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TerryS

Autoland flare but no touchdown

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Hi everyone, I've been scratching my head over this one and I can't figure out what I'm doing wrong. I'm attempting an autoland at Newcastle, UK (EGNT). Both NAV radios are tuned to correct ILS frequency, both course dials set, speed correct, flaps correct, barometer set, both autopilots on, both FDs on etc. The NGX flys the approach perfectly down the GS with 'GS' in green and 'flare' in white letters. About 10 feet from touchdown, the aircraft begins to flare and the white 'flare' turns to green. That's it. The aircraft flys along the runway at about 5 feet altitude and wont touchdown. Eventually it turns gently to the right and lands in the terminal! I've tried to turn the autopilots and autothrottle off just prior to touchdown however despite the switches moving it seems as if the autopilot still has the aircraft and I cannot regain control, where's the ejection handle. Has anyone else encountered this or is it just me who thinks they know what they're doing but really hasn't a clue. The landing gear was down BTW and I've installed the hotfix. Terry

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As far as I know, the A/P disengages a few seconds before touchdown, so maybe that is the issue? EDIT: Actually, I think I misread the post

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As far as I know, the A/P disengages a few seconds before touchdown, so maybe that is the issue?
The autopilot has to be disengaged manually after touch down ! The autothrottle should disengage automatically just after touchdown.2 seconds according to Boeing. Fred.

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Hi Andrew, I wish it did then I could manually land it but no matter what I do, the controls don't respond. I thought it may have been a symptom of the 'panel freeze' however I've installed the hotfix and it made no difference. Thanks Terry

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I flew TTCP to KMCO last night 4 hours without a hitch. Then did KMCO to KBOS today without any issues. I do get those freezes a couple times during a flight but they only last 2 seconds, but FSX does not crash it just resumes after a 2 second delay. I can overlook that little quirk and enjoy the NGX until they get the kinks worked out. As for the Autoland I tested that out myself the last 2 flights. After wheels down on the runway you have to disconnect the autopilot manually and hit the thrust reversers and guide the plane down the middle of the runway steering manually. The 737-NGX is not like 747-400x where it will auto tune everything for you and then land and steer itself down the runway. Why it is like this I don't know but it is modeled after how the real aircraft works. So you will just need to learn how to manually take control at wheels down and then do the rest of the work. Or do a full manual land which is the best and most fun part of any flight. I am going to do a Ryan Air Flight from Boston to Dublin next, will let you know how that goes.

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Hi Paul, Ithink the autopilot should disconnect automatically when it detects touchdown, however it doesn't touchdown therefore the autopilot remains on. It will not disconnect manually either and the aircraft just flys along 5ft off the ground. I now think it's a problem with the airport scenery as I just flew into EGGD (Bristol) and the autoland worked perfectly. I've run AFD scanner to see if there are any duplicate sceneries but everything checks out. I'll just avoid EGNT for a while, or manually land. Up until recently I always manually landed but I find the autoland quite interesting especially in poor visibility and because I'm not used to it. Thanks Terry

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I am going to do a Ryan Air Flight from Boston to Dublin next, will let you know how that goes.
For those that wondering if I made it to Ireland and were thinking about a Transcontinental Flight in the 737-800 here is my stats. KBOS to EIDWPassengers 150Fuel 46,057 lbsCargo 10,600 lbsFlight Time: 5hrs 45minTotal Fuel Used 35,857lbsReserve at Arrival 10,200 lbs One Important thing to note was I had 50 to 100 knot tail winds most of the way over there and was cruising at Mach .81 and my average Ground Speed was 550 to 570 knots with the tail. Not likely I will make it back to Boston if I run into headwinds like that. But going to give it a shot. Might have to come back less than MTOW. LOL.gif With over 5,000 hours in the 747-400 and MD-11 combined I figured out the Fuel Burn Rate pretty close. If you throw out the taxi, climb, descent and just add the fuel on a per hour basis I bet you will see it comes out close every time. Calculate the total number of hours for the flight and then add one hour extra for reserve.737-NGX 6,200 Light - 6,800 lbs Heavy - per hourMD-11X 16,000 Light - 17,500 lbs Heavy - per hour747-400X 22,000 Light - 25,000 lbs Heavy - per hour
I just flew into EGGD (Bristol) and the autoland worked perfectly
Glad it worked for ya. Is probably a Scenery Glitch or else the NGX doesn't like that Airport. When I flew into Dublin tonight it would not lock onto the ILS 16 for some reason but I might have missed setting something. (EIREsim EIDW Scenery)

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I suspect that the airport altitude was set wrong (he doesn't mention it in his specs) and the plane thought that the runway was higher. Henri

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By the way, I believe the NGX will steer down the centerline IF you have the AP option set to operational-fail as opposed to passive.

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The 737 is not like the 747-400 and has to be manually be steered down the runway with the autopilot off. Test it yourself.

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If you don't turn the autopilot off after touchdown, the plane will begin to steer towards the ILS transmitters. At least mine did.

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Terry, did you have the horrid loaded?

If you don't turn the autopilot off after touchdown, the plane will begin to steer towards the ILS transmitters. At least mine did.
Please provide further info.

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I'm actually pretty sure that on aircraft installed with fail-operational autoland do provide rollout guidance and control, hence the 'rollout' annunciation of the PFD after Land 2/3 is the current mode and after the flare. FCTM 5.19, FCOM Vol. 2 4.20.5 FCOM Vol 2 - 4.20.19

Rollout[Option - Fail-Operational Autoland]ROLLOUT arms when LAND 2 or LAND 3 annunciates.At approximately two feet radio altitude, rollout activates:• ROLLOUT replaces the VOR/LOC roll flight mode annunciation• the autopilot controls the rudder and nose wheel steering to keep theairplane on the localizer centerline.• rollout guidance continues until a full stop or until the autopilots aredisengaged.

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Terry, did you have the horrid loaded? Please provide further info.
While flying the tutorial, I noticed that when I landed at Schipol, the airplane wanted to turn hard to the right. I thought I had a problem, but re-read the tutorial and noticed I had missed a step by not turning off the A/P. On subsequent landings the airplane acted normally when I disconnected both autopilots after touchdown. The attached pictures are from an elaborate preliminary preparation for a support ticket, one that I obviously didn't need.

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I have just posted about this ocurrence, but i don,t have a problem disconnecting the AP, just without that, the ac will not touch down.

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