Pack status during engine start

Start the first engine

APU start setup / ECS ^[101]

With a normal APU-supported start setup, display ECS and note both pack indications.

Start the first engine following the documented procedure.

ERAV BIT effect

Pack / bleed / start

ERAV BIT can hold PACK 1 phase off

The CAS page describes an emergency ram-air-valve test that holds PACK 1 off for about 90 seconds on the first engine start of the UTC flight day; a turnaround spawn skips it.

Observe the pack and bleed indications throughout the start and again after stabilisation.

CAS and start state

Check the start phase, actual CAS messages and post-start state before diagnosing a persistent pack failure. ^[102]