Learning to fly, or thinking of learning? Post your questions, comments and experiences here

Moderator: AndyR

  • 1
  • 7
  • 8
  • 9
  • 10
  • 11
User avatar
By lobstaboy
#1871502
Let's say the wind is from the left. As you round out you feed in a bit of right rudder to align the wheels with the direction of travel (no "kicking " please) and some left aileron to keep to the centre line - ie crossed controls aka side slip.
I find it very difficult to get right though. If your timing is perfect you can get away without the aileron input, yes.
Coming from a gliding background I feel much more comfortable with the crabbed approach as that's all we were taught (wings too big for wing down method).
T6Harvard liked this
By TopCat
#1871595
lobstaboy wrote:Let's say the wind is from the left. As you round out you feed in a bit of right rudder to align the wheels with the direction of travel (no "kicking " please) and some left aileron to keep to the centre line - ie crossed controls aka side slip.

Yes, I understand the theory all right, I just didn't know anyone does it that way, much less that it's the 'correct' way.

'Kicking it straight' is just a figure of speech. Of course it's not 'stamp' it straight. But once the wheels are about to touch, you want the yaw to be as brisk as possible if you're not changing to the wing-down method as you describe. So it can't afford to be too gradual.

I find it very difficult to get right though.

I'm not surprised! I'd want to practise this sort of thing in a nice steady crosswind that was strong enough to be able to see what was going on, as I know I wouldn't have the finesse straightaway.
If your timing is perfect you can get away without the aileron input, yes.

As I say, it doesn't have to be perfect, although it mustn't be late, else you'll land sideways which is uncomfortable even on grass, and most unpleasant on a hard surface.

But you can usually afford to be a second or so early in all but the strongest crosswinds. You know when you're going to touch to within a couple of seconds, right? :wink:
By Harry.Brown
#1872630

If you land properly, then at touchdown you should be be at stall speed, at whatever flap setting you choose.

So you have to slow down from your final approach speed to achieve that. The flare, that is the pitch up to level flight above the runway, will absorb a little of that speed due to the increase in drag that you get when the angle of attack increases.

But the rest of that speed has to bleed off in level flight during the hold-off. The more you have, the longer it will take, and the more runway you'll waste behind you.

If you've got miles of runway to play with, it doesn't matter, as you can afford to wait.

But one day it will matter. Landing on a short runway requires a disciplined approach to speed control, and that takes practice. Also in light or nil wind, your ground speed will be higher, so all that runway going to waste will disappear behind you even quicker.

.

Aiming to be at the aircrafts stalling speed at touchdown is one of the common Tiger Moth Instructor myths that has prevailed since the 1940’s, its also favoured by American light aircraft pilots too.

The threshold speed is the last speed target on the final approach ( not a touchdown speed) whether you are flying an Airbus or an Auster and that target speed can be calculated by multiplying the stall speed, at the configuration you are landing with by 1.3. This gives you an increment of 30% above the stall speed, this 30% allows for power reduction, attitude change and most importantly, minor error before touchdown. The stall warner, ( if fitted) should sound 5 to 10 knots above the stall. ( check your aircraft during stall/ loss of control practice). So before touchdown you should hear the stall warner, ‘ simmer’ ( my description).

The stall angle is the critical angle of attack at which LOSS OF CONTROL takes place. Loss of Control is very rarely mentioned by GA flying instructors, yet it is the most important lesson behind Ex 10 and 11 and it’s true understanding is essential to safe flight. If you want to experience loss of control at the point of touchdown my only advice is ‘ good luck’! The aircraft before touchdown should ALWAYS be at a safe increment ABOVE the Stall speed which is guaranteed by adherence to the calculated target threshold speed and crossing the threshold fully stabilised at 50 feet. This speed discipline also guarantees the landing performance of the aircraft but it must be always considered that an unfactored flight manual shows the test pilot performance obtained by the best pilot, on the best day, in the best aircraft.

We teach an increment of 1. 2 x stall speed for the Performance or Short Field Landing. This is combined with precise throttle control in the flair to ensure the aircraft immediately sinks onto the touchdown area without float. It it is not just speed that needs to be disciplined, as the poster above mentioned, in fact speed, height, rate of descent and glide path all need to be disciplined and stabilised. Glide path is rarely considered when these landings are being taught, it’s importance should not be overlooked because most short grass strips are unlicensed and many have approach obstructions which require a steeper approach angle.

Looking back through some of the posts on here I would caution the OP in relation to the advice given and this also applies to most Internet advice. Trying to learn to fly through a forum isn’t the best way forward, be careful!

One piece of advice given here was to try to pick up a dropped stalled wing with either aileron or rudder. This is the sort of advice that could cause a very serious accident especially at low level.
jcal, tr7v8 liked this
By Harry.Brown
#1872636
lobstaboy wrote:
jcal wrote: Given that I'd be trimmed for a descent I didn't realise it could also help at the round out which is effectively "level" flight.


That's not quite right. The aeroplane is trimmed for a particular airspeed. .


Not quite right either! The elevator or stabilator trim is used to assist the pilot maintain a specific PITCH attitude. It’s the power and attitude combination that gives you the airspeed!

The problems with many aircraft in the round out/ flare is there is a large trim change caused by speed and power reduction and attitude change. The PA 28 in particular, with its stabilator, is a good example and the reason why so many pilots land this aircraft flat with two hands! We teach, for PPL holders ( not students), nose up trim at 200 feet ( stabilisation height) to allow for this. The major problem for PA 28 pilots is over speed at the threshold which assists a flat landing attitude.
jcal, tr7v8 liked this
By jcal
#1872676
Harry.Brown wrote:Looking back through some of the posts on here I would caution the OP in relation to the advice given and this also applies to most Internet advice. Trying to learn to fly through a forum isn’t the best way forward, be careful!

Thanks @Harry.Brown , lots of insightful stuff!

As the OP I just want to say that, as much as I appreciate the advice in this thread I don't take it as flight training. It's insightful and lets me look at things from different perspectives, but my training is 99% from my instructor and the rest from the official materials.

That said, I do think discussing why people handle aircrafts in certain ways and the way people approach manaeuvers, either by experienced pilots or less so, correctly or incorrectly, is a useful thing! So I wouldn't want anyone to stop :). I will always take it with the weight of "someone on the internet said this" and not as official training advice.
T6Harvard liked this
By TopCat
#1872757
Harry.Brown wrote:Aiming to be at the aircrafts stalling speed at touchdown is one of the common Tiger Moth Instructor myths that has prevailed since the 1940’s, its also favoured by American light aircraft pilots too.

It's a myth is it? Why do you think so many POHs say "touch down at the minimum possible airspeed", then? What do you think 'minimum possible airspeed' means?

The threshold speed is the last speed target on the final approach ( not a touchdown speed) whether you are flying an Airbus or an Auster and that target speed can be calculated by multiplying the stall speed, at the configuration you are landing with by 1.3.

1.3 Vs regardless of aeroplane? So you are actively advising a 'one-size fits all' speed rather than flying the speeds recommended by the POH for each aeroplane?

The stall angle is the critical angle of attack at which LOSS OF CONTROL takes place.

Dangerous rubbish. The stall angle at 1G (which applies during the approach) is the angle at which the wing cannot generate quite as much lift as the weight. If you stall at a height of a few inches the aircraft will settle on to the ground gently. Other than in extreme crosswinds there is still plenty enough control authority in all three axes to keep straight on the runway and lower the nose gently.

Obviously no one is recommending stalling it on from a height of several feet. And of course a good landing can be achieved with a touch down a shade higher than the absolute minimum. But in ordinary conditions, 'minimum possible airspeed' is a good target to aim for, and close to this will be achieved by holding off for as long as possible.

We teach an increment of 1. 2 x stall speed for the Performance or Short Field Landing.

Who is this 'we' that thinks a blanket approach is correct? POH speeds will often be different from this. My aircraft's POH recommends 65 kt for a normal approach with full flap. At max weight, this is about 1.2 Vs. 1.3x would be 69 kt which would generate a lot of float.

It also recommends 61 kt for a short field approach. This is 1.15 Vs at max weight. That might not sound like much of a difference from your 1.2 but an excess of 2.5 kt is not negligible.

Not only that but flying substantially below max weight reduces the stall speed considerably - 20% below max weight will reduce the stall speed by about 10%.

One piece of advice given here was to try to pick up a dropped stalled wing with either aileron or rudder. This is the sort of advice that could cause a very serious accident especially at low level.

If you stall at low level, especially in a turn close to the ground, you may not have the height to recover, and as you say if you botch the control inputs you may make the situation worse. Avoiding the stall turning base to final is vital, as others have said.

But at a safe altitude, how would you recommend maintaining wings level in the stall?
User avatar
By Rob P
#1872761
jcal wrote:discussing why people handle aircrafts in certain ways


As light relief from the weighty matters above can we stamp on this one early in your aviation career?

"Aircraft" can be singular or plural. Therefore "aircrafts" is as uncomfortable as using "sheeps" to describe more than one woolly animal.

I think this is leaking from across the Atlantic; however it's still not as unacceptable as "airplane" :D

Rob P
TopCat, mick w, lobstaboy and 1 others liked this
User avatar
By lobstaboy
#1872782
Rob P wrote:As light relief from the weighty matters above
Rob P


You mean people quoting from how to land an airliner textbooks?

Seriously though, this is the students forum, and I like to think the idea is to post useful hints and suggestions that will help the learning process, not to overwhelm with theory that's inappropriate for a PPL student.
Rob P, JAFO liked this
User avatar
By lobstaboy
#1872785
TopCat wrote:But at a safe altitude, how would you recommend maintaining wings level in the stall?


When practicing the stall at safe altitude you don't try to keep the wings level (except by making sure the ball is in the middle before hand). You unstall the wing and then sort out whatever you're left with in terms of attitude.

(Btw I agree with all the rest of your post that this is a quote from).
Rob P, TopCat, T6Harvard and 1 others liked this
By TopCat
#1872799
lobstaboy wrote:
TopCat wrote:But at a safe altitude, how would you recommend maintaining wings level in the stall?


When practicing the stall at safe altitude you don't try to keep the wings level (except by making sure the ball is in the middle before hand). You unstall the wing and then sort out whatever you're left with in terms of attitude.

For practising recovery from the stall, of course, this is entirely correct.

Sorry for any ambiguity, I wasn't talking about recovering. I was talking about not recovering, and maintaining wings level while stalled.

I realise that this isn't part of the PPL syllabus.
By jcal
#1872801
Rob P wrote:
jcal wrote:discussing why people handle aircrafts in certain ways


As light relief from the weighty matters above can we stamp on this one early in your aviation career?

"Aircraft" can be singular or plural. Therefore "aircrafts" is as uncomfortable as using "sheeps" to describe more than one woolly animal.

I think this is leaking from across the Atlantic; however it's still not as unacceptable as "airplane" :D

Rob P

Haha, please let's! Reading back what I wrote I cringe a little :lol:.
Rob P liked this
By Harry.Brown
#1872995
Thanks @Harry.Brown , lots of insightful stuff.


You seem have a very good attitude and believe me attitude is everything in flying. Unfortunately some advice can be very confusing especially when it comes from myth. I wanted to clarify a point that was mentioned in which a previous poster stated that, and I quote

If you land properly, then at touchdown you should be at stall speed, at whatever flap setting you choose.

Yes this is a student forum and this is why you need to understand that that statement is misleading and incorrect.

The operative words here are LANDING PROPERLY and AT STALL SPEED, those words are incorrectly used in the above context.

The only speed to target after the stabilisation point on an approach( in fact years ago it was called Vat, target threshold speed) is the speed where the last check of the speed is made at the threshold, deemed to be at 50 feet. After the threshold it’s eyes outside, fly attitude and respect the stall warner on ALL conventional aircraft.

As I pointed out, the Americans ( and Tiger Moth FI’s) favour the statement about stalling the aircraft onto the ground, it's a widely heard folklore myth from the heroes and cowboys.

This is what the US FAA state in their manual

Touchdown
The touchdown is the gentle settling of the airplane onto the landing surface. The round out and touchdown are normally made with the engine idling and the airplane at minimum controllable airspeed so that the airplane touches down on the main gear at approximately stalling speed. As the airplane settles, the proper landing attitude is attained by application of whatever back-elevator pressure is necessary.

The New Zealand CAA Flight Instructors guide says.

The landing is one smooth manoeuvre designed to slow the rate of descent to zero and the speed to just above the stall speed, as the wheels touch the ground

We use two books on our Flight Instructor Courses, neither of which I fully recommend because they are written by former Tiger Moth FI’s and are outdated but in their day and I have been using them for nearly forty years on FI Courses, do contain useful information.

1 The Instructor Patter Manual
Makes no reference to airspeed after the threshold and certainly no mention of landing at stall speed.

2. The Campbell Flight Instructor's Manual
Flying Training For The Private Pilots Licence. Instructor Manual
No mention of speed or stall is mentioned after the approach and certainly no mention of landing at stall speed. No mention on his pre flight briefing either

However especially for the Tiger Moth flying instructors this is what Air Ministry 1942 RAF Instructors Handbook says

From the point at which the descent is checked, the pilot, by gentle gentle backward pressure on the stick, first alters the flight path until it is approximately parallel to the ground, and then continues to alter the attitude as the speed falls off, keeping the aeroplane just above the ground until it lands gently on it when the angle of attack has very nearly reached the stalling angle..

The AFE manual, which is the most widely used training manual says this:

The aim of the hold off is to ensure that the aircraft touches down at the correct airspeed ( slightly faster than the stall), on the main wheels with the nosewheel still in the air.

The most useful FI Course book around at the moment is Pad Pilot’s, The Complete Flight Instructor ( only 10 years out of date) but I do recommend it for FI Courses.

It makes no further mention either of speed after the 300 feet stabilisation check on the approach and certainly no mention of landing at stall speed.

Note none of these publications support the view that If you land properly, then at touchdown you should be at stall speed, at whatever flap setting you choose.

Take the AFE manual it says, touchdown slightly faster than the stalling speed. If you can interpret that as saying touch down AT the stall speed I would just like to say good luck.

The key to landing the aircraft correctly is to fly the aircraft to the threshold at the correct threshold speed and then make the appropriate attitude and power changes to touch down in the correct landing attitude while always respecting the stall warner. It’s worked for me for over 40 years in an Airbus to an Auster, it should work for you.
User avatar
By VRB_20kt
#1872999
Ok. This is the student forum so let’s keep it simple.

If you try and force the aircraft at anything like a normal flying speed onto the runway you’re likely to break something.

If you stall the aircraft a few feet above the runway you’re likely to break something.

If you land on the main wheels on the centreline and at a reasonably slow flying speed then things should normally turn out ok.


There are a number of ways to teach how to land. If one isn’t working the instructor’s job is to find another that works for you. If you/your instructor aren’t seeing an improvement - even if it’s a slow improvement - then try another solution. Like so much of learning to fly, get the basic building blocks firmly established and the you’ll have a firm foundation to build upon.
By Harry.Brown
#1873002
TopCat wrote:Having said that, if you ever touchdown nose first, go around immediately. Otherwise there's a pretty good chance of a very badly ruined day. But hopefully there is absolutely no chance of your doing that, if you're being taught properly.

Yeah, that's unlikely to happen. We're comfortably far away from any nose landings. Besides, that video you posted of the Piper Warrior bouncing on the runway is still firmly etched in my mind :shock:.[/quote]

Bad advice because if you make a nose first arrival and strike the prop last thing you ever want to do is go around. On tarmac you will hear the prop hit the runway, on grass you may not. Checking the oleo extension on the walk around is a very important check before every flight, especially on training aircraft. Low oleo extension increases the risk of prop strike. Do you know what the oleo extension should be on your aircraft?

It also depends on your rate of descent on touchdown on whether you should go around or not, although of course it’s always the sole decision of the commander on whether or not to go around. Wheel barrowing it on with a low ROD can be harmless but it’s certainly not the correct landing attitude and not something to be encouraged.

High RODs with pitch down are a completely different matter as they may break the nosewheel assembly. One of the major learning aims during landing training is the correct touchdown attitude, learn that and you will never have a wheelbarrow incident provided you also fly accurate threshold speeds. Most wheelbarrowing incidents are caused by checking forward in the round out and this is a really bad habit to get into. Never check forward in the round out , let the aircraft settle or Go Around.

Nose first arrivals are often caused by low speed at the threshold and thus low speed in the round out, EG closer to the stall ,. If you are trying to land AT the stall speed (as some hero pilots do) and just before touchdown you make a large balloon you’ve nothing left in the tank because you are now below the stall speed with an increased rate of descent from a higher height which will need even more up elevator to arrest, only problem, as you are now below the stall speed is you’ve got no elevator left and any further increase in the angle of attack will actually increase the ROD and unless you add power you are going to hit the runway with a Big Bang, remembering also that at the stall the aircraft pitches forward so you can kiss the nosewheel and prop goodbye.

Adding power at the stall with full up elevator can produce some interesting affects which I can assure you , you may not want to experience at 10 feet. Try it at height, with a FI, in the landing configuration.

Way to stop the above is always cross the 50 feet threshold at 30% above the configured stall speed, now where have I heard that before? ( 20 % short field)

Spending some time understanding why the aircraft is speed unstable below Vmd also goes a long way to understanding Rates of Descent close to the runway.
  • 1
  • 7
  • 8
  • 9
  • 10
  • 11