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vgbaron

Lear ALT HOLD issue

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Running P3D 3.1 under W7 - using latest Lear Update

 

did NOT have this issue with version pre update

 

Also using GTN750 - tried it in the freighter and the ELLB paint

 

Select ready to start - start engines

 

input plan to GTN750

 

Set altitude selector for specified altitude - say 10000 feet

 

Take off - establish climb rate of 1500fpm

 

AP ON

AP ENG ON

NAV ON (ARM)

ALT SEL ON (ARM)

 

a/c climbs - as it nears selected altitude

 

ALT alert sounds and light shown

ALT SEL shows CAP

 

now the problem - I would expect the rate of climb to decrease as the a/c nears the selected altitude.

it does not

 

ALT SEL goes OFF

ALT HOLD goes ON as we climb THROUGH the selected altitude

 

I let it alone expecting it to quickly cycle down to desired altitude - I manually took over at 20000 feet!

 

Tried with and without using the VS to control rate of climb

 

Only way I can get it to work properly is to take over manually just before desired altitude - stabilize at altitude and enable alt hold. Then it would hold altitude.

 

Is there something that I missed in the documentation?

 

As I said, this did not occur with earlier version - the when ALT HOLD went on the a/c would maintain that alt as long as the AP was active

 

 

Thanx,

 

Vic

 

 


 

P3D#1 - 7700K 5.0g ROG X270F 3600 15-15-15 - EVGA RTX 2080ti 1000W PSU 1- 850G EVO SSD, 2-256G OCZ SSD, 1TB,HAF942-H100 Water W1064Pro
40" 4K Monitor 3840x2160 - AS16, ASCA, GEP3D, UTX, Toposim, ORBX Regions, TrackIR
P3D#2 - 3770K 4.7g Asus Z77 1600 7-8-7 GTX1080ti DH14 850W 2-1TB WD HDD,1tb VRap, Armor+ W10 Pro 2 - HannsG 28" Monitors
 

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I see the exact same behavior. I have tested with both V/S and SPD mode. I get several 1000ft overshot. If I turn and have V/S at about 2000ft the V/S drops below 0 and my altitude decreases during the turn.

 

Is there something wrong with the AP or is there something wrong with my settings/usage?

 

A simple tutorial or a video of the AP usage would be much appreciated (or if there are bugs in the AP a confirmation of those bugs will do...).

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It should be transitioning for the capture, as is you must have a shallow rate of climb or descent other wise it will blow right through the altitude.I decreased rate to about 500 fpm and it would capture at that rate.From practical experience with the actual autopilot I would always use SPD for climb and V/S for descent. About a 1000 feet before capture I would transition to pitch mode using the control wheel pitch/roll knob (not modeled in this FSW version) to reduce the vertical rate for passenger comfort and capture.I simulate that function by disengaging the vertical mode in use and use my controller pitch trim to reduce the rate for capture.

 

The actual 430 autopilot is smooth and precise in use, more like the default FSX versions which work pretty well and do not exhibit this behaviour. 


Gary Stewart

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Tnx for your reply.

 

Hmm, I'll try to use SPD mode and reduce V/S close to the target altitude. I report back.

 

How about the fact that I can't maintain 2000fpm when turning and even drop in altitude in V/S mode? Can that be explained?

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The auto pilot will adjust the pitch attitude to maintain V/S or SPD when selected, the reason SPD is used for climb is that as altitude increases climb performance decreases. If you use V/S mode to top of climb eventually you will may reach a condition that is not possible to maintain.Normal recommended climb speed was 250KT (or greater if performance allowed or ATC requested) until achieving .72 mach.This would occur around FL290 typically and the mach reference would be used for the remainder of the climb.Obviously the autopilot can lower the pitch attitude to maintain the climb mach number if required until altitude capture.

 

At high altitude you may not be able to achieve a 2000 fpm climb rate as it was not unusual to see climb rates well under 1000 fpm if climbing above FL410. It is all dependent on outside air temperature and weight.The aircraft would require a weight under 15,000 pounds to attain FL450 for any kind of cruise performance and typically requires a intermediate altitude to burn off fuel before resuming a climb to final cruise altitude.Your loss of altitude in a turn might be related to being too high and too heavy but I have no idea of what FSW used as a performance model for this product.


Gary Stewart

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ILS MODE:

 

ILS at KSFO runway 19L 108.90 course 193..................

 

1.Set the nav 1 frequency using the GNS 530 to 109.90

2.Set the course on the HSI to 193.

3.Fly toward the approach at 30 degrees of the lateral direction.

4.AP on set the NAV and GS mode on. I already have the HDG and ALT/HLD on for holding current path.

5.When you get within the CDI distance and it starts to slide it will start to turn toward the runway and the HDG MODE will switch off and the NAV MODE will now say CAP for capture.

6.When the GSI indicator starts to drop and get half way down the scale the GS mode will say CAP and the ALT/HLD mode will switch off. 

7.When you get to 500ft AGL turn off the GS mode and hand fly the landing. 

8. Having the Radio ALT switch on you can see the last 200ft as your prepare to touchdown.

 

 

SPD MODE:

Using SPD make sure you can maintain the speed before you engage. The pitch changes based on the speed when engaged as it's trying to maintain the speed when you engaged. You can adjust the thrust lever to help maintain the pitch.

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Keeping the VS under 2k fpm seems to work. The AP will transition as expected.

 

 

Vic


 

P3D#1 - 7700K 5.0g ROG X270F 3600 15-15-15 - EVGA RTX 2080ti 1000W PSU 1- 850G EVO SSD, 2-256G OCZ SSD, 1TB,HAF942-H100 Water W1064Pro
40" 4K Monitor 3840x2160 - AS16, ASCA, GEP3D, UTX, Toposim, ORBX Regions, TrackIR
P3D#2 - 3770K 4.7g Asus Z77 1600 7-8-7 GTX1080ti DH14 850W 2-1TB WD HDD,1tb VRap, Armor+ W10 Pro 2 - HannsG 28" Monitors
 

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Actually the auto pilot is certified for use to whatever DA or MDA is authorized for the specific approach procedure but not below 200' for an ILS or published MDA for a non precision procedure. At minimums you disengage the autopilot for continued descent below the minimum altitude, the flight director, NAV and GS  modes should remain active.This is especially true when the approach is at minimums and although you may have the approach lights in sight there are not adequate visual references to disregard ILS guidance.Try an 1800 RVR approach sometime and you will know what I am talking about.


Gary Stewart

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It should be transitioning for the capture, as is you must have a shallow rate of climb or descent other wise it will blow right through the altitude.I decreased rate to about 500 fpm and it would capture at that rate.From practical experience with the actual autopilot I would always use SPD for climb and V/S for descent. About a 1000 feet before capture I would transition to pitch mode using the control wheel pitch/roll knob (not modeled in this FSW version) to reduce the vertical rate for passenger comfort and capture.I simulate that function by disengaging the vertical mode in use and use my controller pitch trim to reduce the rate for capture.

 

The actual 430 autopilot is smooth and precise in use, more like the default FSX versions which work pretty well and do not exhibit this behaviour.

Understood. Most other a/p's will NOT blow through the selected altitude even at VS of 4000fpm. the design *should* reduce that climb rate as you approach the selected altitude.

 

My comment was that the AP in the Lear did NOT reduce VS as it got closer and even when the ALT HOLD illuminated and the VS and ALT SEL went out, it continued to climb.

 

Only by keeping the climb rate below 2000 fpm will the AP reduce speed and capture at altitude.

 

I have no issue intercepting the GS or any other function of the ILS. I might have mistitled the post - meaning AP issue not ILS. (edit: changed title)

 

Anyhow, I know how to make the altitude capture work so all is well.

 

Vic


 

P3D#1 - 7700K 5.0g ROG X270F 3600 15-15-15 - EVGA RTX 2080ti 1000W PSU 1- 850G EVO SSD, 2-256G OCZ SSD, 1TB,HAF942-H100 Water W1064Pro
40" 4K Monitor 3840x2160 - AS16, ASCA, GEP3D, UTX, Toposim, ORBX Regions, TrackIR
P3D#2 - 3770K 4.7g Asus Z77 1600 7-8-7 GTX1080ti DH14 850W 2-1TB WD HDD,1tb VRap, Armor+ W10 Pro 2 - HannsG 28" Monitors
 

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I am going to make a AP tutorial today. All of the issues you guys mention does not happen to me or the beta team.

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I read all posts and can't get these issues you mentioned. Here is a new video tutorial video showing all AP functions. And all worked as they should!

 

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Requirements:  " FSX SP2 or ACC / Steam Edition / Prepar3D All Versions! "

 

Was testing by you or your "beta team" done in Prepar3D?

 

If so, which version of P3D was used for testing and confirmed by you that there are no issues?


Gary Stewart

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Requirements:  " FSX SP2 or ACC / Steam Edition / Prepar3D All Versions! "

 

Was testing by you or your "beta team" done in Prepar3D?

 

If so, which version of P3D was used for testing and confirmed by you that there are no issues?

Tested on FSX..................P3D V2.5 V3.0 and V3.1

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I must have the only P3D / Win 8.1 install allergic to your code, mean while everything else purrs like a kitten.Too many updates to fix things that should have been obvious in testing before the product was released for sale.May be try again when update ver.4.x is released  :wink:


Gary Stewart

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Me too, I can't get the autopilot to level off with ALT SEL and even a simple ALT HLD does not work.

I use W10 P3D 3.1.

Can't complain otherwise.

Nonetheless this makes the product unusable for me at the moment, as I don't intend to use it for local flights and hand flying only.


Regards, Perry

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