I use autothrottle when flying manual ILS. During manual landing, will autothrottle retard to idle by itself 50" above runway or should I disengage autothrottle before approaching the threshold and manually set it to idle?Thanks,Wayne Chan

Personally, I disengage the autothrottle once I'm established on the loc and g/s, and fly her in that way, so I'm not sure if it auto-disengages or not.. but I'd suggest the manual approach.

Humm that's a good question. Well it's true it will go idle at 27RA and disconnect 2 seconds after TD in a dual autoland. I believe if you have the A/T set to ARM and manually landing that it will command idle at 27RA (pilot can chime in). If you are manually controling speed I think it's best to de-select the MCP SPD button on approach and hit F1 to go idle just in case your joystick is not completly at idle. Now there are those who say that keeping the A/T armed in this situation is a good thing because it gives you stall protection (ALPHA) and others that a possiblity of a sudden burst of throttle during the flare (below REF) followed by retard is not a good thing either. So one CAN just turn it off if they desire and would be in sync with some pilot's techniques and choosing to leave it on is also done. Knowledge of what CAN happen is key ;-)[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | WD SATA 80 GIG | 512 DDR 400 |

Hi Guys,IRL.. Boeing recommend A/T disengaged when hand flying. Even if A/T is on unless you are in a full autoland mode then the A/T will not RETARD thrust levers for the flare etc. Some companies like you to leave A/T armed when you are flying a manual approach but that is all. Being in ARM means A/T will add thrust shoudl you apporach stall. This is not really ALPHA Floor protection as it is in the Airbus. Consider it just to be a speed swithed application of thrust.Rgds,

"Even if A/T is on unless you are in a full autoland mode then the A/T will not RETARD thrust levers for the flare etc."Hi, Brad...Our company NG manuals are telling us that the A/T will retard the throttles at 27' if the DFCS is not engaged for approach, IF...On Glideslope ANDIn MCP Speed Mode ANDFlaps greater than 12.5No definition is given for "on glideslope".... Do your manuals have any details on this?An option perhaps?Thnx.Cheers.Ian.

I agree with Randy. When you disengage the auto pilot on approach, also deselect the MCP speed button. You have the Autothrottle disengaged but it is still armed. If you need to Go-around then the Autothrottle is armed already.Cheers,Dinshaw.

As usual, its amazing to see the same child-like (not childish) arguments among the real-world guys that we have here in our hobby.The PPRUNE forums:http://www.pprune.org/forums/showthread.ph...37+autothrottleAfter a post by T. Metz. and reading through the PPRUNE forums on that subject, I now leave AutoThrottle armed with spd selected at VREF while controlling the plane with the yoke (Autopilot off). At 50ft, I hit a button on my throttle which disengages the SPD mode then another button which is tied to F1 therefore bringing the throttles to Idle (that way I have no problem with spoilers either).I don't really have a choice because my throttles are extra sensitive and when I bring them back to idle, sometimes they go to 21% N1 (when on the ground of course) and sometimes they stop at 27%. So I always have to hit F1 to get them to idle. (This is a calibration problem with my throttle (Saitek X45) and NOT a flaw with PMDG).I'm just reading up on FSUIPC to see if its possible to help solve this problem with its settings.

Why use A/T, when you can manually control the thrust.?That's what Boeing recommends, and that's how its best done. Keeps the hand flying skills better as well.Tero

Yes Wayne it will retard if you're using both autopilots.If I'm flying a straight in landing I'll disconnect the autopilot when flying manually to track either loc or GS or even both but leave AT on, the only time I'll desengage AT is when I have a strong cross-wind component and on challenging approaches where there is some sort of a turn involved before landing.David

The method of flying an approach that I have been taught (and God help me if my instructor ever catches me doing it differently!) is to adjust speed with pitch and altitude with power. In other words, if below the glideslope; add power. If above the glideslope; reduce power. If fast; pitch up. If slow; pitch down.Now, my instructor is teaching me to fly a C-150! BUT, I have seen this method advocated by commercial pilots flying heavy iron as well. Clearly, if the AT is on then it will be adjusting power to maintain speed, therefore the PF will be adjusting pitch to maintain GS and if I do that I get a fuel dip-stick across the knuckles!For me, when flying a manual approach in the PMDG bird, I have the AT OFF. The only time I leave the AT ARMED is when flying a full autoland.I suppose it's horses for courses and different airlines probably have different policies.Chris Kirk

According to PPRUNE posts, the B737 A/T retards at 27ft on a manual landing. Does the PMDG B737 do the same or does it set the thrust to idle at touch down only?ThanksStephan

Don't pay attention to PPRUNE all the time since not everyone talking is a real pilot and even if some are not all of them on an NG. And by the looks of Brad Marsh's post and Q there seems to be a difference of opine and maybe even an option. Will have to look it up..[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

Hmm.. I may be wrong then Chaps.Will do some research.. just goes to show you never know enough :)Seriously though, I apologise if I have misled anyone and would appreciate a reference for further reading as all I can see is in Vol 2 4.20.14 under the section on AFDS Approach and Landing where it talks about Flare and says the A/T will start retarding at approx 27' RA and will disengage 2 seconds after touchdown.

When flying manually, fly manually (ie. leave A/T off).WRT to flying techniques. With heavier jets it's more common to use the "point and shoot" approach. This means that you basically regulate your vertical speed mainly by pointing your nose at different angles. Speed is then (again) mainly controlled by thrust.This is an entirely different approach than that of the one light aircraft pilots are taught in their initial training.Main reason for such a different method is the inertia of the bigger aircraft. To remain on a perfect 3 degree glideslope one needs constant finetuning of the nose position, and typically power is set to achieve the desired approach speed region approximately, and then fine tuned to achieve correct attitude for the approach. Of course it's not all black and white and you obviously need certain amounts of power in different situations, but this is how it's mainly done in real life. Also, typically heavy iron pilots learn by experience the approximate power settings for different situations which makes the power management a lot easier. Relying solely on the lighter a/c method "pitch for speed" in a heavier jet will tend to make things more difficult.Tero

Remember that just having the A/T ON does not mean that it is controlling anything if one has SPD de-selected. One must keep in mind that some real NG pilots do in fact use this technique while others turn of the A/T. Not any one way is better than the other and again the A/T with SPD de-selected is not controlling anything.[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |