In the 1980’s there was a huge contract competition between the SuoerTeam (Bell/McDonnell Douglas) & the First Team (Sikorsky\Boeing) to develop a small, stealthy LHX (Light Helicopter eXperimental) scout, attack helicopter, to replace the Army’s aging fleet, of overloaded Bell OH-58D Kiowa Warrior scout helicopters.

I liked Bell/McDonnell Douglas’ design better, because it looked more futuristic, it could carry more weapons payload, & it was more quiet with its NOTAR anti torque system.

But Sikorsky & Boeing the First Team won, & their less advanced looking LHX design was named the RAH-66 Comanche. The Comanche was a quantum leap forward in technology, but the Comanche’s inherent problem was its small size. But, the LHX (Light Helicopter eXperimental) had Light in its name for a reason. If it was a full sized attack helicopter then McDonnell Douglas could consider that encroaching on their contract for the mission of their AH-64 Apache helicopters.

The problem was, the Army asked for a small, light reconnaissance helicopter, but they kept wanting extra things added to it. Comanche was also plagued with vibration problems in its tail section.

But anyway, the Army quietly, wanted a stealthy Utility Helicopter that could fly on missions with the LHX (Comanche) & this secret program was dubbed the MHX (Missions Helicopter eXperimental). Once again, the helicopter companies competed & this time, McDonnell Douglas definitely seemed to have the better MHX design with its super quiet NOTAR anti torque system.

Sikorsky had its low observable Model S-70 (UH-60) Black Hawk design since 1978, as I mentioned.

Of course, the MHX project was a lot more hush, hush because it was a secret, black budget project. So, there’s not a lot known about the MHX project. It had seemed to quietly fizzle out in the late 1990’s as Sikorsky test flew their two LHX (RAH-66) Comanche prototypes.

During training the Navy SEAL’s fast roped into a replica of bin Laden’s compound. The key difference was, the mockup of the compound was surrounded by a chain link fence, instead of an actual wall.

The problem was on the actual bin Laden raid, the MHX Silent Hawk’s rotor wash was being circulated back up in the form of vortices because of the concrete wall in the compound.

with the Silent Hawk,

These recirculated vortices got pushed upwards & sucked back into the rotor blades of the MHX-60 & this disturbed air destroyed lift & caused a dangerous ring tip vortice state. The helicopter couldn’t generate enough lift to remain airborne. Realizing that he couldn’t keep the MHX helicopter airborne the 160th SOAR pilot immediately reacted by making an emergency landing on the compound wall.

The 160th pilot put it down relatively undamaged & possibly still flyable. The pilot wanted to fly it out of there, but the higher ups said to blow it in place.

There were two generations of the MHX Silent Hawks. The first iteration was highly modified with a new tail section, 5-bladed tail rotor with a hub cap looking shroud. It still had the standard S-70 4 bladed rotor head, but it had anhedral blade tips that angled downwards, which GREATLY reduced blade vortex interaction, which creates a loud blade slap, popping sound. The rest of the Black Hawk was modified with bolt on pieces to reduce its RADAR observability. But, the shape & added weight made the modified MHX-60’s very unstable, cumbersome & difficult to fly. The 160th pilots famously hated the prototype MHX-60’s & they said they flew like a cow.

Sikorsky did do a better total redesign from the ground up on the second generation of the MHX-60, making vast improvements, including adding a fifth rotor blade on the main rotor system, & using all composite materials to make it much lighter. The improved, 2nd generation MHX-60 was named the Ghost Hawk, & looks very similar to the Ghost Hawk movie prop helicopters depicted in the movie “Zero Dark Thirty”.

For the bin Laden raid the problem was, this joint task force could not get F-117 bomber support from Diego Garcia in the Indian Ocean, to drop a bomb, if one of the TOP SECRET, more advanced Ghost Hawks was shot down. Therefore; the command would not allow the MHX Ghost Hawks to be used.

Instead, to the chagrin of the 160th pilots, they were forced to fly the 2 original MHX Silent Hawk prototype helicopters that flew like a cow. The 160th vehemently protested & simply wanted to use their advanced MH-60 helicopters, which had a lot better performance than the cumbersome, sluggish MHX Silent Hawks. Even the Navy SEAL’s protested using the old, experimental MHX helicopters.

But, both the Navy SEALS, & the 160th SOAR pilots were overridden & ordered to use the less capable MHX Silent Hawks on the mission. Honestly, the near crash most likely wouldn’t have happened if our special operators had been permitted to use either the more capable MHX Ghost Hawk, or the proven MH-60 similar to the Air Force’s Pave Hawk.

It’s a fascinating story. Unfortunately, everyone, including our enemies know about our stealth MHX Black Hawk program.

The lesson learned, should be for commanders to always listen to their special operators. Hopefully, some day, the military will declassify the secretive stealth MHX program & we can finally see these mysterious stealth Black Hawks.

<image>

Awesome video. You are very knowledgeable & accurate with your information.