correct as is Engine startup sequence

[Maksim Savelev]

Hello. Just started to follow the  manual and compare it to the module, so some more  question will follow. For now I have this one. I  think there is a misinterpretation from my or ED side about correct sequence of engine start.

Manual says that ignition is switched off when 35% are reached and APU and starting system are shut-down when 50% are reached. In auto sequence LHenginestarts after the 10sec rest of APU. In module we can see that this 10sec rest period starts at 35% when the RHENG START (lit when ignition is running)  goes off, but not 10sec after the 50% reached

[BIGNEWY]

Hi, thank you for the PM with the other manual information. 

I asked the team and they have checked their sources for our aircraft, the manual we have is very specific about this.

APU goes on idle (not shut-down) for 4 seconds (+ dynamic process to idle and back ~ 3 sec) between engines.
Conditions for it: right engine's rpm > 50% OR time > ~40 sec from process beginning.
Сonditions for right engine ignition: right engine's rpm < 35% AND time <40 sec from process beginning.
 

We have checked in DCS and it is correct based on our sources for our version of the MiG-29A 9.12A 

 

[Maksim Savelev]

Thank you for the quick respond! It really means a lot!

I can see that your answer only confirms my point and there is a discrepancy in current sequence in module of MiG-29.

So based on info provided above which is actually in line with what I've messaged you we should have it like this:

This cycle: "APU goes on idle (not shut-down) for 4 seconds (+ dynamic process to idle and back ~ 3 sec) between engines" - in total of about 7 sec of rest period from the time when RH engine will reach 50% or 40sec elapsed, which is not a factor, since 50% are reached by 37sec elapsed since the start button pushed. 

But in fact in a module LH startup sequence starts  when total 36sec elapsed from the time start button pressed which is exactly 7sec apart from 29sec of elapsed time when RH engine is only  reaching  it's 35%. 

All measured at standard ISA conditions

So it's clear for me that someone mismatched these two different factors: point of disengaging of APU and disengaging of ignition.

1 hour ago, BIGNEWY said:

We have checked in DCS and it is correct based on our sources for our version of the MiG-29A 9.12A 

Not sure what you've been measuring, maybe you're using already different version of the Module

Edited 8 hours ago by Maksim Savelev

[BIGNEWY]

1 minute ago, Maksim Savelev said:

Thank you for the quick respond! It really means a lot!

I can see that your answer only confirms my point and there is a discrepancy in current sequence in module of MiG-29.

So based on info provided above which is actually in line with what I've messaged you we should have it like this:

This cycle: "APU goes on idle (not shut-down) for 4 seconds (+ dynamic process to idle and back ~ 3 sec) between engines" of about 7 sec should start when RH engine will reach 50% or 40sec elapsed, which is not a factor, since 50% are reached by 37sec elapsed since the start button pushed. 

But in fact in a module LH startup sequence starts  when total 36sec elapsed from the time start button pressed which is exactly 7sec apart from 29sec of elapsed time when RH engine is only  reaching  it's 35%. 

All measured at standard ISA conditions

So it's clear for me that someone mismatched these two different factors: point of disengaging of APU and disengaging of ignition.

Not sure what you've been measuring, maybe you're using already different version of the Module

please include a track replay example on Caucasus terrain and we will take a look, but as mentioned the team have checked and all seems correct. 

thank you 

[Maksim Savelev]

Well I have nothing to add to this I don't see a need to attach any track to it, to make it overcomplicated. 

Run the sequence measure and check timings. Nothing more. I lean to believe that someone who was checking is  mismatching it and counts 7sec from StartUp light extinguished, but not from 50% reached that's it  

[BIGNEWY]

I asked the team for a better explanation, 

1. Lamps indicate IGNITION (right and left),
2. At 35% N2 right ignition switches off, lamp off.
3. At 50% N2 left ignition switches on, lamp on, APU disconnects from right engine and starts idling.
4. After approximately 10 seconds, left engine starts to spool-up.

The main thing to note here, using the lamps to judge if the start up sequence is correct is not a good way to go. Basically the time between two lamps does not correspond to timing in manual. This is the time engine spools-up from 35 to 50%.

I hope that helps explain why we are confident the timings for the engines are correct in DCS. 

thank you 

[Maksim Savelev]

That exactly what I'm saying to you)))!

You just described the correct way! that exactly what I was trying to explain, how to make it correct)

Problem is its not like that in a simulation which comes with this module/ 

So please fix it by implementing the correct way of things you just mentioned)

Edited 5 hours ago by Maksim Savelev

[BIGNEWY]

Ive passed on your feedback but as mentioned it is correct in game. 

thank you