Ballooning on landing

[funfly]

Assuming that airspeed is correct, what other factors can contribute to an aircraft 'balloon' on landing?

[FlyingForFun]

Over-flaring?

FFF
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[hugh flung_dung]

looking too near?
Look further away so the gradual flattening is easier to react to and use peripheral vision to judge what the ground is doing.

HFD

[slim_slag]

Chuck Ellsworth used to contribute some really good stuff, try this (http://www.pprune.org/forums/showthread.php?threadid=74587). Lots of experience behind the guy.

[Craggenmore]

Uneven runway? Every hollow counts.......!!!

(ignore this bracket as I can't seem to post 2 words without being told off by an automatic message!!)

[Skytrucker]

Not taking all the power off.

Too high a pitch rate on roundout.

Gusts.

Speed incorrect for AUW.

Larger aircraft at very light weights influenced by ground effect to a much greater degree than puddle jumpers.

Too low RoD often combined with low approach angle.

Runway sloping away.

[hugh flung_dung]

slimslag:
I just followed your link and read through the Ellsworth (and other) contributions - an interesting debate. His style of writing is very much "elderly american" but, filtering that out, I think he's advocating what many of us here would call "point and power" for the approach to the flare; I thoroughly agree with that providing the aircraft has sufficient power and drag.
When it comes to the flare and hold-off the cause of balloons is simply lack of recognition that the aircraft is moving away from the ground, this cured by actively looking (not staring) further away once the flare has started and using peripheral vision to keep the ground "around your ears" - if the ground starts to move away stop the rearward movement of the stick (DO NOT MOVE IT FORWARDS, except maybe in a go-around) until the aircraft starts to settle.

HFD

[FlyingForFun]

And a new one (new as in it happened to me for the first time earlier today):

Student does not appreciate that there are two distinct phases: the round-out where you transition from descent to straight+level, and the hold-off where you maintain straight+level as the aircraft slows down. Student therefore merges the two phases into one and applies a continuous pull on the controls.

(However, as well as lack of understanding, which is easilly fixed, this is also symptomatic of what HFD says about looking further away.)

FFF
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[BigEndBob]

Lack of surface definition.
Noticed this when taking students from a long 2000m runway thats is smooth and so wide the edges can't be seen at roundout, to a short rough runway where the patchwork quilt of tarmac seems to give some height reference.
Bit like the old problem of landing on snow.

[1McLay]

Quite often during the summer, sealed runways get so hot that the thermal effect takes hold during the flare...up she goes!

[funfly]

What about 'brain overload'?
I must come clean here and admit that I am a PPL with about 260 hours Trained on Cessna, PA28 & PA38 my landings have always been my pride and joy.
Recently bought another aircraft, low wing, fibreglass and a bit of a 'hot ship' with an approach speed of 80 kts. (75 kts over the fence). I find that I can fly it pretty well and can 'nail' the approach speed but I started to balloon on landing. Everyone started giving me suggestions - and I just get worse.
Pride dented, confidence shattered, I had a very experienced instructor to come up with me and demonstrate my embarrasment. He told me "forget what everyone has told you - disengage your brain and land it as if it was any other aircraft". This seemed to work and although I am not yet my old confident self at least I can get it down without too much embarassment.
Analyses seems to indicate that I was actually landing it a bit flat and possible even touching the front wheel first.
Silly thing is that I still fly a PA28 regularly and have no problems with this.
There - I've admitted that I am a crap flyer!

[Send Clowns]

Sorry, but Chuck Ellsworth starts off his contribution on the other thread with a piece of complete misinformation. It certainly is possible to judge height by looking at the distance. It is what solved my PPL landing issue, and is still what I teach. In fact I would go so far as to say that looking too close makes rate of descent impossible to judge, and therefore makes the flare much more difficult as this is the other part of the equation.

Ballooning is not caused by over speed. I have flown an approach in a C-150 at 100 kts, well above its cruising speed!* Ballooning is caused by flaring too quickly, over flaring for the given speed. It is perfectly possible to land from a high speed (given the 10,000 feet I had in the case mentioned!). The point is to teach the student to flare progressively, keeping the aircraft descending but at a reducing rate, proportional to the height above the runway i.e. flares for the conditions not for a standard "flare" for that aircraft (although that is an over simplification, and FFF gives a good description of the stereotype flare from which we build each landing in a light aircraft). The aircraft only balloons due to excess speed if the pilot flares in the same way as at lower speeds, rather than responding to the aircraft for each landing.

funfly has it right - what happens when we disengage brain is hopefully that the pilots responds to stimulus, doesn't just make a pre-programmed "flare" he might if he thinks too much.

Sounds like not a crap flyer, fun, just have to trust the good pilot within you!

*There was an A340 behind me :ooh:

[Gazsc]

Lack of experience of the visual cues required, combined with an unsympathetic mechanical input. Practicing low approach and go around at a suitable height is priceless when dealing with the "ground shy" student. Fly level at five feet and don't try to land. When happy, close throttle and don't try to land. Demonstrate to the student just how much elevator authority they really do have. At five hundred feet, brief "never ever put the control forward, just fly level" Learning not to put the aircraft on the runway is paramount to not nosing-in. The landing attitude is the same as the take-off attitude. Remind them of that when they line up. Above all, relax and fly. Don't intellectualise.

[homeguard]

Landing
I'm not happy with the word 'rounding out'. It is not the best phrase when refering to a modern nose wheel aircraft. It should be noted that a typical approach angle for current aircraft types will be in the region of the standard 3 degrees. Not much of a change from that angle of approach to level flight although it may appear so. I prefer the term 'hold off' so as not to infer that a large change of attitude is required by the student. Having held off and the flight is level with the runway the aircraft begins to slow and sink and the nose should be raised further to a PRE-DETERMINED attitude.

In all other phases of flight we teach and refer to setting the correct power plus an attitude to a reference (the horizon, a cloud or a place). Why not the same for landing. i.e. Power; idle, Attitude; with reference to the far extent of the runway (if there is a hump use the top of the hump - the attitude should be demonstrated for the student pilot to repeat). They should then maintain that pitch attitude reference - as thay are already used to doing at all other times - while keeping the wings level with aileron but using rudder to maintain the centre line (that is different. Allow the aeroplane to settle onto the runway in its own time maintaining the reference but as the aircraft slows to a taxi speed following the landing gently lower the nosewheel onto the runway.

Commonly so many treat the landing as being completely different from all other phases of flight, which it is not. A common technique for those that have a phobia about the landing is to have them repeatedly not land but rather fly, with a higher power setting, level with the runway at a few feet and NOT touchdown. They will find this very difficult to do and invariably touch down. You have then made your point and their confidence should build rapidl

[FlyingForFun]

Homeguard,

That's certainly not the way I land an aircraft, nor the way I teach it.It is not the best phrase when refering to a modern nose wheel aircraftWhat relevance is the fact that we are flying modern nose wheel aircraft? A good landing in a C152 involves exactly the same technique as a 3-pointer in a tail-dragger, the only exception being that the nose-wheel aircraft are slightly more tollerant of poor technique.It should be noted that a typical approach angle for current aircraft types will be in the region of the standard 3 degreesI think you will find that most people on this forum will advocate an approach that's considerably steeper than 3 degrees.Not much of a change from that angle of approach to level flight There is certainly a significant change in attitude.Having held off and the flight is level with the runway the aircraft begins to slow and sink and the nose should be raised further to a PRE-DETERMINED attitudeThe attitude required for straight+level flight depends on the airspeed. We teach this in ex 6b. After the aircraft has been levelled, its speed is continuously reducing, therefore requiring a progressively higher attitude.

FFF
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[homeguard]

FFF

I don't agree with you and nor do I think that you speak for most people and nor do I. The instigator of this thread asked for contributions and they have mine and yours and those from others. The readers will take advice from who they chose.

As for your last point you only state the obvious and there was nothing written by me that contridicts that. Indeed my observation underlines that very thing.

Please read my contribution with more care as I have read yours.

[funfly]

Thanks for all your contributions guys!
Another point that no-one suggested is that my (new) aircraft has a bl**dy great Lycoming IO/360 hanging on the front, which is quite a weight for a fibreglass aeroplane. I am now of the opinion that this extra weight makes the 'feel' of the roundout quite different than, for example, a PA28. When it starts to settle down the pull force on the stick to keep the nose off the deck is more than I have previously been used to and maybe this is why I am not pulling it back enough.
The worst thing for me is loosing 'face' after having been able to land a whole range of aircraft without problems for the last three years - we're all human :uhoh:

[Send Clowns]

Don't worry. I had over 400 hours when I calmly bounced the aircraft down the runway, wih my boss checking me for an LPC :ooh: :O "You'e paying for this you know! Do another circuit"

I knew exactly why it happened* so was not too concerned, but the point is we all foul up landings sometimes. You are now starting to see why you are struggling, which not only allows you to address it but to feel less bad about it.

*and it was partly his fault - all instructors out there, don't start to debrief a student in the flare - especially in a 172 when he's used to a 152 and hasn't flown for a while! I learned a valuable lesson that day about instructing :p

[pilotbear]

If the aircraft feels heavy then you are not trimming enough. The a/c should be in trim right down to the runway otherwise you have no feel to your control. Any attitude or power change must be followed with an equivalent trim change, then it flies itself.

If the aircraft is at the correct vref speed, which equates to angle of attack...then it is in the landing attitude. That is how the manufacturer designed it.
That is why you can do a power on landing without flaring, to an exact aiming point. Get the speed correct and trimmed, use power for ROD (150'/min) and the aircraft will land exactly right, where you have aimed it, flown to the runway.
When you hold off, flare etc. you are waiting for the aircraft to run out of energy at point unknown to you.....no wonder students cannot get it right..

If the aircraft balloons then usually the speed is too high. If you are not at mauw then the vref should be recalculated.

Vref is based on stall speed in landing configuration, (Vso x 1.25). Therefore, any change in stall speed affects vref.

so if the wt is different i.e. 2000lb instead of MAUW of 2500 the calculation is

new Vso = old Vso x sqroot of(w2/w1)

W1 =mauw
W2 =actual weight

for example.

Vso = 48kt (giving a vref of 60kt)
mauw = 2500lb
actual wt = 2000lb

2000/2500 = 0.8

sq rt of 0.8 = 0.89

48kt x 0.89 = 43kt

so new Vref for this new wt is 43kt x 1.25 = 54kts. A difference of 8 kts.

Any speed based on stall speed should adjusted if the stall speed is affected.

This calculation can be used for landing with partial flap etc. where there are no manufacturers figures. Find out the stall speed with 2 stages / 1 stage of flap then multiply by 1.25 to give Vref for that configuration.

Homeguard, I agree with you.:ok:

Where do they get the idea that more than a 3deg approach is necessary? very odd.:confused:

[sgsslok]

First off, I admit I didn't read the previous posts in detail, so I apologize in advance if this has been brought up already.

Ballooning is usually caused by the misjudge of the sink rate of the aircraft. The pilot, probably not looking far enough down the runway, thought the plane was sinking faster than it actually was, thus applied more back pressure than needed, so the plane ballooned.

Trimming of the aircraft to the desire approach speed is important, as it would reduce the pilot's workload in round-out as well as flaring.

Also, knowing where to look during the flare is important. The rule of thumb I use is to look about 8 times the approach speed, in feet, down the runway. In a Cessna 172, where the approach speed is 65kts, I would look about 500 feet down the runway. In a Cirrus, with an approach speed of 85kts, I would look about 700 feet down the runway.

Of course, looking too far down would cause misjudge of the sink rate (too slow instead of too fast) and result in a nose-gear landing.

[cadaha]

Where do they get the idea that more than a 3deg approach is necessary? very odd.

I think it's because if the approach is steeper i.e you start to descend later and in a single engine that if the engine quits on final you still have a chance making it to the rwy safely.

[pilotbear]

Sorry, but I cannot advocate that idea. At what point on the approach do you decide OK I can glide from here? Or is it another one of those standard guesses like 'the approach speed for partial flap'?

You are not going to make the runway unless you are almost over the threshold which should be at 50'.
You will nearly always have a headwind which will reduce the range.
If there is a crosswind you will be crabbing or wingdown to aim for the runway reducing the range.
You will not be at 'best glide speed' so you will have to lower the nose, reducing your range.
You will have flaps extended reducing the range; how many of you know the best glide speed in landing configuration?
With full flaps, the nose will have to pitch down maybe 10deg to regain and maintain the speed lost during the thinking time.
How many will try and extend the glide to the runway because you have taught them that they will make it from a slightly steeper approach, when a landing ahead in a field (but not on top of the approach lights) would be safer for them if not your aeroplane.
Better to teach a consistant approach angle, accurate speed control and then if the engine fails teach how to react quickly, safely and practice choosing a safe landing spot from low altitude.

3deg is standard unless there are obstacles. No wonder it is hard for people to learn to flare if it is from from steep approaches. Ballooning is bound to occur. The attitude change is too great.
3deg gives 300' at 1 mile, 4deg 400', 5deg 500' etc.

Try cutting the engine at 500', at 1 mile from the threshold, at the correct approach speed and count to 5 before you react; making it more realistic. You won't make it to the runway

3deg makes for easy standard calculations;
5x groundspeed gives rate of descent,
3x distance gives height you should be at.

We have to be certified for London City at only 5.5deg which indicates to me a more difficult scenario.

Only my opinion of course:ok:

[mad_jock]

You are not going to make the runway unless you are almost over the threshold which should be at 50'

Ehh in a light aircraft you have got to be joking. I will be at 1ft if your lucky depending on the runway lights and students will be expect to be under 50ft with the flap selected only when the engine can fail and it not matter a jot.

You are talking about instrument approaches or pref A machines.
I presume you want them to be full stabilised by 500ft as well.

Thats not the way we teach in the UK for SEP unless it all change in the last 4 years since my FI course.

They should be taught to pick an aiming point 1/3 of the way down the runway and use the flap when they are assured that they can make the aim point. At the point when they select full flap they should be able to glide the rest of the way and make the threshold. The flap is only used to bring the point of impact nearer the threshold.

At no point after passing the downwind end of the runway should the aircraft be in the position of not being able to perform a forced landing and not make the runway.

In fact if you are doing a CPL test doing the circuits and the examiner pulls the engine if you don't make the threshold its an instant fail. And I know a few that have had partials for getting outside the glide range while doing an approach. The examiner spots it, pulls the throttle they can't make it. The caa has another 400 quid.


MJ

[Classic]

They should be taught to pick an aiming point 1/3 of the way down the runway and use the flap when they are assured that they can make the aim point. At the point when they select full flap they should be able to glide the rest of the way and make the threshold. The flap is only used to bring the point of impact nearer the threshold.

At no point after passing the downwind end of the runway should the aircraft be in the position of not being able to perform a forced landing and not make the runway.

In fact if you are doing a CPL test doing the circuits and the examiner pulls the engine if you don't make the threshold its an instant fail. And I know a few that have had partials for getting outside the glide range while doing an approach. The examiner spots it, pulls the throttle they can't make it. The caa has another 400 quid.



I'm afraid I disagree. For the benefit of students looking at this thread who are confused by the varying answers this forum throws up:

There is no requirement for the aircraft to be able to reach the threshold on a normal circuit, that's why we teach, fly and test glide circuits. Nowhere in the CAA standards documents does it stipulate that in the circuit the runway must always be reachable if the engine fails, and that applies to the CPL skills test too. Please show me any such stipulation from the CAA.

There may be some confusion here with the glide circuit where the student is required to demonstrate the ability to make a glide approach to a safe landing, but that is demonstrated academically from a differently set up circuit, ie the glide circuit.

A powered approach should be flown with power applied, aiming for touchdown close after the threshold. You will not be able to make the runway if the engine fails at 100'on a powered approach to a 500m strip, in the same way you won't make the runway if it fails at 250' after take off.

[Centaurus]

Homeguard and Pilot Bear

A 3 degree approach is optimum for larger GA twins and jets because of their greater inertia. That is why an ILS and VASIS is set at three degrees.

Just because 3 degrees is the standard for those types it does not follow that light trainers should follow suit - far from it in fact. Try a full flap approach in a Cessna 172 at 3 degrees and even if the pilot can accurately judge three degrees without an electronic or visual glide slope, he will need considerable power to maintain such a flat angle.

The Cessna 172 POH states " Normal landings can be made with power-on or power-off with any flap setting desired".

Normal power-off angle with full flap will be around 6-7 degrees and with a trickle of power, around 5 degrees. Perfectly safe and normal for light aircraft with very little intertia at the flare. Thousands of wartime trainee pilots were taught glide approaches on Tiger Moths as the standard method of landing. The glide angle of a Tiger Moth at 58 knots with no flaps of course was around 5 degrees.

The most common cause of ballooning is excess airspeed beyond the manufacturer's recommended speed. This excess speed is very often mandated by the instructor in the mistaken belief it allows more room for error. On the contrary, it encourages slack airspeed control and the excess speed invariably converts into a balloon because the student is caught unawares by the increased sensitivity of the elevators.

If the manufacturer's recommended threshold speed is used, balloons are less likely and the problem is solved for the time being.

Of course, winds can cause airspeed excursions and an inexperienced student can be caught out. This is where recovery technique from a balloon by landing ahead on the remaining landing area should be taught to the student. It is not good enough to advise the student to always go-around off a balloon. In fact it could be ill-judged advice.

A low speed , full flap go-around at full power and considerable yaw takes careful, concise handling. A stuff-up here can be dangerous because of the low speed and yaw. Mis-handling can lead to a full power incipient spin at very low level.

Far better to teach the student to take the lesser of two evils and simply recover from a balloon by judicious use of power and carefully judged nose attitude to land straight ahead within the available length. Students will need plenty of practice at this manoeuvre and they will gain confidence. Of course they should also be competent at go-arounds of impossibly high balloons and therefore they must be afforded practice until quite safe at this very trickly low speed high drag manoeuvre.