a whole lot of airframe and volume for the fuel needed to make things go for more than a few miles!

Enjoy the Day! Mark

 

[Mark Nankivil]

Greetings All -

Here are two more 3 views for the V-517 out of different documents. You'll note the use of two lift engines vs. three as shown on the first drawings I posted and other minor details/refinements too. The listing of the engines is useful too.

Enjoy the Day! Mark

 

[Mark Nankivil]

Greetings All -

Here's two more 3 views of the V-517 - one has three lift engines as per the previous drawing posted and the other has only two lift engines and wing folding too.

Enjoy the Day! Mark

 

[Steve Pace]

"Fixed" engine, I think, means fixed air inlet for speeds in the 1.5 Mach number range.

 

[Bill S]

Late to the party as always. The reasoning between three fixed lift engine vs two was Vought's desire to cut cost by using two Allison J99 lift engines in place of three Rolls Royce R.B. 162 engines which was estimated to save $20 million in the prototype program.
A little more on the engines The J99s were expected to have a thrust of 8510 lbs with an allowable 5% bleed to provide roll control for the aircraft in hover and transition. The combination lift/cruise engine is the P&W JTF22A-30 a version of the F401-PW-400 that was anticipated for use in the F-14B by 1978.
Vought ultimately offered two versions of the V-517 for consideration.
V-517A was to be powered by a TF30-P-100 modified for lift cruise for program cost and risk reduction.
V-517B was to be powered by the F401-PW-400. The aircraft was essentially the same as the V-517A with the exception of an airframe mounted accessory gearbox, and the risk of delays in the engine development program. These was also the mention "the Navy may desire to develop the swivel nozzle for the F401,"

Mark pretty well drained the pool of illustrations, I have a couple scanned from a view foil presentation that are attached including an Isometric view, V-517A General Arrangement and the production version (IOC 1978) General Arrangement for your viewing pleasure.

 

[Bill S]

Not much to add on the V-520 for the moment. I do have this illustration that shows a little more of the lift fans. There again a scan of a view foil, doing the best I can with those images!

 

[blackkite]

I'm little worried that the main engine will suck in the exhaust from the lift engine.

 

[overscan (PaulMM)]

Not much to add on the V-520 for the moment. I do have this illustration that shows a little more of the lift fans. There again a scan of a view foil, doing the best I can with those images!

If you feel like sending me higher res scans I'm pretty sure I can do better.

 

[H_K]

Love these drawings! Was any thought given to STOL instead of STOVL?

I.e. Low speed approach with some wing lift and the rest from the lift jets and swivel nozzle. Like a precursor to SRVL...