For cabin altitudes of 10,000 feet and above, the
oxygen duration times listed in the AFM include
cabin altitude ascent time from 8,000 feet to the
final stabilized cabin altitude (assuming a fully
charged system of 1,850 psi). The pilot may use
the following formula to calculate the oxygen
duration for a partially charged oxygen system:
System Pressure
Duration (per AFM) X
1,850
NOTE
This is an estimate only. Flight should
be planned to arrive at an altitude not
requiring supplemental oxygen when
gage indicates 300 psi.
DRAG CHUTE
GENERAL
The drag chute is an optional deceleration
device. It, like the thrust reverser system, may be
used to produce shorter stopping distances. The
greatest deceleration rate is produced at the
highest speed; however, the chute is still
effective at speeds as low as 60 knots.
The chute is stored in a removable canister
which is mounted inside the tailcone access door
(Figure 17-11). The canister lid is released from
the canister when the drag chute handle is
pulled, allowing the pilot chute to deploy. The
pilot chute then pulls the main chute canopy out
of the canister.
The main chute riser attaches to the airplane at
the chute control mechanism just forward of the
canister (Figure 17-12). The loop at the end of
the main riser slips over a recessed metal pin
which is held in position by spring pressure
when the drag chute is stowed. Therefore, if the
chute should inadvertently deploy (handle in
stowed position), the main chute riser will slip
free of the pin and separate from the airplane.
When the drag chute handle (Figure 17-13) is
pulled, the pin is mechanically locked in position
to retain the chute riser. Simultaneous
functioning of the mechanical canister control
mechanism releases the canister lid, thereby
deploying the chute.
17-10
FOR TRAINING PURPOSES ONLY
LEARJET 20 SERIES PILOT TRAINING MANUAL
FlightSafety
international
Figure 17-13. Drag Chute Handle
Figure 17-11. Tailcone Access Door and
Drag Chute
Figure 17-12. Drag Chute Riser
Attachment Hook