landing technique B737NG
 

hi,
I`m currently doing the line intro on a B737NG for a Uk carrier. The one thing I can`t get my head around, is the flare phase during the landing. Basically the last 50feet. Does anybody have some hints on how to improve on that?
It just seems I can`t find the right moment on when to chop the power.
Thanks for any inputs,
cheers

737NG Landing technique
 

As far as I can 'see' and remember from the FCTM [B737-200 and B747 Classics] the technique stressed on by Boeing for a Jet is to have the 'TLA' [throttle lever angle] at zero '0' and the wheels touching down at the same time, or even later for the TLA. Anything else would mean either higher/lower approach speed or some different technique.!:ok:

i just maintain the G/S all the way down to around 20-30ft,i check a bit on the control column,and then i just flare around 15ft at the same time closing the throttles(the rate of the pitch down moment from the loss of thrust is the same as the rate that i flare),and then it just touches down gently without floating..:ok:

50' feet call out is your "wake up" call
30' you brake the descent with slight nose up pitch.
10' you cut the power - don't pull it slowly, cut it.

Reason for cutting the power and not pulling them slowly is that you might land with some thrust on if you don't cut them. And reverse thrust is only available when engines have spooled down to idle.

Astrocaryum vulgare has it right. Flare at 15', details in the FCTM. Very good explanation of how to fly a jet down finals in Handling The Big Jets as well.

Anyone telling you to check descent at 20-30' is giving you duff gen, that only results in a long touchdown.

Remember you are aiming for positive contact in the right place at the right speed. Far too many people are ground shy.

Agree with the above - in simple terms start the flare when it says 20, smoothly bring the thrust back when it says 10 and fly her onto the ground. Try not to pull the thrust off before you start the flare as the pitch/thrust couple then gives you a nose down tendency and a high rate of descent - which can hurt if not anticipated.

I'll go ahead and apologize for the length of this before I write it ... this is simply an attempt to do justice to this particular question.

I know, and I recognize, that “landing an airplane” is everyone’s point of pride – and everyone has their own technique for getting to that point. So, without trying to step on anyone’s technique (or their pride) I thought I’d offer my version of 2 cents (or pence) on the things that pretty much have to go right as a result of whatever technique is applied.

Almost everyone knows about and understands the term, “flare,” when talking about landing an airplane. However, not everyone understands this term in the same way. Basically, the flare is pulling back on the elevator controls to raise the nose (increase the pitch attitude) to “break” or “reduce” the rate of descent prior to touchdown. But, where is that you want the nose to go? Can you put it anywhere? No, certainly not. Well, if that’s true, then you want it to go to some specific spot. What is that spot? It is whatever attitude that is the “level flight” attitude for that airplane, in that configuration, and at that airspeed. What airspeed? The airspeed you have upon completing the flare. What height above the runway should you be at the completion of the flare? Well, the closer to the runway the better, as long as you don’t drive it into the runway before completing the flare. Most people believe that something between 2 and 5 feet above the surface is a good target to shoot for at the end of the flare, just to help ensure that you don’t land before you are ready to land.

By deflecting the elevator and rotating the airplane to the flare attitude, kinetic energy is dissipated – the airplane slows down – in fact, it slows so much that the “level flight attitude” will not keep the airplane in level flight; it WILL descend – unless you increase the attitude to something higher OR you add power. The fact is that if you flared to the level flight attitude and left the power alone (i.e., kept what you had to maintain airspeed on final), the airplane would descend – just not as fast and you’d be much farther down the runway by the time you actually touched down – but you WOULD touch down. If you pushed the power up a bit, you could maintain that level flight attitude AND airspeed and fly at that altitude and airspeed. If you pulled the power OFF, you would descend a bit more quickly than you would without the power reduction, but at a significantly less rate than what you had on final – and this is precisely what you’re trying to do – descend the airplane at a rate that will allow a firm but satisfactory touchdown.

An aside: why you might need or want to I wouldn’t know, and I would never recommend doing this in a transport category airplane, but if you had the runway necessary, you could keep the nose attitude coming up to keep the airplane from descending (because you would need a higher and higher angle of attack to compensate for the slower and slower forward speed) until you get to that point where the wing would stall. If you did this correctly you would have landed the airplane with the least amount of forward velocity. Of course your nose position would be really high and you very well may not have enough forward velocity to keep the elevator effective, and, as a result, the nose would likely fall.

So, as I said, you have to pull back on the elevator control to arrest your rate of descent – the flare. OK. You pull back on the controls to raise the nose to the level flight attitude. THIS is the attitude in which you want to touch down. However, from this point the airplane is going to slow – and more so as you pull the throttle(s) to idle. This will cause the airplane to want to pitch down. Why? Because you would have had the airplane trimmed for the final approach – configuration, airspeed, power, and rate of descent. You’ve now changed this. You now are at the level flight attitude and probably beginning to reduce power (if you haven’t started already). The airplane will want to pitch down, but you must not let it. To keep the airplane from pitching down, you would need to pull back on the elevator control. Notice, this “pull” is to keep the nose of the airplane in the level flight attitude; it is NOT to bring the nose any higher than what is necessary to maintain level flight. If you do bring the nose any higher, while you may continue to descend, you will increase the likelihood of touching down and “skipping” back into the air – sometimes before the signal to deploy the spoilers is generated; and sometimes just after – meaning that you might get airborne a bit, have the spoilers deploy – and drop whatever distance you’ve managed to skip to! Not very pleasant!

This may seem to be a rather small point, but it is significant in landing the airplane. Normally, it should take a pilot between 1½ and 3 seconds to flare the airplane – and the airplane should not be held in the flare (off the ground) for more than 3 seconds … this means reaching the level flight attitude and saying “thousand one, thousand two, thousand three, touchdown” (uh … I’d do this to myself or in a whisper if there is someone else one the flightdeck with you). This is true in no wind, headwind, tailwind, and crosswind conditions. And, also importantly, at the end of that 3 seconds, I’d recommend PUTTING the airplane on the ground, now! You chew up a good deal of runway while in the air, giving you less and less concrete on which you can count for good surface contact and good brakes to get you stopped.

There are several techniques regarding the retardation of the throttles – and each airplane requires that you become familiar with the technique that best fits the way you fly and how the airplane responds. Some pilots will start retarding the throttles over the runway threshold; others will wait until level flight attitude is achieved. The speed at which the throttles are retarded will be directly dependent on where you start to reduce power and how quickly the airplane will decelerate in this configuration and in ground effect. The throttle(s) should be in idle at, or just prior to, touchdown.

Airplanes are designed, for the greater part, to be landed from the level flight attitude; and by that I mean the attitude that would produce level flight at the airspeed achieved at the end of the flare, the existing GW, and the existing configuration. When I teach, to help my students to understand, for themselves, what this attitude really is, I have often asked them to make an approach to land the airplane, except that when they complete the flare, I ask them to continue to fly down the entire length of the runway AT THAT ALTITUDE and AT THAT AIRSPEED, without climbing or descending; and without accelerating or decelerating. The height I ask them to shoot for is something less than 5 feet. As you would understand, no doubt, in order to do this, the pilot MUST achieve, and keep, the airplane at “the level flight attitude;” or the height would not be maintained. This practice helps to “fix” the level flight attitude picture for them. If we are fortunate enough over a several-day period to have varying weather conditions, I’ll ask them to do the same thing in each of those different conditions. This allows them to see that level flight attitude is the same (as long as the weight and configuration of the airplane is the same) regardless of the weather conditions; and, most importantly, it allows them to find what cues they want to use to determine that the airplane IS in that level flight attitude; i.e., they are not dependent on what someone else has used and likes … they can “do it for themselves.” Admittedly, we don't often get a chance to do this in larger airplanes anymore, alas. But, this can also be done very satisfactorily in a properly qualified flight simulator with sufficient motion, sound, and visual cues. Why do I recommend this approach? It’s my opinion that landing an airplane is anything BUT a mechanical exercise. In my years of doing this, I have found that by asking my students to do something “the way I do it” works only for a small fraction of my students. But when I describe what I want as an “outcome,” and let them determine, on their own, “how” to do what I’ve asked them to do, they normally learn it better and learn it faster, because it’s something with which they feel comfortable, and it seems more “natural” for them. Therefore when I say, “flare the airplane to achieve a level flight attitude a small distance above the runway surface,” it makes little difference to me what technique they use to achieve that specific goal (within reason, of course) – as long as that goal is achieved. The biggest reason landing “mechanically” won’t work, is that none of us humans are as precise and as capable of repeatable performance as we would like to think we are. Remember, when we depend on the autopilot to land, we usually rely on 3 of them, at least two of which must be in agreement – and as you all know, “George” is a lot better at doing things precisely and repeatably. The only thing that shouldn’t change from landing to landing (and the thing that “George” gets right all the time) is that the airplane lands from the level flight attitude – for that configuration and that airspeed.

Couple of points on the above

You are NOT trying to find a level attitude. When you flare you are merely slowing the rate of descent.

You do NOT allow the airplane to float and certainly not for 3 seconds.

Boeing are very clear on both these points and it is a boeing we are talking about. That said its true for any aircraft.

Irrespective of the runway available if you keep raising the nose to prevent the aircraft descending you will bang the tail before you stall on.

To flare the NG you start at about 15' then increase pitch attitude by 2-3 degrees. After you initiate the flare smoothly retard the thrust levers to idle aiming for idle as the wheels touchdown. Make small pitch adjustments after the flare to maintain the desired descent rate to the runway.

I certainly don't mean to get into a "technique discussion" with you, but a pilot most definitely IS, or SHOULD BE, trying to find the level flight attitude - please note, I did not say that you are going to "level off." That would only be possible if you added power. If you read through my comments completely I think I mentioned that. If you flare to the level flight attitude (the attitude from which the airplane SHOULD be landed all the time, in any and all weather conditions) and do nothing else, you will land - it will just be farther down the runway than desired. If you flare to the level flight attitude either while you are reducing power, or reduce power reasonably quickly after reaching that attitude, you will continue your descent (even though you maintain that level flight ATTITIDE - not altitude - and WILL likely require a small but definite increase in back pressure if not a small amount of back-stick movement to maintain that level flight attitude) and you should land comfortably (not a "greased" landing, but very acceptable) within the touchdown zone. However, if you do as I have suggeted, you will be in a position for YOU to land the airplane if you need to get it on the ground sooner - for example, on a 6000-foot runway. Here, you'd want to be on the ground within the first 2000 feet - NOT take the traditional 3000 as a touchdown zone.

Also the 3 seconds I referenced, was, as you should note, a maximum time to stay in the "flared," level flight, attitude. You should also know that I am describing the time to descend from the height above the runway that was achieved during the flare. A pilot is NOT doing himself (herself) any favors by flaring at a height above the runway that will take anything beyond 3 seconds to reach the runway. Of course, unless you touchdown at the end of the flare (which is not recommended because of the possibility of misjudging and contacting the runway prior to reducing the rate of descent sufficiently), you are going to end the flare at some distance above the runway. It is going to take some amount of time to close that distance to the runway. I'm suggesting that anything beyond that 3-second time should be avoided in almost all cases - the only exception is those very rare cases where you are completely knowledgeable about the runway remaining, it is more than sufficient for you to complete the landing and roll-out, and you are planning to land "long" down the runway. The 1 1/2-second timing is merely an estimated time for the aircraft to continue the shorter descent from the height above the runway that was achieved at the end of the flare maneuver.

This procedure applies to every airplane. There are several "techniques" that can be used to accomplish what I have suggested, and I don't care (within reason) what technique is used. In fact, if the student selects and uses his or her own cues to accomplish what I've described - then they will learn better, and it will provide them a sound basis for landing the airplane in any weather conditions - AND - perhaps most importantly - they will NOT be trying to fly their airplane the way I fly mine.

Boeing tell you to raise the nose attitude by 2-3 degrees from the approach attitude in order to reduce the rate of descent then smoothly close the thrust levers. So you are shooting for an attitude a little lower than the staight and level one. If you raise the nose by the maximum they recommend you will approach the level attitude (for the approach config and speed) briefly but that is clearly not their aim especially as the 2-3 degrees are based on approach speed and attitudes. They will also tell you that 3 secs airborne after the flare will use between 515' and 775' of extra runway. As a comparison 10 kts extra speed uses 170' - 310' extra. Boeing figures. You aim to put the wheels on firmly at the normal touchdown point.

You defined your level attitude "It is whatever attitude that is the “level flight” attitude for that airplane, in that configuration, and at that airspeed. What airspeed? The airspeed you have upon completing the flare."

So level attitude at the airspeed AFTER the flare. As speed reduces in the flare that will raise your nose higher than Boeings 2-3 degrees on the approach attitude. Now your potentialy in tailstrike territory as the level attitude will adjust by approx 1 degree for every 5 kts of speed in a NG and given that you will bleed 5-10kts in the flare you could be raiseing your attitude by 5 degrees in total over the approach attitude.

You went on to say "If you flare to the level flight attitude (the attitude from which the airplane SHOULD be landed all the time, in any and all weather conditions) "

Snag is on wet or contaminated runways you risk too gentle a touchdown when you need a firm one to break through the surface layer and avoid aquaplaning.

Boeings Flight Crew Training Manual for the type gives you a perfectly good repeatable technique for landing the aircraft. Its written down for a purpose I suggest you read it.

start the flare at 15'. Bit late !! Especially for the inexperienced.

Have a look how the B737 autoland systems works, it begins to start the flare at 50 ft.
Thrust retards to idle at 27 ft.

For new students, if you follow these parameters you cant go to far wrong.

Would also add, that landing a -700 or a -800 and even -800W requires quite different technique, landing speeds (in a -700) is generally 7kts slower for any given weight, and the -700 mlw is about 58tonnes / -800 about 65tonnes, hence the -700 requires thrust closer to the ground to avoid planting it into the runway. I found the 737NG is quite hard:} (at least initially) to land smooth with good consistency, but never mind you will get the hang of it! :D
Cheers:ok:

Ignore AirRabbit's advice, it is NOT 737 technique as has been pointed out by others. The FCTM is the definitive guide and input from your Training Captains. AirRabbit's overly complicated waffle will lead you into flight regimes close to the ground that could result in tailstrike, and you don't want to be there.

If you follow Airbond's advice you WILL end up falling out of the sky onto the runway and probably beyond the touchdown point. It could well be a HARD landing.

The FCTM says to flare at 15' AGL and to reduce the thrust to be at idle when the main gear touches down. That is what you are aiming for having flown a stabilised approach. How do you best achieve that? Consistent stable approaches, fully configured early until you have mastered it and only then do low drag approaches. Think about nailing the centreline with whatever aileron control inputs you need, don't let it diverge. Same with the glideslope, remember how sensitive it gets as you get closer; nail it and keep it there with elevator. Start the transition from instruments to visual (on a cavok day) at about 1000'. Start bringing the touchdown zone into your instrument scan. Ensure you are fully trimmed and then don't trim below 500'. Make sure you have a target thrust setting in your head for your fully configured approach (get it before you descend from the PI). Make small adjustments as required to this target and THINK about the cause and effect (I mean if your set target is not enough and you as decelerating down the approach then you will need more thrust to regain speed and then slightly less to maintain speed, but this figure will be more than your original target and thus becomes your new target).

At 500' you should be bringing the touchdown point outside even more into your scan. As you approach 200' you want that touchdown point nailed in your screen, just like in a C152. Keep scanning speed, G/S and PAPIs to ensure all is well though. As you cross the fence at 50' you should be looking completely outside, with small inputs of aileron to nail that centreline and elevator to maintain your rate of descent. When you hear that call of "FIFTY" you should raise your stare from the touchdown point that is going to disappear under the nose, to 2/3 the way down the runway (I just look to the end personally), which gives you the horizon in your peripheral vision to judge your sink rate.

Keep it descending and listen to the "FORTY", "THIRTY", "TWENTY" calls. The speed at which these occur tells you how quickly you are sinking! When you hear the "TWENTY" you should be starting the flare, as there will be a delay between you hearing it and applying the required control input to actually initiate the flare. If you leave it below the call of "TWENTY" you will probably hit the ground with too high a rate of descent. Remember, with experience this can all be fine tuned, but to start with you will not have quite the same 'feel' as an experienced pilot on type.

There are many variables, but assuming you are ON SPEED exactly as you initiate the flare, in smooth light wind conditions, then you can start to close the thrust levers as per the FCTM so that the main gear touches as they reach the back stops. One such variable is if you have carried an extra few knots; you may need to close the levers earlier, if you are a few knots slower than your Vref you may need to slightly delay closing of the thrust levers to prevent a harsh touchdown. This comes with experience. Add in crosswinds, gusty winds, lots of rain etc and it all gets a little harder still, but the same principles apply.

When the main gear touches down, swiftly apply reverse thrust to the interlocks and apply slight back pressure on the reverse levers until the interlocks release. Avoid pulling back or pushing forward on the column. FLY the nose down onto the runway (which requires a check back on the column to prevent it 'falling' onto the runway). Put the upwind aileron into wind (if required) and nail that centreline with rudder inputs. Take more than idle reverse thrust as required and/ or briefed. As an F/O or S/O in the right seat, keep control of the aircraft until it is relinquished. Do not start 'thinking' that the captain is going to take it from you. Disarm the autobrakes (usually by pushing the toe-brakes) before you come to a stop and pull up straight ahead on the centreline unless you have briefed that you are going to steer the aircraft off on a high speed exit. Even if you have briefed this intention, ensure you are at a suitably slow groundspeed before turning off the centreline; it can be deceptive looking outside, when you think you are going quite slowly, but in fact you are still doing 70kts! Ensure that when you briefed you used the landing performance figures and measured the distance from the thrshold to the intended turnoff to ensure your autobrake setting is going to give you a reasonable chance of making that turnoff. If you hear nothing from the left seat (like our standard "SIXTY" knots call), pull up straight ahead, the captain may be incapacitated......

Keep reverse thrust as taken until below 60kts. When you hear the sixty knot call, REDUCE REVERSE THRUST TO BE AT REVERSE IDLE AS YOU SLOW TO TAXI SPEED and then stow the reversers, don't (as many do), stow the reversers abruptly when they hear the 60kt call.

The one thing to remember is the option to GO AROUND if you get it all wrong (until reverse thrust is initiated). When this is necessary will not ALWAYS be obvious to you in the heat of the moment, even when you get more experienced as we have all landed an aircraft when with hindsight we should have gone around.:ok: That is where a positive call from the PM can be worth its weight in gold.

Happy landings.

PP

One addition here on PilotPete's generally excellent post.

Do not overcontrol when trying flying the ILS! I see way to many pilots battling the controls in order not to be 1/4th of a dot high/low or left/right:ugh:
Don't constantly yank the controls, this is a jet and all control inputs need to be done smoothly, including the throttle controls. Start the flare at around 20'. If you are used to the EFIS B737's, you will notice that you have to flare around 8' later then with the classic, due to a greater ground-effect ( much larger wings remember:ok:)
Finally, try to feel the aircraft. Don't just mechanise your landings according to what a book says, again, feel what the plane is doing and wants you to do.
And one more thing: RELAX!

Also , if your company allows it, and on long, dry runways, keep the Autobrake off. It will give you much better ideas how to handle the aircraft after touchdown.

airbond
The thrust levers start to retard to idle at 27' to be at idle as the wheels touch. They are not at idle at 27'. The Flare mode does become active at 50' and that is when the mvr begins but the aircraft does not pitch until much lower it starts by feeding in additional trim and the gap between the mode becoming active and the pitch occuring gives the PM a chance to call if the mode fails to become active.

Anyone beginning a visual flare at 50' will land long, or level too high stall on and have a heavy landing, it is the wrong visual technique. 15' is not too late and is easily judged using the auto callouts as astro described earlier and if these are not available your mate can call 20' for you.

Boeing FCTM

If automatic callots are not available, the radio altimeter should be used to assist the pilot in judging terrain clearance, threshold height and flare initiation height.

Maintaining a constant airspeed and descent rate assists in determining the flare point. Initiate the flare when the main gear is approximately 15 feet above the runway by increasing pitch attitude approximately 2-3 degrees. This slows the rate of descent.

AFTER the flare is initiated, smoothly retard the thrust levers to idle, and make small pitch attitude adjustments to maintain the desired descent rate to the runway. Ideally, main gear touchdown should occur simultaneously with thrust levers reaching idle.

Me again

One of the main reasons people find the NG and in particular the 700 tricky to land is because they persist in using their own technique rather than the one written down by the manufacturer. As far as I know no airline has written a different technique into their ops manual for the landing. If others feel they know better than Boeing fine but I'll be sticking to their way of doing things. I would suggest we all do.

Pilot Pete, I was busy typing so didn't see your post until I put my latest one up but yours puts the meat on the bones of the FCTM nicely although personaly I do trim below 500'

Depesques tip about the autobrake is a good one. Far too many people touch down then do little in the way of braking and then realise the high speed they briefed is rushing up which is followed by a large, clumsy and uncomfortable application of the brakes which could have been avoided by a consistent brake application on touchdown.

I usually flare when the guy in the other seat says "OMG" or something similar, did it as an F/O and I'm still doing it. It only fails if he's asleep also! :E

Regards,
BH.

No quite true. Just because the throttles are closed at touch down does not mean the engines are at idle thrust - in fact they could be passing through 45%-50% and that means spooling up to high power reverse will be quicker and thus more effective retardation.

I've flown many variants of the 73, and each feel a slight bit different. But the one thing that seems to work well for me is to start my transition from the glideslope to the runway at or slightly below 200' with no power change. At 30', begin to slowly reduce power and start a very light flare to attain a shallower descent rate (I don't look at vsi, but I'm guessing about 2-400 fpm). At 10' start to slowly reduce the pitch (the roll-on technique). If you have plenty of runway, and the other pilot doesn't mind, try this with the power set until touchdown, as it will help you learn to fly it onto the runway instead of planting it. Hope this helps, and good luck!

B 737 landig techniques
 

flare technique for all the aircraft i ve already flown (B737-200, B737-800, A330),(the A330 was the easiest):
1. Being stabilised with appropriate thrust settig, spped, vs etc.
2.The last 100 feet AGL are crucial to achieve a normal landing, be stabilised, ie if for any reason you became above the G/S do not chase it by increasing the rate of descent but shift your new aim point beyond the touch down zone to remain on a constant 3 degrees angle, obviously this is valid if you have a long RWY, otherwise a GO AROUND should be considered.
3.When passing above the RWY threshold, shift your angle of view to the end of the RWY or 3/4 of it, this gives a very good assessement of your height above the paved and helps you to commence your flare when apropriate.
4.When comencing the flare manoeuver thrust reduction must be smooth and continous to reach idle or nerar idle thrust at touchdown.
5.RDO ALT call out are useful on those acft,( especialy during night ldg,poor visi etc), but in my opinion, pilots should rely on their skills and judgement during landing flare.