General Dynamics E-3/E-5/E-7 VSTOL Fighters

[overscan (PaulMM)]

General Dynamics E-3/E-5

 

[overscan (PaulMM)]

General Dynamics E-7

 

[Dronte]

It photographs of the wind tunnel model of the E-7 and outline of the operation of the power plant
(sourceopular Mechanics edition Argentinean Nov. 1989)

 

[overscan (PaulMM)]

General Dynamics E3 VTOL fighter using ejector lift

Source:

D. Koenig, F. Stoll and K. Aoyagi (NASA Ames Research Center) Application of Thrusting Ejectors to Tactical Aircraft Having Vertical Lift and Short-Field Capability AIAA article 81-2629

 

[overscan (PaulMM)]

GD E-7 (?) model

 

[rousseau]

This one was called E-7,

 

[starviking]

I once found this photo in the net, unfortunately I haven't
the link anymore. The E-7 seems to be based on a vectored
thrust engine .

The E-7 VTOL concept relied on a thrust deflector at the rear and Thrust Augmented Ejectors near the front.

Air was diverted from the rear of the engine to the front via a long pipe and ejected down - balancing the thrust deflected at the rear.

There are some NASA PDFs on featuring the E-7 on the web:

V/STOL and STOVL Aerodynamic Performance:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840014468_1984014468.pdf

VSTOL Concepts Past, Present and Future:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840014464_1984014464.pdf

Wave-Drag and High Speed Performance of Supersonic Fighter Configurations:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890000646_1989000646.pdf

Looks like a lot of interesting stuff in them - I just haven't had time for more than a quick browse.

Starviking

 

[elmayerle]

E-7 was yet another design intended to use exhaust-driven ejectors for vstol lift. After the fiasco of the XFV-12A, following on the failure of the XV-4A (it had to be rebuilt as the XV-4B with a battery of lift jets to do any vstol ops), you'd think people would finally realize that there's a fatal disconnect as you scale up from wind tunnel to full scale.

 

[overscan (PaulMM)]

Moved to own topic

 

[overscan (PaulMM)]

E-2, E-3, E-4, E-5, E-6, E-7

 

[overscan (PaulMM)]

E-7 profiles and warload.

From GD NASA contractor report:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/9840019625_1984019625.pdf

 

[overscan (PaulMM)]

Interesting angle here. Cranked wing suggests maybe E-3/DFE?

 

[hesham]

Hi,

and from Flightglobal;
http://www.flightglobal.com/pdfarchive/view/1988/1988%20-%200935.html
http://www.flightglobal.com/pdfarchive/view/1988/1988%20-%200639.html

 

[hesham]

Hi,

E-7 from NASA;

http://www.iasa.com.au/folders/Publications/pdf_library/ospreypdfs/ar93.pdf

 

[ysi_maniac]

Source: Joint Strike Fighter by Bill Sweetman

 

[overscan (PaulMM)]

From http://ails.arc.nasa.gov

 

[Skyraider3D]

Interesting NASA report: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900002435_1990002435.pdf


Here are further General Dynamics STOVL fighter designs, which may be related to the above F-16 lookalike:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810014497_1981014497.pdf

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790001853_1979001853.pdf

There appear to be many more reports related to General Dynamics STOVL fighter designs from around the 1980 period.


Thanks for moving my post! I suspected there would be a topic on the subject already, but didn't find it.

 

[overscan (PaulMM)]

NASA model of E-7

http://crgis.ndc.nasa.gov/historic/Additional_Photos_for_30_X_60_Full_Scale_Tunnel:_Other_Tests#E-7A

 

[Stargazer]

Have these been added?? When I indexed all the pics at CRgis two months ago, I don't recall seeing these...

 

[overscan (PaulMM)]

I don't think so - I recall them being there before, just didn't post at the time.

 

[hesham]

Hi,


was that from General dynamics E series ?.

 

[hesham]

Hi;


http://airborn12.com/extras/attack_aircraft.html

 

[flateric]

it's just very poor artist's representation by David Palmer (Salamander Books 'An illustrated Guide...' series) of one of E-series

 

[Stargazer]

Apparently, the E-7 design continued to be studied after Lockheed's takeover of General Dynamics.

Here is a 1995 report describing the "E-7D, an ejector-augmentor powered-lift aircraft designed by Lockheed Fort Worth Company (LFWC)", subcontracting to General Electric Aircraft
Engines (GEAE). The E-7D is said to differ from the earlier E-7A in details of the propulsion system, and having a more complex engine and a DMICS-based flight-control system.

Moving Base Simulation of an Integrated Flight and Propulsion Control System for an Ejector-Augmenter STOVL Aircraft in Hover, June 1995
NASA Technical Memorandum 108867, NASA Ames Research Center

 

[cqya888]

Ťhanks

 

[Sundog]

Interesting angle here. Cranked wing suggests maybe E-3/DFE?

I just read this post. That appears to me to be a modified F-16XL converted into a demonstrator for the program, rather than building an entirely new airframe.

 

[Fluff]

I once found this photo in the net, unfortunately I haven't
the link anymore. The E-7 seems to be based on a vectored
thrust engine .

The E-7 VTOL concept relied on a thrust deflector at the rear and Thrust Augmented Ejectors near the front.

Air was diverted from the rear of the engine to the front via a long pipe and ejected down - balancing the thrust deflected at the rear.

There are some NASA PDFs on featuring the E-7 on the web:

V/STOL and STOVL Aerodynamic Performance:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840014468_1984014468.pdf

VSTOL Concepts Past, Present and Future:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840014464_1984014464.pdf

Wave-Drag and High Speed Performance of Supersonic Fighter Configurations:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890000646_1989000646.pdf

Looks like a lot of interesting stuff in them - I just haven't had time for more than a quick browse.

Starviking

Somewhat surprised in the past present document, they describe the AV8B, the key feature(to me) is the front nozzles are cold, the rear are hot - doesn't get a mention.

If your job is to summarise different ideas that seems worth mentioning.

This E7 routing hot air forward then down, seems like a lot of work, those ducts look draggy. Appreciate it was POC.

 

[asiscan]

I

Interesting angle here. Cranked wing suggests maybe E-3/DFE?

I just read this post. That appears to me to be a modified F-16XL converted into a demonstrator for the program, rather than building an entirely new airframe.

Yes seems to be a vestigial feature from the F-16E/"SCAMP" and later the "XL". The E-7A routed cool fan air forwards to the wing root ejectors, while the E-7D used a mixed flow (cool bypass air and hot core air) for the same effect.. nothing. Claims that the ejector could increase the fan flow by 50% seem (I say hesitantly) - overblown.. Sounds too much like a repetition ofthe failings of the XV-12A. The magical "entrainment" effect and getting more from less scuttled many concepts, particulary the Avro Canada efforts of the 1950-60. Even so, a very interesting concept if it could work.

 

[hesham]

From Krila 3/1988.

 

[asiscan]

Nice find Hesham! Thanks. All the pictures I have seen of the E-7 have never shown wing twist.
I don't know if this has already been mentioned but what I have found is:

- E-7A: Part of US/Canadian ejector program. With Rolls-Royce "Spey" engine (possibly RB-168-25R Mk-202/3).
- E-7B: Part of US/Canadian ejector program. With General Electric F110 engine. Aft fan nozzle deleted.
- E-7C: Mixed fan and core engine air flow. Axisymmetric gimballed core stream nozzle directly aft of vectoring lift nozzle.
- E-7D: Mixed fan and core engine air flow. 2 dimensional, convergent-divergent vectoring aft nozzle directly aft of vectoring lift nozzle.

Of course these were all just proposed static research examples.

 

[Apophenia]

... E-7A: Part of US/Canadian ejector program. With Rolls-Royce "Spey" engine (possibly RB-168-25R Mk-202/3)...

Under the US/Canada Focused Ejector Technology Program, the de Havilland division of Boeing Canada built a full-scale wind tunnel model of the E-7A. As you say, it was that model which had powered generated by "a Rolls-Royce 'Spey' engine obtained from a previous research program."*

So, the Spey was something that NASA had in stock. Rather than ex-RAF Phantom engines, the powerplant would more likely be the Spey MK 801-SF (Split Flow) - a Spey Mk 611 previously modified by Rolls-Royce (Canada) for NASA's AWJSRA (V/STOL Buffalo) programme. Removing that engine's transition section, colander-plate connector, and bifurcated Pegasus Mk.5 nozzles wouldn't have been difficult.

BTW: the plan for the full-scale powered wind tunnel model was to return it to DHC for a rebuild into a Phase II configuration with an F110 replacing the Spey and a 2D-CD nozzle to represent the E-7D rather than an E-7A.

* Configuration E-7 Supersonic Fighter/Attack Technology Program, John E. Jenista & David S. Bodden, General Dynamics Fort Worth Division, 1988, page 3

 

[asiscan]

... E-7A: Part of US/Canadian ejector program. With Rolls-Royce "Spey" engine (possibly RB-168-25R Mk-202/3)...

Under the US/Canada Focused Ejector Technology Program, the de Havilland division of Boeing Canada built a full-scale wind tunnel model of the E-7A. As you say, it was that model which had powered generated by "a Rolls-Royce 'Spey' engine obtained from a previous research program."*

So, the Spey was something that NASA had in stock. Rather than ex-RAF Phantom engines, the powerplant would more likely be the Spey MK 801-SF (Split Flow) - a Spey Mk 611 previously modified by Rolls-Royce (Canada) for NASA's AWJSRA (V/STOL Buffalo) programme. Removing that engine's transition section, colander-plate connector, and bifurcated Pegasus Mk.5 nozzles wouldn't have been difficult.

BTW: the plan for the full-scale powered wind tunnel model was to return it to DHC for a rebuild into a Phase II configuration with an F110 replacing the Spey and a 2D-CD nozzle to represent the E-7D rather than an E-7A.

* Configuration E-7 Supersonic Fighter/Attack Technology Program, John E. Jenista & David S. Bodden, General Dynamics Fort Worth Division, 1988, page 3

Thanks for clarifying Apophenia.
I wasn't sure about the "Spey" model, but i've concluded that either way the rolls-royce rig wold need modding..
just found it (RR Spey 801-SF) here:

NASA Technical Memorandum

books.google.com.au

 

[asVAL]

So apparently NASA organized an auction for a whole load of experimental aircrafts and this guy bought the E7 model.

View: https://www.youtube.com/watch?v=YBxfFbPpEUE

 

[asiscan]

So apparently NASA organized an auction for a whole load of experimental aircrafts and this guy bought the E7 model.

View: https://www.youtube.com/watch?v=YBxfFbPpEUE

I don't think it will be going anywhere anytime soon

 

[Scott Kenny]

E-7 was yet another design intended to use exhaust-driven ejectors for vstol lift. After the fiasco of the XFV-12A, following on the failure of the XV-4A (it had to be rebuilt as the XV-4B with a battery of lift jets to do any vstol ops), you'd think people would finally realize that there's a fatal disconnect as you scale up from wind tunnel to full scale.

Pardon the ancient response, but I suspect that a lot of the failure with the XFV-12 augmentors was the rough interior of the pipes. For cost reasons the insides of the pipes weren't cleaned up, when the part of the pipes that needed to be smooth to not reduce airflow was the interior, not the exterior!

I get that the prototype was built on the super cheap, but having the thing fail possibly because the builder cheaped out in the wrong place just annoys me to no end.

 

[VTOLicious]

Pardon the ancient response, but I suspect that a lot of the failure with the XFV-12 augmentors was the rough interior of the pipes. For cost reasons the insides of the pipes weren't cleaned up, when the part of the pipes that needed to be smooth to not reduce airflow was the interior, not the exterior!

I get that the prototype was built on the super cheap, but having the thing fail possibly because the builder cheaped out in the wrong place just annoys me to no end.

Do you have any references? Or is this pure speculation?

 

[Scott Kenny]

Do you have any references? Or is this pure speculation?

There's comments in the XFV-12 thread about the inside of the pipes being rough.