Approach and landing speeds

[pilotbear]

I was wondering how many of you work for CFI's or Flight school owners who insist on teaching increased, and might I say incorrect, approach and landing speeds; with the excuse that the student might fly too slow and stall?

With the result that (for example) the PA28 warrior floats half way down the runway before touch down if you are lucky and the student has no idea of what is going on.:( :hmm:

[justanotherflyer]

One often sees this when doing checkrides or familiarisation with new club or school members.

The manual may recommend threshold speed of, say, 65kt, as 1.3 x Vs, but the pilot will coast in at between 70-80kt, to use up half the runway bleeding off speed, ballooning, etc. It comes from an excessive fear and misunderstanding of slow flight, probably due to ill-conceived stall / slow flight initial training.

I apportion a fair bit of blame to instructors who make initial stall awareness and recovery training into a big piece of drama for nervous students, instead of imparting it as an understandable, practical acquisition of a flying skill.

[pilotbear]

Do you feel, as I do, that slow flight in landing configuration should be given more attention, ie setting up rates of descent with the throttle while maintaining speed with elevators, until it is a run of the mill part of the flying. I find it hard to believe that the most important moment of the flight is really not explained or practised more.
All I get from other instructors is "why bother because they won't do it right anyway"., or "it is too complex for the student":confused:

[BEagle]

We did some research and discovered that there had been some wrong teaching about the approach speeds at my RF. People had been told to use 65kt as a Vat, not an approach speed - and to add another 5 for gusty conditions over 15kt, plus yet another 5 if there were 3 or more PoB.

All of which is complete :mad: ! The correct approach speed for a Warrior at max weight in any condition is 63 kts APPROACH SPEED! There is no real 'Vat' - if you fly the correct approach speed, 'pointing and powering' all the way down, then flare correctly having closed the throttle it will land properly.

Since I reduced the speeds to 70mph (Cherokee) and 65 Kts (Warrior), we haven't, touch wood, had any noswheel damage. But if someone flies at 70K-80K, the out-of-trim force at the flare will be substantial. They probably won't be able to control the eventual landing very accurately and an untidy effort will result!

I've heard that the fast, flat 3 deg approach with an enormously long final used to be favoured by one of those schools which trained future airline pilots - to 'get them used to the aspect'. Bolleaux!!

[MAXX]

I suppose i must have been lucky i guess.when i did my intial training my instructor spent a couple of hrs with me doing just what has been suggested on other posts,slow flying,flap use and effective elevator and rudder control.to finish me off and to get rid of my death grip on the control column he also took me through some basic aerobatics.(all of this really helped as i felt i could really fly the aircraft after that) of course that was 5000+hrs ago and i realize that i still cant fly and am still learning :ok:

[pilotbear]

Nice to see that some instructors are interested in the flying aspect. BEagle - I wonder if that is the same school that teach circuits in a Katana that go outside the ATZ by two miles to 'get the aspect of a 737 approach', thereby p.....g every body off including the tower.

the classic quote I heard today was from someone who said that were having trouble landing the Cherokee six. The problem being it wont stay on the ground. I said fly the accurate VAT speed from the book. the response was 'I don't need the book, I have tried all speeds, nothing seems to work'.

MAXX, you are right. A couple of hrs spent just flying the aeroplane pays huge dividends.

ps Is anyone interested in a discussion on use (or mostly misuse of the rudder):ok:

[justanotherflyer]

I don't need the book, I have tried all speeds, nothing seems to work

Interesting (i.e. depressing, if not worrying) comment from a pilot of a relatively sophisticated craft such as the Cherokee Six.

To me it betrays a serious deficiency in understanding of what is actually happening aerodynamically. The mantra slow=bad, fast=good, is taught so routinely during initial training, that students (later PPLs and more) often never get their heads around the idea that slow can=good in certain circumstances. E.g. landing on a 400m runway.

One technique I use to to try to enhance students' intellectual understanding of what is happening to the airflow, lift, etc., by asking them visualise the air as a coloured, weighty fluid, and to try to see, feel and hear what it is doing in every regime of flight, what is happening to the angle of attack, and to describe it to me in physical (non formulaic) terms. I spend plenty of time getting them to fly various manouevers in the slow flight regime. When they see it doesn't fall out of the air, they get more comfortable with very precise speed control in the landing sequence.

Re the rudder: fruit for much discussion! I defy most successful PPL candidates to explain why it's needed at all... What are your specific thoughts on that forgotten control, pilotbear? :8

[pilotbear]

When I first did my PPL ( many moons ago) it was in a 'Learn in three weeks' school in sunny Florida. The worst mistake I ever made. I can remember now tightening climbing and descending turns by putting in more rudder and wondering if there was something wrong with ball as it was never in the centre, I am amazed I am still alive!

I came back here and and had some lessons with Dave Coulson and it was like a revelation. He taught me to lead the turn and more so, the rollout with the rudder assisted with aileron. It makes such a difference to the way the aircraft flies especially at slower speeds. (this paid dividends when I went on to fly seaplanes in the mountains of BC Canada where an uncoordinated turn will spin you in every time).

I am now sadly fanatical about rudder/aileron use.
For instance on the approach to landing I find that wing drop or misalignment with the runway is usually corrected by 80% of the pilots and students I get with hefty use of the ailerons, with the result that the nose ends up pointing in the wrong direction due to the adverse yaw, or we do a falling leaf approach (PIO).

In the PA 28 arrow if you use small aileron corrections for wing drop on approach the only thing that happens is that the ball moves from side to side. If however we feed the rudder into the equation not only do we get accurate small heading corrections, we find that we hardly need the ailerons at all.
In fact I get people to fly the approach with just rudder to make the point.
I have had people tell me that in a Cessna they need a bit of rudder on the full power climb but in a PA 28/38 you dont need it at all???
In a medium turn in a warrior it tends to overbank, so you need opposite aileron. ie in a right turn - left aileron. Therefore you need rudder to match this. So in a right turn you need left (or less right) rudder. This takes an inordinate amount of persuading of people who think the rudder turns the aeroplane like a boat.
I teach "you use the rudder because you use the ailerons". This is taught unequivocally frrom trial lesson onwards with no options.
I find that the people willing to take this on board can cope with a higher workload in the cockpit as the can fly S&L with just their feet while map reading or plog filling, and they have no trouble making smooth approaches even in windy conditions.
What do you think?


:ok:

[Tinstaafl]

I always insisted on coordinated controls from their first lesson. About the only time they got to use aileron without rudder input was the very first part of 'effects of controls': Here's what the ailerons do, now you have a go... After that it was always with rudder.

[fireflybob]

>Do you feel, as I do, that slow flight in landing configuration should be given more attention, ie setting up rates of descent with the throttle while maintaining speed with elevators, until it is a run of the mill part of the flying. I find it hard to believe that the most important moment of the flight is really not explained or practised more. <

Funny but I always thought this is what, amongst other things, we were supposed to teach on Descending Part 2?

[FormationFlyer]

heheh. Chuckle. Well as BEagle is my CFI... :) - time to own up I guess ...

...only joking :p

We dont have a problem at our club - and most of our club PPLs are pretty good on these too - despite rather more tarmac available than one would ideally like for teaching landing....

Personally I use 75kts initial app speed @ 2 stages (Pa28) or 70kts 20deg in C152....becoming 65kts (pa28) and 60kts (c152) once full flap has been deployed.

I also insist on accurate speed control. By students and ppls alike. Proper speed control on final at the above speeds is critical to a good landing. I have never used them as Vat figures (as I said above - I use them as full flap approach figures).

I have never had a student or ppl stall on final approach. Not even with the ASI covered(!).

I dont teach higher speeds for more weight - these figures are already based on MAUW as BEagle said.

Regards
FF

[pilotbear]

Fireflybob, I am well aware of what we are supposed to teach - however, My point is that more time should be spent on that particular item, because like it or not I have found that speed control/rate of descent coordination is poor.
It may or may not be through poor instruction, more like underemphasis of the importance of it and lack of specific practice.
And as for slow flight, I have asked ppls and students how they have practiced this and why. The most common answer is as a precursor to stall recovery.
So as Justanotherflyer intimated, an important normal part of flying skill is associated in in the pilots mind with some thing scary so they avoid it.

Many hours ago when I was teaching float ratings in Canada, I found myself time and time again teaching the above flying skills to experienced British (sorry) pilots, along with how to use the moveable footrests - instead of just teaching landing on the water which is scary enough.:ooh:

[FormationFlyer]

Interesting. I have to say that it is a sad enditement of many UK instructors that ex10A (slow flight) is not taught properly - and indeed it is not often explained to the student the situations (every day) that they can find themselves in this stage of flight (approach, go around from hold off etc)...

I personally think it is a very important lesson and well worth the 45mins spent flying it...would appear that many 'older' (i.e. non-JAR or rather > 20 years ago qualified instructors) seem to think differently.

One instructor who I know of used to say 'slow flight - thjats the stage between S&L & the stall' argh. He has now lost his medical - thank god - he should have lost his licence! (his own skills werent that great either) - p.s. he doesnt teach at the same schools as I do...

I think it is somewhat revealling to look at logbooks and try to find Ex10A and Ex11A logged as lessons...most logbooks either say Ex10. (another words they did stalling not slow flight) or the exercise isnt logged at all and you ust see 10B or 10B.1/10B.2.

Ho Hum. One can but try and encourage good standards though.

Regards,
FF

p.p.s Floatplanes are fantastic fun! :)

[poteroo]

Slow Flight/Use of Rudder

Interesting thread which developed out of the too fast approach speed post. Agree with just about everything said too

See a lot of the '2 - on - the - floor' syndrome here in my corner of Oz. Mostly Piper trained pilots too. Also, most PPL's seem to think that Vfe is the lowest end of the white arc you should dwell in until over the threshold. I don't think this is just a UK problem. It's very impressive watching them try to get a Cub on the deck at 60 kts approach!!

The slow flight training is IMHO essential to so many maneouvres, including precautionaries, low flying, bad weather flying, go rounds, orbiting etc, that there should be much more emphasis on it. Due our greater amount of rough air flying out here - hotter wx - it's useful to teach S&L using a rudder 'lead', which saves the pilot a lot of arm wrestling with aileronswhen they could be navving.

One of the other safety aspects of teaching slow flight is to teach them to 'lead' into the turns with power and rudder, and to look to make slow flight turns as minimum radius turns - not steep turns per se. Too much emphasis on high wing loading / steep turns at cruise speed,(which most pilots will never do in their lifetime). Not enough emphasis on the subtle skills of low wing loading, balanced, minimum radius turns at slow speeds.

For info, we specialise in low flying and tailwheel work in a C170 and a Supercub.

cheers,

[pilotbear]

I used to teach on the floatplane 'canyon turns', which as you described are min raduius turns, (slow with power and 2 stage flap C185). It used to scare people to death as they thought slow steep turns = spin in. However, this was a normal procedure in mountain flying. It is not encouraged by many people I know.

your place sounds like my kind of school RV6-VNE. Now that I am back in England the first time I got to fly low, someone rang the CAA to complain.
:sad:

Formation flyer, you have had some floatplane experience then?:D

[justanotherflyer]

Excellent discussion, guys, with much food for instructional thought. I'm going to work with students more on the "minimum radius" concept from now on. Most students seem to be taught that minimum radius is obtained by adding power / speed and a massive bank angle.

When you think about it, the classical approach-to-landing accidents don't happen because the aircraft is "low, slow and turning" per se ... they happen because of a failure of control within that regime. It stands to reason therefore that a lot of work should be done in mastering the skills of control therein, instead of the unrealistic tactic of avoiding the regime altogether.

Pilotbear - not to go on a tangent (though isn't that the joy of bulletin boards... :8 ), but have you any opinions on what might be a suitable float configuration for salt water operations. I'm thinking of moving to the seashore, dreaming of a little jetty with say, a cub or 172 on floats parked outside. But is it feasible on salt - corrosion, etc?

[pilotbear]

The problem you quite rightly said is the salt water. It gets in everywhere. You need to have the space to get the aroeplane out of the water to regularly hose it down with clean water.

A cub is fine if it is just for you to play around with, although a bit small. A 172 tends to be underpowered, however a C180/182 or ideally a C185 is an ideal combination of size and power.

On the sea you have to be very careful of waves and worse is the swell, particularly in a a/c like a cub or even a C172. in fact I would say no to that.

If you get amphibious floats you can then land on water and drive off up your ramp to wash the aeroplane down.

[kabz]

This one of the best threads I've seen in a while.

I spent my first 20 hours wrestling with the trim forces trying to land a 172 from too high approach speeds.

I didn't get taught about trim or rudder either, so you can imagine it was a bit traumatic.

I won't do the same thing to my students. (When I get to that point ... ;-) )

[FormationFlyer]

justanotherflyer Dont get confused here between min radius and max rate - what you described - high power high bank angle (pull to buffet) is a *max rate* turn. What pilotbear was talking about was a min radius turn...different beasty altogether.

pilotbear Indeed I do. I have a current SEP (Sea) rating on my licence :cool:

[pilotbear]

FF, did you do the professional seamanship written exam (CAA 30 Questions), or the PPL 20 question exam?

[BEagle]

Interestingly, it has come to my attention that a certain Oxonian flying school (not far from Mad Jamie's gaff) teaches its students that a Warrior's normal powered approach should be flown at 70 KIAS and that this speed may be increased 'slightly' (meaning what?) in conditions of (unspecified) turbulence - and that the 'threshold speed' should be increased by 5 kts with 3 or more PoB.....

DICKHEADS!!! READ THE POH!!!!!!

[pilotbear]

Quite so BEagle, The reason I started this thread was because I am becoming increasingly concerned with the inability of the average PPL to land an aeroplane consistantly. I mean by that statement, with consistent technique. They can all land. Why is this?
I put it down to (and please don't anyone take offence as none is meant) the 250hr CAP 509 instructor culture.
I feel the comment made earlier by firefly bob makes my point.

I do check rides for for hirers fresh from these courses and generally the same observation as above applies. They try to fly a warrior or katana or whatever like a heavy jet because that is what they have been taught. Well, you cannot as the aerodynamics are different.:=
Before this becomes too gloomy a picture - I might add that I do see some very talented pilots with very low hrs.:ok:

How can you be expected to teach something that you do not understand yourself, especially if the goal is just to gain hrs? Surely the student suffers and the standards become increasingly bad.:sad:
I know there are a lot of us that do take the time to teach properly and I hope that this observation will be understood.

:ok:

[FormationFlyer]

Here. Here. Quite so PilotBear.

Re: Seamanship - Im gonna take the Commercial paper - I did the PPL paper merely for rating issue as the CAA have to arrange specific exam dates - so Im starting to study again now so that I can get the last bit sorted :)

[justanotherflyer]

Pilotbear, formationflyer:

I'm also planning to take the Seamanship exam at commercial level sometime soon. I wonder if either (or both) of you would be interested in corresponding to exchange study notes and ideas, clarify what's required, etc. If so please feel free to PM or email me via Pprune. Pilotbear I gather you already have the CPL sea qualification - any exam tips most welcome.

One way or the other... good luck, chaps.... :ok:

[pilotbear]

Yes I do have the Commercial Seaplane licence. I would be happy to help. Send me your email address to the pprune email address.

Mostly concentrate on Bouys (know them absolutely), Lights on the the water and rights of way on the water.
:ok:

[NorthSouth]

Ahhhhh, you've really poked my nest now. I have recently been trying to make sense of the POHs, including the UK Supplements, for the Warrior and Archer. The former advocates an approach speed of 63kts irrespective of weight, the latter a variety of speeds ranging from 75kts at max weight down to 63kts at 1800lbs.

I can't see the logic in this. I can see that the extra 10% weight of an Archer should require a higher Vref than the Warrior, but why so high? If you come down the approach at 75kts in a fully-laden Archer you will find it difficult to get rid of the 11kts or so necessary to bring you down to Vat.

And why no reduction in speed for the Warrior when operating at less than max weight?

[Dude~]

North SOuth - I recently notice the same oddity on the POH for an Arrow II. Whilst 1.3 Vs1 is approx 60kts, the poh approach speeds varies in a linear fashion from, if I recall correctly, 78kts to 66kts. Actually, that may have been for the PA32, I dont have the figures to hand, but I do know that the lowest approach speed recommended in the POH (which incidentally was for zero fuel weight - ?!) is significantly more than 1.3 VS1. Is it normal practise to land larger light aircraft on the edge of the stall, like a small cesssna, or is it recommended practise to touch down with more control authority at a slightly higher speed, though, inevitably, a smaller percentage increase than say touching down at 65kts in a Warrior?

[John Farley]

I am not taking sides here because I don’t know enough about the specific types being talked about.

However, while 1.3 Vs is certainly the certification basis so far as lift goes, do not forget the issue of controllability.

Quite a lot of aircraft have minimum speeds higher than 1.3Vs to improve controllability. A non controversial one (in this forum) being the Vulcan, more lift than you could ever want but lateral control in turbulence set a min speed of 125 even at the lightest weights. So it did with the Viscount. And closer to home (here) so it did with Dove G-ASMG if there were serious turbs about.

[pilotbear]

I find that on the Arrow or Archer with the straight wing that 65 kt threshold with power works really well with negligable flaring required. Power off on TD.
However, that cursed warrior with the tapered wing will not touchdown at more than 60kts so you just have to be patient with it and not try to force it to come down. It is not a good aeroplane if you are ground shy. However, it seems to be a better aircraft for power off over the threshold landings provided you cross at 65kt (full flap).:ok:

[poteroo]

Approach Speeds & 'Controllability'

In a perfect world - we would all use 1.3Vsf, and that would be it.

Of course, this number changes with several factors,so it would differ from flight to flight - hence common practice is to use Vsf @ MAUW as the reference. This gives a number which is almost always higher than 1.3Vsf 'on the day'. So, we are going too fast, before we begin to add 5KIAS for Mum and the kids, and another 5KIAS for grannie, and 5 more for the insurers etc.

In the real world, turbulence and wind shear lurk in waiting near the ground. Because of them, there can be stall warning incursions as we slow to Vsf, and this frightens not just the passengers, but also the student. This particularly so if said student has been trained to beleive that the onset of stall warning is highly dangerous and to be avoided at all cost.

One of the main reasons I hear for higher approach speeds is that your ailerons are more effective, and a dropped wing can be quickly picked up, and the aircraft can be cross controlled for a cross wind landing without going too near stall. There is a certain fearful logic to this in windy conditions, and where shear is likely, as behind trees, buildings.

Would this work for a pilot landing on a short strip in Alaska,PNG,outback Aus - or anywhere for that matter? Hell no - you'll be off the end and into the scrub! Do they exceed 1.3 Vsf - not b....y likely! So how do they manage, and is there a lesson there for Mr average PPL flying into a country airport or farm strip?

So- what about RUDDER? Go back to Lesson 1 Effect and Operation of Controls. Why do we show students the secondary effects of controls? For the good of their health? Is their any application of this knowledge in later flying? No,Yes? Of course there is - and it's never so useful as on approach in turbulence and shear. Don't think that shear is just some phenomhena associated with obstacles and gales either. It's everywhere. And once mastered, using rudder intelligently will smooth out your S&L - particularly in rough air.

What about other controls? POWER should be used sparingly, but if you don't use it, then icing is much more likely, and a baulked approach is delayed by having to 'ease' the throttle through the first couple hundred RPM, or the engine can falter alarmingly. Better to have a little power on, for this, and for better RUDDER controllability.

As you continue down final, shear will cause you to suffer decreased IAS/or increased ROD, or both, unless you ADD POWER. Often, you can anticipate these effects, and add power on cutting the top - of - obstacle line. In winds over 20 kts on open ground, probably at 200 ft you could start. By doing this, 1.3 Vsf is maintained, as is the angle of approach, without having to lose it first. Prevention is better than cure!

Now, we're at 200 ft on final, and strike turbulence/shear, the aircraft drops a wing and sinks. First reaction of student is to heave ho on the elevators and muscle in big amounts of aileron. We're now off on a low speed 'snaking' approach, of the falling leaf type mentioned by earlier posts. Isn't it far easier to use those feet, applying rudder to pick up the low wing, (via the secondary effect), and adding some power? You avoid the snake, and the ROD increase,and the IAS decrease, all in a very short time.

By avoiding this horrendous 'snake' effect, the pilot can keep focussed on the aiming point, and prepare for the crosswind correction inputs as necessary.

Therefore, I offer no support for increased approach speeds, because the means, (power + rudder), are at hand to hold Vsf without struggling for control.

Instructors - it's in your court to fix this high speed approach problem.


cheers,

[Tinstaafl]

Disagree with using rudder as an aileron replacement. Use the controls in a co-ordinated manner. Otherwise pretty much what was said, esp. using power. I fly in some high winds,very rough, high windshear conditions and it's quite common for me to need to vary between full power & idle and this is into very short strips (380m the shortest) with obstacles.

[BEagle]

Quite so. Large, uncoordinated rudder deflections at low IAS positively invite disaster. Just use the rudder to keep the ball in the middle and the control column to maintain the required attitude.

[pilotbear]

The problem with using aileron in the appraoach is as you know if a wing drops it will usually return by itself, and usually just as the student is applying the aileron correction ending up with a wing drop in the other direction. Gentle use of rudder assisted with a little aileron helps the nose remain pointed at the runway and eliminates the falling leaf.:ok:

[BEagle]

Huh? Sorry, but that's total bolleaux.

[FormationFlyer]

Lost me too Im afraid. I cant say that coordinated use of aileron and rudder to balance left me in a 'falling leaf' scenario - indeed - if you pick the wing up fast enough with aileron then all you have done is roll - no yaw had time to affect the aircraft...

One exercise I do with my students in med level turns - pior to going through the turn is to 'roll around a point'....its an exercise in foot control - all planes have adverse yaw - even nice PA28 & C152 do. So I roll the wings back and forth which shows the student how much adverse yaw is apparent - and the balance ball is diving out all over the place. I then show that by coordinated use of the controls I can remove all visual artifacts of yaw and the aircraft rolls around a point - and the ball stays in the middle - it is then impressed on them that the amount of rudder needed is directly proportional to the amount of deflection of the aileron and that they must remember how much rudder they had to use - as the same amount will be needed when rolling into turns...i.e. use your feet....

Now...back to the approach wing drop...anyone who advocates use of rudder to 'pick up wings' is asking for trouble. stall + yaw = spin. Yep. But how many of you impress upon the student that if the aircraft (or part of it) stalls with yaw already presented that a flick/spin will result - ask your students - I have had answers from 2-5 seconds after a stall with yaw before the spin starts....they are most suprised when I tell them that the spin can start sub-second and that some a/c can flick very violently....

Re: student who applies to much aileron....well if they are looking out the front that wont happen - either that or they need to be lighter, less cumbersome and quicker on the controls...which is something they learn..I think its wrong to teach bad habits to correct minor, newbie 'habits'.

Regards,
FF

[MAXX]

ive been flying for nearly 15 years now in many different area's from light singles up to light weight jets.an interesting comment that ive heard many times from many different pilots is that "0h thats a real numbers a\c,fly it by the numbers and it does just what you want it to".(regarding a specific type)

well guess what guys,thats what the POH is for in any a/c type.
it doesnt make any difference if your flying a c-152 or a learjet,VFR or IFR if you fly it by the numbers it works
:ok:

ps this is not having a go at anyone on here just a general observation

cheers

[Dude~]

I checked my POH this weekend, and its states that the approach speed for this PA28 Arrow II is between 80kts at 1800lbs and 90kts at 2600lbs on a linear scale. However, Vs is about 56kts at max weight, 1.3vs is therefore 73kts, but flying the numbers means I have to lose up to 34kts before touchdown. Well, I got a friend to concentrate on my ASI on sat evening when all was calm. He noted that I approached at 80kts, then over the threshold at 75kts, rounding out, then a hold off and touchdown at just below 60. Distance from the numbers to walking pace was about 400m with slight down slope. It doesnt take long in an arrow with full flap gear down, level flight, idle power to lose 15kts.

Pilotbear, I cant say I aim for a particular threshold speed. I just try and reduce whatever my approach speed is, to a touchdown as slow as poss. Sometimes I'll approach faster and when I know I am going to make it, reduce power, and decelerate in anticipation of the flare.

[DFC]

My POH for the arrow uses the same numbers as quoted above. However, the units are MPH.

Are you sure that you are not mixing up Knots and MPH?

Regards,

DFC

[Dude~]

DFC - Very sharp! Now I come to think about it, I'm sure you're right about it being 80-90 MPH instead of kts., but I'll definately be checking before I fly again!