Slow prop pitch to reverse???

[tkyler]

Hey guys, is anybody else seeing very slow prop pitch rates when going into reverse?   i.e you slam the levers into reverse and it takes anywhere from 5-10 seconds for the props to actually reach fully reverse pitch..... in XP 12.05r1?   If so...are you aware of when this started to change?   In XP11, the prop pitch in BETA mode is near 1:1 with the levers as it should be....and if I recall, in early V12 runs, it seemed the same.  Being on the IXEG for a few XP versions...I took a look at the Moo and ran into this issue right away.  I've ping'd Austin about, but curious if anybody is aware of what version of XP it started to go south.  Thx for any inputs.

-tkyler

Edited May 6, 2023 by tkyler

[tkyler]

So spoke with Laminar and as it turns out,  their TPE model is off currently in this area.  The 'missing piece' (for the mechanical prop-governor nerds out there)  is a "recalibration of the prop governor to 105%" when in BETA mode, which guarantees that what is called an "underspeed condition" ensues.  An underspeed condition then facilitates a "wide open" oil port that provides maximum oil pressure to the prop pitch control tied to the power levers.  This is so you get immediate control of the prop pitch at landing for reverse...you don't want to be waiting on the delayed response of a prop governor (which is what is happening now) .   X-Plane currently limits the prop governor to 100% (*cough..PT6), which keeps their code path out of the 'underspeed' state and basically "governs the prop" (with a slow response) towards reverse pitch, which isn't the way it works.  In BETA, the prop governor does not influence prop pitch at all.

It worked well in XP11, but Laminar improved the TPE model in many other areas, rewriting the governor code and missed the "105% calibration" detail.  So hopefull we'll see a change in the next update....but even then, unsure how well it'll perform across all regimes.

-tkyler

Edited May 6, 2023 by tkyler

[OneOffRegistrationUser]

Hi -tkyler,
tested few minutes ago with latest XP12 beta.
What I did: Started engines on ramp, RPM Lever on Taxi, moved throttle with TM Airbus TCA Q-Eng backward. Plane start moving backward amost immideatelly after passing reverse gate. Reverse sound appears at the same time.
In general MU's reverse is responcive as usual and quite precise.

Reverse on landing: In tooks approx 2 seconds (looking on torque meters) to engage reverse and start decceleration, after zero-throttle moving levers to reverse.
Hope it helps.

P.S. Happy you found some time to look after Mu!

 

P.P.S. Just saw your post and now bit confused, since Mu works OK on my end. Or I'm using incorrect test sequence.

Edited May 6, 2023 by OneOffRegistrationUser

[tkyler]

1 minute ago, OneOffRegistrationUser said:

In tooks approx 2 seconds (looking on torque meters) to engage reverse and start decceleration

Thank you for the input.  Yea, that reverse should be immediate....as fast as you can move the levers back, there should be no lag.  I've found the pitch time to be variable...on one landing, it took over 8 seconds to reach full reverse pitch and I lost a good 900' of runway waiting for it.  Hopefully we'll see an improvement in the next version of XP.

-tk