entire range of vertical and fore-and-aft ejection seat assembly adjustment.
Aircrewmembers within the specified population range shall be able to reach
and fully actuate their escape system controls while restrained in the full
back position by the restraint system.
188.8.131.52 Field of vision. The escape system shall minimize degradation
of the aircrewmember's field of vision. The ejection seat headrest shall
be designed to be the minimum width possible, but not less than that specified
in 184.108.40.206 .1.3 in order to maximize the aft vision of all aircrewmembers and
forward vision of the rear-most aircrewmembers in tandem seat aircraft.
220.127.116.11 Impulse noise levels. As a result of the operation of the escape
system, impulse noise levels measured at the design eye position in each
aircrewmember station shall not exceed the damage risk criterion of MIL-STD-
1474 for beta-duration impulse noise. Since the probable maximum exposure
of any aircrewmember to repeated-impulse noise is limited to the minimal
number of impulses occurring during the operation of the escape system, the
damage risk criterion shall be corrected to permit an additional 10dB.
Since all aircrewmembers are equipped with approved helmet assemblies with
integral ear protection, an additional correction shall be made to the damage
risk criterion to permit an additional increase of 20dB.
18.104.22.168 Design strength. The ejection seat assembly, the ejection seat
attachment fitting, and the ejection seat supporting structure shall be capable
of withstanding the following types of loads without failure and without
degrading or compromising escape system performance:
Acceleration loads resulting from the aircraft flight loading
as specified in the aircraft detail specifications
Windblast loads resulting from the escape system performing
as specified in 3.3.2.
Ejection loads resulting from simultaneous upward accelera-
tions of 27g's along the ejection guide rails and dynamic
pressures sustained during sea level escape at maximum
aircraft equivalent airspeed or 600 KEAS, whichever is less.
Loads resulting from deployment and operation of the deceleration
and stabilization subsystem.
Loads resulting from deployment and operation of the recovery
Impact loads as a result of ejection seat assembly contact with
aircraft structure during the escape path clearing sequence.
Crash loads applied at the ejection seat assembly interface
and having the acceleration profile shown in figure 1. Crash
loads are further specified to have a resultant vector lying
in the plane formed by the roll and yaw axes of the aircraft
and directed at any angle from forward along the roll axis
to downward along the yaw axis. The escape system and its
components shall be designed to preclude premature or inadver-
tent actuation during, or resulting from, the application of
the crash loads.