Autoland

Question 1

During an auto land, when does the electric system isolate to 3 sources?

Answer 1

When the third autopilot gets armed, ie: select APP and arm the other 2 autopilots

Question 2

During an autoland, when will the other 2 autopilots engage after being armed?

Answer 2

1500 ft RA

Question 3

What are the indications of auto land capability?

Answer 3

FLARE and ROLLOUT armed (white) on the ADIs. Also a green bar (LAND 3 or LAND 2) on the Autoland Status Annunciator.

Question 4

If you’re down to say 300 feet and the glide slope transmitter fails, what are your indications?

Answer 4

The glide slope bug will disappear, then a few seconds later, I’ll get a yellow bar through GS pitch mode and an AUTOPILOT Caution and beeper.

Question 5

At 300 feet, the left generator fails with no APU running. What are the indications?

Answer 5

The right generator picks up the left and center buses (drops off the battery and the inverter) and the ASA downgrades to LAND 2 / NO LAND 3.

Question 6

200 feet, the left generator fails with no APU running. What are the indications

Answer 6

Below 200 feet, the right bus tie won’t allow the right generator to pick up the left bus, the center buses stay on the battery and the inverter, and there is no downgrade on the ASA.

Basically, the only thing that happened is that the left bus died (ie: upper EICAS plus some other stuff). However, you have to remember that the autothrottle gets powered off the left side so I’ll get an A/T DISC Caution and so manually retard throttles in the flare.