Hi all, The APU bleed normally supplies only the left pneumatic duct. If you are going to start right engine first as most of real world operations, you must set the isolation valve switch to OPEN before turning the start switch of right engine to GRD. So if you forget to open the isolation valve before attempting to start the right engine, there should be no air pressure to open the starter valve or to rotate the N2 spool. The NGX actually simulates this system correctly except for the starter nice roaring sound. This nice roar actually plays even when there is no N2 rotation as described above. Please advise if any one has experienced this condition. I will include here brief steps to reproduce the problem from cold and dark state: 1. Turn up the volume at your system, and you better use a high quality headset so that you can clearly hear the very nice realistic roaring of the starter. 2. Battery switch ON. 3. Standby Power switch AUTO. 4. Bus Transfer switch AUTO. 5. APU switch START then ON. 6. After APU GEN OFF BUS light comes on, both APU GEN switches ON. 7. APU bleed switch ON. 8. Make sure ISOLATION VALVE switch is in CLOSE position. 9. Set right engine staring switch to GRD. You now should be seeing no N2 rotation, but unfortunately starter roaring sound plays! Please give me your feedback before I file a ticket.

Did you set the start switch to right for engine 2?

Confirmed, starter sound plays but no engine rotation. BestHolger Kneib

Did you set the start switch to right for engine 2?

I set the start switch to GRD for engine 2.

Confirmed, starter sound plays but no engine rotation. Best Holger Kneib

Thanks Holger. I guess I shall go for a ticket then.

The engine start switch needs to be set to the right, Eng No. 2. Your procedures above don't advise this.....In this case the engine start switch would be set to the left, Eng No.1.......

There is an independent start switch for each engine Graham, i. e. there are two start switches in the overhead panel. Any of them must be rotated left (GRD position) to start an engine.

I understand that.....It's the center engine start switch I'm referring to, but reading the original post I may have mistaken the point of the topic.....

Center Engine Start Switch?????

I understand that.....It's the center engine start switch I'm referring to, but reading the original post I may have mistaken the point of the topic.....

The switch between the two engine start switches is the ignition system selector - I think that is the one you are referring to. It doesn't have to be set to IGN 2 to start engine 2; each engine has two separate ignition systems, this selector just lets you choose which one to use. I believe a common practice is to move it to the opposite position on each flight, to make sure that both ignition systems are used about the same. I've noticed the same as the OP, starter sound seems to be linked to the position of the engine start switch, not actual N2 rotation.

I think he is referring to the Ignition system.That switch only select wich spark, for each engine, will work.If selected Left, only the ENG2 and ENG1 left sparks will work at start up, if selected right only right sparks ON BOTH engines will work during startup.Both is both... :)

Tried and yes, its a very little bug... :)