INU and the ADI

[AussieFX]

Aussie, is there some sort of control lockout that prevents the pilot for advancing the engines to full power? If not, what would happen if an impatient pilot stepped an engine up to full power as soon as he/she could (BTW, I'm not recommending you do actually try this!)?

My long post has disappeared. :cry:

 

In short no there is no lockout. I'm not sure about the FADEC models but apart from the autostart feature I think they're the same.

 

It comes down to metallurgy, the hot and cold ends are made of differing materials that heat/cool at different rates.

When combustion begins the core can heat up to temperatures ranging anywhere from 800-1000°c in a matter of seconds so they have ernormous stresses placed on them.

You need to remember these engines are very expensive costing in the hundreds of thousands of dollars. Consequently you treat them like babies.

 

Lubrication isn't really an issue, when you first hit the starter you should watch for movement in the oil pressure gauge. You have 10-15 seconds before combustion starts anyway so damage is possible but unlikely.

 

2 minute cool down is just as important as warming up.

 

EDIT: Note this is the requirement for Allison C20-250 engines, others may have different requirements.

Edited June 16, 2009 by AussieFX
Added note.

[mvsgas]

Aussie, is there some sort of control lockout that prevents the pilot for advancing the engines to full power? If not, what would happen if an impatient pilot stepped an engine up to full power as soon as he/she could (BTW, I'm not recommending you do actually try this!)?

Obviously there are many variables here and are very dependent on the specific systems. Talking generally on jet engine (and solely base on my experience with F-100-PW, F-110-GE and the F404) time limits help the engine stabilize and archive idle. This means that you are allowing the engine oil system to achieve optimum temperatures and to start distributing to the many bearing compartments. This is important because beside lubrication, oil serves as a coolant in many areas of the engine. You are allowing the combustion chamber and the high pressure turbine (HPT), low pressure turbine (LPT) and many other components to get a stable tempt and speed, again this is important because the range of temperature are very big and rapid increase of power could affect the integrity of the metal strength. Keep in mind that some of this engine produce so much power that some of this compressor blades ( some made from titanium) will flex and twist during operation. You are also checking for proper engine parameters ( EGT, RPM, PPH or fuel flow) and looking for signs that everything is working properly before advancing the throttle above idle.

 

No obvious damage may happen if this time table are not follow, but the damage you can not see is what pilot should be worried about. Over enemy territory is no time to have a component failure because of improper utilization.

[AussieFX]

Interestingly in the game I have had an engine shutdown on me due to excess vibration. I wonder how some here are getting away with these quick starts.

[ericinexile]

Interestingly in the game I have had an engine shutdown on me due to excess vibration. I wonder how some here are getting away with these quick starts.

 

When that happens to me it is because I failed to turn the governors on.

[EinsteinEP]

Interestingly in the game I have had an engine shutdown on me due to excess vibration. I wonder how some here are getting away with these quick starts.

Aussie,

 

Attached is a .trk of my quickstart, no engine shutdown.

 

Hopefully the next patch (or hopefully a later patch/mod?) will introduce a more realistic INU alignment to make the startup procedure more satsifyingly realistic, but I have to admit, only having about 100 seconds between flipping the first swtich and being wheels up is pretty convenient!