Lonewolf, re the 30 minute requirement. I believe this first appeared in the UTTAS Material Need document which then became the UTTAS Request For Proposal in terms of the design/test requirements for the aircraft. There was an Army board headed up by a Colonel Bud Patnode which was charged with coming up with the requirements. I talked with him a few times during the fly-off competition, but never about the 30 minute rule. His stories about the internal fights about the skids vs wheels decision were " entertaining ". That group started their work around 1968 I believe, so it is probably safe to say that UH-1 experience in Vietnam influenced the 30 minute number. I do recall that a UH-1 down south ( I was in the Central Highlands 65-66 ) had a transmission oil problem, tried to stretch it and the following aircraft saw his rotor slow down and they went in. There may have been others. Someone with access to the Army Aviation Systems Command, Flight Standards Div records should be able to answer your question definitively.
Last edited by JohnDixson; 28th Jul 2017 at 01:50.
Reason: Typo