New Fulcrum PFM is very susceptible to PIO and excessive bounce. - Page 3 - ED Forums
 


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Old 10-29-2018, 12:17 AM   #21
Lixma 06
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The pitch thing is related to the leading edge flaps....the moment they deploy the nose pitches up suddenly.

Whether that signifies cause and effect I don't know - but watching real-life in-cockpit Mig-29 footage (the rear facing videos where you can see the LEFs deploy during maneuvering) I haven't yet seen anything like the behaviour of our 29.

The flight model is still being worked on so maybe this is all v0.99 gremlins.
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Old 10-29-2018, 04:09 AM   #22
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Quote:
Originally Posted by DmitriKozlowsky View Post
I don't think the problem is my technique. I land F-5E, Mig-21, and AV-8B, without a problem. There are two issues with Mig-29 PFM (both A & S). First is pitch control. I use X56, and my pitch curve for -29PFM is 40. Normally it is 25. So a pixel's worth of pitch deflection, as seen in on screen stick control, causes inordinate amount of pitch. Second is exaggerated bounce. There are two types of bad bounce. First is main gear bounce, due to excessive VV. Second, more insidious one, and one that does not make sense, is front gear bounce and rebounce, with each one picking up more energy, untill A/C is back in the air, despite throttle down to idle, and drogue chute out. Like Flubber from Disney.
The main on the current MiG bounce if you land too fast, but I have never had the nose wheel bounce. I don't believe that is n issue with the MiG-29.
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Old 10-29-2018, 07:17 AM   #23
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Quote:
Originally Posted by DmitriKozlowsky View Post
I don't think the problem is my technique. I land F-5E, Mig-21, and AV-8B, without a problem. There are two issues with Mig-29 PFM (both A & S). First is pitch control. I use X56, and my pitch curve for -29PFM is 40. Normally it is 25. So a pixel's worth of pitch deflection, as seen in on screen stick control, causes inordinate amount of pitch. Second is exaggerated bounce. There are two types of bad bounce. First is main gear bounce, due to excessive VV. Second, more insidious one, and one that does not make sense, is front gear bounce and rebounce, with each one picking up more energy, untill A/C is back in the air, despite throttle down to idle, and drogue chute out. Like Flubber from Disney.
You're spinning the wheels here. Post a track or it didn't happen.
As for the pitch - yes, it's sensitive. Be gentle. I didn't hear any SME complaining.
And remember there's a big difference between the landing where you just don't break anything and the perfect landing.
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Old 10-29-2018, 10:51 AM   #24
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Quote:
Originally Posted by DmitriKozlowsky View Post
Second, more insidious one, and one that does not make sense, is front gear bounce and rebounce, with each one picking up more energy, untill A/C is back in the air, despite throttle down to idle, and drogue chute out. Like Flubber from Disney.
Yes, I've had a front wheel bounce. My solution is not to loose the stick after the main landing gear hits the ground. Even it's ok to keep the stick all the time. That's why I found 65 knots to lift the front wheel. https://forums.eagle.ru/showthread.php?t=223311
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Old 10-29-2018, 11:09 AM   #25
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Originally Posted by Xtan View Post
Yes, I've had a front wheel bounce. My solution is not to loose the stick after the main landing gear hits the ground. Even it's ok to keep the stick all the time.
It's not OK. It's mandatory. From manual > normal procedures > normal landing: "At touchdown, reduce power to idle, maintaining stick position and deploy chute." and also "NOTE: At excessive touchdown speeds, the aircraft has a tendency to bounce."
You can't just leave the stick or let the nose slam into the ground.
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Old 11-01-2018, 04:51 PM   #26
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Hello,


two points in addition to the above posts:

Quote:
Originally Posted by AeriaGloria View Post
Be aware of slat behavior, deploy at,roughly 10 degrees AoA but stay on until 7 degrees. Keep approach speed over the fence 300kpm and no less than 250kmh at touchdown
"and "

Quote:
Originally Posted by Lixma 06 View Post
The pitch thing is related to the leading edge flaps....the moment they deploy the nose pitches up suddenly.

Whether that signifies cause and effect I don't know - but watching real-life in-cockpit Mig-29 footage (the rear facing videos where you can see the LEFs deploy during maneuvering) I haven't yet seen anything like the behaviour of our 29.
.


Well the LEF should be out anyway as long as the trailing edge flaps and / or the gear is lowered. So there should be no sudden surprises from that end.

Second point is even when the LEF extend or retract during maneuvering flight (with the gear and flaps up) due to AOA , the pitch damper, or more precise the longtitudinal stability control adjusts the tailerons to counteract pitch movements due the LEF movement.
So even there, this should not interfere or cause oscillations in pitch.


Kind regards,


Snappy
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Old 11-01-2018, 06:08 PM   #27
Lixma 06
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Good info, thanks - it seems our 29 has a dicky damper.
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Old 11-01-2018, 07:09 PM   #28
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You're welcome,


yes I agree, the pitch damper is certainly sub par.There really seem to be too much tendency for oscillations in pitch my opinion as well.
Hopefully this can be at least slightly improved.

Kind regards,

Snappy
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Old 11-01-2018, 08:03 PM   #29
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Quote:
Originally Posted by Snappy View Post
You're welcome,


yes I agree, the pitch damper is certainly sub par.There really seem to be too much tendency for oscillations in pitch my opinion as well.
Hopefully this can be at least slightly improved.

Kind regards,

Snappy
Question is, how much the oscillations are caused by our controller setup. I use the virpil mongoose t-50 with 17,5cm extension and don’t experience strange oscillating movements even without curvature set on the y-axis.

With my TM Warthog grip without extensions on the other hand…she’s a little touchy to say at least.

Controller setup plays a huge role here
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Old 11-02-2018, 05:33 AM   #30
Snappy
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Well,

of course controller setup influences this too.However since probably the vast majority of users flies with some sort of „desktop“-flightstick and is not using any extension which emulates real world stick travel distances it would be preferable to gear the flight control response towards the shorter desktop length sticks.


Just my personal opinion anyway.


I already played with the axis tuning but so far had only limited success.


Kind regards,


Snappy

Last edited by Snappy; 11-02-2018 at 05:49 AM.
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