AFFDL Tactical High Altitude Penetrator (THAP)

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I wanted to see if anybody had more information about the "Tactical High Altitude Penetrator" sketch that's been in the public view for several years. The earliest reference to it that I can find comes from Bill Sweetman's 1986 book "Stealth Aircraft." It's attributed to the USAF Aeronautical Systems Division c. 1980.

If THAP is an internal USAF design study, I would suspect that it was generated by people who were not aware of SENIOR TREND or any of the other active stealth programs during the time of the study.
 

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CFE said:
I wanted to see if anybody had more information about the "Tactical High Altitude Penetrator" sketch that's been in the public view for several years. The earliest reference to it that I can find comes from Bill Sweetman's 1986 book "Stealth Aircraft." It's attributed to the USAF Aeronautical Systems Division c. 1980.

If THAP is an internal USAF design study, I would suspect that it was generated by people who were not aware of SENIOR TREND or any of the other active stealth programs during the time of the study.
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Yup.
 
I've seen the Zinnegrabe TR-3 page before, but there's little in the way of verifiable facts. It's not even certain that THAP was the result of a Northrop study. If I had to guess, THAP was probably studied during the mid-70's around the time of XST. It certainly predates Northrop's early ATB studies and their method of aligning the leading and trailing edges to dissipate radar returns.
 
The source reference for this is:

Flight Vehicle Technology for Aerospace Systems 9th Edition, Page 40

Drawing was then in Interavia in 1981.
 
If it was truly a Northrop study, then it may well have "disappeared" from public view along with any other recent flying wing work when Northrop got the ATB contract.
 
CFE said:
I've seen the Zinnegrabe TR-3 page before, but there's little in the way of verifiable facts. It's not even certain that THAP was the result of a Northrop study. If I had to guess, THAP was probably studied during the mid-70's around the time of XST. It certainly predates Northrop's early ATB studies and their method of aligning the leading and trailing edges to dissipate radar returns.
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Only one "e", please.
There is little in the way of verifable facts on THAP period. I had to do a *lot* of digging to find that single reference, and before and after that had filed a number of FOIA requests. I am now on the same page as Overscan - that THAP was more related to the ATB programs than not. It now seems very unlikely that a "TR-3" or flying THAP demonstrator ever flew, especially with SNEAKY PETE to account for so many of the eyewitness sightings at the time.
The TR-3 legend was born mostly of those sightings and the vivid imaginations of two persons who for now will remain nameless. THAP existed at least as a study. TR-3 likely did not exist at all. While there is some evidence still that there was a requirement for such an aircraft, it does not seem likely that anything was built.


If THAP was studied at the time you are suggesting it would most likely have been attached to the ASTEI programs that lead to HAVE BLUE. THAP, though, is almost identical to a TR RPV design of the same period, though manned and scaled up. It seems likely at this point that USAF created a paper THAP based on the TR work for the LO studies of the time. Knowing what is in the public domain now about signature reduction, it is actually easy to say that THAP would not have worked very well at all.
 
for those who dont understand, Zinngrabe = Quellish

well, this project was always a mystery for me...
 
Food for thought?

Top: Northrop Low Altitude Penetrator
Middle: Tactical High Altitude Penetrator
Bottom: Northrop High Altitude Penetrator

HAP intakes, exhausts, tails are all very similar to THAP.
 

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The radar plot and information in the Teledyne patent is pretty interesting. Its a three lobe design like the A-12.

"A radar return from such a target would be no more than a momentary flicker, similar to that from a bird or other insignificant object".
"Tests have shown that such an aircraft can have a radar cross section of as little as 1% of that of a conventional type of aircraft in the same performance class"
 
Thanks for the interesting discussion up to this point, especially the contrast between THAP and the acknowledged "penetrator" designs from the early stages of SENIOR ICE. I would be surprised if there wasn't a link between the cited Teledyne-Ryan patent and the THAP schematic.

I'm not too surprised that a FOIA search turned up nothing on THAP. It seems like the standard Air Force practice is to slap "For Official Use Only" on everything. That way you can conceal it from the public without going through the hassle of making it classified. (You can tell that I have a very cynical perspective on DoD security policy.)

I also share the view that much of the TR-3 lore comes from the actual Tier-III program, but I'd be skeptical about "Sneaky Pete" making it to flight stage without some kind of photographic evidence.
 
CFE said:
I also share the view that much of the TR-3 lore comes from the actual Tier-III program, but I'd be skeptical about "Sneaky Pete" making it to flight stage without some kind of photographic evidence.
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Why? The facilities at Groom Lake exist almost exclusively to protect "sight sensitive" projects. This would include a flying dorito in the 1980s. No observer caught TACIT BLUE, SENIOR TREND, Bird of Prey, TSSAM, SENIOR PROM or any number of other known secret projects on film while the programs were covert. A lack of a photograph does not mean there is a lack of something to photograph.

I would have to check The Big Box in the Closet, but I think the reference cited above actually came from one of my FOIA requests. It was either that or many hours in a particularly restrictive library. I do have copies of the source page somewhere.
 
quellish said:
If THAP was studied at the time you are suggesting it would most likely have been attached to the ASTEI programs that lead to HAVE BLUE.
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Does it excuse quellish, but thing they are the ASTEI programs? And that relationship they have with Have Blue.
 
rocketman said:
quellish said:
If THAP was studied at the time you are suggesting it would most likely have been attached to the ASTEI programs that lead to HAVE BLUE.
Click to expand...

Does it excuse quellish, but thing they are the ASTEI programs? And that relationship they have with Have Blue.
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Air To Surface Technology Evaluation and Integration was one of the USAF studies around 1976 that generated interest in pursuing very low RCS aircraft. ASTEI was one of the studys that lead to HAVE BLUE, it investigated the maturity of certain technologies that lead to the Air Force deciding that a low RCS aircraft may be feasible.
 
Slightly OT, but if Sneaky Pete is truly out there, would it have retired a lot of the risk that GD and McDD encountered on the A-12 program? If Sneaky Pete/Model 100 had flown prior to the A-12 proposal, I think GD could have come up with more realistic mass estimates for what eventually became an overweight airplane.
 
CFE said:
Slightly OT, but if Sneaky Pete is truly out there, would it have retired a lot of the risk that GD and McDD encountered on the A-12 program? If Sneaky Pete/Model 100 had flown prior to the A-12 proposal, I think GD could have come up with more realistic mass estimates for what eventually became an overweight airplane.
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Doubtful. The requirements for the A-12 were a far cry from anything Sneaky Pete would have been designed for. Northrop's team had the same issues - driven by the requirements - and bowed out of the program.
 
Matej said:
quellish said:
...especially with SNEAKY PETE to account for so many of the eyewitness sightings at the time.
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It means that Sneaky Pete was build and flew?
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It is very likely that a Sneaky Pete demonstrator flew, as a project of USAF Aeronautical Systems Division - which was an outsider to the DARPA VLO programs. Sneaky Pete's configuration was actually fairly mature by 1977, when the ATS/ASTEI studies were conducted (it figures prominently in a number of the studies that lead to the ATF requirements). DARPA and ASD didn't share much information, and it's not likely that ASD (with Sneaky Pete) got the level of signature reduction that HAVE BLUE did. Sneaky Pete was considered state of the art by ASD until the early 80s, but ASD did not know that had been well surpassed.

Going into the A-12 program, GD thought that the work on the Sneaky Pete concept (under COLD PIGEON/Model 100/VX-11/HAVE KEY, at various times) gave them a leg up in the stealth game. As it turns out, it didn't. GD thought they were prepared to meet aggressive signature and weight goals given their experience with Sneaky Pete, but it turned out they were unprepared. GD's team needed access to more modern tools and materials for the A-12, and didn't get them - which is part of what the A-12 lawsuits are about.

If Sneaky Pete were to become public knowledge, the lawsuit could become a lot more complicated.
 

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Very interesting, thanks. It is ironical that G.D. could not have access to data on Have Blue/F-117 but eventually got absorbed into the Lockheed company...
 
Stargazer2006 said:
G.D. could not have access to data on Have Blue/F-117 but eventually got absorbed into the Lockheed company
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Cause and effect?
 
PaulMM (Overscan) said:
Food for thought?

Top: Northrop Low Altitude Penetrator
Middle: Tactical High Altitude Penetrator
Bottom: Northrop High Altitude Penetrator

HAP intakes, exhausts, tails are all very similar to THAP.
Click to expand...




Note especially the internal metallic structure. This vehicle was part of a DoD funded low RCS vehicle study that grew out of Ryan's Mini-RPV work (the manta, model..... 262?). The low RCS study itself is on the GWU national security archive with the illustrations redacted.


THAP certainly looks like an evolution of Ryan's previous RCS reduction efforts.
 

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"Surface to air missile (SAM) system threats were analyzed to determine which ones were viable threats and under what conditions they would be a threat to a very low signature, very high altitude aircraft (THAP ). The cost of balloon-borne expendable jammers targeted against search and height finder radars to aid the penetration of THAP was calculated. The first task determined which SAM systems could engage THAP. The second task evaluated tactics and countermeasures which would be appropriate to prevent successful engagements of THAP by SAM systems. To evaluate tactics and countermeasures to protect THAP, digital electronic warfare models updated to 1990 threat systems were used with aircraft radar cross section (RCS) estimates provided by AFAL, and aircraft altitude, speed, and roll estimates provided by AFFDL. The costs of expendable jammer systems to adequately protect THAP in a specified corridor as a function of conflict duration were calculated. Computation of penetration aid costs involved parametric balloon borne expendable characteristics (electronics, batteries, and platforms) provided by ASD, AFAPL, and AFFDL and standard meteorological data. Estimates of the costs of aircraft to deliver the penetration aids were made assuming the very low signature aircraft were used to dispense the expendable jammers."

Release balloons with jammers, I mean.... obviously.
 
Interesting piece from GlobalSecurity, suggesting that "TR-3A" was a Technical Refresh of an existing programme and not a Tactical Reconnaissance aircraft designation. It might therefore have been the third technical refresh of the THAP programme. I have certainly seen TR- designations used in this context elsewhere.

Mystery - TR-3A

www.globalsecurity.org www.globalsecurity.org
 
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The program reported upon in this document was conducted as part of
Project 2404 " Aeromechanics Technology" by the Air Force Flight
Dynamics Laboratory , Aeromechanics Division , Aerodynamics and Airframe
Branch ( AFFDL / FXM ) . Mr. Russell F. Osborn and Lt. Charles R. Gallaway
were Project Engineers .

The objective of the program was to quantify the unpowered aero
dynamic performance of an air vehicle designed for low radar cross
section characteristics .

Wind tunnel testing during this program was conducted at Arnold
Engineering Development Center, Propulsion Wind Tunnel Facility.
Special acknowledgement is given to Mr. P. L. Yeakley who served as
Test Engineer for the project.
Click to expand...

INTRODUCTION
Recent Air Force interest in low signature aircraft has lead to the
development of several air vehicle designs of unconventional aerodynamic
shape . The Tactical High Altitude Penetrator ( THAP ) configuration is one
of these designs .
The THAP design was conceived and developed by the Design Branch of
the Aeromechanics Division with radar and infrared detection considerations
overshadowing aerodynamics . The unorthodox planform and airfoil shape
which resulted did not lend itself well to aerodynamic analysis . This
lead to an exploratory test of the THAP configuration in the Trisonic
Gasdynamics Facility ( Reference 1 ) . Data from this program supported a
configuration development effort which resulted in the current THAP shape
illustrated in Figure 1. This configuration was tested in the Arnold
Engineering Development Center Aerodynamic ( AEDC ) Wind Tunnel ( 4T ) .
Three model configurations : wing alone , wing with two vertical
stabilizers ( V - Tail ) and wing with T - Tail were investigated in the
AEDC test . Data were collected over an angle - of - attack range from
-2 to 10 degrees ( 18 degrees at Mach 0.40 ) at sideslip angles between
-10 and 5 degrees . Stabilizer settings of -5 , 0 and 5 degrees were
investigated on the T - Tail configuration to acquire pitch control
characteristics . Boundary layer and surface flow characteristics
were obtained using fluorine sublimitation and oil flow techniques .
Click to expand...

TEST PURPOSE
1. NEW THAP AIRFOIL SECTIONS
The primary purpose of the 4T wind tunnel test program was to
quantify aerodynamic characteristics of the current THAP configuration
which utilizes an airfoil section designed specifically for low radar
signature . Figure 2 dimensionally and pictorially defines this airfoil .

The airfoil shown is significantly different from the one used on
the Reference 1 model . The Reference 1 airfoil was a NASA 66-212 which
has a 0.95 percent chord leading edge radius . The THAP airfoil , on the
other hand , was designed with a much smaller 0.225 percent L.E. radius
and only one percent camber . A comparison of the two airfoil geometries
is shown in Figure 3 .

At the same time the THAP wind tunnel test was taking place , a
second test of the Reference 1 model was being conducted in the AFFDL
Trisonic Gasdynamics Facility ( Reference 2 ) . An important part of this
test was to determine the impact of leading edge radius variation on
THAP aerodynamics. Results of this test effort show a reduced leading
edge radius has minimal effect on cruise performance .
2 .
Click to expand...
 
This is actually one of the documents I have been trying to get via FOIA, Google apparently scanned a library that held a copy.

THAP was apparently an internal USAF project. There is (so far) no documented connection to Northrop or Teledyne Ryan. It does have features that suggest Ryan lineage, but these may have been the USAF using the Ryan Low RCS Vehicle Study as a starting point for THAP.
 
Overall THAP tagline may sound like 'Someone at Wright-Patt was not briefed'
 
I had a copy of a Northrop Fellowship Program (circa 1990's) brochure with a triangular-shaped vehicle, looked like a wind tunnel model with rounded wing tips on the cover, gonna have to look for it.
 
Seems that the THAP WT photo was in AvLeak back then...
 
Must be why modellers thought F-19 was similar shape. Someone's lips were loose.

f19da_1.jpg
 
flateric said:
Seems that the THAP WT photo was in AvLeak back then...
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I think, but am not certain, that was a photo of something not at all related to THAP. Some other span loader concept
 
June 10, 1991 pp.20-21

"Wind tunnel tests were conducted on this model of a Tactical High-Altitude Penetrator (THAP) in 1976. The concept evolved into the U.S. Air Force TR-3A stealth reconnaissance aircraft that is believed to operate with Lockheed F-117A fighters."

Or did not. Well, it didn't.
 

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flateric said:
June 10, 1991 pp.20-21

"Wind tunnel tests were conducted on this model of a Tactical High-Altitude Penetrator (THAP) in 1976. The concept evolved into the U.S. Air Force TR-3A stealth reconnaissance aircraft that is believed to operate with Lockheed F-117A fighters."

Or did not. Well, it didn't.
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Yes, I don’t think that matches the THAP wind tunnel models in the AFFDL document
 
but why? shape and sting placement are the same, it's just turned up down
 

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overscan (PaulMM) said:
I brightened it up a bit. Its not the same shape exactly, for sure, but close.
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Two thoughts:
1) is that the shape of a canopy up front?
2) The "canopy" blends into a cylinder that runs to the trailing edge. It's a mating feature for the sting... but it's notably larger in diameter than the sting. Larger, it seems, than it would necessarily need to be. Could this mean the cylindrical "fuselage" might be an actual part of the design?
 

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