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Airbrakes

744 FS9 Autoland

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I have a question requarding the autoland of the 744. I have the latest version installed and Ive noticed a problem when performing a autoland, the plane wants to turn violently to the right once under 80KTS. This only happens during the autoland.I did a flight today KSFO-RJAA using FSACARS so I could see what kind of touchdown rate the autoland was giving me: -56FPM.... Wow.Is this normal for a autopilot??? The autopilot didint float down the runway and landed me right where it was supposed to, but I never seen an autopilot give that low of a touchdown rate ( on any aircraft ). Could this be the issue?


Kevin Hester,

 

Indianapolis, Indiana

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Hi Kevin.I take it from your wording that this issue is happening at a variety of airports? If it is just RJAA it could potentially be an AFCAD issue, as the guidance rollout is predicated upon the localiser beam for that runway (ie it tracks the localiser right down the runway just as it does on the approach). If there was a problem with the positioning of the localiser beam in the RJAA AFCAD file that might be the culprit. Are you using an add-on for Narita or just the stock airport?Assuming the above doesn't check out, it might help to know if there are any changes to the autopilot modes showing on the FMA (top of your PFD screen) when this sudden swerve occurs. Is it definitely occuring right on 80 knots? When you disengage, does the turning effort immediately stop?The Autoland on the PMDG 744 is one of the finest in the business and consistently makes smooth touchdowns. A very nice piece of work indeed. While I don't doubt you're having a problem, I'd cautiously suggest the fault isn't in the 744 itself.As a matter of interest, the wind limitations for Autolanding as below are taken from the limitation section.True Headwind Component 25 KnotsTrue Tailwind Component 10 KnotsMaximum Crosswind Component 25 KnotsMaximum One Engine-Out Crosswind 5 KnotsMaximum CAT III Autoland Crosswind 10 KnotsI've had rock-steady approaches and autolandings with fairly significant crosswinds and it's a complete marvel to watch. :-)


Mark Adeane - NZWN
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Disconnect the AP as soon as you are rolling out straight, and have enough runway environment cues to allow for it.Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 | 2 x APC UPS | Coolermaster Stacker 830 SE | Gigabyte P35 DS3R | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Creative X-Fi Fatal1ty | 2 x 1 GB Corsair XMS2 | 2 x 320GB WD Caviar RAID 0 | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |


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Carl Avari-Cooper

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I usually disconnect the autopilot after the rollout. It happens at every airport not just RJAA. It even happens with the 737NG. As soon as the speed drops below 80 KTS and I engage the manual brakes it steers to the right. A quick check of the ECAS STS revealed everything was normal: the rutter wasint out of place etc. Ill try letting the autobrakes stop the plane completly on the runway, or not use them at all and see if this helps. I have FSUIPC ver 3.7 ( registered ) so maybe there is a tweak I can do?


Kevin Hester,

 

Indianapolis, Indiana

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Kevin, I'd be interested to hear whether or not the problem occurs when you leave the autobrakes on. It's unlikely, but if manual braking triggers the swerve AND it happens on the 737 as well it may be something to do with the brake assignment in FS itself. Do you have a button or trigger assigned to braking? Make sure it is assigned to the general 'brakes' command and not the right side differential brake (which would explain the powerful right turn.


Mark Adeane - NZWN
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Guest Worldliner

From 747-400 FAQ at PMDG Ops:Why does the 747-400/400F pull to either side after landing?After performing an autoland you must disconnect the autopilot after slowing down. The PMDG 747 uses the runway's localizer signal to hold the centerline while in ROLLOUT mode. Due to an MSFS limitation, this signal can become eratic further down the runway. The result is that the plane starts pulling to whichever side it thinks it needs to go to to continue following the signal. Once you disengage the AP either by pulling the command bar out or by pressing the yoke switch, the plane should steer normally on the ground.Regards,Stjepan

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I do have a button on my controller assigned to the brakes, but its not the differintal brakes. Im doing a flight right now back to KSFO from RJAA and Ill try the autoland without the autobrakes to see if it helps.


Kevin Hester,

 

Indianapolis, Indiana

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Cool kevin, look forward to hearing how you get on!


Mark Adeane - NZWN
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>From 747-400 FAQ at PMDG Ops:>>Why does the 747-400/400F pull to either side after>landing?>>After performing an autoland you must disconnect the autopilot>after slowing down. The PMDG 747 uses the runway's localizer>signal to hold the centerline while in ROLLOUT mode. Due to an>MSFS limitation, this signal can become eratic further down>the runway. The result is that the plane starts pulling to>whichever side it thinks it needs to go to to continue>following the signal. Once you disengage the AP either by>pulling the command bar out or by pressing the yoke switch,>the plane should steer normally on the ground.>>Regards,>StjepanThanks for the reply but I stated above that I disconnect the autopilot after the rollout. This problem seems to occur after I apply the manual brakes and continues untill I shut down the sim. Even as I increased the throttle the plane still pulled. It dosent pull to either side, just to the right.


Kevin Hester,

 

Indianapolis, Indiana

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Well turning the autobrakes off didint help any :-hmmm.


Kevin Hester,

 

Indianapolis, Indiana

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Did it still occur at 80 knots or sooner?Any other differences or were the symptoms the very same?


Mark Adeane - NZWN
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>Did it still occur at 80 knots or sooner?>>Any other differences or were the symptoms the very same?It seems to occur right at 80KTS. The autobrakes dont matter ( I found that out last night ). I know this affects both of the PMDG aircraft in my hanger, so Im going to try the LDS 763 to see if I get the same problem there. The symptoms were identical.I know the plane isint trying to keep inline with the ILS because I have the autopilot disengaged after the rollout. If I let the rutter go, the plane just goes in circles. Im thinking this is a problem with the settings in FS9 and not in particular with the PMDG planes. Thats why Im testing the LDS 763 to see if I get the same problem.


Kevin Hester,

 

Indianapolis, Indiana

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Let us know Kevin!Also, I'd be looking at your joystick (or rudder pedals if you have them) as being possible culprits.I'm no expert on FSUIPC, but could anyone suggest if it might have a role in this issue?


Mark Adeane - NZWN
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Negative on the joystick, I checked the EICAS to confirm that. The 763 didint go right like I expected it to. Now Im a little confused. It just seems to be isolated with the PMDG planes. Well I guess untill I figure this out, Im ganna have to land the planes manually which is alroght with me, the Queen is fun to fly.


Kevin Hester,

 

Indianapolis, Indiana

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Hi,It depends on the airport. Some do it, some don't.Best regards,Robin.

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