Thrust on during flare...Q for AIRBUS test pilots...
 

Any Airbus test pilots out there?

I've noticed quite a few pilots in my company who, when flying a manual thrust approach, will leave thrust on during the flare after noticing sink or turbulence approaching the flare…sometimes resulting in either floating, or a firm landing.

Is there ANY reason to leave thrust on during the flare? Can you confirm that correct technique is to use thrust to compensate (aggressively if required) for a sudden sink approaching the flare, but not to maintain thrust on during the entire flare maneuver? This results in 3 or 4 "RETARD" calls.

You'll feel it in your bum and see it out the window, if you feel that you need thrust in the flare then do it.

Remember that in a Jet Pitch controls Sink rate and thrust controls Speed.

So, if the A/C is sinking too much at say 100' you will need to pull back to arrest the sink and THEN add thrust to stop the speed decay. If it's big enough you will need to keep the thrust on all the way to touchdown and then close the thrust.

One problem, not adding thrust will require the pitch attitude to be higher than normal to arrest the sink thus a tail strike is possible in extreme situations. Watch out. Sometimes in extreme undershoot shears it could require a lot of thrust to arrest the sink, in that case I'd strongly suggest a missed approach be conducted even if you touch down.

In a A/THR approach the A/THR will obviously add the thrust for you, all be it a little slowly for some!! ( another story )

On a normal stabilized landing in the A330 you'll need to close the thrust levers as you commence the flare otherwise it won't land!!

Glad we final have the answer to the whole thrust vs pitch discussion.

Question - on the descent today I increased the thrust. Speed remain constant but our rate of descent was reduced. Should we have written the jet up?

Don't think he has heard of CFS...................:)

See the Habsheim discussion about thrust and AoA and speed for controlling flight path.

CFS…Country Fire Service or Central Flying School??:} (I've been to one of them)

String through the ears…one hand goes forward, one hand goes back…right!!??!

I'm not referring to making adjustments to flight path for sink…I'm referring to maintaining thrust on during the flare. There seems to be a tendency to avoid seeing VLS at all costs. (Which incidentally, is maybe why many will choose manual thrust when landing in turbulence…Airbus auto thrust is designed to maintain speed from -5 to +10kts, but if some guys see VLS, they seem to think the jet is about to fall out of the sky!).

The A330 flies like a glider compared to other jets I've flown, so I don't see any reason to deviate from the tried and true technique of closing the thrust levers as the flare is commenced, unless compensating for very late sink (string through the ears). If correct landing technique is used (look to the far end of the runway at the commencement of the flare), any unusual sink can be picked up (unless you are in Hong Kong and can't see the other end of the runway!) and compensated for with slightly higher flare attitude and a slight delay in closing the thrust levers.


Again…any LONG COURSE TEST PILOTS who can confirm if there is a reason to keep thrust on during flare in an A330?

There is not one single recipe for every situation. Your question needs some serious rethinking.

For a trainee pilot: do what the FCTM tells you to do, and finetune it as you get more experienced.
For experienced pilots: fly the aircraft

Most of jets have the main landing gear well behind the center of gravity, thus the landing gear is behind the pivoting point. So you can easily drive the landing gear onto the runway when pitching up close to the ground.

Even with autothrust you will need to vary the height at which you put the thrust levers to idle.

Oh Yeah and Vapp with manual thrust = Vls according to airbus in zero wind.

Hot and/or high ops with a gusty head wind. Just to have enough energy to have THREE smooth touch downs. If not, then you might want to watch your nose.

misd again--- very appropriate user name my friend.

Yes you increased thrust on descent? Mmmmm and the relevance is?

Well I'll tell you AGAIN..

Yes normally on a stabilized landing you will need to close the thrust at the beginning of the flare, that's normal and sometimes the speed may decay to VLS before touchdown.....ok I think we are agreed on that.

There are times during a late low level undershoot sinking shear you may need to leave the thrust on until touchdown to prevent speed decay, especially below VLS.......ok

That's the ONLY time I leave thrust on late in the flare......ok

It's not rocket science.....

Go the Picker!
 

Got a job for you. Take over our jet induction course and teach them properly! :D

"Always remember and forever take heed: left hand for glidepath and right hand for speed!" (Reverse for first officers).

Hey he asked, don't have a cheap shot at me for trying to answer him by using pretty basic stuff.

One wonders why he had to ask but if I take him at face value it was apparently about why do some guys get upset if the speed falls in the flare and insist on delaying idle thrust......

My answer was correct and inferred basic handling abilities and seat of the pants instinct.......

Not having a shot, I'm agreeing with you 100%. :ok:

Fair enough.....all good

I thought proper thrust at proper place was part of a stabilised approach..
Sink sink thrust thrust bounce bounce go around.:E

Yes that's where the "aviate" part comes in, you decide how bad it is........before it gets to bounce bounce go around...:ok:

On the wrong foot….
 

Quote
"Remember that in a Jet Pitch controls Sink rate and thrust controls Speed."

Maybe I've been through all the wrong trainings, instructors, career, everything…

But last time I checked, IN JET AIRCRAFT, pitch controls speed, then we control flightpath with thrust.
I dont recall any Boeing manuals (or Airbus for the sake of this thread) teaching it differently. Our military background friends with AoA experience will certainly confirm the same.

This can be a VERY long discussion of course (Pitch or power etc etc) but regarding your specific question relative to flare, your experience will prove that in order to arrest descent, you add thrust. The reason you pitch up is to bleed off excess speed during flare.

If you are coming down fast (on VS rates that is) and you pitch up without adding thrust, you'll probably have an unpleasant experience.

Anyway, thats the way I've seen it happening, medium and heavy jets for 20 years +, but as always, I just might have been lucky, doing it the wrong way all this time and getting away with it.

Personal advice, keeping some thrust in, or adding a short burst during flare if needed, decreases the required pitch and you touch down smoother (because of the angle of the landing gear compression strut in relation to the horizontal).

There even used to be a term called "the Boeing flare" in the older days (before Airbus), where the pilot would pitch the nose over momentarily during flare in order to "grease it". Different wings too, I know.

Nowadays of course, pilots care too much about flying the numbers, making a big fuss for keeping 1 knot over Vref+5. I still keep Vref+10 min and fly a manual approach almost always, so flare is hardly ever an issue.
Nobody got hurt for carrying 5 extra knots, remind yourself to remain a pilot and refuse to become an accountant.

I know there will be comments but at my age, I can take them. Fire on…..

So next time I want to takeoff I should line up and lower the nose to accelerate down the runway? :}

It's no different for prop driven aeroplanes, either. :8

Is Pitch+Thrust=Performance ok for everyone?:p

Are you "flying" when you are accelerating down the runway mate?

Tell us about your experience without any childish comments. Unless you are only an armchair pilot.

I admire your sense of humor…….. you must be a very popular guy:}

Generally, if you do one without the other then you could end up having a bad day. They both go hand in hand and they can both do the others job.

For the OP - if you need it, use it.

It shouldnt even starting from Vref with a standard technique.
You keep +10 kts for your mum?to keep a safety buffer on your flying skills,to keep your FO "speed low" at bay or because you enjoy floating?:E
Tongue in cheek mate:p

Armchair pilot eh? The reason you pitch up during landing is so you don't hit the ground too hard!! Watch a few Youtube videos and note the nose coming up a bit just before touchdown... that's not the power making that happen. :hmm:

defacto, you should try it before commenting in such a manner.

You never "float" when you fly the aircraft all the way down. You float when you carry excess speed and then try to bleed off before touchdown.

If you keep the speed where you want it in order to keep your pitch angle at your desired number, then thrust controls your rate of descent. You always touch right where you want to, and always smoother than when you keep Vref.

Are you saying that the aircraft cannot land and it will float because you're doing 150 instead of 140? Its the AoA that makes you float. Flaring for speed is also the reason for almost all tail strikes.

Don't try playing it smart mate, keep your tongue in your cheek.
Try giving us your explanation of how this works instead. The way you would have taught this guy that asked the original question.

Lord Spandex, I agree. Both go hand in hand.

Bloggs, so if you would add thrust and keep your pitch you hit hard? I don't watch youtube to learn how to fly son. It is the power that makes it happen. Pitch is only for speed. You can keep the same pitch, same speed, and climb out before touchdown. Its all in the trust levers.

Well I don't know who taught you to fly Jets mate but I was taught 30 years ago that Thrust controls the speed ( just like the Autothrust does on a coupled approach, the Autothrust is in SPEED mode isn't it??????) and Pitch controls the sink ( ie keeps the G/S )Naturally they go hand in hand as one effects the other and yes you could reverse the two if you feel that way BUT that's not the way Boeing and Airbus designed the machine to be flown.

Copy from the A330 FCTM:---

USE OF A/THR
The pilot should use the A/THR for approaches as it provides accurate speed control. The pilot will keep the hand on the thrust levers so as to be prepared to react if needed.

Who teaches these guys anyway????????????:mad:

So you pitch for path and use thrust for your speed, right?

And you say that you've been flying jets for 30 years……:}
Maybe props, if not only sims.

I know its the oldest argument in the book but still, you have to be a bit more careful with you comments.

Regarding the A/T modes, what tems Boeing is using is totally irrelevant to the basic principles of flying we are discussing here.

I would suggest you buy a classic book, like Aerodynamics for Naval Aviators, and try studying again what controls what in large jet aircraft.

Go on, keep it coming.

Whatever you say buddy boy.:bored:

I've managed to cope for quite a while now thanks after learning my trade from highly experienced training Captains trained by Boeing. I appreciate your concern though!!

The basics we all use are as I've said above, feel free to do otherwise if it makes you happy.:{

I Haven't fired up XPlane for a while now, might see if it still works although the DVD drive is playing up a bit.

I only have 384 hours on F50's if that helps ya? The rest of my experience is on Boeing and Bus...

Oh and that FCTM quote was from AIRBUS not Boeing.....and the modes I quoted were Airbus as well. If you flew either of these you would know the difference.

but then...
No, it's the (excess) speed that makes you float if you used the "normal" landing attitude: you flared/pulled to the normal landing AoA. Going fast? Flare Less. Going slow? Flare more. If you have to do a massive flare, jam on power as well to stop the speed reducing below your normal landing speed. Go Around if looking shaky.

Seen it time and again. Aircraft falls into a hole, FO jams on power to save it, bang. Spoolup time too slow, didn't pull the stick back a bit. Then what happens (if we don't touch down) is we end up fast as the thrust kicks in and landing long. The secondary effect of controls will always ensure that eventually the downward thrust vector will change the flight path if you give it enough time.

Perhaps you should, old man. I can't believe you actually think that the nose coming up before touchdown (the flare manoeuvre) is caused by a power increase. I'll second Nitpicker's question; who's training you?

I can read all right.

384 hours. Very precise. Probably recent too and most probably not any on Boeing or Airbus.
"You all use"? Who are you all? Being part of many that do it the wrong way doesn't mean it makes it right sonny.

Read this book I told you and then re-read your "authority" comments on jet control. It will keep you laughing for hours……

Bloggs, I never said that the nose comes up because of power. Try to read the comment thoroughly. I said it doesn't even need to come up. I like the comments on the age. Shows your attitude. I am sure it will help you a lot in the future.

Its a pity you were trained the wrong landing technique. But its never too late to learn the correct one. Thats what makes you a good pilot, always learning.

I'm shaking my head Bloggsy?????? I'm at a loss for words to describe what he says mainly because I don't understand it....:eek:

Please tell me he doesn't command anything serious?

Yes 384 on the F50's in Australia before being upgraded to the 733 way back in 1988. Problem with me knowing that?? I'm not that old my memory is going!!

Think I bought a copy of Aerodynamics for a Naval aviators back in 1982 when I did my ATPL subjects? Heavy reading.

Handling the Big Jets is another good read, perhaps you have read it? Perhaps you SHOULD read it.

NoodleAir
There is not doubt that you flare to reduce ROD (change flight path). You do not add thrust, now depending on your ROD in last 100 feet you may flare early and also hold on to thrust till you are sure that the ROD is reduced sufficiently and then bring thrust to idle. If this is not good enough then you should go around. That is as far as landing is concerned.

From a 2009 737 NG FCTM:

You can fly the book.

I can fly the plane.

Read the book I told you, most of the Boeing test and certification pilots have used it for their whole career.
Then we can talk on the techniques and what is exactly you disagree with in my comments.

Blah blah blah, he said, she said etc etc..

My Dick is bigger than yours etc etc ( I do suspect you have a big watch )

Your technique is WRONG.

unless of course we don't understand what it is you are trying to say??

Perhaps explain to the world exactly how you control the approach and what you do to flare the a/c? Point out to me the error in my ways......

Noodle, you've lost it.

You said:
and then you said:
How then do you explain that every reasonable landing has the nose pitching up a couple of degrees? If this power increase of yours to arrest descent is not the reason, then what causes it??

You would be well advised to do some flying with Vilas. You need some staightening out on a few fundamentals... :ok:

You started it. I very much doubt I'm young enough to be your son...

I am saying -not trying to say- that when you say that you control your path in a jet by pointing your nose up or down, then you are not entitled to comment on this thread.
Not in any helpful way at least.

You are lacking elementary knowledge and obviously, experience.

It is a free forum, you can say whatever you want and jump into discussions way too deep for you, but it is evident that you have no idea how things are in reality.

I guess I won't have to go flying in my 233 tonne A330 on Sunday then.....

Yay, sleep in...:ok:

You still haven't explained your technique for flight path management, speed control and flare to us yet......

Care to try?

Oh an I've read enough of Capn Bloggs posts oven the last years to know he's the real deal, suggest you read some of my previous posts.

Read my posts.

You pitch for your desired airspeed and adjust thrust for desired path.

Simple as that.

Flare needs depend on a thousand different factors. Too complicated for you when you can't even grasp the basics.

Typical Magenda kid. Poor passengers…..

English isn't your first language is it??:D

The word is Magenta...:=

The saying is "sons and daughters of the Magenta line" do you even know what the magenta line is young fella?

I've managed not to bend anything since I started flying in 1979, only 14 more years to retirement!!

When you can match that then come and talk to me....:mad:

Whoop Whoop! Windup alert! Whoop Whoop! Noodle Alert! :)