escapement mechanism. The gear train consists of a
primary wheel and pinion, secondary wheel and pinion,
The time-release mechanism assembly is on the
and escapement wheel and rocker. A barostat assembly
upper right portion of the main beam assembly (fig.
consisting of an aneroid capsule in a housing is screwed
1-8). This assembly provides automatic actuation of the
into the case in a position that allows a peg attached to
harness release mechanism, releasing the drogue
the capsule to engage the teeth of the escapement wheel
parachute and deploying the personnel parachute,
and prevent the release mechanism from operating.
which releases all occupant restraints between 1.9 and
The time-release mechanism assembly trip rod also
2.1 seconds after initiation of the escapement
is used to check that the ejection seat is properly
mechanism. The barostat assembly governs initiation
installed in the aircraft. When the seat is properly
of the escapement mechanism until both the seat and
installed, the insignia red portion of the inner rod of the
occupant have descended to an altitude between 14,500
trip rod is not visible. If the seat is improperly installed
and 11,500 feet. The time-release mechanism assembly
and the trip rod is connected, the trip rod extends and
is a spring-loaded harness release plunger controlled by
causes the insignia red portion of the inner rod to extend
a spring-loaded rack plunger. The spring-loaded rack
beyond the yellow-orange trip rod barrel.
plunger is meshed with a gear train controlled by an
(TRIP ROD DISASSEMBLED)
Figure 1-8.--Time-release mechanism.