5
$\begingroup$

I've read in FCOM that, during engine start reopening of the pack flow valve is delayed for 30-60 s to allow second engine start? But isn't it that the pack flow remains closed only for the side the master switch is on? So how does that evgen affect second engine?

$\endgroup$
0

1 Answer 1

1
$\begingroup$

But isn't it that the pack flow remains closed only for the side the master switch is on?

This is correct, when the crossbleed valve is closed only one pack valve is closed and reopened with a delay. When the crossbleed valve is open, then both pack valves are closed and both are reopened with a delay.

enter image description here
Source: A320 FCOM

The documentation, which could be improved, must be interpreted this way:

  1. Crossbleed valve closed:

    In this case only one pack is connected to the starting engine. Only one pack vane is closed, according to bullet 1. It is reopened when the conditions are no more the ones in bullet 2.

    When the second engine is started, the same sequence applies on the other pack vane.

  2. Crossbleed valve open:

    In this case the two packs are connected to both engines. When the first engine is started both pack valves close, according to note on bullet 2. The reopening is delayed on both valves, according to bullet 3. This delay anticipates the start of the second engine which would need to close them again.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .