The Sikorsky CH-3 is based on the S-61 design, and was first developed for the military by the US Navy as the SH-3. The first model for the USAF was the CH-3B, three built, externally identical to the Navy SH-3. This was followed by the CH-3C, 74 built, which featured a redesigned rear fuselage incorporating a loading ramp for small vehicles and cargo. A retractable landing gear was added and the tail wheel was moved forward and made steerable. Beginning in 1966 all CH-3Cs were modified with the T58GE-5 engine which changed their designation to CH-3E and an APU was installed making the CH-3E self-starting.
The HH-3C/E was a dedicated rescue version, with protective armor, self-sealing tanks, a retractable inflight refueling probe, jettisonable external tanks, a high-speed hoist, and other specialized equipment. A dimensions drawing in T.O. 1H-3(C)C-1 says: "Note: Helicopters fitted with an air refueling probe are designated HH-3E helicopters". So far, no photos have surfaced that combine the air refueling probe and the MARS equipment, therefore all MARS helicopters are assumed to be CH-3Es.
As an alternative to the drone landing on its belly under a big chute, it was more effective to snatch it from the sky with a helicopter. This prevented damage, an unpredicatble landing spot, and speeded up operations considerably. It sounds like it's very difficult, but the execution was fairly simple and achieved a 97% success rate during Vietnam operations (2655 catches out of 2745 attempts). The picture below explains it better than lots of text. Source: Wikipedia. The video links below show MARS in action. The method was used operationally in Vietnam from April 1966 on. It even affected the design of the latest versions of the drones: the 32 ft wing versions (147H, T, TE, TF) no longer had structural provsions to allow for heavy-impact belly landings.
The following was added to the basic CH-3 to make it MARS-capable:
a heavy winch inside the cabin, computer controlled, made by All American Engineering. The drone is suspended from a single line
a well through the floor (roughly 2' x 2') that had a fairlead roller at the bottom and top of the well to guide the cable up to the winch. The bottom of the well also had a rounded bulge around the edges to ease the contours, so there were no sharp edges for the chute or rigging to catch on as it was all reeled in after a catch. The fairlead bulge design changed over the years and became bigger
the rear loading ramp was absent, and two extendable catch poles hang out the back, that could be stored internally
an angled deflector plate in front of the nose wheel well, since the nose wheels hang out of the well a bit when fully retracted.
This provisonal serial list was based on the Jolly Green Association website. I think the website was ended in 2015 or 2016, but the Wayback Machine came to the rescue again. The site had a webpage with A history of CH/HH-3E's by tail number, that was last archived in 2015. The individual histories were last archived in 2008, it seems. A selection was made of the CH-3s that served at Davis-Monthan and/or in the 6514th Test Squadron at Edwards and later Hill. At Tyndall, Detachment 5 of the 39th ARRW also had four MARS equiped CH-3s, but that wasn't clear when the selection was made. The list could therefore be imcomplete.
63-09687, confirmed MARS
63-09690, confirmed MARS, serial presentation 39690
64-14223, confirmed MARS
64-14226, confirmed MARS
64-14228, confirmed MARS
65-15690, confirmed MARS
65-15696, confirmed MARS
65-12788, confirmed MARS
65-12790, confirmed MARS
65-12797, confirmed MARS, serial presentation 12797
65-12800, confirmed MARS, serial presentation 12800
Here's a selection of the listing of 200+ Teledyne-Ryan films that the San Diego Air and Space Museum put on YouTube. These videos all show some aspect of MARS recoveries.
F-0528 Ryan Firebee Missile Retrieval - launch, MARS retrieval, BGM-34A at the end?
F-1174 Ryan Aeronautical Firebee Drone 34A and 34E on DP2E - Firebee II: CH-53 MARS, manufacturing, in-flight, on pylon
F-1346 Ryan Aeronautical William Tell 58, 59, 61 - with 147A recovery at 21:12, continuation of F-2817
F-1423 Ryan Aeronautical Model 234A - two ground-filmed BGM-34A missions, one including MARS, pylon mounting
F-1758 Ryan Model 234 BGM-34 Hobo & Maverick weapons system - BGM-34A Maverick loading, target hit, mission footage, MARS
F-1780 Ryan Mars mid-air retrieval system, Lockheed C-130 and Firebee Drone - tests with CH-37 and CH-3
F-1854 Ryan AQM 34A Drone first flight launch - flight - MARS 5/13/1976 - AQM-34V in first flight, launch, parachute
F-1929 Ryan Model 234 Firebee Drone RPV Footage and C-130 - MARS, DC-130, Shrike on pylon
F-1933 Ryan Model 234 Firebee Drone RPV - bits and pieces: MARS, shop testing, ground filmed mission
F-2324 Ryan model 147 TE/TF at OL OA AFB April 1973 - OL OA = Osan Korea. Model 147TE and TF, MARS recovery, CH-3s, DC-130 take-off, ground control, drone pre-flighting, Osan city, another two MARSs, DC-130 cockpit
F-2348 Nobody's Perfect..Accident B-Roll from Ryan - short MARS clip, bare metal DC-130A 496
F-2817 Sikorsky CH-37 Mojave and Ryan RPV - CH-37 trying MARS on Q-2C and Model 147A (@10:30). Continued in F-1346 @21:12
Rotorheads: Buffalo Hunters about MARS CH-3s
Rotorheads: MARS recovery showing the whole sequence with photos
ARC forum: Some Pics from Army Flight Test that includes a discussion of the MARS-equiped CH-3C/E, with photos
