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FS2004 Engine surge

I've done something like this for FSX, but the code is out of reach at the moment.

Basically, all you need to do is defining typical surge conditions, like:

- Ice ingestion
- Angle of attack (F-14...)
- Bird strikes (a bit more complicated to implement)
- Thrust reverser abuse (if present)
- ...etc...

And then just play a "BANG! BANG! BANG!" sound and cut the fuel switch of the affected engine (or give the pilot a chance to react) if one of these conditions is met.


Bonus points for obfuscating any messing about with the fuel switch on the 2D/3D throttle quadrant.
 
I'll have to do something that makes all the engine T's & P's go haywire. I can play a sound too. Anything above FL250 and below -25c if the Wing Stop Valve is closed and the airframe anti-ice hasn't been selected.
This is a never ending story!!!!!!!! (As I finish one component another needs adding to the list!)
vololiberista
 
With Turboprops, you adjust Beta_min in the 'aircraft.cfg' and that will cause spiking in the surge. Zero will be zero spike where 15 will be a 'slight over spool' which can get exciting. 15 is the number that MS uses on TP's. 5 is probably more realistic in FSX, 15 is good in FS9.

Adjusting the time delay has always had me curious as to how that would be adjusted.
 
This for a bypass jet though: Rco.43 Mk.550 22,500 lb (100.1 kN) turbofans. The aircraft model uses a single airfile for both Standard and Super VC10's. So the engine model is also for one engine type i.e. Super. The standard was 21,000 lb (94.1 kN).
The Super's engine is/was prone to surging above 25,000ft if the a/c anti-ice had not been selected!
vololiberista
 
Man, its too bad you arent already using Spoilers as you could create a fake effect with those, a hidden gauge using speeds, alt, etc.

What would be easy is a drag enducer that is always on unless the surge tags appear, then it releases the drag.

If only the tailhook had drag. You could use that.



Bill
 
Engine surges don't create a "surge" in thrust or anything like that. They stop producing reliable thrust even though RPM is about the same or increasing. The flow is destabilized or reversing.

The only way to reproduce it in the sim is to reduce thrust without reducing throttle.
 
You could simulate a surge by briefly shutting off the fuel supply. Do it with the Mixture control (acts as a fuel shut-off with jets in FS) Depending on the type of ignition set-up you will get a relight on fuel supply restoration.
Roy
 
Roy Holmes said:
You could simulate a surge by briefly shutting off the fuel supply. Do it with the Mixture control (acts as a fuel shut-off with jets in FS) Depending on the type of ignition set-up you will get a relight on fuel supply restoration.
Roy
Click to expand...

So far I've tested, turbine engines will shut off as soon as fuel is cut off, with no relight possible, even when the cut off lasted for one single frame...:(

Tom
 
taguilo said:
So far I've tested, turbine engines will shut off as soon as fuel is cut off, with no relight possible, even when the cut off lasted for one single frame...:(

Tom
Click to expand...

you must trigger the starter.

fuel cut--> starter--> fuel on.

FS combustion will only start if the starter is engaged.
 
If it is set up with a Turb Eng Master Starter switch, you do not shut off the starters, they are on continuously. Consequently the fuel can be shut off, turned back on again and the engine relights with no other action needed.

Roy
 
jx_ said:
you must trigger the starter.

fuel cut--> starter--> fuel on.

FS combustion will only start if the starter is engaged.
Click to expand...

Roy Holmes said:
If it is set up with a Turb Eng Master Starter switch, you do not shut off the starters, they are on continuously. Consequently the fuel can be shut off, turned back on again and the engine relights with no other action needed.

Roy
Click to expand...

Yes, of course. But the problem is that when you engage the starter (or it is "autoengaged"), the start cycle forces N2 RPM to rotate from init values, something totally unrealistic.
For example, if engine surges with N2 at 90 %, and fuel/starter are added, N2 RPM drop immediately to around 20s and a normal, ramp start is initiated. This is not what happens in RL. Indeed, starters in turbine engines are disabled above a certain N2 RPM (50 %-up usually) to avoid being damaged by overspeed. Are the igniters in good health what make engines start in flight at high RPM.
And btw, an inflight start at high altitude usually is a slow process, lasting almost double of time compared to standard, with high chances to sustain hot temperatures, nothing good for the health of the engine. FSX model is completely out of this scenario, unfortunately.

Tom
 
Tom
FYI. With the engine running at 95% N1, turning fuel off and on again quickly results in a 5% N1 drop and immediate recovery to 95%.
Remember the Turb Eng Master Starter switch was introduced to simulate continuous igniters.
However, I think it was introduced with FSX (A321) so it may not work in FS2004.

Roy
 
Probably all an EO would notice apart from the pop sound would be a spike in the EGT. Even for that he would have to be staring at his instruments, it's so quick!
vololiberista
 
In FS2004 if the start is triggered constantly...

(>K:TOGGLE_STARTER1)

...the engine will relight from wherever it is, as if the engine was never turned off.

(A:Master Ignition Switch, bool) must be on as well and simulates constant igniters.


This will not work with autostart, the autostart function cuts off the igniters and fuel.
 
Roy Holmes said:
Tom
FYI. With the engine running at 95% N1, turning fuel off and on again quickly results in a 5% N1 drop and immediate recovery to 95%.
Remember the Turb Eng Master Starter switch was introduced to simulate continuous igniters.
However, I think it was introduced with FSX (A321) so it may not work in FS2004.

Roy
Click to expand...

Roy,

You're right, TURB ENG MASTER STARTER SWITCH is present in the A321. Unfortunately, it is not available in some turboprops I'm working on (C208,B1900) so the only way to test it in these aircraft is by custom coding Ignition and Start. So far I noticed a drop greater than the 5 % you stated in the 321 at 30,000 ft.; I'll make deeper test on the turboprops directly.

Tom
 
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