Landing technique - keeping thrust on until touchdown

[Propellerhead]

Most Captains I fly with (Boeing short-haul) seem to keep approach thrust on all the way down to touchdown (or 1-2ft above) before closing them to effect a touchdown. In extremis I flew with a guy who actually kept thrust on until 2 secs. after touchdown before closing them! This resulted in a very flat touchdown and I was concerned at one point he was going to land nose wheel first. Many guys add large amount of thrust at 10-20 feet to arrest the ROD, instead of flaring.

In contrast, I (on a calm day) gradually close the thrust levers at around 30' so they are idle around 10'. As I do this I am subconciously pulling back to stop the nose dropping and keep an acceptable ROD. At 10' I can either let the descent continue and land flattish (esp. if the speed is more than Vref+5 / short rwy), or if long rwy/vacating at end/blonde on jumpseat, can actually flare to a higher nose attitude to reduce ROD to near zero a few feet (or hopefully zero feet) above the rwy.

I am relatively inexperienced, have I just not been 'burnt' yet by sink developing below 30'? If sink develops over the rwy I simply keep the thrust on longer, or even increase it, but if none develops, why keep it on?

I am just slightly paranoid that I seem to be the only person who does what I describe, and yet I understood that to be correct, and it works for me!

[18-Wheeler]

Depends on the plane and the weight of the plane.
In the 747 I drive, when we're light I start to pull the power off between 30' - 50' depending on the conditions and then start flaring at just over 20'.
When we're heavy, I start flaring at about 30' and leave the power on until the flare attitude is nearly settled. At weights inbetween, I do a bit of a blend.

[Zico]

I do as 18wheeler, although at a little lower heights above runway (MD80). But nothing wrong with your technique Propellorhead. In fact, your´re probably doing it more by the book than I do, making shorter landings. When I´m flying my company´s northern routes with sometimes short (1600m) and icy runways, your technique is the thechnique to use.
Keep doing what works for you!

[411A]

Generally, up to the flying pilot/technique. I personally like to use a speed additive...+10 usually works OK in most circumstances.
With most jet transports, throttles should be closed just before touchdown (20 feet radio height, give or take).

[Flying Clog]

My technique in the ERJ 145: idle thrust at 50 feet, 30 feet in a crosswind or turbulence. Seems to work very well. However, these techniques will vary greatly between aircraft types and weights on the day.

Clog

[777AV8R]

Seems like everyone wants to re-invent the flying wheel.

Each aircraft, at least Boeing, has a flight crew training manual associated with it. The test pilots who write these books are charged with developing the proper techniques and procedures to fly the aircraft in the most efficent and above all...Safe manner.

The procedures written in the manuals, come about after hours of testing and are updated as they refine the profiles. The flight test department at Boeing has made all the errors for us and corrected them by making the training manuals available for each model.

Follow what they have told us and there can be few problems. It's when a few people decide to become their own test pilots, that in certain situations, lead to difficulties.

[411A]

All very true 777AV8R, however in many larger multi-fleet companies, the DirOps, system Chief Pilot, DirTraining etc....
will at some stage come to the conclusion that all fleets should be "standarized", ie: common operating procedures for all types, whether in makes sense or not.
Have seen this happen many times, and the results are generally not good.
At one SE Asian company where I worked a long time ago, they had what I thought was a very good policy at the time. The largest fleet was the Boeing 707, and the company took the Boeing manual/checklists/procedures and simply printed their logo on the cover and said....do it this way please.
Worked like a charm.

[777AV8R]

Yup, 411..I've seen that done too. Mostly operators tried to develop an SOP based on one type of aircraft so that transition through the fleet was easier.

Maybe I was missing the thread...but the discussion was on landing technique, which is not based on standard operating procedure, but on pilot training.

I've seen all types of landings on the 737 in my 8,000 hrs. on it, from idle at 50 feet, to an engine acceleration at touchdown. None of these are found in an SOP, but the correct methods are in a Training Manual.

[Cold Soak]

Whatever works for you really but landing performance normally dictates my technique.

I fly Dash-8's and on a nice long runway, say Gatwick or Manchester, I approach the flare at Vref 10-15kts close the powers during the flare and settle her on nicely 9 out ten times. :cool: :D

However operating heavy into short runways like Enniskillen, Sheffield or Plymouth performance dictates that you have to approach the flare at full flap Vref plus zero so closing powers means falling out of the sky so it becomes a tricky co-ordination exercise to close and flare at very precise moments... .success rate for a smooooth touchdown: 2 out 10 times :(

[Track]

My 737 training manual dictates a gradual closing of the thrustlevers just after the passing 50 ft so as to touchdown on the markers with Vref (+ the gustfactor). Works for me, especially useful on 1400 mtr runways....

[Slasher]

Airmanship dictates a power off touchdown so the AFM landing charts arent invalidated, UNLESS a loss of airspeed associated with sudden unexpected decreasing headwind/increasing tailwind dictates power be carried through the flare, and in extreme cases (-10 to-15 kts) to touchdown.

Ive flown a few heavey types like the 18-wheel whale, FLUF, and 727 and landed them like any other bloodey aeroplane. At the right height start closing the throttles while initiating the flare and touchdown at idle power.

It might be useful to note that, while not an AFM P-chart consideration, reverse generaly wont be available past the first interlock until the engines have spooled down to a pre-reverse value. That will seem like eternity if you happen to be slipping and sliding down a rain-soaked runway equivalant to the length of a cricket pitch with the maxurettes (anti-skid) twitching like crazey.

Landing with power on is like braking a car to stop while your other foot is still on the acellerater. Its a sloppey practice and doesnt beget confidence in others if a landing with a busted-up aircraft onto a very short wet runway be called for one day.

[Scando]

It depends on the weather. It depends on the rwy lenght. It depends on the ac weight. It depends on the ac type. It depends on the ap elevation. It depends on your experience. It depends on your fatigue level. It depends...
I appreciate the advice given by the testpilots, as 777something said, Mr Boeing, Airbus , etc, has done hours and hours of flighttesting. The airlines on the other hand, are operating these aircraft for thousands of hours.
Strictly following your AOM is as wrong as disregarding it.
I will add 40 kts to Vref if the conditions and rwy lenght so dictates. Its not in the book, but its my decision. Im am paid to think.
Same time, landing at 15 kts overspeed every time, just to do a smooooth touchdown, is just poor airmanship.
You are not wrong. You are doing what the book says, and what you have been taught. More important, what you are doing is not unsafe.
You will be burnt below 30 ft sooner or later, but it will only bruise you pride. Next time into the same airport, on the same rwy, you will maybe keep the thrust on a bit longer. Because it feels right.

Happy landings!

[jalbert]

Errr....should we really be modifying our landing techniques with each runway we use?
I know we all do it ,mostly for reasons of vanity (you old smoothies)but is it professional?
Surely same technique equals same touchdown point equals same margins of safety? No?
Shouldn't comfort come second ?The passsengers are not always right.
Cover your ass and do it by the book I say.

[GlueBall]

You can also monitor the "A/P technique" while in A/L mode; the throttles come back about one half second before touchdown.

[411A]

...except in the TriStar, where you will notice a slight INCREASE just before touchdown, but still closed when the wheels spin up.
Designed in by .... Lockheed.:D :D

[Scando]

And the MD-80 retard at 50 ft. You don't see many pilots closing the trottle at that altitude when they are flying manually. It's possible, but you will find yourself running out of elevator control sooner or later. Not a good feeling.

[thermostat]

So far no has mentioned the type on engine.
On the older non by-pass engines - DC-9, B727 etc removing the thrust too soon would cause early deceleration and maybe a hard landing.
Not so with the newer large N1 by-pass engines.
The fan produces 75% of the thrust and is free turning (no gearbox to restrict it). Closing the thrust lever slowly at 50 ft has less effect on the N1 fan so there is sufficient residual thrust to prevent rapid deceleration, hence a good landing - just like the auto pilot/auto thrust. Close it at 10 ft and you'll burn up a lot more runway. If you don't need it, don't use it.
Thermostat.

[Propellerhead]

Thanks for the replies everyone. Interesting point about the engines. The 737 also has quite a high flight idle because of spool up times of around 32%N1. This reduces to 22% 4 secs after t/down to allow rapid accel. in reverse (another reason for getting the thrust levers closed and reverse selected early).

It's interesting that several people seem to pick their own app. speeds. On the 737 it is very specific at Vref + 1/2 the steady h/wind componant + all the gust, with a min of Vref+5, and max of Vref+20.
eg) 14kts = +7, 14G20 = 7+6=Vref+13
However, whilst the gust correction should be maintained to t/down, the steady wind correction should be bled off as the a/c approaches touchdown. Therefore, if the wind is less than 10kts, you should approach at vref+5, touching down at Vref. Clearly this cannot be achieved unless the thrust is gradually reduced on crossing the t/hold.

Interesting that Scando says you run out of elevator on the MD80 if you close the thrust levers at 50'. On most other a/c (Boeing / Airbus) you will scrape the tail long before that! If sink develops you can't haul back beyond 10 degrees so I guess you have to add thrust.