If the steering system is inoperative, differential
power and braking can be used to taxi the air-
plane. Pulling the 28 VDC NOSE STEER circuit
breaker will make it easier to steer, but must be
reset prior to takeoff or landing to provide shim-
my dampening.
OPERATION—WITH VARIABLE
AUTHORITY (SNS 24-258, -260,
-264, AND SUBSEQUENT AND
25-104 AND SUBSEQUENT)
Steering authority varies with airplane model.
On model 24 airplanes, steering varies from 45°
in either direction below 12 knots to 8° at 20
knots. On model 25 airplanes, steering varies
from 50° below 10 knots to 8° at 45 knots.
Variable-authority steering commands to the
computer-amplifier are controlled by wheel
speed transducers. The system reverts to
maximum travel and should not be used above
10 knots if the following conditions exist:
• Model 24 airplanes—Both inboard green
ANTI-SKID GEN lights are off.
• Model 25 airplanes—Two or more of the
following red ANTI-SKID GEN lights are
on: Left inboard, right inboard, and right
outboard.
Nosewheel steering is engaged by actuating the
wheel master or STEER LOCK switch.
To engage wheel master mode, depress and
hold the wheel master switch on either control
wheel; disengage it by releasing the switch
(Figure 14-14).
14-16
FOR TRAINING PURPOSES ONLY
LEARJET 20 SERIES PILOT TRAINING MANUAL
FlightSafety
international
Figure 14-14. Nosewheel Steering System (Airplanes with Variable Authority Steering)
WHEEL
MASTER
SWITCH
