Technical data

13773-001
21-60
Page 1
TEMPERATURE CONTROL
1. DESCRIPTION
The amount of cooling air allowed into the air mixing plenum is controlled by rotating the Cabin Cold Con-
trol Knob, located outboard of the Cabin Air Selector (Defrost-Floor). The control is mechanically linked to
a butterfly valve at the fresh air entrance to the mixing plenum. Rotating the control full counterclockwise
shuts down cooling airflow to the mixing plenum from the fresh air inlet in the right wing root. Rotating the
control clockwise opens the butterfly allowing fresh cooling air to enter the mixing plenum. Rotating the
control to the full clockwise (COLD) position provides maximum cooling airflow to the mixing plenum.
Conditioned air from the mixing plenum can be proportioned and directed to the windshield or passengers
by manipulating the Cabin Air Selector. The control is linked to a door at the outlet end of the mixing ple-
num. Rotating the control full counterclockwise to the miniature windshield icon shuts off airflow to the pas-
senger air distribution system and allows maximum airflow to the windshield diffuser. Rotating the knob full
clockwise to the seated person icon shuts off airflow to the windshield diffuser and allows maximum airflow
to the passenger air distribution system. The control can be positioned to allow any proportion of wind-
shield and passenger air.
Conditioned air for the forward seats is routed to outlets under the instrument panel at knee level. Condi-
tioned air for the aft seats is ducted to outlets beneath the forward seats near the door posts and exits at
floor level.
2. MAINTENANCE PRACTICES
A. Temperature Control Knobs
(1) Removal - Temperature Control Knob
(a) Rotate the control knob to gain access to setscrews.
(b) Loosen the two setscrews. Remove the control knob.
(2) Installation - Temperature Control Knob
(a) Rotate the linkage shaft counterclockwise.
(b) Slide the control knob onto the linkage shaft in the full counterclockwise position.
(c) Secure the two setscrews.
(d) Verify operation of the Temperature Control Knob.
(3) Adjustment - Heat Position Control
(a) Loosen the stop on the end of the cable.
(b) Move the butterfly in the heat box to the full hot position (downward).
(c) Rotate the heat position control knob to the full heat position (clockwise).
(d) Secure stop on end of cable.
(e) Verify operation of the Heat Position Control knob.
(4) Adjustment/Test - Defrost and Cold Air Position Linkage
(a) Rotate the control knob to gain access to the two setscrews.
(b) Loosen the two setscrews. Remove the control knob.
(c) Rotate the linkage shaft counterclockwise.
(d) Slide the control knob onto the linkage shaft.
(e) Rotate the control knob to the full counterclockwise position.
(f) Secure the two setscrews.
(g) Verify operation of the Defrost and Cold Air Position control knob.
30 Nov 2000