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[NO BUG - AS INTENDED] Engine Spool time and responsiveness


Shrike88

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Greetings

 

Would like to report a bug and issue with the significant length of time the AV8 -408 engine takes to make any large change in power settings. I have noticed an increase in the amount of time this latest update now is taking near 7-8 seconds from 32.5% to max (109/110) and equally as long for a reduction to flight idle.

 

Am unable to reference document flight checks (R1.16)as the exact amount of time that is within limits is notated, and we currently are exceeding these numbers by several seconds as currently modeled in the sim.

 

Can you please pass this to testing to and hopefully augment these numbers. We are currently hovering around the turbine responsiveness of a A321.

 

There are several locations for other information for a more ballpark idea on how long the engine lag time should take for changing power changes, especially siting videos

 

RPM and HUD indicated information is displayed as a reference from HOV to idle on touchdown.

 

Thank you.

 

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What you said above, plus the "fast deceleration solenoid" is not implemented, something I have asked about several times without ever getting any answer...

Windows 10 - Intel i7 7700K 4.2 Ghz (no OC) - Asus Strix GTX 1080 8Gb - 16GB DDR4 (3000 MHz) - SSD 500GB + WD Black FZEX 1TB 6Gb/s

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What you said above, plus the "fast deceleration solenoid" is not implemented, something I have asked about several times without ever getting any answer...

 

Yes. I know they are quick to respond on Reddit. @Decoy any idea if this is getting looked at or is known about? Very frustrating on Vertical Landing the lag on engine spool down.

 

Engine Spool up also needs to be 2.4-3.seconds 32% to 65%.

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Could this also be finally addressed (or at least on the list) and be connected with this issue:

...Furthermore the spool down sound is audible during flight which shouldn't be the case as the fast deceleration solenoid is only activated with weight on wheels, if I'm correctly informed.

 

The fast deceleration solenoid was removed and the cannon plug tied off almost 15 years ago. The spool down sound I believe you are referring to can be heard anytime that you retract the throttle from high RPM location to idle quickly. I will agree that the sounds are now horrible in the cockpit as they used to be pretty darn spot on. The only time you should hear the spool down sound is as the RPM comes down rapidly, like from max to idle in <2 secs. but it seems like any rapid retraction causes that spool down sound to play and mixed with the normal sound of the motor it sounds like a dying cat.

 

 

As I understand it now you have to be on the ground to hear that sound, while in vertical flight it would mean that you are in free fall before you are able to hear it. In horizontal flight, the air which enters the engine will prevent a rapid reduction of the RPM anyway.

 

But, in this case I've no idea how a trackfile would be of any help...


Edited by Cornelius
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Just stumbled on an interesting video on YT. Here, from idle to max RPM it took him about 6.5 seconds, and nearly the same from max to idle (no HUD or engine page showing, so I was going by the amount of whine)

 

 

 

 

Sounds awesome wish ours sounded like that inside the cockpit

Sounds like your close on the numbers as well and still shorter accel and decel from what we currently have in the sim

 

Thanks for sharing.

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Just letting you guys know I'm going through stuff and having a look at things. This might not be a #1 priority for th team but know that I am looking into EVERy issue reported.

Know and use all the capabilities in your airplane. If you don't, sooner or later, some guy who does use them all will kick your ass.

 

— Dave 'Preacher' Pace, USN.

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Sounds awesome wish ours sounded like that inside the cockpit

Sounds like your close on the numbers as well and still shorter accel and decel from what we currently have in the sim

 

Thanks for sharing.

 

 

Oh yeah, these sounds.... I wouldn't mind in just ripping the sound from this video and jamming it in the sim. Really sounds awesome.

 

 

 

Also, If I saw correctly it has 408 engine, same as we have in the sim so it is a relevant video in showing the engine performance and also, some HUD things. Mainly, I noticed that there's a "W" flashing when he goes over 100% RPM, but I'm not sure if that means no water intake is enabled or that it is enabled (W lighting up on the engine panel is not shown clearly)

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Engine Performance

 

In regards to the acceleration times, I have been testing them and they are pretty spot on, at least in the lower end RPM ranges. The limits are 35%-60% in 2.4 - 3.1 seconds. I have tested this several times in different maps and they are usually anywhere from 2.7-2.9 seconds. It's not a one value place holder as I suspected, where it is always the same value, so that's a good simulation. I have checked manually and the values I get on a manual timer are about as close to what we see in the jet, so it's fairly accurate.

 

The higher end RPM acceleration check (60%-105%) is not modeled as accurately, in that you can get a value even if you don't get up to 105%. There should never be a value if the RPM never reaches the upper number. You should be able to do a lower end acceleration check from 35-60%, pause and bring the throttle below 60% and then do an upper end acceleration check from 60-105%, but as soon as you go over 60%, whenever you bring it back below 60% it fills out the acceleration time it was above 60%.

 

All times from 60%-105% that I have gotten when I went full power and back to idle after going above 105% are within limits, fastest is 2.2 secs and slowest I've seen is 2.4 secs. It's been a hot minute since I did a high power but I believe the limits are 2.1-2.8, but that is a guess. The times from idle to 35% and anything above 105% is not timed and does not matter. Currently I'm seeing anywhere from 7.9 to 8.2 secs from idle to full 113.5%. I did not test the full wet datum, idle to 120% because it is still not modeled correctly due to misunderstanding non-dimensional RPM limits below 10,000 feet and limiting it to 116.8%.

 

There are several warnings in the NATOPS that warn full power could take up to 8 seconds to reach, depending on atmospheric conditions and initial throttle position. The way it is now, seems more accurate to me TBH and comparable to what it is IRL. The sound is horrible when coming back down and the engine noise is a lot more muted in the cockpit IRL, but the performance and timing seem to be modeled fairly well.

 

All acceleration checks are done with water off and nozzles at 0* to ensure that there is no bleed air coming off the engine. Nozzle deflection should cause slower times since when they are below 0* they are bleeding 8th stage air from the HP compressor, which in turn would cause a longer acceleration time. You can put the nozzles to any angle and will get the exact same acceleration times.


Edited by vstolmech513
Updated wet datum checks
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