reported SEC shows signs of stagnation/stall ver 2.5.2.36986

Caucasus Map

Single player

Starting running from runway

Engine placed in SEC mode.

Throttle snap to mil

RMP fails to rise above 70%

FTIT has a rapid rise through 750C

With engine on SEC, Rapid Throttle movement should not cause this effect. This is normally checked during aircraft launch.

SEC Check compressor stalls?

Is it normal to get a compressor stall/thud/bang when doing SEC checks?

I snap my throttle to MIL then back to IDLE, the RPM goes to around 73-74%, briefly goes up to 77% or so, I hear a bang from the rear of the jet, then RPM goes back to idle.

Anyone else noticed the same?

There are many problems with SEC and other engine details. To mention a few: Currently SEC causes Stagnations (non recoverable Stalls). Using NTTR summer temps in the mission weather, will always cause Hot starts and anticipated hot starts .

https://forums.eagle.ru/showthread.php?t=250834&highlight=engine

https://forums.eagle.ru/showthread.php?t=251863&highlight=engine

Could not find a solid report of this before, so apologies if this is a repost. I realize all this is WIP but the bug report rules said engine operations are fair game for reports

Open Beta 2.7.1.6430 - instant action - cold & dark - caucuses

The SEC implementation appears to be broken. When doing a SEC check on ground, the RPM drops ~10%, however snapping the throttle to MIL and back before RPM hits 85% is impossible since the RPM hardly rises at all. Extended stay in MIL causes FTIT to peg at 1200 before RPM drops below 60% and you loose the main generator. Retarding the throttle will bring the engine back to normal and the main generator back online.

Reproduce:

Start the engine normally.

Enter SEC mode.

Advance throttle to MIL and snap it back to idle before RPM hits 85% | or advance throttle to MIL and leave it there.

Expected behaviour:

SEC caution light - On [ ok ]

RPM - Stabilized [ ok ]

RPM may drop up to 10% from PRI value before stabilizing. Stabilized SEC idle rpm may be up to 5% lower then that in PRI [ ok ]

Throttle - Snap to MIL and then snap to IDLE when rpm reaches 85%. Check for normal indications and smooth operations [ Fail ].

Actual results: Engine rpm does not increase. FTIT runaway ( would probably be a catastrophic engine failiure/fire ). RPM decreases below 60%. Main generator dies.

NOZ POS - 10 % or less within 30 seconds after selecting SEC [ Fail ]

Actual results: remains pegged at 0%.

Track file ( showing only the above scenario ).

https://drive.google.com/file/d/1dkAxWVgEXsKfZxjhwjN1VQqqRzaZDl9b/view?usp=sharing

Also reported here:

https://forums.eagle.ru/topic/214651-known-issue-sec-shows-signs-of-stagnationstall-ver-25236986/

Hey Gas you have messages disabled sorry to post here but trying to get a hold of you. hop on the discord server

still cant send you a msg mvsgas I see you followed me says your msgs are disabled

This is still broken following the update to SEC in latest DCS version. SEC is essentially useless until this is fixed.

As far as I can tell nothing has changed with regards to SEC, how Wags showed it in this video is how it's always behaved, since the initial release into OB IIRC - not sure why it was described as being added when it always there.

On 11/19/2022 at 3:47 PM, BIGNEWY said:

Incorrect, nozzle position was added. 

The nozzles close when engine control switch is set to SEC

thank you

In Wags' F-16 Cold Start tutorial video (~3 years ago) you can see the nozzle position gauge going to 0% when SEC is selected and returning to normal (~97%) when PRI is selected. The same can be seen in every Cold Start video I can find when the SEC check is performed (such as this one, from ~1 year ago).

I just rolled back to the initial 2.8.0.32066 version, released on the 28th of October - over 2 weeks before this change to the SEC mode was even announced (announced on the 15th of November) and I've got the nozzle opening and closing when selecting SEC and back to PRI - nothing has changed in the November update in this regard and I’m pretty confident this has always been the case.

2.8.0.32066_F-16_SEC.trk

Still Broken...

Still the case.

I noticed the same problem yesterday during in-book ramp start. Tried multiple times. Sec test fails when you snap the throttle to mil. Rpm goes down and FTIT temperature raises too much and engine fails.

The only way you can pass the test is that you increase the throttle very slowly. I totally confirm the problem told by other users here e.g @Jestr.

Sec checks are still impossible to perform at ramp due to the above.

so kind bump for this issue hoping to see it solved one day

On 5/25/2021 at 5:51 PM, Jestr said:

Throttle - Snap to MIL and then snap to IDLE when rpm reaches 85%. Check for normal indications and smooth operations [ Fail ].

 

Actual results: Engine rpm does not increase. FTIT runaway ( would probably be a catastrophic engine failiure/fire ). RPM decreases below 60%. Main generator dies.

Confirmed.

Still broken yes