From the late 1980's, the americans have been working on an advanced tactical transport aircraft. The requirement for this aircraft stems from the YMH-130H 'Credible Sport', a heavily modified C130 Hercules, that employed rocket assistance to give exceptional short-field performance, in one test taking off in under 10ft. The aircraft was developed in late 1980 in order to rescue the American hostages being held in the Iranian capital Tehran from 1979 to 1981, using a football stadium as an airfield. The hostages were released and the mission became unnecessary, but the requirement for a VSTOL transport aircraft remained.
Senior Citizen was developed by Northrop Grumman to meet this requirement, mainly due to it's work on the X-21 laminar flow research aircraft. The stealthy shape was developed during testing at Northrop's microwave testing facility in southern California and at the USAF's facility at Holloman AFB in New Mexico. The clipped diamond shape that was tested also appeared in the YF-23 ATF protoype.
Senior Citizen featues many advanced technologies:
Stealth - While Senior Citizen has a very low RCS, it is not in the same class as the B2 'Spirit' bomber. As it is required to operate at low levels, much attention has been paid to reducing engine noise, and infra-red emmissions. Also, Senior Citizen employs visual stealth. At night, it has a pattern of three lights to disguise it's characteristic shape, while in daylight 'Yehudi' type lights are used to make it difficult to spot beyond 1.5 miles.
STOL Peformance - The C41-SR employs the enhanced 'Coanda' effect with an energised upper wing surface - also thought to have been used on the YF-23 - to give exceptional STOL performance.
Circulation Control - By using an arrangement of valves and ducts in the leading and trailing edges of the wing, air is accelerated over the wing, increasing lift and decreasing drag. This technique is also employed on the B2 and the YF-23.
Contractor: Northop Grummans Black Widow Group
Payload: 14 troops plus 5,000lb cargo