4. INSPECTION / CHECK
A. Tools and consumable materials
None
B. Checking of vacuum pump circuit — refer to 37-11-00
Check that the vacuum pump circuit filter is not clogged. Access to filter can be gained through the L.H. upper door on firewall or (if installed) through the L.H. door in front of windshield.
C. Functional check
Check operation on aircraft after any rectification on servo—actuators, so as to make sure that no electrical or mechanical reversal was carried out during corrective action.
1) Tests on ground
NOTE : Aircraft levelled.
Engine running, gyros cranked, before engagement of the autopilot, check that the suction gage lies between 4.4 and 5.2 in.Hg and that the aircraft mains voltage power system is not under 12 volts.
Center heading bug on the HSI indicator (or heading indicator according to the system).
a) Roll function
— Autopilot : "ON".
— Select HDG mode.
— Turn heading bug to the right 20° : . control wheel turns to the right, . R.H. aileron lifts up.
— Turn heading bug to the left 20° . control wheel turns to the left, . L.H. aileron lifts up.
— With heading bug to the left and control wheel fully deflected to the left, check that it is possible to manually override the autopilot action by bringing the control wheel back to the centre.
— Autopilot : "OFF".
b) Electric pitch trim function
— With the pilot's wheel knob, operate "TRIM UP" :
. Trim knurling wheel moves rearward (nose—up position), . Anti—tab trailing edge lifts down.
— Operate "TRIM DN" :
. Trim knurling wheel moves forward (nose—down position), . Anti—tab trailing edge lifts up.
— Operate "TRIM DN" and check that it is possible to prevent manually the movement of the pitch trim control wheel.
— Release the electric pitch trim control.
c) Pitch function
— Autopilot : "ON".
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本文鏈接地址：TB20 MAINTENANCE MANUAL 22 AUTO FLIGHT TB20飛機維護手冊 22 自動飛行(15)
