Technical data

13773-001
27-50
Page 1
FLAPS
1. GENERAL
This section describes that portion of the flight control system which controls the position and movement of
the flaps. Included are the torque tube assembly, flap actuator assembly, flap indicator and switch.
Flap control is achieved via a flap activation switch mounted on the center console. Indicator lights identify
flap position. A linear actuator, located under the baggage floor, drives a torque tube interconnect between
the left and right flaps. A load limiting clutch on the actuator prevents flap deployment at high speeds. Prox-
imity sensors on the flap linear actuator identify flap position and surface travel. In the event of a sensor
failure, torque tube/actuator geometry prevents the flaps from causing an uncontrollable flight condition.
2. MAINTENANCE PRACTICES
A. Flap Actuator Assembly (See Figure 27-501)
(1) Removal - Flap Actuator Assembly
(a) Pull FLAPS circuit breaker.
(b) Remove passenger compartment seats. (Refer to 25-10)
(c) Remove carpet and access panels CF4C and CF5. (Refer to 6-00)
(d) Remove cotter pin, castellated nut, washers, and bolt securing flap actuator to torque tube
coupler.
(e) Disconnect flap actuator electrical connector.
(f) Remove bolts, washers, and radius blocks securing flap actuator assembly to actuator
bracket and remove from airplane.
(2) Installation - Flap Actuator Assembly
(a) Position flap actuator assembly to actuator bracket and install bolts and washers.
(b) Manually extend actuator to approximately 50% full deployment.
(c) Connect flap actuator electrical connector.
(d) Reset FLAPS circuit breaker.
(e) Turn flap switch to UP.
(f) Turn MASTER SWITCH to ON.
(g) After flap actuator stops, turn flap switch to 50%.
(h) Loosen adjustment screws and reposition full up proximity sensor to within 1.0 inch (2.5
cm) of middle proximity sensor.
(i) Loosen adjustment screws and reposition full down proximity sensor to within 1.0 inch (2.5
cm) of middle proximity sensor.
(j) Install bolt, washers, castellated nut, and cotter pin securing flap actuator push/pull rod to
torque tube coupler.
(k) Perform Flap Travel Adjustment/Test. (Refer to 27-50)
(l) Install access panels and carpet. (Refer to 6-00)
(m) Install passenger compartment seats. (Refer to 25-10)
B. Torque Tube Assembly (See Figure 27-501)
(1) Removal -Torque Tube Assembly
(a) Remove nuts, washers, spacers, and bolts securing torque tube thrust collar and end fit-
ting to flap torque tube.
(b) Remove passenger compartment seats. (Refer to 25-10)
(c) Remove carpet and access panel CF4C. (Refer to 6-00)
(d) Remove cotter pin, castellated nut, washers, and bolt securing flap actuator push/pull rod
to torque tube coupler.
30 Nov 2000