T-34C AIRCRAFT SYSTEMS FAMILIARIZATION
While closing front canopy, adjust seat height to ensure the canopy
bow clears the helmet; otherwise, there exists the danger of the
canopy bow striking the helmet during emergency operations.
The canopy emergency (pneumatic) system assures the occupants that in case of emergency the
canopies may be opened simultaneously to permit escape from the aircraft. When actuated, the
system high pressure nitrogen moves a cylinder assembly attached to the canopies by cables.
The nitrogen storage bottle is mounted in the avionics compartment, right side, and is equipped
with a temperature-compensated gauge, which can be viewed through a window on the right side
of the fuselage aft of the wing. When the nitrogen is released from the bottle it is discharged into
the pneumatic cylinder mounted on the ledge behind the aft cockpit seat. As the nitrogen forces
a piston into the cylinder, the piston pulls cables attached to both canopy assemblies. Canopy
emergency open handles are located on the right sidewall of each cockpit and on the exterior
right side of the forward cockpit. All three emergency open handles are attached to a common
cable which is attached to the nitrogen bottle valve.
To operate the emergency open system, pull any emergency open handle. Both canopies will
open in 1-4 seconds to a position 2 inches less than when manually opened. The canopy will be
locked open and cannot be closed.
Seats in each cockpit are adjustable 5 inches vertically in 1-inch increments by pulling up on the
spring-loaded handle on the right side of each seat (Figure 17-2). There are no horizontal
adjustments of the seat.
The restraint harness holds the pilot in the seat by an integrated harness assembly consisting of a
crotch strap, lap belts, and shoulder straps attached to an inertial reel lock that are all a part of the
seat. All of the belts/straps lock into a common five-point rotary padded buckle. Release from
the harness assembly is accomplished by turning the rotary buckle ⅛ turn in either direction. All
belts/straps are adjustable. The shoulder harness inertia reel is locked or unlocked by movement
of the lock handle (forward and aft movement) on the left of the seat. When unlocked (aft) the
inertia reel allows pilot mobility, but will provide restraint in the event of rapid linear
CANOPY/COCKPIT FURNISHINGS 17-3