February 14, 2012

What Brought Down 160th SOAR's Stealth Black Hawk?

Bin Laden gets face-shot

When the Osama Bin Laden raid went down, there was a flurry of news reporting, many initial reports stumbling over themselves as both the media and the White House struggled to get their stories straight.  Who executed the raid?  How was Bin Laden killed?  Who is Seal Team Six?  Our readers already knew the answer to that last one, but you get the idea.  From what I gather, and we don’t have the whole story even today, is that the actions on the objective were fairly straight forward.  Maybe there were one or two terrorists who had armed themselves, but it doesn’t sound like that slowed ST6 down much, if at all.  Everything was kosher until they began to exfil off the objective.

What happened next would reveal a previously classified aviation program to the world and potentially create an international crisis.

160th Special Operations Aviation Regiment’s Secret Helicopter

From a training event with 160th back in 2006

As a member of 3rd Ranger Battalion and 5th Special Forces Group, I flew with 160th numerous times in both Afghanistan and Iraq.  I’ve seen 160th pilots do some amazing things with their aircraft.  They put us down on roof tops, they’ve had the co-pilot lean out of the helicopter and deliver fire support with an M4, and I’ve even been on a MH-60 as the pilot navigated his helicopter between power lines with surgical precision to insert my ODA on an objective.  I have nothing but respect for these guys, and it surprises no one that it was 160th that successfully conducted the OBL raid with the SEALs.

While I was in Army Special Operations, I heard nothing, and I mean not even a whisper of any secret helicopter projects.  Not even a rumor about stealth helicopters.  This goes to show how tight the Army’s OPSEC was around this project, and with good reason.  As we now know from the wreckage left behind in Pakistan, at least one stealth helicopter was on the mission, but probably two or three as that is how many helicopters would be needed at a minimum for the raid, and having one stealth helicopter and two non-stealth MH-60’s flying in formation together would kind of negate the purpose.

In this case, the stealth capabilities of these helicopters would be needed to insert a Ground Assault Force into the target area while evading Pakistani radar stations during this cross border operation.  Bin Laden was living near a Pakistani military base in Abbottabad, a town filled with active duty and retired military officers.  Who would’ve thought…

While 160th is based at Ft. Campbell, Kentucky, it turns out that there is also a element of the Special Operations aviation unit located off-site called Echo Squadron.  The exact location of Echo Squadron will remain undisclosed due to OPSEC considerations.

Stealth Hawk Down

Stealth Hawk tail section

While it appears that one helicopter landed inside the compound and extracted successfully, another crash landed.  This forced the ST6 operators, pilots, and any flight crew to initiate the destruction plan.  More than likely they popped some thermite grenades inside the downed Stealth Hawk and cross loaded onto one of the other aircraft.  This is another reason why you never have just one bird on station for a mission like this, if one aircraft goes down, you have men stranded on the ground.  But why did the crash happen to begin with?

After consulting with experts in the field of rotary wing aircraft, it seems that the most likely cause of the crash was due to a phenomena known to pilots as “settling with power” with atmospheric conditions potentially playing a role as well.  Helicopter pilots will almost always attempt to land while facing into the wind, however, the pre-determined approach into the objective in this case may have actually given them a down wind landing.  If the rotor wash pushed from the rotors down to the ground, then comes back up and pushes into the decent path of the helicopter, it can then make the aircraft unstable.  This is how settling with power can destabilize a helicopter.  The rotors essentially created a vortex of dead air space that could no longer generate lift.

The rotor blade system needs clean, that is, uniform air to produce lift.  If instead it gets un-uniform air, such as air previously disturbed by the helicopter’s own rotor wash, than the pilot could be in for some trouble.

At this point, the pilot would have begun to lose control of the aircraft from self-induced turbulence.  Without lift and maneuverability, he would have to conduct a controlled crash as a last resort.  As we see in the pictures, the tail rotor section split over an outer wall of the compound.  Did this obstacle also disrupt the air flow from the main rotor system and destabilize the aircraft?  Maybe.

What is it?

Artists rendering of the Stealth Black Hawk

As pictures of the wreckage began to filter out to the media from Pakistan, the main question became: What the hell is it?  There was speculation that it was an entirely new type of helicopter cooked up deep inside some black budget Special Access Program at Area 51.  Others made the observation that it was more likely a highly modified MH-60 helicopter.  I pulled the following picture off the comments section of an Aviation Weekly article not long after the OBL raid:

Stealth Hawk/UH-60 comparison

As you can see above, the main rotor system of a conventional Black Hawk does look an awful lot like that of the wreckage left behind in Pakistan.

Aftermath

While the OBL raid was an overwhelming success, it also exposed a Top-Secret helicopter program.  Certainly this was something taken into account by both military planners at JSOC as well as political leadership in Washington, DC.  They would have worked a risk mitigation strategy and determined that the intelligence justified the raid even if it came at the expense of compromising a classified program and certain Special Operations Tactics, Techniques, and Procedures.  I think I join the vast majority of Americans in agreeing with this decision, but let’s also examine the negative effects.

Within weeks the press was reporting that Pakistan was letting officials from the Chinese government look at the wreckage of the Stealth Black Hawk.  Some experts, optimistically in my opinion, have weighed in saying that the Chinese will be able to reverse engineer the stealth helicopter technology in a matter of months.  I’m not so sure. The Clinton administration initiated a series of technology transfers to China and we’ve all heard about Chinese hackers engaging in industrial espionage.  It seems that it was only relatively recently that the Chinese built a functioning stealth fighter.

Chinese J-20 Stealth Fighter

At any rate, it seems beyond a shadow of a doubt that at some point countries antagonistic towards the United States will reverse engineer stealth technology, it’s just a question of when.  As for the Stealth Black Hawk (the official designation of this aircraft remains unknown) you can be sure that 160th combed over every piece of intel and technical detail when working up their After Action Review to avoid a similar incident in future operations.

About the Author

is an eight year Army Special Operations veteran who served as a Sniper and Team Leader in 3rd Ranger Battalion and as a Senior Weapons Sergeant on a Military Free Fall team in 5th Special Forces Group. Having left the military in 2010, he is now working towards a degree in Political Science at Columbia University. Murphy is the author of Reflexive Fire, Target Deck, the PROMIS series, and numerous non-fiction articles about Weapons, Tactics, Special Operations, Terrorism, and Counter-Terrorism. He has appeared in documentaries, national television, and syndicated radio.

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  • Afghan1

    It should be noted that there is difference between "settling with power" and "vortex ring state", although they are sometime used erroneously as the same thing. "Recirculation" is also another seperate phenomenon. Settling with power means not having enough power available to arrest your rate of descent. High density altitude and heavy gross weight both contribute very much to this. Vortex ring is basically falling into your own downwash. Low forward airspeed (made worse by landing downwind) combined with a decent rate of descent can cause this condition. To recover you have a couple options; get airspeed or remove yourself from the vortices. An underused technique is to quickly put in lateral cyclic to move the aircraft sideways into clean air. Recirculation is when there are obstacles (wall, heavy treeline, etc) that force the downwash back vertically where the air is then reintroduced back into the rotor system. It isn't the vortices that are the problem, but the movement of the air. The induced airspeed changes the angle of attack of the blades and leaded to less available lift. Anyways, just giving a bit more info on the phenomenons that could have contributed to this incident. Without more info it's hard to know what exactly caused it. All of these events are pilot induced, but the operational need of the mission obviously force the pilots to take greater risks when selecting their approaches then in a non-combat situation.

  • usapatriotonthemove

    Dang, can't believe I missed this article?  This is good stuff! Thanks Jack.  I'm sure it's been brought up? Maybe not? But if the mock up had been built to spec and not with chain link fences, I wonder if the condition's would've been close enough to create the same kind of issues with the choppers?  Mute point now, but that attention to detail thing will get yah every time..;)

  • Darkstar11

    Vortex Ring, its a state most likely to occur in a hover over a box or "compound" where the air gets re-cycled through the main rotor at increasing velocities causing loss of lift, requiring more throttle and collective (FADEC intercontingency/auth) until either you just crash, run out of power and crash or run out of tail rotor authority, over-torque and crash, the latter is the least controllable.This pilot opted for scenario 3. it is a Blackhawk Nighthawk SMH and the openengs in the fore tail top duct engine gasses/heat down a decreasingly insulated tail boom in order to gradually cool the heat signature the cooler air then gets re washed by the tailrotor upwardly making it dissipate even more quickly. The aperture will also be tuned so bleed air is distrbuted across the tail rotor at its noise cancelling frequency during tac transit modes.

  • LCpl X

     @JackMurphyRGR    Army Helicopter Crashes in the Philippines; 10 AboardThe WorldMilitary: Fishermen rescue three people, but a search fails to locate more survivors.   February 22, 2002   Before the crash, the MH-47 Chinook had just finished ferrying dozens of Special Forces troops to the island of Basilan, where they are assisting and training Philippine troops combating the Abu Sayyaf, an Islamic rebel group whose hostages include two American missionaries. http://articles.latimes.com/2002/feb/22/news/mn-29313 It was unclear what caused the crash, but there were no reports of hostile fire, the Pentagon and Philippine military officials said. Philippine Armed Forces Chief of Staff Diomedio Villanueva blamed the crash on a systems malfunction, according to television reports.   "There were no hostilities; there was no hostile ground fire," said Col. Danilo Servando, spokesman for the joint U.S.-Philippine exercise in Zamboanga on Mindanao island. "It would be more of a technical problem."   The aircraft crashed in darkness en route to Mactan air base, a Philippine facility in the central part of the country being used by U.S. forces in the anti-terrorism campaign.  

  • JackMurphyRGR

     @Iassen Donov Iassen Donov. I was not aware of the 47 that went down in PI...when was this?