YMC-130H were three modified Lockheed Hercules Aircraft for Top Secret "Operation Credible Sport", for second Iran hostage crisis rescue attempt.
One of the measures considered for a second hostage rescue attempt in Iran was a project to develop a "Super STOL" aircraft, to be flown by Combat Talon crews, that would use a soccer stadium near the US Embassy as an improvised landing field. Called Credible Sport, the project acquired three C-130H transports from an airlift unit in late August 1980, one as a test bed and two for the mission, and modified them on an accelerated basis.
Designated as the XFC-130H, the aircraft were modified by the installation of 30 rockets in five sets: eight firing forward to stop the aircraft, eight downward to brake its descent rate, eight rearward for takeoff assist, four mounted on the wings to stabilize them during takeoff transition, and two at the rear of the tail to prevent it from striking the ground because of over-rotation. Other STOL features included a dorsal and two ventral fins on the rear fuselage, double-slotted flaps and extended ailerons, a new radome, a tailhook for landing aboard an aircraft carrier, and Combat Talon avionics, including a TF/TA radar, a defensive countermeasures suite, and a Doppler radar/GPS tie-in to the aircraft's inertial navigation system.
Of the three aircraft, only one received full modification. The program abruptly ended when it crashed during testing on October 29, 1980, and international events soon after rendered another rescue attempt moot.