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Inadequate negative Gz restraint has been cited as a factor preventing pilots from recovering control of their aircraft after a departure from positive G maneuvers. Several prototype XV seat-mounted harnesses were designed and tested to determine if they might provide improved inflight restraint. Although they were able to improve restraint, none of them could meet the rigid and conflicting demands which were imposed. The restraint which met most of the requirements was the MA-2 Torso Harness with the addition of a seat-mounted 'Y' shoulder strap. The 'Y' strap reduced average head displacement to about one-third of its former value (from 6cm to 2cm for a 50% subject at -1Gz). No problems were uncovered during seat/man separation tests, and the 'Y' strap did not restrict upper torso rotation. Originator-supplied keywords include: Restraint, Inflight, Negative Gz, and Aircrewman.

The S-3A aircraft has (4) ejection seats. Both the pilot and copilot have Comand Eject Selector levers which allow them the option to eject all crewmembers or 'Self Eject.' If one of the aft seats is unoccupied, and 'Command Eject' is selected, the unoccupied seat will accelerate ahead of the occupied seat next to it. Two hazards exist; first, the crewmember next to the unoccupied seat could be burned by the rocket plume from the empty seat which has a higher acceleration; second, the empty seat could tumble into one of the other seats because the center of gravity and the center of rocket thrust are too far apart. To eliminate these hazards it is necessary to ballast the unoccupied seat. This is presently being done with anthropomorphic test dummies, if they can be obtained. Unfortunately these dummies have various weights and are usually damaged (i.e. arms, legs, or head missing). There is no guarantee that the center of gravity is in the proper location to prevent tumbling. To correct this potentially dangerous situation the Naval Air Systems Command tasked the Naval Air Development Center to design a ballast block. After the initial prototype was developed and tested, references (1) and (2) recommended changes to be incorporated into the final design. All of these recommendations have been incorporated into the final design. The S-3A Ballast Block is a 169 pound (77 Kg) assembly of four (4) interlocking aluminum blocks. It is used to control the trajectory of an unoccupied 1E-1 ejection seat. Tests indicate that it meets all functional and structural requirements for use in the S-3A aircraft.

This patent discloses a harness system for releasably restraining the torso of a crewman in a set aboard an aircraft. The harness system includes an upper torso restraint adapted to engage the seat at points on either side thereof and wherein a pair of chest straps connected to either side of a backpad are slidingly routed through respective roller fittings in a criss-cross fashion across the crewman to permit upper torso rotation. A separate lower torso restraint is coupled to the upper torso restraint and adapted to engage the seat at the same points of engagement as the upper torso restraint. A single-action release mechanism, actuated manually or automatically by water immersion, disengages both the upper and lower restraints from the seat thereby divesting the crewman of the harness system., Supersedes PAT-APPL-453 444-82, AD-D010 207.

An air bag restraint system is disclosed for protecting an occupant in a seat during ejection from a vehicle, particularly an aircraft. In one perferred embodiment, an air bag member is deployed from a stored position frontally to the chest of the occupant and guided upward and downward along tracks on either side of the seat so that the upper body of the occupant is enclosed within the seat just prior to ejection. In another preferred embodiment, the air bag is stowed within a cover about a semi-circular hoop releasably connected to the seat about the chest of the occupant. At the initiation of the ejection sequence, the cover is released and the air bag inflated, expanded into the proper shape by external restraint straps, so that the head, arms and torso of the occupant are encapsulated at the time of ejection., Supersedes PAT-APPL-490 827-83, AD-D010 486.