PMDG 737NGX Handlandings

[Leo schoonbroodt 1]

Ok guys, a lot of different opinions.
In the mean time I did several succesfull handlandings with disconnecting AP and AT at several heights and I get the feeling that I just need more practice!

Jason, could it be this ground effect You mentioned that I experience as an automatic flare when I dont flare at 10 foot?

Because when I don't flare and watch the vertical speed, I can see that it decreases when about 15 feet AFL and the plane settles quit smooth on the runway.

On the other hand, if I flare albeit a little it starts floating above the runway when on AT and when not on AT my airspeed drops.

[downscc 1,327]

23 minutes ago, Leo schoonbroodt said:

Ok guys, a lot of different opinions.
In the mean time I did several succesfull handlandings with disconnecting AP and AT at several heights and I get the feeling that I just need more practice!

Jason, could it be this ground effect You mentioned that I experience as an automatic flare when I dont flare at 10 foot?

Because when I don't flare and watch the vertical speed, I can see that it decreases when about 15 feet AFL and the plane settles quit smooth on the runway.

On the other hand, if I flare albeit a little it starts floating above the runway when on AT and when not on AT my airspeed drops.

Transition your view or focus to the far end of the runway just as you think you are going to flare and let that view reveal the sink rate.  Flare only as needed and only as a smooth slight change if pitch.  Don't try for a smooth landing, best ones are solid or as said earlier make the sound "Boeing."

[MeatServo 10]

On 10/11/2017 at 11:45 AM, JoeDiamond said:

 

Not necessarily. My company allows, and encourages the use of A/T to touchdown on all landings.  Unless a QRH procedure requires the A/T to be off I leave it on all the time.

Straight from Boeing out of multiple different company FTM's both for Classics and NG's: "Autothrottle use is recommended during takeoff and climb in either automatic or manual flight. During all other phases of flight, autothrottle use is recommended only when the autopilot is engaged in CMD." The paragraph reference PMDG FTM 1.43 and worded identical to my company FTM and other FTM's I have on file. :) Granted each company can modify and add to the documents as they see fit, and it's only a recommendation not a limitation.

[MeatServo 10]

On 10/11/2017 at 2:46 PM, Leo schoonbroodt said:

Ok guys, a lot of different opinions.
In the mean time I did several succesfull handlandings with disconnecting AP and AT at several heights and I get the feeling that I just need more practice!

Jason, could it be this ground effect You mentioned that I experience as an automatic flare when I dont flare at 10 foot?

Because when I don't flare and watch the vertical speed, I can see that it decreases when about 15 feet AFL and the plane settles quit smooth on the runway.

On the other hand, if I flare albeit a little it starts floating above the runway when on AT and when not on AT my airspeed drops.

No, not an automatic flare. Just ground effect slowing your descent. Out of the 20+ airplanes in my career, the 737 has the most pronounced effect I've seen. It also has nose up attitude for the entire approach. About 3 degrees, practically already in the touchdown attitude, maybe 5-6 degree's but I've never noticed as my eyes are outside at this point down the runway. What I can tell you that landing PMDG in the sim is much harder due the lack of tactile and visual cues. Even a Level D sim fails to reproduce these cues faithful. If you're using auto throttle in manual flight it will most likely be in a SPD mode, and if you flare the thrust will come up and try to maintain speed. You will need to pull thrust manually and override the clutch mechanism which the sim doesn't allow you to do. (Unless you have the PMDG setup to always override autothrottles, but I find joystick spikes etc makes this mode even less ideal.) You need to land with thrust off for the autobrake system to work. You also need weight on wheels and thrust idle for the EEC(PMC's on the classics) to put the engines in ground idle. All eats up runway and is another reason not to have AT on when landing manually, and to never land with power on.

[JoeDiamond 67]

53 minutes ago, MeatServo said:

The paragraph reference PMDG FTM 1.43 and worded identical to my company FTM and other FTM's I have on file.

The only one that really matters is the one your paycheck comes from. :)

[MeatServo 10]

16 hours ago, JoeDiamond said:

The only one that really matters is the one your paycheck comes from. :)

For sure but my take is your company is ignoring a Boeing recommendation. Disconnect the AP and watch the thrust next time you fly an approach in VFR conditions. Most of the pitch corrections your going to have to make is going to be from the autothrottle, and it's going to have trouble keeping up. Ive flown theses things from T/D with the AT engaged in manual flight. It'll make the backend sick. Part of the cause with the Asiana crash in FSO was over relying on the autopilot/autothrottles. Left it in level change but in manual flight.

[JoeDiamond 67]

32 minutes ago, MeatServo said:

For sure but my take is your company is ignoring a Boeing recommendation.

Boeing is well aware of how we operate the airplane and is quite happy with it.

 

40 minutes ago, MeatServo said:

Most of the pitch corrections your going to have to make is going to be from the autothrottle, and it's going to have trouble keeping up. Ive flown theses things from T/D with the AT engaged in manual flight. It'll make the backend sick. Part of the cause with the Asiana crash in FSO was over relying on the autopilot/autothrottles.

You seem to be under the assumption that I'm blissfully letting the autothrottle do whatever it wants.  What do you suppose my left hand is doing all this time?  Perhaps it's on the thrust levers and even controlling them, you know, actually doing pilot stuff.

[MeatServo 10]

On 13/10/2017 at 10:02 AM, JoeDiamond said:

Boeing is well aware of how we operate the airplane and is quite happy with it.

 

You seem to be under the assumption that I'm blissfully letting the autothrottle do whatever it wants.  What do you suppose my left hand is doing all this time?  Perhaps it's on the thrust levers and even controlling them, you know, actually doing pilot stuff.

I never never said anything of the sort. Try not to take it personally. I'm not here to argue or attack you or your company but rather to have professional discussion for our mutual benefit collectively as a pilot/flightsim group.

I encourage you to start thinking of the "why" of procedures. Take a vested interest in your procedures and your airplane. You have the right to be involved with their development, improvement, and ammendment. This is part of being a professional and thinking like a Captain. Continual improvement and learning. Striving for the perfection we can never obtain.

"Boeing is aware", and "my company does it that way" do not answer the question of why behind an SOP.  I'm curious as to why your company does it that way. Maybe I can glean something from it to incorporate into our operation. Why are they ignoring Boeing's recommendation? Deviations outside the manuals, procedures, and manufacturers recommendations always need to be justified. Possibly it's a carry over from a previous design philosophy.

My intent was to explain the logic behind Boeing's recommendation. Like I said, it's not a limitation but a recommendation. It comes straight from Boeing and experience with the airplane from multiple operators.

I shared my experience when not following this specific recommendation. I have more examples of slow autothrottles, autothrottle failures, etc during my experience on the line with the '37 that I'd be willing to discuss with you that support this recommendation.

My take is that if I'm going to ignore a recommendation I'd better have a valid reason.

Going back to the PMDG sim, depending on how you have your throttle set up, you may not be able to override the autothrottle in the flare. I recommend disengaging it for all landings except an autoland for the reasons I have already stated.

[HamSammich 17]

There's a good (and heated) RW debate here:

http://www.pprune.org/tech-log/279544-t-speed-mode-landing-737-a.html

 

Enjoy!

[Leo schoonbroodt 1]

Learned a lot, think I go with AT off like Boeing recommends and just practice this more.

Especially now I know about this ground effect, last landings (with AT off) where a lot easier than the ones I experienced before!

Thanks guys for the clarifications!