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School methods and landings

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School methods and landings

Old 10th Nov 2021, 19:28
  #61 (permalink)  
 
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Congrats to Flyingheels on soloing. For other readers struggling with landing technique:

The approach and landing can be considered as defined vertical flight paths, with path controlled by pitch inputs and speed by power inputs (in much the same way as in straight and level flight). This technique differs from descending flight, in which speed is controlled by pitch inputs and rate (and therefore gradient) of descent are controlled by power setting.

The first phase of the landing technique - the flare - concerns the flight path from the transition point to the threshold, during which the power is gradually reduced to minimum. At the same time, the attitude is raised at such a rate, and to such an extent, that the aircraft arrives at the threshold in level flight just above the runway.

diagram here: www.steemrok.com/hlaflare.jpg

The asterisk shows the approach path 'sighting point' coinciding with the runway threshold.

During the second phase - the hold off - pilots should continuously alternate their vision direction to simultaneously assess height above ground and pitch attitude (which is adjusted to maintain constant height just above the runway. When the landing attitude has been reached the aircraft is allowed to sink onto the runway. This attitude does not need exact precision, merely the nosewheel comfortably off the runway (to reduce nosewheel stress and minimise potential for porpoising).

diagram here: www.steemrok.com/hlaholdoff.jpg

Last edited by Discorde; 10th Nov 2021 at 20:43.
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Old 11th Nov 2021, 10:15
  #62 (permalink)  
 
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The approach and landing can be considered as defined vertical flight paths, with path controlled by pitch inputs and speed by power inputs (in much the same way as in straight and level flight). This technique differs from descending flight, in which speed is controlled by pitch inputs and rate (and therefore gradient) of descent are controlled by power setting.
This is rubbish!
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Old 11th Nov 2021, 10:16
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Originally Posted by Discorde View Post
During the second phase - the hold off - pilots should continuously alternate their vision direction to simultaneously assess height above ground and pitch attitude (which is adjusted to maintain constant height just above the runway. When the landing attitude has been reached the aircraft is allowed to sink onto the runway. This attitude does not need exact precision, merely the nosewheel comfortably off the runway (to reduce nosewheel stress and minimise potential for porpoising).

diagram here: www.steemrok.com/hlaholdoff.jpg
Yes, all good. But this explanation misses out the most important thing about the hold off. This is that you are trying to arrange things so that the mains touch when the aircraft has the lowest possible airspeed you can manage. This is so important I'll say it again.
The lowest possible airspeed.
That should be the aim in a light SEP.
This might mean large control deflections in any or all of the three axes to maintain the Centreline and to align the aircraft in a cross wind - but that's ok. That's what the designer gave them to you for.

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Old 11th Nov 2021, 10:19
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Originally Posted by Fl1ingfrog View Post
This is rubbish!
Well I'm not going to get drawn into a debate about point and power except to say that it is what the RAF teach for the approach.
Personally I'm more comfortable with stick for speed and power for descent, but then these days I only fly baby airplanes.
In other words, it depends on type.
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Old 11th Nov 2021, 11:22
  #65 (permalink)  
 
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@Fl1ingfrog

Thank you for your input.

On the approach (and in level flight) autopilots and flight directors use pitch for path and power for speed. In climbing and descending flight (non-defined vertical flight paths) they use pitch for speed and power for vertical gradient. Climb gradient (fixed power setting) depends on speed (controlled by pitch). The laws of aerodynamics apply to all aircraft, regardless of size and regardless of whether humans or autopilots are flying them.

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Old 11th Nov 2021, 11:33
  #66 (permalink)  
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Personally I'm more comfortable with stick for speed and power for descent,
I'm more comfortable with stick for speed and descent, and power for flying the airplane beyond its gliding distance. I'm not saying that all landings need be power off, but all SEP pilots should be comfortable landing with no engine power.

with path controlled by pitch inputs and speed by power inputs (in much the same way as in straight and level flight)
The airplanes I fly don't fly this way. If I increase power during level flight, the speed will increase, and it will begin to climb. I will adjust the pitch to maintain level flight if that is that I intend. Inversely, when I would like to descend from level flight, the first thing I'll do will be to reduce power, and all the plan to pitch down slightly, uncorrected. The plane will descend at the same speed I was flying before the power change.

In very slow flight, if I increase power, the plane will fly more slowly.

On short final approach, you're probably in between those two conditions, where power changes will be very slow to result in a speed or pitch change, but will change the point ahead where the plane will slow to a stall, all other things unchanged. When I'm training a pilot who appears to be using power for fine glidepath control, our next circuits will be power idle from long final, until they build that judgement and skill - I spend a lot more time teaching power idle approaches, than approaches supplemented by power.

In a private flying forum, how the RAF teaches flying is of less relevance to me. I think most of their aircraft differ considerably from SEPs. That said, I understand that jet powered airplanes are even slower to react to power changes than propeller powered in slow flight, so glidepath control in a jet, with power as the primary factor, must be very challenging!

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Old 11th Nov 2021, 11:53
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In a private flying forum, how the RAF teaches flying is of less relevance to me. I think most of their aircraft differ considerably from SEPs. That said, I understand that jet powered airplanes are even slower to react to power changes than propeller powered in slow flight, so glidepath control in a jet, with power as the primary factor, must be very challenging!
Nope - 'point and power' works just as well in a PA-28 as it did in the F-4 or VC10! Glide path control in the Buccaneer was instant in the blown configuration by thrust adjustment.

We found that students who'd been taught 'point and power' gnerally soloed about an hour earlier than those taught the old way.
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Old 11th Nov 2021, 15:40
  #68 (permalink)  
 
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I've taught point and power for many years having previously taught pitch for speed and power for height on the approach, which was the convention at the time. A method I'd always found frustrating as much as I know my students did. In all other exercises it was power + attitude so why isolate this into two separate actions on the approach the student forever being behind the curve. Having corrected the height they then discovered they had lost the speed and vice versa. With point and power you are, of course, applying pitch and power simultaneously as the aircraft gains and loses height around the glide path. Most importantly for the ab-initio you are not contradicting all that you had previously taught.

Glide approaches as the primary method was very much the conventions when engines at low power were considered unreliable. Pitch dominated therefore and power an added benefit rather than side slipping but not to be relied upon. With the modern reliable engines, carburettor icing now understood and plugs not oiling up so easily the benefits of power became an equal part of the approach particularly with flap. Old ways don't change that easily and steep approaches with power reserved for maintaining the glide slope. This remains sometimes with good reason and Pilot DAR explains this well.
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Old 11th Nov 2021, 16:16
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This old "chestnut" about Airspeed with Elevator and Glide Path with Power versus Point and Power comes up time and again!

My own view about this stems from the observation that most flight training starts on single engined arcraft and has since the Wrights. Therefore for the student to be prepared to survive a forced landing he has to be taught the former technique - if he happened to be a glider pilot then this would be instinctive to him (speed/elevator glidepath/spoilers) To state the obvious - with no engine then power cannot be used for speed control.

Neither technique is the only way to do things. With a jet there tends to be a flatter Lift/Drag Curve thus if lift has to be increased then either the pitch has to be increased or the aerofoil accelerated - there is no benefit from increased airflow over the wing from increased power.

John Farley tells an amusing story in his book about being subjected dogmatically to the first technique on a CFS course so he deliberately flew an approach too slowly to 50 ft. then passed control to his instructor and said "now show me Pitch for Airspeed, Sir!!"

Point and Power is definitely an easier technique to master- in my opinion. (standing by for incoming!!)
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Old 11th Nov 2021, 16:35
  #70 (permalink)  
 
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Point and Power is definitely an easier technique to master- in my opinion.
A major concern of mine is the lack of glide approach training and this must be laid at the door of FIC schools. Glide approaches seem to be taught only as an emergency and not as a valuable technique. Taught only as a demonstration, sandwiched in passing into a lesson. A practice PFL onto the runway is often what counts. Like so many other elements of the syllabus, power off, steep approaches are treated with contempt and given lip service.
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Old 11th Nov 2021, 20:19
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"During the second phase - the hold off - pilots should continuously alternate their vision direction to simultaneously assess height above ground and pitch attitude (which is adjusted to maintain constant height just above the runway. When the landing attitude has been reached the aircraft is allowed to sink onto the runway. This attitude does not need exact precision, merely the nosewheel comfortably off the runway (to reduce nosewheel stress and minimise potential for porpoising)."
I look well along the runway, but don't know what else my vision is doing.
With a Jodel DR1050 my total cerebrum (and possibly cerebellum) neurons were involved in touching down and keeping straight. If told to alternate vision I'd never have got a PPL on a DH82 modification.
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Old 12th Nov 2021, 01:30
  #72 (permalink)  
 
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Now done 33 odd hours of circuits and its still Carp with the same faults as I had 20 hours ago.
It is hard not to see this and become despondent about the state of flight training

Towards the end of my time as a full time instructor, I tended to get the "problem" students. Almost invariably the complaint was they could not land. Unfortunately all too often the problem was they couldn't fly period. This was almost invariably the result of the instructor rushing through the foundation air exercises, Attitudes and Movements, Straight and Level, Turns, and Climbs and Descents. The result was they could not accurately asses the flight path of the aircraft and make the appropriate corrections at any stage of the circuit but especially on final and the flare.

To the Original Poster. If you want advice then here it is: Insist that you get a senior instructor and go to the practice area and review the foundation exercises. Do not let any instructor take you to the circuit until you have mastered the basics.
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Old 12th Nov 2021, 11:16
  #73 (permalink)  
 
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"During the second phase - the hold off - pilots should continuously alternate their vision direction to simultaneously assess height above ground and pitch attitude (which is adjusted to maintain constant height just above the runway). When the landing attitude has been reached the aircraft is allowed to sink onto the runway. This attitude does not need exact precision, merely the nosewheel comfortably off the runway (to reduce nosewheel stress and minimise potential for porpoising)."
Originally Posted by Maoraigh1 View Post
I look well along the runway, but don't know what else my vision is doing.
With a Jodel DR1050 my total cerebrum (and possibly cerebellum) neurons were involved in touching down and keeping straight. If told to alternate vision I'd never have got a PPL on a DH82 modification.
You've got me thinking.

Perhaps 'pilots should simultaneously assess both height above ground and pitch attitude (which is adjusted to maintain constant height just above the runway)' would be less prescriptive. Perhaps during the hold off it is peripheral vision which monitors height.

I recall the technique my (RAF) instructor used when I was learning to fly (Chipmunk). We lined up for take-off but before letting me open the throttle the instructor said: 'Look ahead and note where the horizon intercepts the cowling. Burn that image into your mind. Now look down slightly and note our height above ground. Burn that image into your mind. Now fly a circuit and don't let the aircraft land until you've got those pictures.' It worked for me.

Obviously in a taildragger landing attitude is critical. Less so on a nosewheel type.
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Old 12th Nov 2021, 17:49
  #74 (permalink)  
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Obviously in a taildragger landing attitude is critical. Less so on a nosewheel type.
I can choose to deliberately land my taildragger on all three wheels at once, or only two. Tricycle planes really must be landed on only two, if you want prevent damage to the plane. When I land a tricycle, I apply increasing pitch control after touchdown, to maintain the touchdown attitude as long as pitch control effectiveness enables to reduce wear and tear on the nosewheel.

When I land my taildragger, I always plan for a wheel landing. Once the mains are on, I'll lift the tail a little with pitch control, to improve the forward view, and reduce the chance of a bounce. I'll hold the tail off as long as control enables, to reduce wear and tear on the tailwheel.
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