A320 Eng Relight Altitude
 

Hi,

For A320 with CFM engines the Max altitude as indicated in the Inflight Engine Relight Envelope is 25000 ft.

Hence in case of engine failure during cruise say at FL 390, what are actions once the ECAM asks for : Eng Relight Consider?? Do we wait till below 25000 ft before attempting a relight?

Thanks

I would swuggest a difference between relight and restart

I believe

Relight is a fadec controlled fuction activated within seconds without pilot interception.

Restart is where the engine has spooled down without enough presurization on its own to support a relight

The latter requires configuring the air entering the engine to support ignition (aircraft speed and altitude pressure)

For restart capabilities you can attempt any attempts you care, but do expect hung starts or hot starts and no sucessful acceleration to power until you achieve the published restart envelop

Lomapseo
Relight and restart are not different. What you are mentioning is the Auto relight feature. But yes for a successfull restart or relight you need to be in the restart envelope.

Hi all,

The max altitude for cfm is 27, 500 ft according to my fcom and not 25, 000.
This altitude represents the max guranteed altitude for engines to restart and it does not mean engines will not restsrt above it.

QRH ABN-70.03

I got 25000ft on mine. But really, it depends on your exact type of engine.

Anyhow, I'm sure it's capable of restarting above FL250 with the master and ignition on and the IAS above 300kts. No reason not to.

That's like saying it can ingest 20 lb birds as well.

The facts are that it could only reliably demonstrate restart in the published envelop

of course your mileage may vary but don't depend on it

....and then there was that little problem that made it flame out in the first place. :ooh:

Recent Airbus presentation on dual engine flame out shows the area above relight envelope as no relight attempt zone where you ensure EMER gen on and initial decsent etc. If engine could start anywhere then where was the need for the graph of relight envelope? Since the air density is low chances of relight are very low, you would not like to end up damaging the engine through repeated hot or hung starts.Latest manuals for CFM show 25000 ft where the envelope begins.

Relight
 

My little rule of thumb over the years is "28/28"
You need to below 28000 ft and above 280 Kias for a successful relight. Simple.
Works for most jets. 28/28
T