Electrical System

Question 1

Symptoms:

1. AFCS pitch and roll channels disengaged.
2. Pilot and copilot ADI’s failed.
3. Loss of cockpit instrument lighting.
4. Loss of all AC powered equipment.
5. STAT page FAIL line:
   a. EGI 1 and 2, HDG 1 and 2 (egi’s aligned and working normally).
   b. TACAN (provides distance only on BDI, direction/distance on MFD bearing needles).

Answer 1

DUAL AC BUS FAILURE

Corrective action:

1. FLIGHT CONTROLS - STABILIZE THE AIRCRAFT.
2. Cool switch - OFF.

If VMC cannot be maintained and AC components are required to stabilize the aircraft:

3. AC 26V xfer switch - CENTER.
4. No.1 main AC bus circuit breaker - Check/reset only if popped (cabin overhead R1 No.2).

If the Number 1 alternator fail light is illuminated:
5. No.1 Alternator - RESET.

If power to the No.1 AC bus is restored:

6. AFCS gyro switch - Move in the direction of the operating EGI.
7. AFCS Pitch and Roll - Reengage.
8. Land as soon as practicable.

If power to the No1. AC bus is not restored:
10-13. Repeat for No.2 alternator.

If power to the No.2 AC bus is not restored, AC power recovery is not possible.

14. Partial panel instrument flight - MAINTAIN UNTIL VMC is ESTABLISHED
15. Land as soon as practicable.

If VMC can be maintained.
3. Land as soon as practicable.