Has anybody been able to carry out a cross-bleed engine start ? I've tried several times but can't get the second engine to start. I get N2 rotation to 15 %as required but there's no lightup when I turn on the fuel switch. (yes - the fuel pumps are on !) Im assuming it doesn't matter which engine is started first. I would be grateful of confirmation from anyone either that it works or doesn't. Regards Fergus Cameron

You have to run up the running engine to get sufficient bleed pressure. 1 engine at idle doesn't provide enough to start the other engine.

Isolation valve Open?

have you increased the thrust on the running engine to acheive a high enough bleed pressure?

That's it, I've been trying with the running engine at idle - too may hours using less realistic aircraft obviously. Thank you ! Regards Fergus

increase engine thrust until you have a duct pressure of around 30. As already mentioned don't forget to open the isolation valve (although with at least one pack off it should be open when the switch is in auto)...regardschristopher volle

Can someone explain under what circumstances you would need to perform a cross-bleed start. Surely to get the first engine started you need either the APU or ground air. Why would you not use this to then start the 2nd engine?Thanks Graeme

Some airlines operate single engine taxi on departure taxi. A cross bleed start could be used in this example. Regards Paul

Can someone explain under what circumstances you would need to perform a cross-bleed start. Surely to get the first engine started you need either the APU or ground air. Why would you not use this to then start the 2nd engine?ThanksGraeme

The connection for the high pressure air is on the right side of the aircraft. That's the reason you start the left engine first. Then the ground crew can safely disconnects the ground equipment. It wouldn't be safe at all if you start both engines on external air because of the ground crew being on the right side (in front of the engine). Regards

I executed a cross-bleed start yesterday no problem anyway...I opened the isolation valve and set the eunning engine at 55% N1%... Ciao Andrea Buono

It's also possibel to do a NO ENGINE BLEED takeoff with just the APU running.Could be needed if the plane needed all the thrust it could get.

for 'no engine bleed air TO (or approach) with APU' just remember the 'C'-pattern:- R pack auto- isolation valve closed- L pack auto- L bleed air off (to avoid backpressuring the apu)- Apu bleed on- R bleed air off (on pack is enough) after TO just do it the other way round (but let the cabin rate stabilize before turning L pack on again)!regards,christopher volle

A crossbleed start is also useful if starting engines using ground cart. A reason maybe APU or APU bleed inop.In this condition it is preferred to start the left engine first, then, the cart can be removed (the ground cart are always on the right side of te plane, and the ground connection for pneumatic system is on the right side, attached to the air conditioning access door).The ground cart provides pressure to the right pneumatic duct, so, to start LH engine you need the isol. valve open.Then start the left engine normally.The ground cart can be removed and removed to clear the RH engine area.The procedure is now the same as most people told you.