Random hot start causing engines to fail

ccmh15
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Re: Random hot start causing engines to fail

Post by ccmh15 » Wed May 06, 2020 8:44 am

There's a small hack, that disables engine wearing that can be seen within MVAMS:
  • Go to C:\Users\[YOUR USERNAME]\AppData\Local\MVAMS\Configurations\KingAir350i
  • Open the file Simulator.ini
  • Set both values to 0 (means engine is fine, 100 means engine failed)
    The file content should look like this:

    Code: Select all

    [CONFIGURATION]
    left_eng_fail=0
    right_eng_fail=0
    
  • Save and Close
  • Right click on the file -> "Properites" -> Tick "Write Protection".

This way, it's not necessary anymore to use the "Restore" function within MVAMS
(which by the way tries to delete the file completely when used)

I know it's not how it was intended by the Devs, but this way you can rule out the engine wearing mechanism as a source for your engines to fail.

If they keep failing, there must be another reason.

Regards,
Chris

henrik.bergvin
Posts: 81
Joined: Sun Apr 12, 2020 9:56 pm
Re: Random hot start causing engines to fail

Post by henrik.bergvin » Wed May 06, 2020 4:52 pm

I did have a proper and understandable engine failure today, something that I expected would happen (icing conditions, engine blew and shut down, was a very interesting flight to the nearest field...), but I do think very little is required to increase wear to a point where it is more frustration than not.
ccmh15 wrote:
Wed May 06, 2020 8:44 am
There's a small hack, that disables engine wearing that can be seen within MVAMS:
<snip>
If they keep failing, there must be another reason.

Regards,
Chris
I will try this, it might save some frustration :)

freeze1058
Posts: 57
Joined: Sun Dec 22, 2019 1:27 pm
Re: Random hot start causing engines to fail

Post by freeze1058 » Thu May 28, 2020 9:18 pm

Hi,

after several uneventful start-ups I just encountered hot start with ITT well beyond limits for several seconds on both engines.

Both times N1 was stabilized above 20% before advancing condition levers to LOW IDLE.

In-flight the engines didn't fail but afterwards the state was:

ka350i_engines.jpg
ka350i_engines.jpg (14.06 KiB) Viewed 3486 times

Note that I am not using any hardware to control power or condition levers but mouse only.

My current version 1.1.29.

Regards,

Stefan

Taguilo
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Joined: Sun May 11, 2014 11:49 am
Re: Random hot start causing engines to fail

Post by Taguilo » Thu May 28, 2020 11:03 pm

Hi,

What was the residual ITT on your engines?
Did you check fuel flow before and after commanding fuel ON?
Did you shut off the starter before 50-55 % of N1?
Did you check that Power Levers were in Idle position?

Thanks!

Tomas

freeze1058
Posts: 57
Joined: Sun Dec 22, 2019 1:27 pm
Re: Random hot start causing engines to fail

Post by freeze1058 » Fri May 29, 2020 9:00 pm

Hi Tomas,
Taguilo wrote:
Thu May 28, 2020 11:03 pm
What was the residual ITT on your engines?
Unknown.
Did you check fuel flow before and after commanding fuel ON?
Before was zero, after unknown.
Did you shut off the starter before 50-55 % of N1?
Yes, at 50% N1.
Did you check that Power Levers were in Idle position?
Will crosscheck more carefully and advise details if happens again.

However, what confuses me is that it happened to both engines. Could there be any reason that this happens on the same start-up?

Thanks,

Stefan

Heronjr
Posts: 110
Joined: Tue Jan 20, 2015 1:04 am
Re: Random hot start causing engines to fail

Post by Heronjr » Sat Jun 13, 2020 12:54 am

I am in a similar situation in relation to hot starts. Since upgraded to 29 (May 24/2020) the hot starts started again after a pause during versions 26-27-28. With 27-28 I did not suffer any hot start but had a couple of engine failures. In this 29, each and every flight HAS a hot start. My flights are usually in the 2 to 3 hs duration.

I did not change the cold start checklists exactly like the commented in this post, followed since January/2020 when I started a round the World trip with the KA350i, changing the versions at the time of their releases. One thing I can make affirmative is that in version 28 I started to inject fuel on the engine from an interval from 12% to 20%, as Ken says the minimum to the stabled behavior, and never had a hot start.

So, did the devs somehow altered any code for the engine start?

I don't use FSUIPC5 for my controls.

Regards

Taguilo
Posts: 658
Joined: Sun May 11, 2014 11:49 am
Re: Random hot start causing engines to fail

Post by Taguilo » Sat Jun 13, 2020 1:14 am

Hi,

Nothing changed related to engine behavior in all of those versions you mention, including SP1 (v.29)


Tomas

Heronjr
Posts: 110
Joined: Tue Jan 20, 2015 1:04 am
Re: Random hot start causing engines to fail

Post by Heronjr » Sat Jun 13, 2020 4:42 pm

Thanks for the info, Tomas. At least I start to suspect there are many variables involved in this matter, because the virtual aircraft is not behaving as the real one where random factors are not common nor permitted involving engine failures. If MVANS is used before flight to correct engines, why suffer a failure during takeoff or cruise if you're sure things were all done by the book and without yellow or red ITT gauges .

Many factors were originally exposed in this post: Throttles, propellers and CL connected to FSUIPC or other software, MVANS with failures activated or not, winds at the time of starting engines (?!?!?!). I remember my last 3 flights were originated at sea level altitude airfields, with practically NO WINDS and temperatures around 25C - hot starts in all three flights. During this round of the World KA350i tour, I have suffered these hot starts in many situations which I simply cannot establish a logic. At first I thought it was temperature, then, altitude, then... luck?

This week I had a hot start leaving Calcutta (India) to Rangoon (Burma). The flight went well over 2 hs and arriving at Rangoon I put the aircraft in cold&dark (I DID NOT restart the simulator) and decided to start the engines right there. The engines started WITHOUT any hot start.

Please, allow me to ask some questions. Which of the items below may cause hot start:

1. Temperature (ranges?)
2. Altitude (ranges?)
3. Winds (humpf!) (direction?) - I just refuse to believe a developer would write a code to simulate such detail. Cruel!
4. Anti-ice on or off?
5. Bleeds on/off/auto?
6. Oxygen valves on/off?
7. Fuel quantity?
8. Throttles in idle or above idle? Mine are always in idle.
9. Any other factor?

Regards,

Taguilo
Posts: 658
Joined: Sun May 11, 2014 11:49 am
Re: Random hot start causing engines to fail

Post by Taguilo » Sat Jun 13, 2020 10:53 pm

Ok,

The same factors that may produce a hot start in our KA are basically the same that may do in real.

-When fuel is injected at startup before Ng (N1) reaches proper light off speed.
-When battery voltage is poor so Ng speed does not rise fast enough to properly burn the air/fuel mix.
-When starter cuts before Ng reaching a self substained speed.
-After a failed light off, when residual fuel is not vented before trying another start.
-When doing an in-flight start at higher than recommended altitudes.

One thing that I suspect might be causing trouble is when the Condition Levers are mapped to a hardware controller. If it is a bit noisy, might be injecting fuel "on its own" and not being noticed. A good procedure is to check Fuel Flow indication in 0 before engaging the starter, and still in 0 after starter engaged but CL remaining cut. Always ensure that there is no Fuel FLow running before moving CL to low idle, which might denote a controller's calibration.

Tomas

Heronjr
Posts: 110
Joined: Tue Jan 20, 2015 1:04 am
Re: Random hot start causing engines to fail

Post by Heronjr » Sun Jun 14, 2020 12:47 am

Taguilo wrote:
Sat Jun 13, 2020 10:53 pm
-When fuel is injected at startup before Ng (N1) reaches proper light off speed.
As I said, my minimum is 12%, but always waiting for more.

-When battery voltage is poor so Ng speed does not rise fast enough to properly burn the air/fuel mix.
I will try to check the correct voltages recommended.

-When starter cuts before Ng reaching a self substained speed.
This I cannot understand because the ITT jumps to red BEFORE I cut. I wait to cut when Ng reaches 50%.

-After a failed light off, when residual fuel is not vented before trying another start.
???

-When doing an in-flight start at higher than recommended altitudes.
Never did that.

One thing that I suspect might be causing trouble is when the Condition Levers are mapped to a hardware controller. If it is a bit noisy, might be injecting fuel "on its own" and not being noticed. A good procedure is to check Fuel Flow indication in 0 before engaging the starter, and still in 0 after starter engaged but CL remaining cut. Always ensure that there is no Fuel FLow running before moving CL to low idle, which might denote a controller's calibration.
I guess THIS IS probably the answer. I have my throttle controlled by SPAD.Next. I will observe with and without this control.
Thanks and regards

Heronjr
Posts: 110
Joined: Tue Jan 20, 2015 1:04 am
Re: Random hot start causing engines to fail

Post by Heronjr » Tue Jun 16, 2020 12:06 am

Tomas,

I just cannot believe in the hot start solution I found. And you knew about that. While researching the "hot start" theme in this Forum, I found a post in which you confirm the issue being ignited by the TIME ADJUSTMENT when the aircraft is already on the chosen departure field. From what I've read, with the time adjustment, some internal variables interfere in the engine wear mechanism and make the conditions ready to provoke a hot start!

No problem if this is the cause, but frankly, this should be written in red letters in your manuals. In this specific post nothing about time was mentioned. That explains the "random" nature of the hot starts.

I've tested twice and it seems my hot starts are history. Choose the airfield and adjust the time before clicking OK on the Scenery Menu.

Regards,

henrik.bergvin
Posts: 81
Joined: Sun Apr 12, 2020 9:56 pm
Re: Random hot start causing engines to fail

Post by henrik.bergvin » Wed Jun 17, 2020 10:29 am

Heronjr wrote:
Tue Jun 16, 2020 12:06 am
No problem if this is the cause, but frankly, this should be written in red letters in your manuals. In this specific post nothing about time was mentioned. That explains the "random" nature of the hot starts.
I agree on this, it should be big bold red letters. I have never *ever* had an addon aircraft get issues because of time adjustment...

Taguilo
Posts: 658
Joined: Sun May 11, 2014 11:49 am
Re: Random hot start causing engines to fail

Post by Taguilo » Wed Jun 17, 2020 1:21 pm

Heronjr wrote:
Tue Jun 16, 2020 12:06 am

No problem if this is the cause, but frankly, this should be written in red letters in your manuals. In this specific post nothing about time was mentioned. That explains the "random" nature of the hot starts.
I'm sorry about that. There is a pinned thread regarding how to properly configure the aircraft with MVMAS, and also from Scenario screen.
I always assumed you had read it, my bad. I think the title of the thread mentioning "MVAMS..." might confuse about its content.
henrik.bergvin wrote:
Wed Jun 17, 2020 10:29 am

I agree on this, it should be big bold red letters. I have never *ever* had an addon aircraft get issues because of time adjustment...
Time adjustment is perfectly possible if done in Scenario screen. The reason of elapsed time being considered within a flight is precisely to be able to execute procedures that are time dependent. For example, doing an engine start with low battery and checking how the aircraft performs, etc.


Tomas

henrik.bergvin
Posts: 81
Joined: Sun Apr 12, 2020 9:56 pm
Re: Random hot start causing engines to fail

Post by henrik.bergvin » Thu Jun 18, 2020 9:29 am

Taguilo wrote:
Wed Jun 17, 2020 1:21 pm
I'm sorry about that. There is a pinned thread regarding how to properly configure the aircraft with MVMAS, and also from Scenario screen.
I always assumed you had read it, my bad. I think the title of the thread mentioning "MVAMS..." might confuse about its content.
Just for what it is worth, the pinned thread does not talk about time being non-changeable when the aircraft is loaded.
Taguilo wrote:
Wed Jun 17, 2020 1:21 pm
Time adjustment is perfectly possible if done in Scenario screen. The reason of elapsed time being considered within a flight is precisely to be able to execute procedures that are time dependent. For example, doing an engine start with low battery and checking how the aircraft performs, etc.
I understand that it works this way, and that's not something I can change - I'm just saying that a LOT of simmers use some form of time adjustment tool - for instance FS Real Time or similar sync measures to make sure sim UTC stays aligned with real time UTC (or with offsets). Having a big red text warning in the manual is a thing that probably would have solved a LOT of error tracking for me, because none of the issues I have had with for instance the engines have happened since I started adjusting time before the plane is loaded.

Again, here's my procedure for FSRealTime:
1. Load simulator to scenario screen.
2. Adjust time to the time you want when the sim starts.
3. Load up the simulator and FSRealTime - make sure FSRealTime does not modify the time yet!
4. Go to Modify Offset in FSRealTime and make sure the offset is correct. MINOR adjustments seem to work, when we're talking +- a few minutes.
5. Set the offset, tell FSRealTime to use the offset, and hit "start autoupdate".

ccmh15
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Re: Random hot start causing engines to fail

Post by ccmh15 » Fri Jun 19, 2020 6:41 am

I use FSUIPC to sync real world and simulator time (I think it's on the Miscellaneous-Tab of FSUIPC), and it works flawlessly. Never have any hot starts.

Whenever there's a difference between real world time and sim time (e.g. after hanging out in the Fuel & Payload dialogue for a while) FSUIPC makes the next few minutes go by faster to catch up, so it's a gradual smooth time synchronisation - maybe that's the difference to any other external tools.

Cheers!
Chris


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