General Dynamics ATS, pre-ATF and ATF designs

[quellish]

The straight trailing edge on the A-12 and Sneaky Pete complicates RCS reduction as it will give a spike directly forward and directly aft, not ideal locations. Presumably they were relying on deep RAM in leading and trailing edges to counteract that (though this isn't really evident in the inboard profiles) but the blunt convex leading edge wing would give more radar return compared to the scalloped profile of the B-2, YF-23 etc edges.

The A-12 detail drawings show no alignment of panel edges with the wing geometry, and the overall "stealth" technology appears no different from Dan Raymer's Delta Spanloader for Rockwell. The landing gear doors, weapons bay doors etc would create additional spikes front, 90 deg abeam each side, and to the rear, for 7 major RCS spikes, not to mention the canopy.

Exactly. Yet this was touted as a VLO design by GD and ASD. This could have been partly because ASD was not fully read into HAVE BLUE, and this was a completely parallel project. Nonetheless, even with deep RAM it does not seem likely that they would have gotten a a huge reduction. These are essentially the same techniques that the Teledyne/McD team used for HAVE BLUE, and Teledyne had been using on their products. Better than nothing, but not the huge reductions seen with the Lockheed and Northrop efforts on HAVE BLUE.
Unless there was something else to it that's not obvious, though if there was why stick to the configuration for so long?

 

[LowObservable]

The CONOPS for the A-12 was rather different from that of the F-117. It had two crew, radar with an air-to-air mode, a very good ESM, a standard defensive armament of AIM-120s and AGM-88s, and it was closely associated with a standoff weapon designed for internal carriage - AIWS, which later became JSOW. So the idea was a combination of LO, situational awareness, self-defense and standoff.

 

[Sundog]

Also, don't forget, the Navy not having any operational knowledge of actually using VLO stealth like the USAF had with the F-117, the Navy was still planning to use NOE flight with the A-12, which is why they had the exhaust/nozzle blocked from above. IIRC, the USAF version of the A-12 was going to have the exhaust/nozzle on the top, since they didn't have any plans of dropping below 20K ft. operationally.

 

[flateric]

from www.codeonemagazine.com

 

[Triton]

Model of General Dynamic ATF submission.

General Dynamics took a unique approach to the sensor requirements, using two radar arrays and one infrared search and track sensor. (Boeing and Lockheed had each used three arrays and two IRST sensors.) One IRST sensor was placed in the nose of the aircraft and the two radar arrays were located aft of the cockpit. The radar beam from each array could be steered sixty degrees from the face of the array, allowing each radar to cover the area from straight ahead to 120 degrees aft. The arrays were located just above the engine inlets.

Source: http://www.codeonemagazine.com/article.html?item_id=40

 

[Triton]

General Dynamics studied a wide range of advanced fighter concepts and modifications to existing fighters. Advanced derivatives of the F-16, F-15, and F-111 competed with the new concepts for the same missions. The advanced concepts included a conventional aircraft called "Plain Jane," a supersonic stealth configuration, a small inexpensive fighter called "Bushwhacker," a large fighter called "Missileer" that could carry many long-range air-to-air missiles, and a highly stealthy all-wing fighter called "Sneaky Pete," which eventually evolved into the Navy's short-lived A-12 Avenger II.

The ability to operate an aircraft from battle-damaged runways was yet another characteristic evaluated in the early ATF studies of the 1970s and 1980s. Designs incorporating this capability are referred to by a number of terms, including short takeoff and landing, short takeoff and vertical landing, and vertical takeoff and landing (STOL, STOVL, and VTOL, respectively). The benefits of abbreviated takeoffs and landings are, however, less clear than benefits associated with stealth, speed, and maneuverability.

"Short Snort"and "Jiminy Cricket" were two General Dynamics designs that addressed short takeoff and landings more directly. Short Snort vectored thrust from the engine over the wing to produce a fighter with runway requirements of only a few hundred feet. The concept employed ducts and ports that diverted engine exhaust out spanwise along the top of the wing. The approach generated tremendous amounts of lift at very low speeds. The ducting, however, was very heavy, and ultimately proved impossible to incorporate in a high-performance supersonic fighter.

Jiminy Cricket attacked the short takeoff and landing problem with multiple engines. The design had a main lift-cruise engine that provided thrust for lift and for up-and-away flight, and it had auxiliary engines mounted vertically that provided lift for takeoffs and landings only. The aircraft could have either short or vertical takeoff capability, depending on the size of the engines.

Source: http://www.codeonemagazine.com/article.html?item_id=40

 

[Triton]

Source:
http://www.militaryphotos.net/forums/showthread.php?166065-YF-23-Black-Widow-II-pictures/page8

[Correction: pictures below are taken from Jay Miller's F-22 Raptor Aerofax book. This is a "must buy" for anyone interested in the F-22. - Admin]

 

[Triton]

Was it this book overscan?

Miller, Jay Lockheed Martin A/F-22 Raptor: Stealth Fighter - Aerofax Midland (August 7, 2005)

There is another Aerofax F-22 book published in 1992 written by Richard Abrams and Jay Miller.

 

[InvisibleDefender]

Can anybody identify this? I have no idea where it came from or when it was drawn... ???

 

[aim9xray]

Rockwell, CAS/Strike study from the very early 80's. You *really* need to get Dan Raymer's autobiography!

 

[InvisibleDefender]

Assuming you mean this one?

Living in the Future: The Education and Adventures of an Advanced Aircraft Designer

 

[aim9xray]

Roger that, Ghostrider! ;D

 

[flateric]

generic GDFW advanced fighter from Chaput, Armand J., Pawloski, Richard A., “Design Considerations for the Next Generation Fighter”,
AIAA 1983-2454
AIAA Aircraft Design Systems and Operations Conference
October 1983

 

[Stargazer]

Not sure if this has been posted on the forum before. It is a chart depicting the evolution of the ATF design that led to the YF-22.

 

[Stargazer]

These appeared in a 1981 article from AW&ST.
I have extracted the text from the article and affixed it to each picture.

 

[sferrin]

Imagine this sucker with a pack of Westinghouse/GD AAAMs. This is what's needed for the Pacific.

 

[TomS]

Imagine this sucker with a pack of Westinghouse/GD AAAMs. This is what's needed for the Pacific.

They certainly do seem to be AAAMs in that pack. Do we know anything more about this design (other than Code One article's assertion that it did not rate well inn the Air force assessments)?

 

[sferrin]

Imagine this sucker with a pack of Westinghouse/GD AAAMs. This is what's needed for the Pacific.

They certainly do seem to be AAAMs in that pack. Do we know anything more about this design (other than Code One article's assertion that it did not rate well inn the Air force assessments)?

Looking at the picture, I wonder if the fairing area in front of the launcher is a magazine for more missiles. Looks big enough.

 

[Stargazer]

Looking at the picture, I wonder if the fairing area in front of the launcher is a magazine for more missiles. Looks big enough.

I couldn't say, but it sure looks to me like a dead giveaway in terms of RCS!

 

[TomS]

This design apparently came out of a study of specifically air-to-air fighters (there was a separate study of air-to-ground designs).

I was wondering the same thing about a second weapon bay, but I suspect the volume was needed for fuel or electronics.

 

[chuck4]

These appeared in a 1981 article from AW&ST.
I have extracted the text from the article and affixed it to each picture.

Seems like either intentional disinformation, or highly speculative fan art to me. Why the big bulky weapon boxes under the fuselage? What's with the shock cone intakes? Looks like someone with drawing skills playing with the F-16XL concept.

 

[sferrin]

Well, it is similar to other companies' speculative artwork in the pre-ATF period. There were numerous studies examining aircraft and weapons optimized for both air to air and air to ground scenarios, and both short-range and longer-range variants. A lot of designs were optimized for high-altitude supercruise and the shock cones, wing planforms, etc. represented the conventional wisdom of how to do that at the time.

As for the F-16XL, I think that was somewhat in the future, although SCAMP was underway.

In fact the more commonly known Rockwell ATF concepts resembled this GD design (half-cones and all).

 

[overscan (PaulMM)]

These appeared in a 1981 article from AW&ST.
I have extracted the text from the article and affixed it to each picture.

Seems like either intentional disinformation, or highly speculative fan art to me. Why the big bulky weapon boxes under the fuselage? What's with the shock cone intakes? Looks like someone with drawing skills playing with the F-16XL concept.

Nope, serious concept from General Dynamics. This is before the ATF was going to be VLO, remember? This design is optimised for supercruise performance with a full payload of AAMs. Instead of an internal bay, the "Missileer" had this external missile launcher concept. Low drag, not low RCS, was the driver.

 

[overscan (PaulMM)]

These appeared in a 1981 article from AW&ST.
I have extracted the text from the article and affixed it to each picture.

Thanks. Note that we did have a better copy of that image already in the topic in the previous page.

 

[overscan (PaulMM)]

The Missileer was designed around the GD Pomona AAAM:

Note the box launcher.

 

[overscan (PaulMM)]

Better copy of image earlier in topic. From defunct site www.­dodmedia.­osd.­mil

Still uncertain if this is a genuine study or not.

 

[overscan (PaulMM)]

.

 

[overscan (PaulMM)]

General Dynamics ATAMS and ASF studies

Source: AIAA Paper 1981-1504 ATES Status at Detroit Diesel Allison, R. Wood

 

[robunos]

THat GD-ASF study looks a lot like a SCAMP version...

cheers,
Robin.

 

[donnage99]

What is the aerodynamic implications with the gigantic sawtooth wing flaps anyone knowledgeable care to shed some light?

 

[Sundog]

What is the aerodynamic implications with the gigantic sawtooth wing flaps anyone knowledgeable care to shed some light?

I don't see a saw tooth leading edge on any of these designs. Please clarify.

 

[donnage99]

What is the aerodynamic implications with the gigantic sawtooth wing flaps anyone knowledgeable care to shed some light?

I don't see a saw tooth leading edge on any of these designs. Please clarify.

I meant the trailing edge


Picture on post 21 posted by hesham

 

[Stargazer]

What is the aerodynamic implications with the gigantic sawtooth wing flaps anyone knowledgeable care to shed some light?

I don't see a saw tooth leading edge on any of these designs. Please clarify.

I meant the trailing edge


Picture on post 21 posted by hesham

So basically you were making a comment on a post dated June 12, 2010, to be found four pages and 53 posts before this one, and expecting everyone to know exactly what you were talking about??!! Gosh! Next time think of right-clicking on the post's title, then copy the link and repaste, it will make things easier...

 

[Sundog]

What is the aerodynamic implications with the gigantic sawtooth wing flaps anyone knowledgeable care to shed some light?

I don't see a saw tooth leading edge on any of these designs. Please clarify.

I meant the trailing edge


Picture on post 21 posted by hesham

Those are just that way for stealth reasons. I would think they would generate somewhat more drag than straight trailing edges, as it seems to me you would get vortices off of the apexes with enough deflection. Conversely, it might also imbue them with more control power as a result. But I haven't seen any research on it, so those are just my best guesses, at least with regard to their aerodynamics.

 

[shedofdread]

In motorsport, wavy TEs [when viewed from above] are used to increase Clmax and therefore downforce. The +ve pressure is 'leaking' through to the suction side of the aerofoil and re-energising the boundary layer near the TE thus maintaining attachment to a higher alpha. In aviation, this might give increased roll rate, decreased take-off run, increased take-off mass etc etc.


The scale at which those on the drawing are done (they're a bit big) makes me think that this is NOT the case here. It's probably something LO related...

 

[hesham]

From, X-planes secret aircraft and secret missions,

in colors.

 

[hesham]

The colours are added for the book, not original, so add no value.

OK my dear Paul.

 

[icyplanetnhc (Steve)]

It's interesting that the EMD/production F-22 fuselage/wing configuration superficially appears to have much in common with that General Dynamics' ATF submission, except for the tail/empennage configuration. One has to wonder how much the Lockheed/Boeing/GD team leveraged the work from GD's ATF during their summer 1987 redesign, and it wouldn't surprise me if it borrowed a substantial amount. Several sources have described the F-22's wings as delta wing, especially with how little mass and volume is behind the trailing edge, and the aircraft certainly resembles a tailed version of GD's delta wing submission (it appears that maneuver and supercruise drove GD's design more than stealth especially in the trailing edge, likely due to a lack of experience compared to Lockheed or Northrop).

EDIT: F-22 for comparison to illustrate the similarities.

 

[Sundog]

It's interesting that the EMD/production F-22 fuselage/wing configuration superficially appears to have much in common with that General Dynamics' ATF submission, except for the tail/empennage configuration. One has to wonder how much the Lockheed/Boeing/GD team leveraged the work from GD's ATF during their summer 1987 redesign, and it wouldn't surprise me if it borrowed a substantial amount. Several sources have described the F-22's wings as delta wing, especially with how little mass and volume is behind the trailing edge, and the aircraft certainly resembles a tailed version of GD's delta wing submission (it appears that maneuver and supercruise drove GD's design more than stealth especially in the trailing edge, likely due to a lack of experience compared to Lockheed or Northrop).

The F-22's wing is a modified delta. A delta wing basically means it has a triangular shape in planform, it's just the trailing edge is slightly swept forward on the F-22. It doesn't have anything to do with whether or not the aircraft has a horizontal tail. The MiG-21 is one of the most famous delta winged aircraft around and it had a horizontal tail. But, I understand that most people think of tailless designs when they think of delta wings.

 

[red admiral]

One has to wonder how much the Lockheed/Boeing/GD team leveraged the work from GD's ATF during their summer 1987 redesign, and it wouldn't surprise me if it borrowed a substantial amount.

Massively as the various materials (e.g. CodeOne magazine) make clear.

The GD team came in and basically re-did the flying surfaces and centre fuselage. LM's original concept had a single bay with bomber-style rotating dispenser...

Likewise Boeing did loads on the Avionics front