Lu Zuckerman provided some additional insight on
The Quiet One in
this thread. The link to the Air America PDF document which I provided appears to be broken, but here are some extracts:
The types of missions flown by Air America’s Hughes 500s:
Most official Air America papers like the Flight Operations Circulars speak of only two Air America Hughes 500s (N353X and N354X), and those aircraft were operated out of Udorn on medivac and communications missions into Laos and could carry 3 passengers (Aircraft and avionics information as of 1 April 73, in: UTD/Kaufman/B1F14). But those two aircraft only served as cover for two others - the “Quiet Ones” - which were used for a secret wiretap mission into North Vietnam and whose complete identities appear only in one Air America paper hidden among others preserved at the Air America Archives: in a letter dated 15 June 73, by which Air America’s Senior Vice President Clyde S. Carter asked the FAA to note a change of ownership for those two Hughes 500Ps. As their conversion to Hughes 500Ps is not mentioned, they may have become regular Hughes 500s again at that time. Those documents also reveal that from the very beginning, the two regular Hughes 500s had only one purpose - to be used as cover for the Hughes 500Ps, as all four aircraft were registered on the same day in April 71, although the regular ones came to Laos only about one year
Hughes 369HS N352X 800248S: bought new, July 1971
Service history: regd. on 15 July 71; believed converted to Hughes 500P (“The Quiet One”) in the USA between July and October 71 for a communications-intercept project called “Main Street”; directly controlled by Washington in September 71; ferried to Air Asia’s base at Tainan about October 71 and used there until the spring of 1972 to train 6 senior officers from the 34th Squadron of the Republic of China Air Force for a wiretap mission into North Vietnam; the project “Main Street”, employing Messrs. Smith and Lamothe as special pilots, ended on 31 December 71; not listed as maintained by Air America, Udorn, on 1 April 72; loaded into an Air America C-130 and flown to Takhli (T-05) about June 72; flown to PS 44 in June 72 for a wiretap mission into North Vietnam; used by Taiwanese crewmen from the RoCAF’s 34th Squadron to practice night missions near PS 44 until early September 72, when the Taiwanese were sent home; then, Air America crews were trained to fly to Vinh in North Vietnam and to tap the telephone line; after several failures, that mission was successfully completed in the night of 6 to 7 December 72. The 2 Hughes 500Ps had been painted in US Army markings and serials painted over, possibly to make believe that they had been stolen from the military. Flown to Thailand on board an Air America C-130 in December 72, immediately after the Vinh mission was completed. Possibly reverted to a regular Hughes 500.
Fate: sold to The Pacific Corp., Washington, in 1973; sold to Southern Sky Inc., Dallas, TX, on 27 June 73 change of registered owner requested on 15 June 73; did no longer exist in 1995.
Hughes OH-6A/500P “12968" 570053 - April 1971, bailed from US Army 65-12968
Service history: prototype of the Hughes OH-6A/500P “The Quiet One” (photo in: Conboy/Morrison, Shadow war, p. 361); believed used to train three Air America pilots at the USAF’s secret Area 51 testing range in Nevada between the end of April 71 and July 71 for a wiretap mission into North Vietnam (Conboy/Morrison, The quiet one, p. 46); then probably served as a model for the conversion of Air America’s own 2 Hughes 369s to Hughes 500Ps.
Fate: eventually became N45780 in December 77; with the US Border Patrol, El Paso TX, as N45780 at least 1995-98.
I have an image of
The Quiet One's engine regenerator somewhere.
I/C