737CL Landing technique
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737CL Landing technique
Hi all,
Ok I've looked it up on the forum here and haven't anything to answer my question, so here it is.
I've been told (and shown) one way to land the aircraft, where at about 400 feet RA(just like the Autoland does it) you trim it nose up a notch or three, then keep the forward pressure on the control column and release it just prior to flare, then bring thrust levers to idle and just raise the nose a bit with the control column this time NOT the trim.
Yes, FCTM says that using trim on flare could result in a tail-strike, however the method I described above is somwhat half true to that.
Is it wrong? Is it good? Has anyone else tried it? Anyone heard about it?
Ok I've looked it up on the forum here and haven't anything to answer my question, so here it is.
I've been told (and shown) one way to land the aircraft, where at about 400 feet RA(just like the Autoland does it) you trim it nose up a notch or three, then keep the forward pressure on the control column and release it just prior to flare, then bring thrust levers to idle and just raise the nose a bit with the control column this time NOT the trim.
Yes, FCTM says that using trim on flare could result in a tail-strike, however the method I described above is somwhat half true to that.
Is it wrong? Is it good? Has anyone else tried it? Anyone heard about it?
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I never trim on the last 500 feet or so :/ never felt the need to either - the reason for the AP mistrim is the limited control authority of the autopilot, it needs the nose up tendency to fly a clean go-around without exceeding its capabilities as far as I understand. The FCTM describes it all pretty well, personally I always found landing with forward pressure extremely awkward (manual CAT II landing)...
Mistrust in Management
Is it wrong?
Yes it is - that why the FCTM says don't do it. Follow the techniques laid down in the FCTM - do not expect, or strive for, smooth touchdowns. With experience your landing technique will improve.
Whoever told you to apply nose up trim (as the A/P does) is quite simply wrong.
Regards
Exeng
Whoever told you to apply nose up trim (as the A/P does) is quite simply wrong.
Regards
Exeng
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Not flying the 737 but I strongly agree with the two posts before.
Doing a landing using a 'mistrimmed' AC (any AC being trimmed, i.e. not an Airbus) is in my personal oppinion an accident waiting to happen.
Let's say for example that - for whatever reason - you have to reject the landing and your colleague has to take over control. He is definately not expecting the aircraft to be out of trim (!) and would have to struggle with that additionally during an already highly dynamic situation. Definately not desireable.
Cheers,
DBate
Doing a landing using a 'mistrimmed' AC (any AC being trimmed, i.e. not an Airbus) is in my personal oppinion an accident waiting to happen.
Let's say for example that - for whatever reason - you have to reject the landing and your colleague has to take over control. He is definately not expecting the aircraft to be out of trim (!) and would have to struggle with that additionally during an already highly dynamic situation. Definately not desireable.
Cheers,
DBate
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Read the manual. Does it recommend that technique? No.
Matter of fact there is wording that talks about keeping the airplane in trim and not trimming during the flare. So trimming at some unknown altitude to avoid trimming in the flare is just as dumb.
Matter of fact there is wording that talks about keeping the airplane in trim and not trimming during the flare. So trimming at some unknown altitude to avoid trimming in the flare is just as dumb.
Mistrust in Management
Vladko
I have seen this done by a Captain - he always did it this way. I questioned him about it - and the answer was he "liked to do it this way".
As an F/O at the time I said very little (apart from mentioning over a beer, tactfully mind you, that his landing technique was crap lazy and dangerous)
Being the nice bloke he was, he just bought me another beer and ignored my comments.
Read the FCTM (written by those people who built it and test flew it) and fly it that way -it is just so much easier.
Regards
Exeng
As an F/O at the time I said very little (apart from mentioning over a beer, tactfully mind you, that his landing technique was crap lazy and dangerous)
Being the nice bloke he was, he just bought me another beer and ignored my comments.
Read the FCTM (written by those people who built it and test flew it) and fly it that way -it is just so much easier.
Regards
Exeng
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There will always be differences of opinion on this type of subject. You have what's in the manuals and then you have what works in the real world. It is the difference between procedure and technique.
My personal technique after 22,000 hours of 737 flying (-100,-200,-300,-500 &-700) is to trim up a little just crossing the threshold followed by a slight push on the yoke at about 2-3 feet. It makes for a soft touchdown and cuts down on the floating that may result with just trim/flare. If your manual prohibits this technique then you will just have to develop something that works for you within the confines of your company's procedure.
In regards to those who say just blindly follow what the engineers who designed it tell you, I say, they are engineers and there is no substitute for an experienced PILOT.
My personal technique after 22,000 hours of 737 flying (-100,-200,-300,-500 &-700) is to trim up a little just crossing the threshold followed by a slight push on the yoke at about 2-3 feet. It makes for a soft touchdown and cuts down on the floating that may result with just trim/flare. If your manual prohibits this technique then you will just have to develop something that works for you within the confines of your company's procedure.
In regards to those who say just blindly follow what the engineers who designed it tell you, I say, they are engineers and there is no substitute for an experienced PILOT.
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Viking...
Very well stated...there is the basis for the engineering for ops...but the the ops refines the engineering...it should always be a collaborative effort, else we both suffer.
Very well stated...there is the basis for the engineering for ops...but the the ops refines the engineering...it should always be a collaborative effort, else we both suffer.
I am appalled by the views that indicate deviation from manufacturer’s advice is to be expected. This is a facet of a hazardous ‘I know better attitude’. Accepting that because something appears to work it will be satisfactory and thus the risks associated with it remain unchanged, is very false safety.
When you encounter one of the remote situations which the manufacturer has had to consider, and possibly demonstrate, deviants will be exposed to the same unknowns of a test flight.
Even a simple mis-judged trim-up might increase the risk of floating, which in the wrong circumstances could result in an accident. Alternatively a tail strike – what defense would you offer your operator against being charged the cost of a repair. A trim-up may skip the weight on wheel / spoiler / reverse / antiskid logic; this won’t be classified an engineering system failure – it’s a ‘wetware’ failure, and the tag of wet behind the ears (inexperienced) would suit the pilot, because in that situation s/he was inexperienced.
Above all else, pilots should look for a safe landing - not a soft one.
Autoland systems trim-up for good reason; the risks in this have to be quantified and judged, and procedures developed for operation.
Similarly crew operating procedures for manual flight are not limited to engineering decisions; they involve all members of the flight test and certification team, the regulator, particularly training Captains and those member pilots of Operations Assessment Boards.
If an operator believes that a change is warranted then there is a process for this; it enables review and experienced cross checks, pilot and engineer.
It does not encourage or condone an individual’s self-appointed risk assessment.
When you encounter one of the remote situations which the manufacturer has had to consider, and possibly demonstrate, deviants will be exposed to the same unknowns of a test flight.
Even a simple mis-judged trim-up might increase the risk of floating, which in the wrong circumstances could result in an accident. Alternatively a tail strike – what defense would you offer your operator against being charged the cost of a repair. A trim-up may skip the weight on wheel / spoiler / reverse / antiskid logic; this won’t be classified an engineering system failure – it’s a ‘wetware’ failure, and the tag of wet behind the ears (inexperienced) would suit the pilot, because in that situation s/he was inexperienced.
Above all else, pilots should look for a safe landing - not a soft one.
Autoland systems trim-up for good reason; the risks in this have to be quantified and judged, and procedures developed for operation.
Similarly crew operating procedures for manual flight are not limited to engineering decisions; they involve all members of the flight test and certification team, the regulator, particularly training Captains and those member pilots of Operations Assessment Boards.
If an operator believes that a change is warranted then there is a process for this; it enables review and experienced cross checks, pilot and engineer.
It does not encourage or condone an individual’s self-appointed risk assessment.
Moderator
Putting SOP and AFM things to one side, what disturbs me is that the 737 Classic is one of the easiest aircraft to land and ought not to require any magic formula.
A while now since I have flown the variant but, as I recall, all one had to do was fly it down the slot, flare a few degrees (with a degree or two extra in a strong crosswind to allow for the bank angle), close the throttles, and sit it on the centreline for the rollout .. the quintessential pussycat.
More particularly, while I can see some logic in having a preset trim for, say, bugging out of a form aero problem (and, even then, I remember watching a recorded TP flight for the Blue Angels when they were investigating this for the F18, as I recall - a bit of roll/yaw coupling and away he went into a gyrating departure - the HUD video was interesting and the TP somewhat chastened as he had been caught out totally unawares) - any routine flying out of trim has to be a bad practice.
Trimming during the flare has to be a great way to set yourself up for interesting control loads during a late miss ... potentially, such a technique could compromise certification considerations for the missed approach.
A while now since I have flown the variant but, as I recall, all one had to do was fly it down the slot, flare a few degrees (with a degree or two extra in a strong crosswind to allow for the bank angle), close the throttles, and sit it on the centreline for the rollout .. the quintessential pussycat.
More particularly, while I can see some logic in having a preset trim for, say, bugging out of a form aero problem (and, even then, I remember watching a recorded TP flight for the Blue Angels when they were investigating this for the F18, as I recall - a bit of roll/yaw coupling and away he went into a gyrating departure - the HUD video was interesting and the TP somewhat chastened as he had been caught out totally unawares) - any routine flying out of trim has to be a bad practice.
Trimming during the flare has to be a great way to set yourself up for interesting control loads during a late miss ... potentially, such a technique could compromise certification considerations for the missed approach.
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Putting SOP and AFM things to one side, what disturbs me is that the 737 Classic is one of the easiest aircraft to land and ought not to require any magic formula.
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Putting SOP and AFM things to one side, what disturbs me is that the 737 Classic is one of the easiest aircraft to land and ought not to require any magic formula.
I think it's a bit of a perversion that nerds sit at home and become 'experts' at flying airliners. I would go so far as to say it positively freaks me out and strikes me as autistic behaviour. Go out and meet girls chaps! Go dancing instead, and get a life. Becoming a total expert like that is not good for you- you're not living a life! This is a teenager who is doing himself no favours and it will get himself no useful skill, but I suppose if the longed for disaster happens and the 2 Ryanair pilots collapse with low blood sugar, then our hero will be able to step in!
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Yes, but here, as in anything up to half of Tech Log nowadays, the burning question is does that apply for the 737CL add-on to Microsoft Flight Simulator?
Everybody else, thank you for the great replies, really useful!
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Vladko: thank you for positive attitude about flightsim. that is not always seen, but we are happy for every real pilot that is willing to share his experience for our benefit. I have a little mailing list of pilots that I can discuss real-life aviation and its implications for flightsim, lately we have discussed the TCX Manchester incident. Mind if I shoot you a message from time to time?
Notso Fantastic: Try to think of this as a hobby. Some people work their backs of in the garden, some knit, some build models. We "fly" the simulator.
Some do it because they wanted to fly for real, but couldnt. Some fly it with aims of someday moving on to real aviation. Some just for fun of it.
That said, PMDG is the NG simulation. Now I have no real experience, but I am told that landing a CL and landing an NG is somewhat different. Also, are you talking NGX or the original FS2002/4 NG? Leaps of advance between those.
papa600: I definitely agree for FS2004, although I am amazed by the NGX. You should try it if you have NGX
Notso Fantastic: Try to think of this as a hobby. Some people work their backs of in the garden, some knit, some build models. We "fly" the simulator.
Some do it because they wanted to fly for real, but couldnt. Some fly it with aims of someday moving on to real aviation. Some just for fun of it.
That said, PMDG is the NG simulation. Now I have no real experience, but I am told that landing a CL and landing an NG is somewhat different. Also, are you talking NGX or the original FS2002/4 NG? Leaps of advance between those.
papa600: I definitely agree for FS2004, although I am amazed by the NGX. You should try it if you have NGX
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Vladko: Thank you, its always nice to see this kind of attitude to flight sim, it is quite rare. I actually have a small group of real pilots that I discuss some real-world aviation and implications for FS with, from time to time. Lately, I asked them for comment on TCX Manchester incident. Mind if I send you a message sometime?
Notso Fantastic: Please think of flightsimming as a regular hobby. Some people break their backs in the garden, some knit, we "fly" the flight simulator.
Some of us use it because they could not get into real aviation, some with the hopes of eventually getting into it. Other just for fun.
That said, the PMDG is an NG simulation, now I dont have any real world experience, but I am told it handles somewhat differently on approach and landing. Also I am not sure if you are talking about the legacy FS2002/4 product? If so, you should definitely take a look at the NGX, its a different world really.
papa600: For FS2004, I agree. But I am amazed by the NGX, you should really try it.
Notso Fantastic: Please think of flightsimming as a regular hobby. Some people break their backs in the garden, some knit, we "fly" the flight simulator.
Some of us use it because they could not get into real aviation, some with the hopes of eventually getting into it. Other just for fun.
That said, the PMDG is an NG simulation, now I dont have any real world experience, but I am told it handles somewhat differently on approach and landing. Also I am not sure if you are talking about the legacy FS2002/4 product? If so, you should definitely take a look at the NGX, its a different world really.
papa600: For FS2004, I agree. But I am amazed by the NGX, you should really try it.
Last edited by Fabo.sk; 15th Dec 2011 at 11:09.