The Multi-Functional Operator’s Seat (MFOS) was originally designed by Martin Baker Aircraft Company Limited (MBA) for use in the HH60L Medevac Blackhawk helicopter, and is qualified to the requirements of FAR 29 but with an increased occupant range. This seat has evolved into a family of seats that are now used in various Blackhawks within the U.S. Air Force, U.S. Army and U.S. National Guards.

This lightweight seat offers the user 360° rotation that can be locked in 15° increments and five inches of vertical height adjustment. The seat traverses on standard MS33601 floor track or aircraft specific floor pallets. Two types of floor fittings are available; a standard fitting that fits into MS33601 that allows fore/aft traversing; or an alternative fitting that interfaces to an aircraft pallet and allows both fore/aft and lateral traversing.

The standard seat has a hoop headrest, a five-point stand up harness with rotary quick release buckle and three MA-16 type inertia reels. The cover options include vinyl for medical applications, a fabric version for military use and a VIP padded kit.

Optional features to suit specific operator requirements include armrests, alternative headrests, black or silver seat structure, specific fabric types and colours.

In addition to the standard MFOS two further unique variants have been qualified. The first has a standard five point harness and a single MA-16 type inertia reel, which has been qualified to FAR 29 with a 170lb (77.1 kg) occupant for the EH101. The second has a commercial TSO C114 harness, mounts on a unique floor interface pallet, and is certified to ETSO C39b with a 170lb (77.1 kg) occupant for the Beechcraft King Air 350.