FSX Afterburner zones?

#1
I'm new to editing and creating XML gauges. Just wondering if anyone has thoughts on what I'm doing wrong with this afterburner zone code?

The effects will display in FSX for the first three zones, but the last two do not show.

Have tried taking the last two effects and placing them in the SMK_CTRL(2) and (3) slots in the aircraft.cfg.
The effects do show than, but not if they're placed in the SMK_CTRL(5) or (6) slots. So it is not an issue with the effects themselves.

Just a note, the throttle is set in the aircraft.cfg to engage afterburner at the 60% mark. Here is the meat of the code:

(A:general eng1 throttle lever position, percent) 60 > @SMK_CTRL(2)
(A:general eng1 throttle lever position, percent) 70 > @SMK_CTRL(3)
(A:general eng1 throttle lever position, percent) 80 > @SMK_CTRL(4)
(A:general eng1 throttle lever position, percent) 90 > @SMK_CTRL(5)
(A:general eng1 throttle lever position, percent) 95 > @SMK_CTRL(6)

Any insight into why the last two do not work would be appreciated.

Thanks!
 

Roy Holmes

Resource contributor
#2
A few comments.
The number of AB stages is an entry in the aircraft.cfg. [TurbineEngineData] afterburner_available = 5. If you want 5 AB stages you need 5 there.
You can have the entry called afterburner_throttle_threshold = at 0.6 if you want that as the point of transition between dry and AB thrust. In the real world that figure would be more like 0.9.
If you have 5 stages and a 90% threshold then Stage 1 starts at 90, stage 2 at 92, stage 3 at 94, stage 4 at 96 and stage 5, full AB at 98% throttle. If you have associated effects with AB stages, you do not need any code to control them.
Your code is incomplete, after each condition "60 >" you need an if statement that calls the macro.
Roy
 
#3
Thanks so much for the advice.

The AB stages and throttle_threshold in the aircraft.cfg all check out. In the actual aircraft the AB détente is just a bit beyond the halfway point.

Updated the code to the following with the ' if '.

(A:general eng1 throttle lever position, percent) 60 > if @SMK_CTRL(2)
(A:general eng1 throttle lever position, percent) 65 > if @SMK_CTRL(3)
(A:general eng1 throttle lever position, percent) 70 > if @SMK_CTRL(4)
(A:general eng1 throttle lever position, percent) 80 > if @SMK_CTRL(5)
(A:general eng1 throttle lever position, percent) 90 > if @SMK_CTRL(6)

(A:general eng2 throttle lever position, percent) 60 > if @SMK_CTRL(7)
(A:general eng2 throttle lever position, percent) 65 > if @SMK_CTRL(8)
(A:general eng2 throttle lever position, percent) 70 > if @SMK_CTRL(9)
(A:general eng2 throttle lever position, percent) 80 > if @SMK_CTRL(10)
(A:general eng2 throttle lever position, percent) 90 > if @SMK_CTRL(11)

The burner effects now show up to Zone 5 in engine 1. So that one seems fine.

In engine 2 goes into burner up to Zone 2, nothing shows after that which is a bit of a puzzle.

Another issue I'm running into now is the throttles jitter and jump back to stage 1 at times when full burners is selected. Any ideas?

Thanks again!
 
#6
Ok, that is great info. Was not aware of that.

Was able to get all the effects to present. Problem turned out to be another gauge which was using the last three slots in the smoke control - so that is why the last three zones in the second engine were not showing. Moved it further down and now it all works fine on both engines.

Can the (A:TURB ENG AFTERBURNER STAGE ACTIVE:index, number) be used for controlling the amount of thrust per stage?
 

Roy Holmes

Resource contributor
#8
The AB stages automatically increase the thrust. If you had 2 stages and the AB increment of thrust compared to the dry value was 1.5 then each stage would add 0.25, so the sequence would be:
dry thust x1 for the throttle setting just below where AB is called
dry thust x1.25 for the throttle setting just above where AB is called
dry thust x1.5 for full throttle.
You do not have to do anything about the thrust increase.
The ratio of AB thrust to dry thrust is in Record 1524 of the air file. The values are dependant on Mach number.
If you had 5 stages each would add 0.2 of AB Thrust scalar in 1524

Unfortunately, although thrust increment is done for you, the fuel used computation is incorrect in that it ignores the amount of fuel used in the front(dry) section of the engine. So the lower stages of AB reduce the total fuel flow even though thrust and therefore fuel flow should increase.
Roy
 
#9
This is all great stuff. Everything is working fine now!

The only issue left was when editing the aircraft.cfg under the: afterburner_throttle_threshold = 0.60

It will activate the afterburners and go through the different zones, but the throttle in the virtual cockpit makes a lot of uncommanded changes in throttle position.
The throttle jumps and jitters a lot and the corresponding afterburner zones jump around. For whatever reason it is not stable.

Have since removed that line and the afterburners are stable, but the throttle range for afterburners is limited and not accurate to the actual aircraft.

Could a gauge be made using the TOGGLE_AFTERBURNER1 to set the starting point for the afterburners?

Still new to this, so don't know if anything like this would work?

(A:general eng1 throttle lever position, percent) 60 > if (K:TOGGLE_AFTERBURNER1)

May encounter the same issue, but thought it may be worth one last try.
 

JB3DG

Resource contributor
#10
(K:TOGGLE_AFTERBURNER1) is incompatible with staged afterburners. Your best bet is to use simconnect to limit the throttle.
 

Roy Holmes

Resource contributor
#11
The easiest way to control anything throttle related is to use a throttle, then you can control the engine directly. If you want to have the afterburner kick in at 60% throttle do it in the aircraft.cfg. Staged afterburners will then work according to how many stages you have and the last 40% of throttle movement. No code needed.
Roy
 
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