<p>The black cylinder wrapped in red stickers is the Drogue Gun, which is triggered by trip-rod connecting the seat and the airplane. As the seat rises, the natural metal rod is withdrawn from a yellow housing. The drogue gun fires a weight which drags a small parachute out of the package at the top of the seat's headrest. (Basically, under the green cover under the black cloth wrapping around various bits of webbing and line here.) The weight, drogue, etc, go right through any turbulence around the seat and out into what racing car drivers call "clean air". 
</p><p>Opening there, the drogue stabilizes the seat so its falling with seat pan and occupants' feet first.. In some cases, a second, larger, drogue is pulled out by the first. In either case, the end of the final drogue's shroud lines is at a fitting which is held by the scissors shackle. The scissors shackle is the curved metal business bolted to the seat above the green housing (and on the other side of the cylindrical catapult at the far right edge). After a fixed delay, or after falling below the barometric threshold, an actuator releases the seat harness, leg restraints, face curtain (if used) and any other connection between the occupant and the seat. Then the scissors shackle operates, releasing the drogue(s) to pull the occupant free of the seat and pull out the main parachute.
</p><p>The anodized green housing is the top latch mechanism.
</p><p>On the other side, a similar housing contains, the Bombardier / Navigator (B/N)'s seat's specific pyro delay. Since the A-6 is a two seat aircraft, either pilot or B/N initiation ejection causes both to eject, unless some positive step is taken to limit the ejection to only of seat. So either seat will usually start both, but each as a different delay, in a different color of anodized housing, so that the go in the right sequence (not both at the same time...) EA-6B Prowlers had 4 seats, 4 different delays, 4 different colors of housing.
</p><p>Three features identify this as a GRU-5 seat: The shoulder harness is attached to the head-box; the face-curtain strap is routed around the head box. This GRU-5 has no rocket motor under the seat, thus, no initiator for the rocket motor. A GRU-7 would have an initiator attached to the drogue gun.
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<a rel="nofollow" class="external text" href="https://www.flickr.com/people/9998127@N06">Bill Abbott</a>
<p><a rel="nofollow" class="external text" href="https://www.flickr.com/photos/wbaiv/6091775248/">Grumman A-6A Simulator Bombardier / Navigator (B/N)'s Martin Baker Mk GRU-5 ejection seat</a>
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