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June737
24th Apr 2018, 02:56
Hello~
I'm B737 FO and I have 1500hrs on type. I'd like to get some advice about my landing.
I have some difficulty to touchdown on centerline. I tend to touch on left of centerline.
A/C is on centerline when passing threshold but during flare it goes to left.
Some people said that I concerned to much about flare and power control so I missed centerline.
I've tried to fix the problem but I couldn't.
Please give me some advice.
Thank you for your help.

RAT 5
24th Apr 2018, 11:35
A/C is on centerline when passing threshold but during flare it goes to left.

Firstly, no it doesn't. You let it or caused it. What is curious is that most F/O's err on landing right of centreline. The centreline is judged by it being right between your legs. Do Not try and offset it. You are sitting <1m from the centreline. You can not judge/assess any offset. I can guarantee that if you taxi the a/c or the captain taxis the a/c with the centreline between your legs, from either seat, you will be on the line.

You can see the centreline accurately from 200'agl. You come over the threshold at 50' and there is no doubt where the centreline is. It should be between your legs. it is your job to keep it there. If you drift off it can be slight left aileron; although that would be strange as you are flying with your right hand and that would mean lifting your hand. A more natural tendency is to pull down, not up. After 1500hrs you should not be nudging the rudders. If this is a frequent error then I assume it's not due to wind.
It's a concentration issue to maintain the centreline during the flare. You mention too much thought about the flare & power. Power is easy as it is idle, but then the nose wants to fall. That's controlled by elevator, as is flare. It's a coordinated controlled combination of elevator & aileron dictated by your eyes.
You say you've tried to fix the problem? How? It's not complicated, but maybe you are making it so.

mcdhu
24th Apr 2018, 12:07
June,
You could be applying left aileron as you pull back on the yoke to flare. I have seen this before when the seating position is not correct. Make sure you are sitting in the right place.
mcdhu

mustangsally
24th Apr 2018, 13:16
June, you have 1500 hours in type, so that would be about 750 touchdowns. You most likely would get about half or something just short of 400 impacts. Now through in something over 40 simulator affairs and you now have a lot of experience. By now you should be getting all most all on the centerline. What is the problem, could be a whole combination of seat height, where are you looking, arm rest, no arm rest, etc... I'd start with seat height, I've seen lots of pilots just sitting to low. Then, where are you looking during the flare? Hopefully still looking toward the end of the runway and horizon. Have had a few who started looking right over the nose and could not pick up the left or right drift.


The 73 is a great airplane and easy of fly, maybe you are overthinking the problem.

Reverserbucket
24th Apr 2018, 13:17
..with the centreline between your legs, from either seat, you will be on the line
RAT 5's recommendation could provide a clue - when you learnt to fly, were you taught to keep the centreline under your right leg to maintain it? Students taught this pre-solo sitting in the right-hand seat of a single-engine trainer find that a move to the right-hand seat in a larger aircraft requires an adjustment to the technique (and no, I'm not suggesting you attempt to land with the centreline under your right leg now, only that you might not have been given a new 'rule of thumb' for the datum during type training).

June737
24th Apr 2018, 16:14
thank for your advice. I tend to sit low and use high arm rest.
I'll try sitting in the right place.

June737
24th Apr 2018, 16:16
RAT5~~thank you for your advice.

piratepete
25th Apr 2018, 04:15
RAT 5, What you say is correct whenever the crosswind is insignificant, however if you use this method on any large jet when there a significant crosswind, and especially if there is a wet runway surface, you risk sliding the main gear off the pavement....In this case your flight deck should be upwind of the center line.

Dan_Brown
25th Apr 2018, 13:53
A/C is on centerline when passing threshold but during flare it goes to left.

Firstly, no it doesn't. You let it or caused it. What is curious is that most F/O's err on landing right of centreline. The centreline is judged by it being right between your legs. Do Not try and offset it. You are sitting <1m from the centreline. You can not judge/assess any offset. I can guarantee that if you taxi the a/c or the captain taxis the a/c with the centreline between your legs, from either seat, you will be on the line.

You can see the centreline accurately from 200'agl. You come over the threshold at 50' and there is no doubt where the centreline is. It should be between your legs. it is your job to keep it there. If you drift off it can be slight left aileron; although that would be strange as you are flying with your right hand and that would mean lifting your hand. A more natural tendency is to pull down, not up. After 1500hrs you should not be nudging the rudders. If this is a frequent error then I assume it's not due to wind.
It's a concentration issue to maintain the centreline during the flare. You mention too much thought about the flare & power. Power is easy as it is idle, but then the nose wants to fall. That's controlled by elevator, as is flare. It's a coordinated controlled combination of elevator & aileron dictated by your eyes.
You say you've tried to fix the problem? How? It's not complicated, but maybe you are making it so.

You sure about that? I have always aimed to land and therefore landed, with the centreline "running up the nearest leg, to the quadrant".

if you are unable to "nail the centreline" you are therefore not in full control of the aircraft. Might sound like a wizeguy statement but it is true.

RAT 5
25th Apr 2018, 14:00
You sure about that?

Yes I am sure about that on a B737. Regarding the crosswind and cockpit offset, that is a given and was not a scenario included in the June737's question.

Eric Janson
26th Apr 2018, 20:33
@June737

What are you doing with the rudder? I'm increasingly seeing rudder not used at all during landing.
If you're not using the rudder you need to start - it's there for a reason.

sheppey
27th Apr 2018, 02:24
The arm rest position is a matter of personal preference. Some check pilots insist you use the arm rests. They are wrong as everyone has personal preferences and what is good for one pilot may be distracting for another. Personally I never use the arm rests until cruise flight as they distract me especially when hand flying the approach and landing

Icelanta
27th Apr 2018, 03:13
You sure about that?

Yes I am sure about that on a B737. Regarding the crosswind and cockpit offset, that is a given and was not a scenario included in the June737's question.

well...
on B737, the centerline is actually aligned with your right leg when sitting left, and the left leg when sitting right when taxying. That is exactly nosewheel on centerline, so Dan Brown is correct.
to keep,things simple really during the landing, centerline between legs is fine too and gives some leeway.

Vessbot
27th Apr 2018, 04:31
well...
on B737, the centerline is actually aligned with your right leg when sitting left, and the left leg when sitting right when taxying. That is exactly nosewheel on centerline, so Dan Brown is correct.
to keep,things simple really during the landing, centerline between legs is fine too and gives some leeway.

Unless both pilots' inboard feet are at the same place at the center of the airplane, this is impossible.

RAT 5
27th Apr 2018, 11:36
Oh please. I'm not into nitpicking. Get a life. I used to fly with a captain who flew takeoffs with dung, dung, dung, dung.....i.e. hitting all the centreline lights. You think that's a good idea. If the outside of the left nose wheel touches the outside of the paint on the right side of the centreline, then I'm satisfied I'm on the centreline. I've watched too any F/O's, in sim & a/c, who try to line up the centreline with their left knee. They are at least 2m minimum, often worse, off the centreline right side. KISS.

Silver Wing
27th Apr 2018, 11:55
Oh please. I'm not into nitpicking. Get a life. I used to fly with a captain who flew takeoffs with dung, dung, dung, dung.....i.e. hitting all the centreline lights. You think that's a good idea. If the outside of the left nose wheel touches the outside of the paint on the right side of the centreline, then I'm satisfied I'm on the centreline. I've watched too any F/O's, in sim & a/c, who try to line up the centreline with their left knee. They are at least 2m minimum, often worse, off the centreline right side. KISS.


In the simulator, every observer sees the exact same image when looking out of the front window. So if the nosewheel is positioned exactly on the centerline both pilots will see the centerline running between their legs.

In the real aircraft the captain and FO donít see the same image. If the nosewheel is on centerline the capt will be positioned slightly left and the FO slightly right. That means that if an FO uses his normal technique of landing with the centerline touching his left leg in the simulator, you as the captain will also see it going through your left leg. So it will look to you as if he landed way right of centerline while from his perspective everything looks normal.

RAT 5
27th Apr 2018, 17:45
After 14 years on type, B737, I proved the point. I let the F/O taxi onto a self manoeuvring stand, once I'd lined him up approximately 100m from the stop line. I then said put the centre line of the lead in line between his legs. Now go outside and look. The line was within the extremities of the twin nose wheels. Crossing the threshold, and in the flare, you are looking a long way down the runway and still quite a distance from touchdown. IMHO there is no way, in such a narrow flight deck, you can judge the offset distance between the centre of your seat and your left knee or centre pedestal. Forget the sim, I spent years of short sectors, therefore many demonstration, where F/O's tried your technique and landed with the left main wheels on the centreline, at best.

We'll have to agree to disagree, but I can't change the facts of 1000's of sectors.

Vessbot
27th Apr 2018, 18:15
Oh please. I'm not into nitpicking. Get a life.

Well, he said "exactly." When someone does that about a fact of geometry that's only true approximately, I sense it like a disturbance in the force... as if millions of voices suddenly cried out in terror.

I used to fly with a captain who flew takeoffs with dung, dung, dung, dung.....i.e. hitting all the centreline lights. You think that's a good idea.

If he was as "exact" as me, the centerline lights would be going between the twin nosewheels and there would be no bumps. :cool:

(And, back to the serious side, what does this have to do with the 737 specifically? I find it so weird when I see a question that goes "on the 737/A320..." and it's about something that applies equally to any airplane. I can't think of any examples right now, but I see them all the time on this board.)

Pugilistic Animus
27th Apr 2018, 19:05
Well, he said "exactly." When someone does that about a fact of geometry that's only true approximately, I sense it like a disturbance in the force... as if millions of voices suddenly cried out in terror.



If he was as "exact" as me, the centerline lights would be going between the twin nosewheels and there would be no bumps. :cool:

(And, back to the serious side, what does this have to do with the 737 specifically? I find it so weird when I see a question that goes "on the 737/A320" and it's about something that applies equally to any airplane. I can't think of any examples right now, but I see them all the time on this board.)

I see them too...all the time

DaveReidUK
27th Apr 2018, 20:46
and it's about something that applies equally to any airplane

Well almost any. :O

https://www.airteamimages.com/pics/49/49648_800.jpg

Meikleour
27th Apr 2018, 22:10
Nice one Dave!

Vessbot
28th Apr 2018, 00:29
Well played! But I'll raise you...

https://i.imgur.com/uT6VvYB.jpg

(Apologies, couldn't find a pic with it on a centerline though)

Pugilistic Animus
28th Apr 2018, 01:35
The Hawker Siddley 727 :ouch:
:}