Assault on Bin Laden: mystery of the downed chopper

[LowObservable]

Not necessarily. LO generally involves compromises and the civil operator may not care enough about noise to accept them.

And then there's the rather obvious point that "quiet" in an urban, civilian environment is not the same as "quiet" when you're trying to get the jump on a twitchy foe in the middle of the night, in a mid-sized town in Pakistan.

 

[TomS]

Yes, according to most responsible and authoritative reporting going back to 1987.

Despite the absence of available noise reduction options/retrofits
for the S-70/UH-60 family + derivatives (S-76 and S-92)?

With ever tightening noise regulations, you should have seen something by now.

I'm not super familiar with helicopter noise regs, but it looks like the new, more stringent Stage 3 rules only apply to new helicopter types, so there may not be a pressing market for hushkits on existing aircraft.

Also, the lack of commercial S-70s might be a factor -- there really don't seem to be any true civilian users at all, just military and a few paramilitary or police users.

 

[TomcatViP]

And the S-70 is heavier. Built for the military. Heavier, more lift (at eq. representative rpm), more noise. It would be like comparing an armored car with a Prius.

 

[marauder2048]

And then there's the rather obvious point that "quiet" in an urban, civilian environment is not the same as "quiet" when you're trying to get the jump on a twitchy foe in the middle of the night, in a mid-sized town in Pakistan.

The CRH-60 has no acoustic reductions; is there a third type of "quiet" for CSAR?

 

[RavenOne]

Yes, according to most responsible and authoritative reporting going back to 1987.

Despite the absence of available noise reduction options/retrofits
for the S-70/UH-60 family + derivatives (S-76 and S-92)?

With ever tightening noise regulations, you should have seen something by now.

I'm not super familiar with helicopter noise regs, but it looks like the new, more stringent Stage 3 rules only apply to new helicopter types, so there may not be a pressing market for hushkits on existing aircraft.

Also, the lack of commercial S-70s might be a factor -- there really don't seem to be any true civilian users at all, just military and a few paramilitary or police users.

Yes there are a lot of former army UH-60A hitting the commercial marketplace ...in last few years.

And S-70i International Blackhawk entering service with likes of LA County FD, Polish Police etc

Here’s Heliops poster of all commercial UH-60A and S-70i

Cheers

 

[marauder2048]

And the S-70 is heavier. Built for the military. Heavier, more lift (at eq. representative rpm), more noise. It would be like comparing an armored car with a Prius.

The S-92 has the same growth rotor blades as the UH-60M in part because they reduce approach noise.

But there's no gain in level flight and it's sort of the low-hanging fruit of acoustic signature reduction.

My suggestion is that the big gains you need to really improve survivability aren't attainable in a
derivative re-hosting of Black Hawk mechanicals/powertrain.

 

[yasotay]

Of course most of the noise on a Blackhawk comes from the tail rotor. Followed closely at distance by the turbines, then the main rotor as you get closer. This is why I thought the very different tail rotor on the Bin Laden raid aircraft of interest.

 

[TomcatViP]

True. Blackhawk are difficult to detect by sound only until you are to be overflown. Then the sound is very rough until the bird fly in the distance.

@Marauder: you are certainly right. With more power (ITEP) and redesigned blades, they might theoretically have to ability to gain a lower rotor diameter, hence lower tip speed. Something that will impact the high pitch part of the noise.

 

[quellish]

Of course most of the noise on a Blackhawk comes from the tail rotor. Followed closely at distance by the turbines, then the main rotor as you get closer. This is why I thought the very different tail rotor on the Bin Laden raid aircraft of interest.

As I would think most readers of this forum would know, RF stealth is based on directing energy away from the receiver. An F-117 is hard to detect because the energy sent to it is reflected elsewhere, with very little sent back to where it came from. The same amount of energy is at work.

Acoustic stealth is (conceptually) similar. In the Hawaiian islands there are many helicopter tour operators. For years several used A-Stars. Not too loud but you did hear them coming. A few years ago some of those operators switched to "eco-stars" - partly for noise reasons. When they are flying straight at you.... yeah they might be quieter. But when they are flying past you, are in the distance, are turning away from you, etc. they are VERY loud.

The sound energy is focused in specific directions. It ends up being quiet from some directions, much louder from others. The SHHHHH-60 probably works in much the same way. The tail rotor works to *shape* the noise signature. The bad guys do not hear the helicopter until it is too late.

What we saw of the wreckage of the SHHHHH-60 clearly shows UH-60 internals. The outer skin may have been too burned to draw useful conclusions about what the outer mold line may have looked like, but significant portions of the main rotor and transmission were clearly from recent UH-60 products. The lack of any significant changes to the main rotor/rotor head was very curious in light of the *extensive* changes to the tail rotor.

 

[yasotay]

The rotor noise is a function of rotor speed (I believe) and is mostly generated off the tips of the rotor. So the faster turning tail rotor is propagating the sound fore and aft of the aircraft. Having been around Blackhawks for some time, i can tell you that you hear the tail rotor more pronounced than the main rotors even though on a quiet day you are likely to "feel" the low frequency of the main rotors near the same time. I believe this is why a MV-22 is very quiet compared to conventional rotorcraft in forward flight as the noise is propagating out the the side of the aircraft. In helicopter mode it is as loud as any helicopter I have ever been around.

 

[Jeb]

Blackhawks also have that distinctive cadence to their rotor beats. I imagine that the redesign of the tail rotor for the SSSSHHHawk (whoever called it that, I salute you) is as much about changing up the sound signature as anything. Imagine if you were able to adjust a helicopter's sonic signature to something more indigenous to the area, so that local observers would think it's just another one of their own helicopters flying around? That's a lot cheaper than a full-on stealth treatment and it nets you the same result, which is getting by without setting off alarms.

 

[Dynoman]

Interesting observations on stealth helicopter concepts from Vertical magazine. Covers the four signatures of radio frequency (RF), infrared (IR), acoustic and visual in the context of helicopter stealth.
https://www.verticalmag.com/features/hide-and-seek-html/

 

[Dynoman]

I have not seen any good pictures of the main rotor blades that would indicate active rotor control techniques, such as harmonic pitch control (HHC) or individual blade control (IBC) through small outboard flaps on the main rotor blades. However, piezoelectric material or shape memory alloys could have been used in the MRB to actively reduce noise and vibration as these technologies were developed in the late 1990's. Blue Edge demonstrated both modified tip sweep and IBC technologies to reduce rotor noise. Maybe someone has better pictures of the MRBs to make an assessment. The rotor mast probably had some form of masking as well (like the anti-torque rotor) to reduce gearbox noise, possibly similar to the RAH-66 or S-92.

 

[yasotay]

Main rotor hub that was standing in the middle of the wreckage appeared to be very much a standard H-60 rotor hub While there could have been much change to the blades they appear to have been mated to a standard hub.

 

[marauder2048]

I suppose if these birds were always intended for SOF missions they may have traded off some of the
more exotic acoustic signature minimizations under the premise that these missions would have
planning times sufficient to accommodate (computationally) very expensive but high-fidelity acoustic route planning.

The AH-64E was supposed to have a real-time acoustic footprint display which when combined with the
offline stuff from the planners could provide a real boost to survivability.

 

[500 Fan]

I have done a little research into the various experimental and prototype versions of the Hughes/MD500 and H-6 helicopters and a huge amount of the various technologies developed and tested by Hughes and McDonnell Douglas Helicopters between 1970 and 1990 have direct applications for use in an LO helicopter. Things like;

Development and flight-testing of quiet rotorcraft with the "Quiet One/500P and NASA/Rotonet 500E

Higher Harmonic Control (can allow the noise signature of the rotor to be "tuned")

Flight-testing of composite main and tail rotor blades

Experiments with fuselage constructed from composites

Reduced radar signature with systems like NOTAR (although not employed on the Bin-Laden Raider)

Expertise in engine exhaust IR reduction

When Hughes were acquired by McDonnell Douglas and the Phantom Works joined up with the expertise at Hughes, it certainly seems likely that they would have done some work on LO helicopters. The 1995 article in Aviation & Space Weekly seems to infer that MDHC might have had two different LO rotorcraft flying in the late 80's and early 90's. One might be an LO version of the MD500 and this might be the TE-K project that crops up on the web. What configuration the other helicopter was in is anyone's guess. Could the Bin-laden Blackhawk be based on this prior test work? Have a look at the topic over on the ARC Air Forum in the helicopter section on the Bin-Laden Raid helicopter. There are some interesting comments there that indicate that the helicopter used in Pakistan was a modified H-60.

In relation to the rotor system on the H-60 and in particular the S-92, it is anything but quiet! The SAR S-92 in Ireland lands at a hospital near where I live and I can hear it at least a solid minute before it appears as a dot in the sky. I'm not sure if disc-loading has anything to do with it but I read somewhere that the S-92 should really have been fitted with a 5-blade main rotor instead of a scaled-up system from the H-60.

500 Fan.

 

[RavenOne]

I have done a little research into the various experimental and prototype versions of the Hughes/MD500 and H-6 helicopters and a huge amount of the various technologies developed and tested by Hughes and McDonnell Douglas Helicopters between 1970 and 1990 have direct applications for use in an LO helicopter. Things like;

Development and flight-testing of quiet rotorcraft with the "Quiet One/500P and NASA/Rotonet 500E

Higher Harmonic Control (can allow the noise signature of the rotor to be "tuned")

Flight-testing of composite main and tail rotor blades

Experiments with fuselage constructed from composites

Reduced radar signature with systems like NOTAR (although not employed on the Bin-Laden Raider)

Expertise in engine exhaust IR reduction

When Hughes were acquired by McDonnell Douglas and the Phantom Works joined up with the expertise at Hughes, it certainly seems likely that they would have done some work on LO helicopters. The 1995 article in Aviation & Space Weekly seems to infer that MDHC might have had two different LO rotorcraft flying in the late 80's and early 90's. One might be an LO version of the MD500 and this might be the TE-K project that crops up on the web. What configuration the other helicopter was in is anyone's guess. Could the Bin-laden Blackhawk be based on this prior test work? Have a look at the topic over on the ARC Air Forum in the helicopter section on the Bin-Laden Raid helicopter. There are some interesting comments there that indicate that the helicopter used in Pakistan was a modified H-60.

In relation to the rotor system on the H-60 and in particular the S-92, it is anything but quiet! The SAR S-92 in Ireland lands at a hospital near where I live and I can hear it at least a solid minute before it appears as a dot in the sky. I'm not sure if disc-loading has anything to do with it but I read somewhere that the S-92 should really have been fitted with a 5-blade main rotor instead of a scaled-up system from the H-60.

500 Fan.

Thanks 500Fan, very in depth analysis. So conceivably with regard to the Little Bird airframe .....could it resemble what The Aviationist theorised ...

https://theaviationist.com/2011/05/25/a-stealth-little-bird/

In the 1998 Stealth Special of the Air Forces Monthly (Key Publishing)...in the section on RAh-66 and low observable helos....there was rumour about LHX competition and then MDH had tested a stealthy NOTAR but the Army picked the Boeing Sikorsky RAh-66 Comanche design instead. However officially as far anyone’s concerned the RAH-66 first flew in 1996.

I see a parallel with the Northrop B-21 and mystery triangles , Northrop won. So many a guess to see if the other OEMs must have built some prototype demonstrator ‘May the best man wins’.

The fighter like single seat fromBell-MDH team looks quite cool...as depicted by then MDH artists . This can be found in the late Bill Gunstons Future Warplanes.

Cheers



Cheers

 

[Mr London 24/7]

Exclusive: Legendary special operations aviator reveals bin Laden mission details for the first time

Doug Englen talked about the bin Laden raid, and his life, for the first time in an exclusive interview with Military Times.

www.militarytimes.com

 

[TomcatViP]

From the link above (Great read) :

Englen has more than 7,000 flight hours. About 4,500 of that was under night vision goggles. In Iraq and Afghanistan alone, he flew more than 2,500 missions.

!!!

Also:

His Chinook picked up Karzai, along with members of other governmental agencies, and repatriated him elsewhere within Afghanistan. It was almost a full moon, and Englen incurred 38 bullet holes in his Chinook.

 

[yasotay]

Understandable but sad that so much of the efforts of Special Operations forces will remain unknown.

 

[TomcatViP]

Nothing is lost into the unknown. On our old days, we fans will enjoy the read and the time that will go by with it.

 

[RavenOne]

This is the narrative so far:

* 24 in the primary assault group
* 80 "commandos" total. Not clear if this includes aircrew on the MH-47, CSAR assets, etc. Likely includes the 24 in the primary assault force.
* Force included tactical SIGINT (ISA), collection team, and "navigators"
* Assault launched from either Jalalabad, Afghanistan, or Ghazi, Pakistan. "Official" reporting is Afghanistan, but it is still possible that it was launched from Ghazi.
* 2 MH-47s as "backup"
* 2 "Modified blackhawks" for the primary assault force. The "modified blackhawks" may be conventional news outlets sourcing a AvWeek story which sources SPF.
* After the loss of 1 assault helicopter, the aircraft was demolished and the orphaned assaulters used one of the MH-47s for exfil.

So given the above, the two "stealth helicopters" flew in with some very unstealthy MH-47s. If the assault launched out of JBad, the SHHHHHH-60s would likely have refueled at some point. A stealthy in flight refueling boom would be an interesting challenge, but a FARP is another possibility.
Given the number of persons in the assault force, and the requirements to conduct an assault like this, the transport capacity seems thin. Since the lessons of EAGLE CLAW US special operations forces have not made it a practice to under resource an assault. It's likely there were more backup assets, that the helicopters were not near max capacity, and that there was replication within the assault force. The loss of an assault helicopter (and its operators) was almost certainly planned for, so it's possible there were additional SHHHHHH-60s. On the ground observers only saw/heard 4 helicopters, though obviously this is not very reliable information. They were stealth helicopters

There are a few possible organizations that could operate a SHHHHHH-60:
* AFSOC
* TF160
* JSOC Aviation SMU(s)

There are a limited number of places you could realistically flight test a low observable helicopter:
* NTS
* Eglin AFB
* Pax river

Specifically for this assault there were two training locations set up, one in the Western US and one in the Eastern US. It's likely that this was NTS and Eglin, but could have been several other locations (China Lake, Chocolate Mountains, Ft. Campbell, Ft. Bragg). A mockup of the compound was also constructed at Bagram. NTS and Eglin have both been used for this type of rehearsal several times in the past.

A helicopter that has a reduced radar signature is an interesting challenge, and very different from a fixed wing aircraft.

You also forgot Edwards AFB ranges, Nellis AFB ranges inc Groom Lake, Area 51 or Dugway Proving Ground.

Not sure if Pax River be a good place as it’s not exactly remote and there’s populated areas around.

Eglin especially Hulbert or even Duke Field be good as they are from far ian roads highways and surrounded by trees.

cheers

 

[yasotay]

This is the narrative so far:

* 24 in the primary assault group
* 80 "commandos" total. Not clear if this includes aircrew on the MH-47, CSAR assets, etc. Likely includes the 24 in the primary assault force.
* Force included tactical SIGINT (ISA), collection team, and "navigators"
* Assault launched from either Jalalabad, Afghanistan, or Ghazi, Pakistan. "Official" reporting is Afghanistan, but it is still possible that it was launched from Ghazi.
* 2 MH-47s as "backup"
* 2 "Modified blackhawks" for the primary assault force. The "modified blackhawks" may be conventional news outlets sourcing a AvWeek story which sources SPF.
* After the loss of 1 assault helicopter, the aircraft was demolished and the orphaned assaulters used one of the MH-47s for exfil.

So given the above, the two "stealth helicopters" flew in with some very unstealthy MH-47s. If the assault launched out of JBad, the SHHHHHH-60s would likely have refueled at some point. A stealthy in flight refueling boom would be an interesting challenge, but a FARP is another possibility.
Given the number of persons in the assault force, and the requirements to conduct an assault like this, the transport capacity seems thin. Since the lessons of EAGLE CLAW US special operations forces have not made it a practice to under resource an assault. It's likely there were more backup assets, that the helicopters were not near max capacity, and that there was replication within the assault force. The loss of an assault helicopter (and its operators) was almost certainly planned for, so it's possible there were additional SHHHHHH-60s. On the ground observers only saw/heard 4 helicopters, though obviously this is not very reliable information. They were stealth helicopters

There are a few possible organizations that could operate a SHHHHHH-60:
* AFSOC
* TF160
* JSOC Aviation SMU(s)

There are a limited number of places you could realistically flight test a low observable helicopter:
* NTS
* Eglin AFB
* Pax river

Specifically for this assault there were two training locations set up, one in the Western US and one in the Eastern US. It's likely that this was NTS and Eglin, but could have been several other locations (China Lake, Chocolate Mountains, Ft. Campbell, Ft. Bragg). A mockup of the compound was also constructed at Bagram. NTS and Eglin have both been used for this type of rehearsal several times in the past.

A helicopter that has a reduced radar signature is an interesting challenge, and very different from a fixed wing aircraft.

You also forgot Edwards AFB ranges, Nellis AFB ranges inc Groom Lake, Area 51 or Dugway Proving Ground.

Not sure if Pax River be a good place as it’s not exactly remote and there’s populated areas around.

Eglin especially Hulbert or even Duke Field be good as they are from far ian roads highways and surrounded by trees.

cheers

Given the mission location I would go with Groom Lake as the likely primary training location.

 

[Dynoman]

According to Naylor's Relentless Strike the stealth helicopter was based out of Groom Lake, where it's initial crews were trained and then stationed alongside the helicopters. He states that the helicopters were used in training at both China Lake NAWS, California and the Yuma Proving Ground in Arizona.

 

[Mr London 24/7]

On the two Stateside compound mock-up sites: one at Harvey Point Defense Testing Activity and the other somewhere in the NTS. From one or more of the books (don’t recall honestly) I got the impression that the Stealth Hawk probably wasn’t used at Harvey Point, but (flying out of Groom) probably was at the NTS (mock-up site was alleged to be at an equivalent altitude to Abbottabad). Don’t think that site has ever been found. Did spend time scouring satellite images some years ago to no avail of course....

 

[quellish]

You also forgot Edwards AFB ranges, Nellis AFB ranges inc Groom Lake, Area 51 or Dugway Proving Ground.

Not sure if Pax River be a good place as it’s not exactly remote and there’s populated areas around.

Eglin especially Hulbert or even Duke Field be good as they are from far ian roads highways and surrounded by trees.

cheers

It is very, very hard to fly something at Edwards without being noticed, which is why I did not include it.
I did include the Nellis ranges, NTS is the Nevada Test Site / Nevada Test and Training Range.
Dugway would also be a poor location for a number of reasons.
Hurlburt is readily visible.

 

[quellish]

On the two Stateside compound mock-up sites: one at Harvey Point Defense Testing Activity and the other somewhere in the NTS. From one or more of the books (don’t recall honestly) I got the impression that the Stealth Hawk probably wasn’t used at Harvey Point, but (flying out of Groom) probably was at the NTS (mock-up site was alleged to be at an equivalent altitude to Abbottabad). Don’t think that site has ever been found. Did spend time scouring satellite images sone years ago to no avail of course....

There was the one at Harvey Point, I did locate what I think was the one at NTS, and another possible mockup at the Eglin ranges. There is no evidence of the one at NTS anymore, the location has been repurposed several times since. The mockup was more ad hoc than Harvey Point (shipping containers, chain link fence, etc.). I don't recall if it was at the same altitude as the actual target.

 

[quellish]

Exclusive: Legendary special operations aviator reveals bin Laden mission details for the first time

Doug Englen talked about the bin Laden raid, and his life, for the first time in an exclusive interview with Military Times.

www.militarytimes.com

 

[jstar]

Exclusive: Legendary special operations aviator reveals bin Laden mission details for the first time

Doug Englen talked about the bin Laden raid, and his life, for the first time in an exclusive interview with Military Times.

www.militarytimes.com

Same post as #504 above, quellish?

 

[bob225]

this-is-the-first-image-ever-of-a-stealthy-black-hawk-helicopter

From the drive / the war zone

 

[sublight_]

 

[fightingirish]

IMHO the picture shows a predecessor to the helicopter, which actual flew on Bin Laden raid in 2011.

 

[quellish]

IMHO the picture shows a predecessor to the helicopter, which actual flew on Bin Laden raid in 2011.

the photo shows an YEH-60A at Edwards in 89/90 flight testing a “kit” modification. Half a dozen of the kits were produced. There were additional components to the kit not shown in the photo (tail modifications)

 

[Mr London 24/7]

The pic was posted and then swiftly removed from another forum some years ago (before the Bin Laden raid). The Test Manager posted some info about it there:

I was going to ask where you got that picture, but I know where it's from, as I was the test manager of that project and I had that photo taken. I hope you don't get into any trouble publishing this, as that aircraft was "sight sensitive" for quite a long time, and there are still aspects of it that are classified, although the external appearance is unrestricted.

I have numerous photos of this aircraft, but have refrained from sharing because of these concerns. At one time we had to take off 1 hour before sunrise and arrive back 1 hour after sunset so the aircraft was not observed.

What I can tell you is that is an EH-60A (the EH-60B was the SOTAS and there was only one) with the "Direction Finding Enhancement Kit" installed. There were several of these kits produced and fielded. At one time, it had a more extensive treatment applied to it, but parts were found to be unnecessary.

There were also similar kits produced for OH-58D's (there's a pic in Floyd Werner's book) and Apache's. It isn't too difficult to guess what the purpose of the kit is. After the sight sensitive restriction was lifted, we could freely park the aircraft on our ramp.

A Lockheed project was in the hangar next door, and a King Air full of Lockheed engineers came up from Burbank and parked on the ramp. You should have seen the looks on their faces when they got out and saw this aircraft!

We used to call this aircraft as the "Black Blackhawk", and the test team picture is amusing, as I had the photog double expose it with us in and out of the picture so we all looked like ghosts. This would be a real head-turner on the contest table.

I can talk a bit about helicopter RCS in general terms. As you might guess, the rotor system (and the rotorhead in particular) are the largest radar reflectors by a large margin. Also, you might be surprised at what levels of signature reduction can be achieved by treatments and coatings. There are also operational strategies that can be employed to reduce rotor system signatures.

That big fairing on the rotorhead was a real PITA from a maintenance and pre-flight standpoint, and tended to collect sand and debris.

When this aircraft was really sensitive, we had to do all our flying at night also.

 

[Mr London 24/7]

And after the Bin Laden raid Tail wreckage images, the same chap:

As some of you on the board know, in my “previous life”, I was a flight test engineer and test project manager for the Army. Some of the work I did was in developmental testing of helicopter L/O technology. There is some information I can share with you (and a whole lot I can’t).

In the late ’80s, the Army began working on trying to apply L/O technologies to helicopters. Several applique kits were developed for a few airframes. This was in the early ’90’s. The ones I’m aware of were for the OH-58D, the AH-64 and the H-60. The OH-58 kit has been pretty well documented – there are pictures of it Floyd’s Walkaround book.

I was somewhat involved with the Apache kit and heavily involved with the H-60. I’ve never seen any information released on the Apache kit, and don’t know if any were ever produced or fielded. The H-60 kit was intended for EH-60’s and was referred to as the “Direction Finding Enhancement kit". The original kit had numerous appliques applied to the entire airframe.

There were some aerodynamic and vibration problems associated with the appliques on the aft portion of the aircraft. It was determined that, for the EH-60 mission, the frontal aspects were the most important, so the aft fuselage portions were eliminated.

Approximately five kits were produced and fielded (with the 101st), and I understand that at least 3 were deployed during Desert Storm. The word we got was that the kits were a maintenance headache, and portions were removed in the desert, and use of the kits was abandoned shortly after. I have also heard rumours that further development of the kit continued.

The kits were developed by Sikorsky. The aircraft was originally ‘Sight-sensitive” for quite some time, and we had to perform much of the testing at night, or at remote, secure locations. Eventually, the restrictions were lifted and we were allowed to park the aircraft on our ramp without restriction. At that time, the YF-22/YF-23 fly-off was underway, based at the hangar directly across the ramp from us. Lockheed would occasionally fly engineers up from Burbank in a King Air. The look on their faces when they got off the airplane and saw the EH-60 (which we nicknamed the “Black Blackhawk”) was absolutely priceless!

What I see in the pictures appears to be a refined form of the original “DF Enhancement” kit. The shapes are similar to, but smoother than the original appliques. The forward swept stab is new – we did not have it in the original. I have no idea if this is an applique kit, or whether there were actually MH-60s produced this way in a permanent configuration. Frankly, I’m fascinated to see these pictures, as I had no idea that they had actually continued to develop and field these kits.

Besides shapes, a component of L/O is coatings, and the silver paint on the stab is very likely similar to what is applied to F-22’s. I suspect this is an advanced form of RF absorbent paint. I can’t tell you exactly what it’s composed of (and I’m sure it’s changed from what we used to use), but i can tell you that it incorporates various heavy metal particles that essentially convert RF energy to electric currents and heat.

As Jon says, ‘helicopter’ and ‘stealth’ don’t belong in the same sentence, but I was honestly astonished by the amount of signature reduction that could be achieved simply by shapings and coatings. Obviously, I can’t give numbers, but they are on an order of magnitude.

There are additional, advanced technologies that I still can’t discuss (some were applied to Comanche, some weren’t) that can achieve even more significant reductions. Although you probably can never achieve B-2 levels of stealth, I think you would be honestly surprised at how stealthy a rotary wing aircraft can be.”

Note that he refers to the ATF Flight Test team being nearby: chiming with Quellish’s recent comment in the Mystery Aircraft Thread: for the doubters.

 

[quellish]

A few documents I have been sitting on for a while after receiving them from an AVSCOM FOIA request. Tail number of the aircraft is 84-24017, still flying out near Pax the last time I looked (not with the kit installed, obviously).

Unsurprisingly, material from this thread is already being posted elsewhere without attribution.

 

[rooster]

I have nothing to ad of consequence other than the photo cannot possibly be the final product from 2011 was my first thought.

 

[quellish]

I have nothing to ad of consequence other than the photo cannot possibly be the final product from 2011 was my first thought.

It is not. It is a different program from the 80s, as described in this thread.

 

[flanker]

I know it has been stated that the picture was uploaded and removed previously, but decided to google the tail number and wow, the picture has been in public (with tail number and date) since atleast 2016.

Also, the frame is no longer operational.

 

[riggerrob]

Odd, because the tail hanging over that Pakistani fence looked more like a much-modified Sikorsky S-76.