View Full Version : Cf6-80c2 relight envelope
tubby linton
18th Mar 2012, 22:58
The qrh for my aircraft only specifies a minimum N2 for a windmill relight,does anybody have a diagram of airspeed and altitude to achieve this figure? I am guessing about 300kt up to FL 300 but would be interested in figures for lower altitudes.
Intruder
19th Mar 2012, 04:06
Your performance manual or FCOM should have an envelope.
tubby linton
19th Mar 2012, 16:26
The FCOM just states for a windmill start below FL 300.
KBPsen
19th Mar 2012, 17:03
Can't find one for a -80C2.
This is for a CF6-80E1.
http://i39.tinypic.com/2u4tx6w.jpg
And for a CF6-50C2
http://i41.tinypic.com/mcrx21.jpg
virustalon
19th Mar 2012, 22:18
Min n2 relight is the fuel on command bug. Represents 15 of n2. Max inflight re engagement of n2 is 30 or u will damage the gearbox
Max on ground is 1% change of n2 in 5 secs
What about HOT Relights - ie within 10 seconds of flame out. If you are quick enough you should be able to get those flames going again at max altitude. Some fighters have auto relighters.
Intruder
20th Mar 2012, 08:17
The EEC has auto relight as installed in the 744, too. Igniters are lit automatically if N2 goes below idle.
QRH sez use the Start switch below 220 KIAS and N2 <20% if the EEC doesn't catch it.
tubby linton
21st Mar 2012, 14:26
Thank you for the info. The CF6 I had in mind only has a pmc and no autorelight.