Watch the speed! [Archive]

Lister Noble

21st Jul 2006, 08:05

Whirlybird

21st Jul 2006, 08:08

The way I got taught landings was to look in turn at the trees beyond the end of runway, then the aiming point, then the ASI, then back to trees etc.

Doesn't everyone learn it that way?

Fournicator

21st Jul 2006, 08:16

Numbers, Speed, Power, Numbers, Speed, Power, Windsock, Numbers, Speed, Power, Numbers, Speed, Power, Ball etc etc!

S-Works

21st Jul 2006, 08:36

Perhaps a bit more emphasis should be place on looking out the window and judging speed and attitude correctly. When I first learnt to fly in microlights I did a good number of circuits with the already sparse instruments covered up, flying totally by the feel of the aircraft and what I saw out the window.

Something that stood me well yesterday when on the climb out an insect flew down my pitout tube and blocked it!! The airspeed dropped off to zero indicated. I flew the 10 miles home and land by the feel of the aircraft judging speed and attitude. A non eventful landing followed by the removal of the offending insect body.

mazzy1026

21st Jul 2006, 08:56

kevwal

21st Jul 2006, 09:26

Learning on a fixed wing microlight at Sywell I have been going through a phase recently of being told to 'fly the attitude, not the instruments'. It is all too easy to get fixated on the instruments, when they might be laggy, might be wrong, etc.

When I finally manage to get the right attitudes into my brain for every flap setting with or without power I might be able to get the landings right :)

My 2p...

Cheers
Kev

wombat13

21st Jul 2006, 09:40

Numbers, Speed, Power, Numbers, Speed, Power, Windsock, Numbers, Speed, Power, Numbers, Speed, Power, Ball etc etc!

Simple and stupid is often best when learning something, especially when there is the capacity for unexpected increased workload.

Fournicator's mantra is a program I like to have running in the background of my mind at all times irrespective of more established checks.

Longbow55

21st Jul 2006, 09:55

Set-up for 70 kts down wind and never look at the ASI again.

Cusco

21st Jul 2006, 10:00

My instructor taught me the landing mantra on base/final:

"Height's good, speed's good, runway's good."

When I'm alone in the a/c I still say it out loud and if any of the 'goods' have to be replaced by something else, such as 'low' or 'high' then I do something about is straightaway.

If I've got a non-pilot passenger then I repeat the mantra silently but I still repeat it.

If I get 3 'non-goods' on final I go around.

Cusco

wombat13

21st Jul 2006, 10:20

Set-up for 70 kts down wind and never look at the ASI again.

yeah, right.

If this is really the best you can contribute, maybe it is best to learn a bit more and hold back on your contributions until you have your licence and some post qualification experience under your belt.

The wombat

Mike Cross

21st Jul 2006, 10:22

No-one has yet mentioned trim.

If you don't trim correctly you will be applying back pressure during the descent to stop the speed increasing. You won't notice it if you are applying more back pressure than necessary.

If properly trimmed it's easy to recognise that you are applying back pressure. Fail to trim and you deprive yourself of one of the cues that something is going wrong.

mazzy1026

21st Jul 2006, 10:22

A little harsh perhaps but I agree, this is not what I was taught! It would take you an eternity to reach the runway, and in effect you'd be flying on the back of the drag curve for ages, thus increasing chances of stalling..:confused:

splatt

21st Jul 2006, 10:26

Stalling or spinning at low altitude and low speed is one thing that scares me for sure.

The trick, I guess, is to recognise the symptoms before the stall actually happens. I'm just a stude myself but I believe I have a pretty good feel for this and I attribute this to quite a bit of time in gliders (albeit always dual) where they sometimes fly very near to the stall for long periods of time and where stall and spin recovery can be practiced for significantly less money than in powered trainer aircraft.

Recovery with an engine is a little different but the onset of a stall seems similar in the aircraft I have flown up to now.

splatt

IO540

21st Jul 2006, 10:27

Trim, IME, is very poorly taught.

I was never taught what the trim does in my PPL training. It was explained that it is used to remove the back pressure, which is true but beside the point. Actually, it sets the speed at which the plane wants to fly. The engine is nothing to do with that.

So if you are trimmed for 50kt, and are flying around at 70kt, and you get distracted, the speed will fall to 50kt (it will fall more actually, due to the phugoid behaviour) and you will plummet.

Correct trimming (for the desired speed) in all phases of flight is absolutely key to safety.

gcolyer

21st Jul 2006, 10:28

A very important point:

'FEEL' - fly it by the seat of your pants also, as touched on by bose. The first thing I usually notice is the stiff controls, followed by the stall warner - then 'something' just doesn't feel quite right...

Safe flying,

Maz :ok:

What aircraft is that in?? I have always experienced sloppy light controls followed by stall warner.

Unless your a refering to stiff controls during a developed spin post stall warner :bored:

mazzy1026

21st Jul 2006, 10:28

The first thing I'd expect to notice is sloppy controls!
Sorry chief - that's what I meant! Stiff in a sense of having to put in a lot more movement of the controls to get a response, if any at all :ok:

Edit: I will dig myself out of the hole I have dug, and replace "Stiff" with "Sloppy".

GC - it's a Tomahwak - the stall warner goes off way before the stall, and is combined with the 'sloppy' controls...

Shaggy Sheep Driver

21st Jul 2006, 10:51

The title of this thread indicates a certain lack of understanding as what stalls a wing. It's not lack of speed, it's exceeding the critical angle of attack (which for any given wing at any given profile never ever changes).

Of course, low speed can be a way of doing just that, but lots of other things can do it as well (excessive loading, for instance, as in pulling 'G'). And there are plenty of instances where low or even zero airspeed does not cause a stall (over the top of a loop, for instance).

I've stalled a Yak52 at about 150 knots indicated, and flown the same aeroplane at zero airspeed with no stall.

The ONLY consistant thing that causes the wing to stall is exceeding that critical angle of attack. Nothing else. So never mind the speed, watch that AoA!

If you do an aeros course, AoA becomes second nature. But it might be a bit much to expect studes to recognise AoA - which is why they are taught 'the numbers' (on the ASI). But for any reasonably experienced pilot, think AoA, not airspeed, and all will be well.

SSD

mazzy1026

21st Jul 2006, 10:55

Genghis the Engineer

21st Jul 2006, 10:59

I didn’t want to post this on the tragic accident thread, as we don’t know the real reason for the crash,and supposition doesn't help anybody.
We were talking about it last night with some very experienced pilots and I recalled that when I was early into solos on the PA28-180, I was on short final and the controls went a bit sloppy, I looked at airspeed and it was 65 knots!
I lowered the nose slightly and increased power and thankfully everything worked out OK, I’ve not done it since because it was a real wake up call and I now always keep my eye alternately on the airspeed and outside view.
I know I’m low hours, but perhaps that makes this more relevant for all students.
There is a high workload on the base and final approach and it is easy to forget the most important thing when you are concentrating on other stuff.
Lister:)

65 knots is the final approach speed for a PA28-180, and the controls do feel sloppy at that speed - requiring you to think well ahead of the aeroplane. (And actually, solo you can come down to 60 quite safely - or at-least I can).

This is not to detract from your very valid point - most major piloting errors in GA do happen on base and short finals, and often do involve speed / pitch control problems. BUT, they aren't helped by low hour pilots not being taught how to fly the aeroplane properly in the first place. Out of interest, what speed were you taught to fly finals at, and how did they justify a departure from the POH? Or did they not even give you a POH to read (a personal crusade of mine)?

G

Shaggy Sheep Driver

21st Jul 2006, 11:02

SSD - in a regular training aircraft (i.e one not capable of aero's) how can you stall with a high airspeed? (Not arguing this - just want to know how).

Perhaps a demo in the chippie at Liverpool this weekend ;) ;) ;) ;) ;) ;)

Love to, but I'll be on hol!

The answer is - increasing the wing loading. Aeros is when you pull serious 'G' and that's how I stalled the Yak at 150knts - pulling out of a loop and pulling too hard. In non-aeros, a steep turn will have a drastic effect of wing loading and enable the wing to rach that critical angle at what one might normally consider a 'safe' airspeed. Lots of guys have done this circling the girlfriend's house.:confused:

SSD

Mike Cross

21st Jul 2006, 11:18

While SSD is right we don't have an AoA indicator in most light aircraft.

The mechanics of the killer spin off the final turn are quite simple.

Assume a LH circuit. Pilot is on base, approaching the extended centreline. He rolls left into the turn and realises he's going to overshoot the centreline so he tightens the turn a bit (maybe he misjudged it, maybe he has a slight tailwind component). So he's now in a steep turn. At 60 deg bank the stall speed (alright the speed at which we reach critical AoA) is getting on for 1.5 times what it is in level flight (if you want the maths behind that it's here) (http://selair.selkirk.bc.ca/aerodynamics1/Lift/Page11.html)

Because of the turn the left wing is going slower than the right wing so that will stall first. The result is a sudden roll to the left and a near vertical arrival.

As an example an Arrow III has a stall speed in the landing config of around 55kt. Heel it into a 60 deg bank and it will become 77.8kt.

Food for thought.

Mike

edited for incorrect numbers

Genghis the Engineer

21st Jul 2006, 11:25

SSD - in a regular training aircraft (i.e one not capable of aero's) how can you stall with a high airspeed? (Not arguing this - just want to know how).

Perhaps a demo in the chippie at Liverpool this weekend ;) ;) ;) ;) ;) ;)

In a turn.

Stall speed in a turn = level stall speed / SQRT [cos (bank angle).]

So if, say, an aeroplane stalls level at 55 knots, then with 60° of bank it'll stall at 78 knots in a balanced turn.

SSD's rather more extreme approach works too!

G

robin

21st Jul 2006, 11:37

Of course there is the other classic stall/spin scenario glider pilots are taught to avoid

Low on the base leg and turning towards finals. Wanting to stretch the glide the nose is held up and speed decays. Left wing is lowered a bit, but not too much, and a lot of left rudder is put in to bring the nose round in a skidding turn. Right wing goes forward generating more lift and left wing goes backwards and stalls

Result a stall/spin at low level and no hope of recovery. It is one reason why glider pilots are/were taught to make a well-banked turn onto finals

It can also happen to power pilots, but from my experience, most power pilots use a gentle turn onto finals and it can catch them out, too

littco

21st Jul 2006, 12:29

In a turn.
Stall speed in a turn = level stall speed / SQRT [cos (bank angle).]
G

Not sure if i've read it wrong but i thought the stall speed is the SQRT of the Load factor * the level flight stall speed.

Load factor = 1/cos bank angle

Therefore stall speed = level flight stall speed * (SQRT of 1/cos bank angle)

In other words

55 * SQRT 1/cos 60

=
55 * SQRT 1/0.5
=
55* SQRT 2
=
55* 1.41
=
78Knts

Which admittely is the same answer as you, sorry to be particular. No offense just looking to clarify

Saab Dastard

21st Jul 2006, 13:41

A couple of posts earlier on placed an emphasis on "attitude" -

'fly the attitude, not the instruments'

Good advice, but one caveat: beware of runways with a pronounced upslope when on final approach - the "correct attitude" (judged wrt. the runway) could cause you to fly too slowly. The opposite occurs with a downslope - flying the "correct attitude" could cause an overly-steep approach, resulting in higher than ideal threshold speed.

SD

Genghis the Engineer

21st Jul 2006, 13:47

littco, you've just done the same maths in a different order.

G

DenhamPPL

21st Jul 2006, 14:04

Must thank Lister Noble for starting this thread. Some very interesting replies after sorting the wheat from the chaff;)

I'm heading towards first solo (next week or the following once I've completed the Air Law exam) and noticed on Tuesday while doing circuits with my instructor how quickly the airspeed can bleed off in the approach configuration especially when turning final if you don't keep the nose down in the turn (I was unconsciously pulling back on the yoke slightly as I banked to line up with the centreline).

I bled off 10kts in the turn (from 70 to 60) but corrected the error before getting too close to the stalling speed. I didn't repeat it on my final circuit and performed the best landing so far in my training apparently:)

I didn't consider the increased stall speed at that angle of attack at the time (15-20 degrees). I will do more in future after reading this thread.

Denham has quite a tight LH circuit on 06 so there isn't much time to do everything - then again I chose Denham for that reason - its quite a challenging circuit for students with a very "short" final.

Thanks again for all your posts. Reading and remembering.

Andy

Lister Noble

21st Jul 2006, 15:21

MichaelJP59

21st Jul 2006, 15:39

bmoorhouse

21st Jul 2006, 15:44

It was mentioned earlier in the thread and then not mentioned again so i'll put my 5 pence worth in on TRIM.

I fly an ageing PA280-140 with a long approach speed of 85 mph (inconsistent units in aviation really wind me up - but the ASI is in mph). It is the short wing version of the PA28 and is very reactive to flap in both attitude and drag.

If you get well trimmed on base so she'll fly hands-off at 85mph with 2 stages of flap it takes only minor yoke and power inputs to follow a perfect glidepath. Even slightly out of trim and it is a struggle right down to the threshold, even more so when there is gusting.

I was lucky with my instructor who explained trimming very comprehensively and after every power change would shout TRIM - it is now second nature to trim to zero input pressure for the power & attitude. It makes flying so much easier because you are flying the plane and not fighting it.

172driver

21st Jul 2006, 15:44

I am definitely with the various posters on the increased stall speed in a bank. Hence my instructor drilled into my head only shallow turns in the pattern (circuit), i.e. max 30 degs bank.

However, I don't believe flying an airplane by feel/seat of pants is a good idea. Read the POH, fly the arplane (ANY airplane!) by the numbers and you'll be fine. Many a pair of pants was lost trying to fly by their seat...:=

IO540

21st Jul 2006, 15:54

I am sure somebody is going to have a go at me for saying this, and I don't wish to start yet another "why do some people fly such big circuits" thread, but isn't there a slight contradiction between safety (careful and correct airspeed maintenance around the circuit) and flying the tightest possible circuit?

I fly a TB20, so by the end of the downwind leg I want to be trimmed at 90kt. Sometimes I have arrived quicker but I make sure I am trimmed to 90kt on the base leg. I verify this trim position with hands off the yoke.

The gear (and 10deg flaps) goes down on the DW leg, and unless descent is desired the MP goes up to 20" to maintain the power over the extra drag.

So the base to final turn is done at 90kt. The stall speed in this config is 70kt (at MTOW, 30deg bank) and 1.3 times that is 91kt which makes 90kt quite reasonable (Vref = Vs * 1.3) for a safe turn. Even safer if the turn is descending, with a slight vertical acceleration during the turn (unloads the wing).

Then landing flap, and speed drops to 80kt. No more 30deg turns now (one hopes) so we have 59x1.3=76.7 which is fine for a Vref of 80kt.

I do the base turn at the proper place for the published circuit, only to find some other pilot cut me up on the inside, having flown a much tighter circuit. OK, in a C150 you can fly a tighter circuit, but not that much tighter. Usually they mis-judge it and I have to go around. Sometimes several times (e.g. Sunday, Stapleford).

Occasionally, it's obvious that there is an instructor on board, so the student is doing this on his orders.

To me, it's patently obvious that at least some poor sods are not taught proper speed management. They are taught to fly a "proper airmanship, young man" tight circuit, which the instructor obviously knows how to do, having been doing it for the last few years. But the student won't know the effect of G (i.e. the combination of the effect of bank angle and vertical acceleration, etc) on the stall speed. Most likely, he won't have a clue what the stall speed is for the various configurations - I never knew this in my PPL training. One should not be flying max-performance tight circuits, say 10kt above level-flight Vs, at this level of training.

I could fly DW a bit slower, with full landing flap which gives a safe speed of 63 x 1.3 = 82kt (or so, the power setting will have quite an effect too) but why should I fly around with a plane which now has a sluggish control response, just to skim off 8kt? The margin for turbulence is now pretty thin and I still have two turns to make, or one longer one if flying an oval circuit which a lot of people don't like.

One can make the same case for any combination of the many types found in GA. Pick any two with a 20-30% difference in Vs, and the slower one will be tempted to cut up on the inside.

People should be taught to fly the proper speeds, and they should be taught to follow the person in front, not to try to save about 50p in fuel by cutting up the person in front.

stiknruda

21st Jul 2006, 16:13

However, I don't believe flying an airplane by feel/seat of pants is a good idea

then

Read the POH, fly the arplane (ANY airplane!) by the numbers and you'll be fine.

You are of course quite right, but I would suggest that you are not flying - you are merely operating an aerial conveyance to a set of prescribed parameters and IF anything were to unbalance that equilibrium, you would be in a whole heap of hurt.

The best ever single lesson I learnt was how to tell that the aeroplane is out of balance just by what it is telling your bum - seat of the pants, flying. The balance ball is handy but I can generally react to an out of balance situation by my subconscious translating the message from my ass and redirecting it to my feet before my eyes notice that the balance ball is out.

The second lesson is that IF THE AIRCRAFT IS ALWAYS FLOWN IN BALANCE IT CAN NOT SPIN.

And the third lesson, far easier in a stick aeroplane than a yolk type but the same principle applies:- the aeroplane will only stall with the stick in two positions regardless of the speed. So in effect, the stick gives you the same information as an AoA indicator but in a less graphic form.

Lister - I made good my promise of last night and have offered to take R spinning after a three axis lecture!

Stik

S-Works

21st Jul 2006, 16:33

Well said Stik....

Genghis the Engineer

21st Jul 2006, 16:48

Genghis we did get a POH to read,we are also taught 80mph up to flare,then reduce power,then throttle off at hold off before landing.
I tend to use slightly lower speeds,ie around 75mph and was told it was Ok if it felt right for me.
And I reckon I had some of the best instructors going!:(
Saab Dastard,it was an uphill runway,07 at Old Buck,the slope does play tricks on the eye but I never thought of that implication before.
Lister

75mph = 65 knots (the value in the -180 POH ).

So why were you worried at seeing 65 knots on short finals then?

(And incidentally, the POH says 75kn/86mph on initials, which is actually slightly faster than your instructors were suggesting, but knowing the type pretty well, I agree with your instructors that it's safe to come down a few knots on that, particularly in a lighter aeroplane, and especially into a relatively short runway since that wing floats forever if you try and land too fast).

G

SAR Bloke

21st Jul 2006, 16:58

I disagree with the 'seat of the pants' brigade. As Lister said in his original post, it was the sloppy controls that alerted him to check the airspeed. This is where low speed/stall/spin awareness training comes in.

However, the way to stop yourself getting into trouble on finals in a light aircraft is to scan the speed. Forget AoA as most light aircraft do not have an AoA gauge fitted.

There is one other important point of accurate airspeed on finals that has not been mentioned yet which I believe is particularly important for low hours pilots. A known speed will have a known control response. Allow the speed to decay and the 'sloppy' elevator response during the flare could cause a heavy landing. Too fast and the 'firm' response could cause a balloon followed by a heavy landing. The old saying of 'a good landing comes from a good approach' is true and speed is one of the important factors.

Rod1

21st Jul 2006, 17:00

Stik, good one.

Rod1

littco

21st Jul 2006, 17:45

Remember also we are talking ISA here and as such a sudden drop in wind speed reduces ISA without you even doing anything, possible windsheer or gusty wind can all contribute to this. A 10Knt drop in ISA due to drop in wind speed isn't that impossible, especially if there are buildings or trees in the local area .

whiskeytangofoxtrot

21st Jul 2006, 17:58

There's this flight instructor podcast around called the Finer Points, the guy posts a short lesson every week in mp3 audio. Quite nice listening for those commuting-to-work trips imho.

Anyway, he gave a quite interesting commentary on how the "usual" case of "turning to final" stal&spin might develop, was very good at least in my opinion. Listen to that episode here. (http://media.libsyn.com/media/jmiller/The-Final-Base-Turn-The-Finer-Points-Jason-Miller.mp3) And the whole site is www.thefinerpoints.net (http://www.thefinerpoints.net).

I'm not in any way connected with the site, apart from finding it a while ago and enjoying it on the way to work and back :)

Whirlybird

21st Jul 2006, 18:56

So it worries me with the above dire warnings of the fatal turn to final and so on - am I missing something that could catch me out big style or is there not enough "flying by feel" taught?

What you're missing is the difference between recognising something when you're concentrating on it 100%, and doing so when a lot else is happening. For a low hours pilot, there's a lot to do in the circuit, and particularly on the turn to final. You're working out where you are, what to do next, what to say on the radio. And if it becomes a bit too much, and you're overloaded, something has to go, and that something could well be your awareness of the speed bleeding off.....just for a few seconds, but that's all it takes. Believe me, it's very, very, very easy to get caught out big time in such a situation. The only way to prevent it is constant vigilance, constant practice, and not pushing yourself beyond your limits to a point where you will get overloaded.

stiknruda

21st Jul 2006, 19:23

SAR Bloke wrote

I disagree with the 'seat of the pants' brigade. As Lister said in his original post, it was the sloppy controls that alerted him to check the airspeed. This is where low speed/stall/spin awareness training comes in.

However, the way to stop yourself getting into trouble on finals in a light aircraft is to scan the speed. Forget AoA as most light aircraft do not have an AoA gauge fitted.

That the controls were sloppy alerted Lister, a lowish hour pilot, to check the ASI proves that Lister had been well trained and correlated sloppy controls with reducing airspeed. He scanned the dials and his diagnosis of the situation was proven to be correct. It was the feel of the controls, not a rigid fixation with the ASI that alerted him to his predicament - I'd call that seat of the pants flying!

Very few light aircraft have AoA indicators fitted but they do have all come with an inbuilt device which alerts you to increasing Alpha and can be mentally calibrated to predict the onset of critical AoA - it is the object held in one hand, namely the stick or control column.

Every (non canard) aeroplane will only stall with that device in one of only two positions at any airspeed.

In my own bipe, I need to bring the stick-top back about 4" to cause the wings to exceed critical Alpha and she will stall, at 60mph, 120mph or at 150mph. The same amount of forward stick and she will break at 60, 120 or 150mph.

This is not rocket science, my muscle-memory causes the hairs on the back of my neck to stand on end when the stick approaches those two positions - even if I have decided to put it there!

The two incidents this week which I believe caused Lister to create this excellent thread did not happen on final, so

However, the way to stop yourself getting into trouble on finals in a light aircraft is to scan the speed.

although excellent advice is not germane to the discussion about spinning on the base to final or downwind to base turn.

Stik

SAR Bloke

21st Jul 2006, 19:54

Stik,

If you re-read the first post THIS incident says nothing about turning downwind to base or base to final.

I agree that 'seat of the pants' alerted him to the situation. However, monitoring the ASI would have prevented the problem arising in the first place. What if this had happened at 20 ft and there was not enough height to recover. Too late for seat of the pants then. You should always be ahead of the aircraft not trying to catch up with it. You say

I would suggest that you are not flying - you are merely operating an aerial conveyance to a set of prescribed parameters and IF anything were to unbalance that equilibrium, you would be in a whole heap of hurt

I would say if you are reacting to what the aircraft is doing, you are not flying it, it is flying you.

IMO the control column does not give a reliable enough indication of AoA (a number of factors may change the AoA for the same stick position - such as the deployment of flaps). Also, if you fly more than one aircraft, especially if you fly it infrequently, you may not remember exactly where this stick position is. Relying on these sorts of sensations can get you into trouble. As a further example, if you have a trim runaway on an aircraft with electric trim the stick position at stall may be the same but feel would be entirely different. This may require you to scan the stick position. Why not just look at the ASI? This is a noddy emergency if you scan the instruments but if you rely on feel then you may be in trouble.

Final 3 Greens

21st Jul 2006, 20:04

That the controls were sloppy alerted Lister, a lowish hour pilot, to check the ASI proves that Lister had been well trained and correlated sloppy controls with reducing airspeed.

What worries me is why Lister felt controls sloppy enough to warrant action on a PA28-180, on short final at 65kias.

Sure, the controls won't be as crisp as at 90kias, but (assuming 3 stages of flap, per the POH) the thing should be slightly above Vs1.3 and flying perfectly happily. In fact, I wouldn't wish to fly the last mile a lot faster than 65kias, especially if light.

So is there some position error or has Lister been trained to fly down short final at a higher airspeed?

Whatever, I do agree that being uncomfortable with the control feel and taking a positive decision is good airmanship for a low hour PPL - well done that man.

Chuck Ellsworth

21st Jul 2006, 20:11

" Doesn't everyone learn it that way? "

Actually..NO.

Why would anyone look at the trees at the far end of the runway?

What have I been missing all these years?

Chuck E. :confused:

S-Works

21st Jul 2006, 21:13

er...... Ok so what about my insect in the pitout this week. scanning the ASI was bugger all use to me! I had to resort to good old seat of the pants flying.

I am an IR Rated Pilot with just on 2000hrs so I am pretty happy with putting my faith in the instruments and flying "hotships" including ex mil jets. But I like to think I have never forgotten seat of the pants flying.

FLYING is Not just operating a mode of transport.

ProfChrisReed

21st Jul 2006, 21:31

What I don't quite understand is that everyone's done basic handling - i.e. taking the aircraft up to a safe height and playing with speed, angles of bank, different configs, finding what it takes to stall the aircraft and so on. In my experience in the trainers I've flown I've found I have to be really and deliberately unfeeling to provoke anything like a stall - such as slowing down until the controls are *really* sloppy then pulling right back ignoring all stall warners.

So it worries me with the above dire warnings of the fatal turn to final and so on - am I missing something that could catch me out big style or is there not enough "flying by feel" taught?

and

Remember also we are talking ISA here and as such a sudden drop in wind speed reduces ISA without you even doing anything, possible windsheer or gusty wind can all contribute to this. A 10Knt drop in ISA due to drop in wind speed isn't that impossible, especially if there are buildings or trees in the local area .

Littco give one reason why you could get caught out near the ground. I've seen 20kt plus wiped off my airspeed flying a glider. The fact that everything felt fine 3 seconds ago is not good enough - you have to fly with sufficient margin of airspeed to cope with this if it happens. Experience teaches you a lot - e.g. gusty days increase the risk, and when it's windy you can expect to find a substantial wind gradient where the wind is much lighter at ground level, often with an abrupt transition. Similarly, crop along the upwind side of the runway can cause a sudden drop in wind speed, or curl over which will lead to an early arrival unless you have sufficient energy.

A second reason, which I think is closer to what worries MichaelJP59, is how you can screw up the final turn when you handle stalls etc, fine in the upper air. Glider pilot training has worked hard on this, because we lost too many pilots from spinning in off the final turn.

The reason is that, off the final turn, the closeness of the ground changes two important factors: (1) your perspective changes - at 2,000 ft in a turn you see very little more ground as you bank, but making the final turn you see lots more ground, and it's easy for your subconscious to pull back to make the picture right; and (2) you *know* you don't want to hit that nasty ground, so you have to stop yourself easing back on the stick to make it go away.

If you're monitoring your airspeed you can catch these trends. If you're flying solely by feel you might miss them.

More experienced pilots internalise these, so that the low and slow final turn feels wrong. However, I'm sure the only safe way is to consciously monitor your airspeed on the final turn and approach.

SAR Bloke

21st Jul 2006, 21:42

er...... Ok so what about my insect in the pitout this week. scanning the ASI was bugger all use to me! I had to resort to good old seat of the pants flying.

So with your experience you don't need me to tell you about using known power settings and attitudes in that scenario. No need for seat of the pants there either;)

Chesty Morgan

21st Jul 2006, 21:48

Bose-X, you beat me to it. I was about to mention POWER ATTITUDE TRIM.

You should all know the required power and attitude for the various speeds and configuraions for each of your aircraft. If you select the required power, and set the required attitude you will fly at the correct speed.

Forgive me if it's all ready been mentioned, I've only had a quick scan through this thread.

SARBloke

I would say if you are reacting to what the aircraft is doing, you are not flying it, it is flying you.

What about turbulence, gusty conditions, windshear etcetera? IMHO this is reacting to what the aircraft is doing, you are however, CONTROLLING the aircraft!

There are pros for "seat of the pants flying" and there are pros for instrument flying and correct scanning. However, to rely on only one is detrimental to your safety.

To become proficient in both disciplines is the advice I would try to impress on you from my 17 years flying.

Chesty

IO540

21st Jul 2006, 21:55

It's all very well for 1000+ hour pilots to argue about how to avoid stall/spin.

Frankly I don't think many 1000+ hour pilots are going to stall on the base/final turn, and one would need to be doing something quite "curious" to stall anywhere else.

The point here, bearing in mind what recent event got this thread started (!!), is how PPL students flying solo, and low-hour PPLs who have just dropped off the end of the PPL sausage machine, can avoid it happening.

My view is that careful airspeed maintenance is the only way at that stage of the game, and that means paying attention to correct trimming at each phase of the flight.

It may well be true that every plane will stall with the yoke in exactly two positions (I can see where that comes from physically but I am not entirely sure it is true in all flight regimes especially if turbulence / windshear is present) but this subtle point of aerodynamics will be completely lost on new pilots.

You may as well try to make the point that - for all flying machines - the best range speed is equal to the best glide speed which is equal to the best rate of climb speed (Vy), ignoring engine efficiency issues of course.

Say again s l o w l y

21st Jul 2006, 22:05

As stated by others, the approach speed in a PA28 with full flap is 65 (66 in the Archer II). So what speeds were you using for the approach.

Far more problems are caused by the "Add 5 kts for the wife and kid's" brigade than by being a bit slow. What are the statistics for over-runs, nose wheel wipeouts etc. compared to stall/spin accidents on approach? I'm betting they are very different.

I teach people to fly the given numbers initially until they gain a feel for the machine. BUT.....

Anyone who thinks that flying isn't about feel is fooling themselves, or they are wearing mittens. I personally don't look at the ASI on the approach very often. I know what it feels like, how it should sound and how the a/c should respond. I will often cover the ASI completely on final with students and when I reveal it at points, they are always amazed at how close they can get to the given speeds without reference to an instrument.

This "feel" has saved my bacon on a couple of occasions, firstly when a load sheet was compiled incorrectly and I thought it felt a bit heavy, so I increased our Vref speeds. On subsequent investigation we were found to be nearly 700kgs heavier than we thought, due to the handling agent's making a mistake. Now, this may not have resulted in our demise, but it shows that the innate ability to know when something is wrong is essential. Without it, we may have never known there was a problem.

Whilst a PA28 has a speed given for final approach, in reality the only time speed is really important is when you are touching down, can anyone really tell me they are looking at the ASI in the flare? Or are you relying on your hands, eyes and experience to judge what's going on?

I have often approached at far in excess of 65/66 kts, especially if I have had someone puking in the back (Don't ask....) and then pulled the throttle closed when at the last possible moment so that I take the least possible time to get on the ground possible. (I don't recommend it. It tends to stuff engines, but sometimes circumstances dictate your actions!) So final approach speed isn't as critical as some make out.

It is true that a stable and controlled approach is more likely to lead to a successful landing, but we mustn't be over-reliant on anything. I try and get students to "tick tock" on approach, between aiming point, windsock and speed. If it's gusty, then you add 50% of the gust factor and be ready for a go around at anytime. Other than that, it's down to what's going on between your backside, hands, eyes, ears and brain. Listen to what they are ALL telling you and you won't go far wrong!

Getting the thing trimmed properly as stated by IO is also absolutely essential, an a/c should be in trim at all times, otherwise you are just creating work for yourself.

Chesty Morgan

21st Jul 2006, 22:12

IO540, Your post comes across as a little bit naive. I hope that isn't really the case.

You ask how low houred PPL pilots can avoid spinning/stalling.

The same way every pilot learns it. Listen to your instructor, listen to the 1000+ hour pilots who aren't arguing but trying to pass on their valuable experience. That is, after all, how we learnt to fly isn't it?

Frankly I don't think many 1000+ hour pilots are going to stall on the base/final turn

.........Exactly!

We don't post on here just for the hell of it. There is a lot of experience on this forum and people would be well advised to heed it.

"The trick is to fill the empty bag of experience before the full bag of luck is emptied"

Listen. Remember. Practice. Discipline..............Pass it on!

Final 3 Greens

21st Jul 2006, 22:34

SAS

So final approach speed isn't as critical as some make out.

I see where you'e coming from, but its probably more critical for low houred pilots.

I'm not averse to coming down short final at 90kias if I needed to (e.g. faster traffic behind), probably slipping to increase the sink rate and then slowing up quickly, dirtying up or even landing flapless. If I wasn't happy at ay stage, I'd go around without hesitation.

But I wouldn't have liked to have tried this when low houred, as the judgment required and workload were beyond my ability.

And if carrying pax (unless I knew that they didn't mind some excitement), I'd still wish to float down the last mile at 65 (+ half the gust) with as little drama as poss (haven't had a puker yet:\ )

And I do agree that feel is very important, which is why I am concerned that Lister Noble felt the controls were too sloppy - someone should be having a look at that to close the loop and understand why.

littco

21st Jul 2006, 23:40

and

Littco give one reason why you could get caught out near the ground. I've seen 20kt plus wiped off my airspeed flying a glider. The fact that everything felt fine 3 seconds ago is not good enough - you have to fly with sufficient margin of airspeed to cope with this if it happens. .

Sorry but I fail to see your point? what exactly are you trying to tell me? I was simply stating that we are talking about Indicated air speed and such while people are talking about flying at 65-70knts for a base/final it is more than important that just because you're flying at that one second doesn't mean that the ISA can't change through no fault of your own. You've asked me you to give one good reason you could get caught out near the ground yet in your next sentence "crop along the upwind side of the runway can cause a sudden drop in wind speed" which to me is one good reason! . Yes you do have to fly with sufficient speed to compensate for this but as people have said earlier they have been in a situation where their ISA got worrying low. My point was it's not always something you have control over but be prepared!

Sorry but I've missed you point!

stiknruda

22nd Jul 2006, 00:27

SAR Bloke
IMO the control column does not give a reliable enough indication of AoA (a number of factors may change the AoA for the same stick position - such as the deployment of flaps). Also, if you fly more than one aircraft, especially if you fly it infrequently, you may not remember exactly where this stick position is. Relying on these sorts of sensations can get you into trouble. As a further example, if you have a trim runaway on an aircraft with electric trim the stick position at stall may be the same but feel would be entirely different. This may require you to scan the stick position. Why not just look at the ASI? This is a noddy emergency if you scan the instruments but if you rely on feel then you may be in trouble.

#1 - Stick position v critical Alpha; I admit that I had omitted flaps from my ever so basic Pitts-centric view of the world but still maintain that the same Stick/yoke lessons could be learned with flap deployed in various configs.

#2 - run away trim. I have had the misfortune to experience this at FL220 in a Be200. Maybe it was because the nose kept rising, the attitude looked different, the airspeed began to bleed - but whatever alerted me to it, I don't think it was ASI scan in the cruise that alerted me to it. The lecky trim disengage was a thumb-nudge. Manualy dialling in correct trim was no big deal, nor was overpowering it with one hand at Vcruise.

I hear what you say perhaps we are confusing the term "seat of the pants"?

Stik

ProfChrisReed

22nd Jul 2006, 06:34

Sorry but I fail to see your point? what exactly are you trying to tell me? I was simply stating that we are talking about Indicated air speed and such while people are talking about flying at 65-70knts for a base/final it is more than important that just because you're flying at that one second doesn't mean that the ISA can't change through no fault of your own. You've asked me you to give one good reason you could get caught out near the ground yet in your next sentence "crop along the upwind side of the runway can cause a sudden drop in wind speed" which to me is one good reason! . Yes you do have to fly with sufficient speed to compensate for this but as people have said earlier they have been in a situation where their ISA got worrying low. My point was it's not always something you have control over but be prepared!

Sorry but I've missed you point!
'Twas a typo - should have read "Littco gives one good reason". I was agreeing with you (or at least, trying to)!

Lister Noble

22nd Jul 2006, 07:00

Final 3 Greens

22nd Jul 2006, 07:18

Lister

Thanks for clarifying that you meant mph.

It is quite understandable that the controls felt unacceptably sloppy at that indicated airspeed, well done for spotting it and taking appropriate action.

Did the stall warner light illuminate? That is if you noticed the thing :-) I always found it ineffective compared to an aural warner, especially in bright sunshine.

High Wing Drifter

22nd Jul 2006, 07:43

IO540, Your post comes across as a little bit naive. I hope that isn't really the case.
Quite the opposite I thought!

Flying Farmer

22nd Jul 2006, 07:52

Lister I think you summed up well what you should be doing to avoid this situation again.

Try thinking about elevator in a different way, it controls your attitude, which in turn controls your speed, at least in a lighty. Power controls your rate of descent or climb.

Some one touched on attitude flying. I think this is the least well taught aspect in inital training, I had it hammered home during my commercial training. Lister go flying, possibly with an instructor who can teach attitude flying well and look closely at attitudes on base with two stages of flap, final with full flap.

If you fly the attitude that gives you the required speed very accurately and trim out all forces accurately I think you will discover the speed looks after itself , power then takes care of the rate of descent and if an accurate approach is flown you will need little in the way of power changes, leading to very little trim change.

It takes practice to fly attitudes accurately but well worth the effort in the long run.

Hope this helps FF

Lister Noble

22nd Jul 2006, 08:23

FF,thank you.
I'm flying at Old Buck tomorrow and will ask the CFI about this.
Lister:)

Genghis the Engineer

22nd Jul 2006, 08:35

Genghis,my sincere apologies,I meant 65mph and controls were sloppy!
115 mph downwind,turn onto base,carb heat ,reduce power,two stages flap,80 mph on final,third stage flap,I prefer a little less speed on final ,around 75-80 mph,control speed with elevator and height with throttle,in fact it is a combination of both.
We are are taught correct trim right from first lesson,setting it up for flaps on base and on final glide path.
The aircraft should always be trimmed to fly itself,except in transitory movements,ie steep turns etc.
I had better go back and edit my first post!:O
Lister:)

Ah, this does make another useful safety point, about the difficulties over multiple units in aviation.

But please, don't go back and edit your original post - it'll make much later discussion extremely confusing for anybody coming to this (very useful) thread in the future.

G

Flying Farmer

22nd Jul 2006, 09:38

A good reason to fly ATTITUDE.

Think attitude attitude attitude it keeps your eyes where they should be, outside the aircraft. The occasional glance at the ASI is all thats needed. Fly the attitude and if its the right attitude for the config I will guarantee the speed will be right.

Flying Farmer

22nd Jul 2006, 10:15

WR attitude achieves an airspeed, don't complicate the issue!! :ok:

One fatefull day when you lose your ASI I know whos gonna make a better job of getting back on the ground.

Lister Noble

22nd Jul 2006, 10:56

Ah, this does make another useful safety point, about the difficulties over multiple units in aviation.
But please, don't go back and edit your original post - it'll make much later discussion extremely confusing for anybody coming to this (very useful) thread in the future.
G

Undid the edit.
The multiple units in the ASI are very confusing,especially around the flap operating range where the numbers are crammed into a small area.
After a while you get to know where the needle is pointing, but at first rather confusing at the student early learning stage when you really need them!
Much better to have just one unit,mph or kts clearly marked.
There have been some very helpful and constructive replies to this thread.
Many thanks
Lister:)

Flying Farmer

22nd Jul 2006, 10:59

If it works for S and L and the climb, why not for the approach?

I have shown it to students who have been passed to me mid course and they have been stunned how much easier it all becomes.

WR all I advocate is looking outside not ignoring the ASI altogether. What worries me is a fixation with instruments when flying VFR. Of course use the ASI but not to the exclusion of all else :ok:

Sorry to bring it up again WR but if they peg the airspeed they will have by default flown an attitude accurately, why not just fly the attitude?

Final 3 Greens

22nd Jul 2006, 11:01

Ah, this does make another useful safety point, about the difficulties over multiple units in aviation.

In the spirit of Ghengis' comment, I once flew an Arrow all the way down final, in the USA, pegging Vref to a knot either way.

Unfortunately the ASI was in mph.

Regression to prior experience is a wonderful thing.

The instructor checking me out wasn't worried, he assumed I was practising a performance landing.

I haven't done the same thing since.

172driver

22nd Jul 2006, 11:10

Well I sort of anticpated getting a bashing from the stick n' rudder brigade :E

Seriously - I'll stick by my guns (or rather - numbers). While we of course all gain experience with every hour flown and increasingly can feel the airplane, this is not something a student can/will. I simply consider it extremely dangerous and indeed irresonsible to tell people w/o experience to fly be the seat of the pants.

As to You are of course quite right, but I would suggest that you are not flying - you are merely operating an aerial conveyance to a set of prescribed parameters and IF anything were to unbalance that equilibrium, you would be in a whole heap of hurt.

Well, I won't be, as I know what the a/c is capable of doing and how it does it - and last time I checked I was indeed heavier than air, hence the need for an aerial conveyance ;) !

Happy - and safe - landings.

QDMQDMQDM

22nd Jul 2006, 11:37

Try thinking about elevator in a different way, it controls your attitude, which in turn controls your speed, at least in a lighty.

One step further: the function of the elevator is simply to alter the angle of attack of the wing. This is the only sensible way to regard the elevator.

If in doubt and you're ever thinking "What's happening here? I don't like this" relax back pressure on the stick and decrease AoA before touching any other control and particularly ailerons.

I keep saying it (but there might be people reading this who didn't see the other thread):

Stick and Rudder by Langewiesche
http://www.amazon.co.uk/gp/product/0070362408/026-3347856-8158829?v=glance&n=266239

In my opinion, no student should go solo without having read parts of this book and been grilled on it thoroughly with their instructor. To think that this was written in 1944 and yet is so relevant today is amazing. It is an indictment of modern flight training that Langewiesche's over-riding emphasis on AoA has not carried through into the cockpit today. Many pilots have only the sketchiest understanding of the relation between AoA and stall speed and the effect of elevator on AoA and that is unsurprising when you look at the written PPL exams.

A deep understanding of AoA and the elevator will help you to rebel against the extraordinarily strong 'common sense' reflexes which can so very easily mislead you into a stall/spin accident. If you always think AoA, then any crash you have is more likely to be with the wings level than with one wing down and the prop drilling into the ground. As Langewiesche said more than 60 years ago, the former type of crash is almost always survivable, the latter type almost always isn't.

QDM

Gertrude the Wombat

22nd Jul 2006, 15:22

... you *know* you don't want to hit that nasty ground, so you have to stop yourself easing back on the stick to make it go away ... More experienced pilots internalise these, so that the low and slow final turn feels wrong
Yes, it's quite instinctive that if I'm too low and too slow I push the nose down, however counter-intuitive that might have been to start with. However it's typically not obvious to passengers that this would be the right thing to do in those circumstances, so it's one of those things I might mention on the drive to the airport.

littco

22nd Jul 2006, 15:43

'Twas a typo - should have read "Littco gives one good reason". I was agreeing with you (or at least, trying to)!

Ok, sorry about the post then, I see what you are saying now and makes sense..

Genghis the Engineer

22nd Jul 2006, 16:38

Undid the edit.
The multiple units in the ASI are very confusing,especially around the flap operating range where the numbers are crammed into a small area.
After a while you get to know where the needle is pointing, but at first rather confusing at the student early learning stage when you really need them!
Much better to have just one unit,mph or kts clearly marked.
There have been some very helpful and constructive replies to this thread.
Many thanks
Lister:)

This is, of-course, why there's a convention for colour coding of ASIs.

It often irritates me that in replacing U/S instruments, or sometimes at new builds (particularly for permit aeroplanes) it's not always ensured that the colour bandings are restored in the right places. Frankly the (common) display of a placard with operating speeds is no substitute for a white arc for flap limits, amber between Va/Vra/Vno and Vne, and so-on.

G

Confabulous

22nd Jul 2006, 16:44

As a PPL student, I agree that Langeweische's book is a great way of learning how AoA and your judgement of it is so critical.

However, Langeweische's means of explaining it hasn't been updated for 30 years and is fairly difficult to understand at first glance. So instead I use John Denker's See How it Flies (www.av8n.com) for a far more in depth, linked understanding of aerodynamics and AoA at work. Best of all, it's free and available online :ok:

Lister Noble

22nd Jul 2006, 17:27

As a PPL student, I agree that Langeweische's book is a great way of learning how AoA and your judgement of it is so critical.
However, Langeweische's means of explaining it hasn't been updated for 30 years and is fairly difficult to understand at first glance. So instead I use John Denker's See How it Flies (www.av8n.com) for a far more in depth, linked understanding of aerodynamics and AoA at work. Best of all, it's free and available online :ok:

Confab
Thanks for that,it looks like a good refference work ,useful and a long read!
I'm now going out to dinner,flying at 9am tomorrow but will inspect in more detail later on tomorrow.
Lister

aluminium persuader

22nd Jul 2006, 20:54

davidatter708

22nd Jul 2006, 20:58

All you need to do is look at the runway and AI. As you can gauge your height from the runway and too high reduce power too low add power just make sure you dont go under the magical speed otherwise ypur in for problems. Works for me and almost all my landings are greasers.:p
David

Say again s l o w l y

22nd Jul 2006, 21:45

Aluminium persuader, the base to final stall, should be taught before going solo. If it isn't, then that is, certainly for me anyway, a cause for concern.

ShyTorque

22nd Jul 2006, 23:45

Good to see all this discussion!

Howver, bearing in mind this has been prompted by a tragic accident in a C150.......In order to apply PAT, one has to ensure that "P" is available.

So don't forget appropriate use of the Carb Heat.....especially on a humid summer day.

Leezyjet

23rd Jul 2006, 00:06

I first got my licence (pilot, that is) overseas and was taught stall recovery before I was allowed solo, but two types of stall - a cruise/climb stall, clean a/c, full or cruise power, s&l - and an approach stall; gear down, flaps down, low power & in a turn, all simulating turning onto base or final which is in my mind the most dangerous place for a tyro. I was speaking to just such a tyro today, & he lead me to believe the "approach stall" isn't taught prior to a student soloing. Is this correct?

I was only taught basic s/l stalls, incipients, and full spins before I went solo, actually thats all I was taught all together. I've never been taught stalls with anything less than gradually reducing to idle power, but did powered and un-powered recoveries.

First time I ever did an approach to landing stall was on a check flight in the UK. Wasn't sure what to do, so just used a bit of common sense and some guess work, must have been ok though as the instructor didn't say I did it wrong.

It's very interesting for me reading these types of threads. Makes me think that doing a PPL in 19 days was a little quick and maybe a few things got missed along the way !!.

:\

IO540

23rd Jul 2006, 06:52

I'd agree with those who say too much instruction is done "by numbers". Aside from speeds, COUNTLESS times I've had PPLs, told they're number x behind something a lot bigger & faster than them turn onto base in very dangerous proximity because "I was taught to turn base at that village" or variations thereon.

The above appears to be missing the point.

It is indeed stupid to tell a student to turn downwind at the B&Q store, turn base at the church with the green roof, etc (as I was taught).

But it is not stupid to drum into the student that he must be at 80kt on downwind (and trimmed), 75kt on base (and trimmed) and fly the final at 70kt (and trimmed). (or whatever figures are right for that type) That's what "flying by numbers" means to me. With a more complex type this will be extended to engine settings e.g. 23"/2300/10.5GPH for a cruise LOP setting which should give 138KTIAS.

Seat of the pants flying is all very well for experienced pilots who have hundreds of hours on the type, and high currency. Most PPL students have few hours on the type, many are constantly changing planes (due to poor availability, planes going "tech", etc) so they fly different types, and many have lessons so rarely that if they were qualified pilots they would probably be slightly dangerous.

I am all in favour of stripping out some 90% of the junk taught in the JAA PPL exam "ground school", but some basic technical understanding of stall speeds, and how to safely operate a plane with the proper margins, is necessary.

172driver

23rd Jul 2006, 08:18

But it is not stupid to drum into the student that he must be at 80kt on downwind (and trimmed), 75kt on base (and trimmed) and fly the final at 70kt (and trimmed). (or whatever figures are right for that type) That's what "flying by numbers" means to me. With a more complex type this will be extended to engine settings e.g. 23"/2300/10.5GPH for a cruise LOP setting which should give 138KTIAS.

Exactly ! :D

Most PPL students have few hours on the type, many are constantly changing planes (due to poor availability, planes going "tech", etc) so they fly different types,........

And this extends to the many of us who don't own their a/c but fly club/rental airplanes.

shortstripper

23rd Jul 2006, 09:04

It's a shame more people don't fly gliders before they (progress?) to power. All the same issues are there and others besides! Due to the nature of soaring, you learn from an early stage to feel for the stall, to fly as slowly as possible even in a very tight turns (to remain in the core of a thermal). Great emphasis is placed on stalls and SPINNING! for reasons of high exposure to the risk. Gliders with their greater wingspan, winch launching and thermalling activities are often flown within a wasps breath of the stall. ASI is important, but it's only feel, attitude and experience (by practice, not hours) that keep it so safe.

I've mostly flown small underpowered PFA types, with dubious ASI's (and sometimes strange flying characteristics) so I've learned to use airspeed as a guide rather than as a dictate. I'm not suggesting everyone ignor their ASI, but I would encourage them to remember attitude, power settings ect for a given airspeed whilst everything is working fine. Then when the day comes (which it will) when a problem occurs, they will be prepared and will automatically fly by instinct and not by numbers. Or course, when near the ground the ASI is invaluble as it's easy to be suckered by wind affects on visual clues ... but if well trained and aware it is still not essential.

I noticed someone mentioned only doing shallow turns onto final. That's great, but don't fall into the trap that of thinking shallow turns are always safe. It's too easy to worry about banking and then feed in more and more rudder to stop from overshooting the centre line. A low, slow skidding turn is a real spin scenario! Banking is fine if properly co-ordinated and the correct attitude (or if you prefer ... airspeed) maintained.

"Seat of the pants" sounds very Gung-Ho and old school, but in reality anyone who has learned to fly, will (even if they don't admit it) fly by visual and sensual clues. The trick is to know when to ignor them!

SS

robin

23rd Jul 2006, 09:33

Hear hear

The low shallow final turn is a real killer, and not enough power pilots realise that. Certainly since I've been flying powered aircraft instructors don't demonstrate that one too often to students

IO540

23rd Jul 2006, 09:48

Why should a shallow final turn be more of a killer than a non-shallow final turn?

Regarding gliding, yes that might be helpful but when I looked into having some lessons a few years ago it became very obvious that in gliding one is going to get to know the other club members exceedingly well ;) ;)

robin

23rd Jul 2006, 10:01

When I was taught the one thing that was drilled into me was the well-banked final turn.

In itself, a shallow turn is not dangerous, but add to that a low final turn and the risks start to build up. The natural reaction for a person is to raise the nose when low to get away from the hard bits, so to turn an inexperienced pilot might over-rudder to line up the nose.

If speed control is not right you have the stall/spin with no height available to recover

Again, since taking up power flying, I have been surprised to see how many pilots 'drag in' low down the approach from a long way out, relying on the donkey to keep going.

They should try a flight in a VW or 0-200 powered aircraft in an icing day - that would teach them a good lesson in positioning the circuit and height on approach

ProfChrisReed

23rd Jul 2006, 20:39

Why should a shallow final turn be more of a killer than a non-shallow final turn?

Because in a glider you have enough elevator authority to stall the glider in a shallow turn, but usually not (except perhaps in a few rare types) in a 45+ degree banked turn. Thus, even if suckered (by ground proximity, other aircraft, events on the runway etc.) into pulling back on the stick, you won't stall, drop a wing and spin in.

Also, a 45 degree turn uses less height overall (in gliders you will necessarily descend during the final turn unless there happens to be lift there) and is easier to judge so you end up pointing in the right direction, rather than displaced to one side of the runway or field.

pulse1

23rd Jul 2006, 23:11

I have seen two gliders spin in from relatively steep final turns. This was because the lower wing was in less wind than the upper wing due to wind gradient. I had landed just before one of them and noticed a sudden 20 kt drop in IAS at the same height. For gliders this, IMO, makes it worth avoiding steep final turns close to the ground in any significant wind.

Say again s l o w l y

23rd Jul 2006, 23:29

Sorry chaps, but I think I must have a different grasp of aerodynamics.

So, if I get this right, it's safer to do a steep turn close to the ground, than do a shallow turn?.......

Any a/c has enough elevator authority to stall itself, especially at increasing angles of bank. How can they not? These aren't tiny little controls with short lever arms we're talking about.
The load factor will also increase with an increasing angle of bank and so therefore will the stall speed decrasing your margin for error.

Making a steep turn onto final approach is as daft an idea as I've heard for a while, especially in a discussion about low houred and inexperienced pilots.

Another one of my bug bears (I'm sure many have nothiced that I have a few!!) is people who teach making small heading changes by using rudder, especially on approach, or even worse on climb out.......:eek: :ugh: :mad:
All turns should be co-ordinated and that means using the rudder to counteract the adverse aileron yaw, NOT as a method of changing direction. At low speeds and low altitudes it is even more important than normal to keep yaw to a minimum, lest you learn first hand that Stall + Yaw = Spin.

Felix Saddler

24th Jul 2006, 01:43

im 3 hours into PPL, what advice and useful info could you give me on flying the circuit, particularly base and final (not forgetting flare as everytime i have landed i have bounced)

shortstripper

24th Jul 2006, 04:14

SAS So, if I get this right, it's safer to do a steep turn close to the ground, than do a shallow turn?.......

I didn't exactly advocate steep turns close to the ground did I? If you read my post again, I was pointing out that a well banked but properly co-ordinated turn onto finals is safer than being afraid to bank and subconciously ruddering around the turn. A slow skidding turn is the perfect recipe for a spin as you know. I say co-ordinated, but actually that's not quite true ... a well banked slipping turn onto finals is actually quite safe.

ProfChrisReed Because in a glider you have enough elevator authority to stall the glider in a shallow turn, but usually not (except perhaps in a few rare types) in a 45+ degree banked turn. Thus, even if suckered (by ground proximity, other aircraft, events on the runway etc.) into pulling back on the stick, you won't stall, drop a wing and spin in.

That's a new one on me? but for once I think you're wrong. Are you confusing the fact that in a slip most gliders will naturally straighten up if you get too slow due to lack of rudder authority?

Pulse1

I was alluding to what you saw when I mentioned a gliders larger wingspan and said that gliders suffer all the same issues and more. It is rare though, but I seem to remember reading in one of Derek Piggots books that it happened to him. His answer was to keep the involuntry turn going as the phenonomen is instantly cured once you've turned downwind ... but then how many of us have his experience to think that cool in such circumstances???

High Wing Drifter

24th Jul 2006, 05:35

Felix Saddler,
im 3 hours into PPL, what advice and useful info could you give me on flying the circuit, particularly base and final
With your experience level I would ignore this thread completely (with the exception of Lister's first post) and concentrate only on what your instructor wants you to know and to do.

IO540

24th Jul 2006, 06:53

im 3 hours into PPL, what advice and useful info could you give me on flying the circuit, particularly base and final (not forgetting flare as everytime i have landed i have bounced)

3 things:

watch your speed
watch your speed
watch your speed

:)

and always trim the plane for the desired speed; don't just hold it there with some combination of power and pulling/pushing the yoke. A correctly trimmed plane should fly at the desired speed with your hands off the yoke.

And find out what speeds you should be flying at on downwind, base, and final.

Basically, unless you do something really daft (like flying into a hill), the only way you will ever crash if you allow the speed to decay into the stall region. All the time you have speed, you have a controllable aircraft.

I was never taught any of the above in my PPL, but think it's a useful summary.

I hope you aren't flying a Tomahawk though. My 20 hours in those is remembered for it having no working trim.

Say again s l o w l y

24th Jul 2006, 07:39

SS, I'm agreeing with you, co-ordinated turns are vitally important, what I'm disagreeing with is the comment that shallow turns are by nature more dangerous than steep turns......

shortstripper

24th Jul 2006, 08:18

Oh I see!

Sorry, that's not at all how I meant it at all. What I meant is that it is easier to fall into the trap of over ruddering (to keep to the centre line if drifting) and perhaps even raising the nose slightly, from a shallow turn than a well banked one. Of course a shallow turn in itself is safer if flown correctly. Here's a (very bad) analogy ... Driving fast is potentially more dangerous than plodding along slowly taking in the view. However, this is often offset slightly by the driver focussing more on the actual driving.

SS

CherokeeDriver

24th Jul 2006, 08:55

High Wing Drifter.

Listen to what your instructor tells, and shows, you.

Main points to remember are:
1. Watch Your Speed (Indicated and also your "feel" for how fast you are going)
2. The Base to Final Turn can be a *major* killer of low time pilots becase of the lack of altitude to recover from stall
3. Incorrect (non) use of Carb Heat will also cause you problems in the UK. Learn your Carb Heat theory thoroughly - remember Carb Heat may be needed on lovely sunny days....

Enjoy your training.

High Wing Drifter

24th Jul 2006, 09:04

High Wing Drifter...Enjoy your training.
Thanks - lol :\

Chesty Morgan

24th Jul 2006, 09:39

im 3 hours into PPL, what advice and useful info could you give me on flying the circuit, particularly base and final (not forgetting flare as everytime i have landed i have bounced)

Hello mate.

As per my previous post.

POWER ATTITUDE TRIM

If the POH can't tell you your instructor can. Set the correct power, fly the right attitude and you WILL fly at the correct speed...then trim it. Remember too that all the prescribed speeds in the POH have a safe working factor added to them. For instance you will not stall if you fly a couple of knots below your final approach speed for a couple of seconds.

Don't fall into the trap of staring at your ASI, because you don't need to if you use the correct power and attitude. Incorporate it into your scan, yes. Scan outside starting behind the left wing, past the nose and behind the right wing, then inside. Check the engine instruments, altimeter, ASI etc. And then start again. Your head should be moving constantly...which leads me on to my next point.

Remember the first rule of airmanship "KEEP A GOOD LOOKOUT". Especially if you're flying in a busy circuit. This helps you with your situational awareness aswell. It will stop you flying into someone else, and will help you get out of the way of someone who's head is inside staring at his ASI.

LANDING.

DON'T be afraid of the ground.

As soon as you turn final stabilise your approach. Configuration, attitude, power, trim and speed should all be steady as soon as possible. Make small corrections as necessary.

Once you're over the threshold ignore the ILS, PAPIs and anything else you were looking at. Ease your nose down a bit to INCREASE very slightly your rate of descent, take off enough power so your speed gradually reduces to your landing speed (if your approach speed and landing speed are different). Between 10 and 20 feet (keep the aeroplane flying towards the runway and don't use your altimeter, this is a judgement call) look at the far end of the runway. This allows your perspective vision to better judge your height. GENTLY check the rate of descent, take off a trickle of power and flare, GENTLY! Arrive!

DON'T be afraid of the ground, DON'T flare too high. DON'T be afraid of the ground, DON'T flare too high.

Keep flying the aeroplane right down and if anything flare later than you think you should. Don't worry, it wont be!

Remember. A good landing is at the correct speed and at the correct place. Not just because it is smooth.

aluminium persuader

24th Jul 2006, 10:18

Just to clarify what I said before; I didn't mean don't teach the numbers - that would obviously be daft! I meant teach how the a/c feels, without reference to the numbers (ie asi covered) too.

Longbow55

24th Jul 2006, 10:52

yeah, right.

If this is really the best you can contribute, maybe it is best to learn a bit more and hold back on your contributions until you have your licence and some post qualification experience under your belt.

The wombat

OK, Now I know why the pM, I have enough hours and a license. set yourself up on down wind, airpeed and trim you should not have to look at airspeed even when applying flaps. want to go flying sometime. on second thought, I don't want you flying with me.

Final 3 Greens

24th Jul 2006, 11:21

Set-up for 70 kts down wind and never look at the ASI again.

Longbow, I would not be so abrasive as wombat13, but if you really think that setting up a PA28-180 downwind at 70kias is good practice, I am a bit worried for you.

70 is a good speed for the start of final, coming back to 65, but it's way too slow for downwind.

As a generic approach I'd plan to fly downwind at 100 coming back to 90kias, base 80-75, final 70-65.

Obviously these numbers would be amended as necessary in the circumstances prevailing at the time.

Also, I would expect to trim quite actively, especially if going to the 2nd stage of flaps from clean and then for 65 on short final.

Using these speeds, I could operate quite happily into 700m of grass, with a final approach of about 1nm, due to local considerations. So no bomber circuit necessary, yet no dawdling to baulk high performance singles or twins.

Just my thoughts.

Longbow55

24th Jul 2006, 16:00

Final, You are correct, as different planes are flown differently. and I should have said at the numbers, and those numbers I gave were for the 172,152 I fly, the 182 is 80 down wind, and 70 with 1st notch of flaps at the numbers. the last time I flew an Archers, 80 down wind, 70 at the numbers and the last time I looked at the ASI (During VFR flight) on final it was right above 65. I am sorry is I offended anyone with my slight courseness, I usually don't say anything.

Final 3 Greens

24th Jul 2006, 16:34

Longbow

Fair enough. Keep posting, all contributions are valuable and welcome.

Chuck Ellsworth

25th Jul 2006, 21:23

I keep reading this advice to look at the far end of the runway to judge height during and after the flare to be able to accurately judge wheel height above the runway.

Can you look at the far end of the runway to wheel land a tail wheel airplane, with power off from 200 feet?

Chuck E.

Say again s l o w l y

25th Jul 2006, 21:54

Nope, you can't. But it is invaluable when you are in the flare in most a/c. As with anything, you teach the best method for the machine you are training in. For instance I wouldn't use C150 techniques in a 737 or vice versa.

I have never had a student who hasn't been able to land when following that advice. Since we use our peripheral vision to judge our rate of descent to the ground, looking at the cowling is a pretty daft idea!

Chuck Ellsworth

25th Jul 2006, 22:45

" I have never had a student who hasn't been able to land when following that advice. Since we use our peripheral vision to judge our rate of descent to the ground, looking at the cowling is a pretty daft idea! "

Well you have me there as I have never taught that you use peripheral vision to judge height, nor have I ever taught them to look at the far end of the runway, ( obviously the far end may be in in their peripherial vision but I except for attitude conformation I fail to see how looking that far ahead gives you an accurate picture of your height above the runway......

I teach the use of peripheral vision for attitude control ( pitch and bank ) and the center of vision area for height and velocity judgement which should be at the point ahead of you down the runway or beside same where apparent movement ceases....works for me from Cubs to heavy jets.

But what ever works for you then by all means use it. :ok:

Chuck E.

Say again s l o w l y

25th Jul 2006, 23:06

I think there are many things we all do without thought, since they just seem to work. It's all semantics really though. If a technique of any kind works reliably for any task, then use it!

Mr Magoo

25th Jul 2006, 23:08

For what it's worth before any of my students were sent first solo I'd ask them what happens if a bumblebee flys down the pitot while we're downwind?

They think for a while then usually answer that the ASI falls to zero, (anyone who thinks it stays at the current indication doesn't know about the drain hole in the pitot head.)

Anyway - I then slap an instrument blank over the ASI and get them to fly the A/C on attitude, power setting and FEEL. I pull the blank off once set up on base and they're usually within 5kts of the speed I ask them they're at.

The blank's then replaced and we fly down to, (usually,) a greaser.

Now, if you're a student, I'd advise you try it with your instructor - it'll give you a BIG confidence boost about keeping your eyes outside the aeroplane and flying by feel - and if ASI faliure happens when your'e on your own you'll handle it OK.

Also try blanking off the altimeter on the upwind leg of a circuit and judge your height once downwind - my guys could get within 50' after a few goes.

To sum it up PAT and APT does 90% of flying in anything from C150 to A380 once you learn how to land you've got the other 10% sussed!

Magoo

Chuck Ellsworth

25th Jul 2006, 23:55

O.K...

seems that we agree we don't look at the far end of the runway to judge height when doing wheel landings..

..so lets think about landing a helicopter on a very small pad, do we look way out in the distance to judge our position, height, and velocity for touch down on the pad?

...I have been involved in the odd airshow display and find that accurate height, attitude and velocity judgement is your paramount concern..so lets think about a ribbon pick up in the normal or inverted attitude...would you look way out into the distance at the far end of the runway to be in the exact right attitude and height to pick up the ribbon instead of smacking into the ground?

Chuck E.

SparkyBoy

26th Jul 2006, 07:03

Last night was my first lesson on Slow Flight (Ex10a). It looked like a really boring lesson during briefing but proved to be quite tough and actually very very scary.

After the lesson the examiner explained that being on the wrong side of the drag curve was the main cause of most PPL accidents and I could really see why!

The problem for me was the temptation to pull back when the nose drops, absolute disaster when approaching the stall!

I have a lot more work to do on this side of things and It looks like it's well needed in light of recent accidents. The news has hit me quite hard as my own first solo is only a few weeks from now. :ooh:

Say again s l o w l y

26th Jul 2006, 07:14

Personally, when landing a helicopter I transfer my view to fairly close by, it let's me judge any movement more accurately. Horses for courses.

I certainly wouldn't be staring at a ribbon if doing something like a pick up., I would be "looking through it". The problem when you are staring at an object is that you generally tend to hit it. Try it in a car or on a bike. If you stare at the kerb in a corner, then you'll go to it, whereas if you look through the corner to where you want to go, then that is what'll happen and it's a lot smoother.

Whirlybird

26th Jul 2006, 09:23

..so lets think about landing a helicopter on a very small pad, do we look way out in the distance to judge our position, height, and velocity for touch down on the pad?

No, of course not. But when teaching students to land helicopters, I tell them to look well ahead, then hover lower, and lower, and just a bit lower....and they land without realising it. I keep insisting they do it that way, because as soon as they look closer and TRY to land, they start mistaking every little movement of a blade of grass for sideways movement of the helicopter, and they never land! But do I do that myself? Well, sort of, and sometimes, depending on circumstances. But it doesn't really matter any more; I just fly the helicopter on to the ground, the same as I fly it anywhere else I need to.

I learned to land nosewheel aircraft by looking well ahead. It worked for me, and prevented that ground rush that's so scary for beginners. Now I just.....land. Not sure how I do it, where I look, or whether I use power for speed or height or all that stuff; I just fly it on to the ground. I've only had a couple of lessons in tailwheel aircraft, but I can see that looking well ahead wouldn't work, especially for someone my height; once I flare, all I can see ahead is the nose!

So there are ways to learn how to do things, and ways you do them when you're reasonably proficient, and maybe they're two different things. I'd appreciate your views on that, Chuck, since I think you've probably more instructing hours than I'll get if I carry on till I'm 100. :(

Unfortunately I'm off flying in France tomorrow for a few days, and probably won't be able to carry on this interesting discussion. :{

Chuck Ellsworth

26th Jul 2006, 17:33

Hi Whirley, hows things going for you these days.

You notice I post here on a random basis, that is because I usually don't have the time avaliable to be a regular.

For the purpose of this discussion regarding where to look when landing any flying device it is not black magic, you only need to get the picture that will best allow you to smoothly control the rate of decent and change your flight path so as to arrive at the desided touch down point in the best attitude for the device you are in at the moment.....

..and looking way into the far distance is not the best method to use...

..lets look at another senario....you are rolling out of a steep turn at low altitude in a flying device applying chemicals to a farm field ( I think its called Aerial application ) You are in a relatively steep nose down attitude having just passed a tree line and you want to flare as close to the start of the field as possible and be two feet above the crop. to start your application run.

How long would you live if you looked a mile ahead to judge your height for the flare?

Chuck E.

Lister Noble

26th Jul 2006, 17:33

When learning landings as a student I had a lot of trouble estimating height above ground on flare and hold off.
Was told imagine a double decker bus,imagine a first floor bedroom window,none of which clicked for me.
Then some wise old bird told me to sit in the aircraft on the ground for a while,peer around and see exactly what it looks like.
This really helped me in my early landings period.
Doesn't always guarantee perfect landings though(could this be me?);) ;)
Lister:)

shortstripper

26th Jul 2006, 19:15

I'm with Chuck on this one,

Even as I sit here trying to analyse where or what I'm looking at when I flare, I can't actually figure it out? I certainly don't gaze at the far end of the runway, never have! In fact, as I've often flown from fields with no actual runway there is no discernable runway edges to use in perhperial vision, and often just a crop line in the distance ... but it makes no difference to my landings (wish it did, perhaps they'd improve?). I remember the old "double decker bus" thing from gliding, but again, I've never thought that either. I'm kind of used to judging distances in the "up to 50 foot" region as a farmer using wide or long farm impliments and when I worked with my father as a proffessional fisherman, bringing a boat up to a bouy to haul lobster pots. I just "know" those distances. I'm sure I'm not unique, I think once most people have got their eye in, there's simply no science to it .... just good old human judgement! :ok:

SS

Chuck Ellsworth

26th Jul 2006, 19:48

Yeh shortstripper it ain't black magic.

I use a very simple method to teach height judgement skills to pilots.

First explain it on the ground

Second I fly the airplane and verbally tell the student what I am looking at and have them look at the same area....and also make sure they are printing the picture in their minds.

Then I have them repeat what I just showed them.

I use a video camera to record these lessons and the video is our debreifing tool...if they have fu.ked up an approach , flare or touch down I stop the video and ask them where they were looking and what they thought they saw...

Works every time and all my students can judge their approaches and are sure of their height above the runway.

Chuck E.