Wind

[boofhead]

What windspeed would you say causes concern to a pilot taxiing in a C152 or C172? What speed would you tell a student pilot to choose not to go?

[Kaptain Kremen]

Depends on whether you are on grass or tarmac. Strong winds for taxiing on grass can be a pain if you are trying to turn on wet grass or muddy conditions. 15 kts can be awkward in these conditions. Tarmac obviously is better therefore. Other than that i think quite strong winds, 25 - 30 kts are ok for taxiing, just that maybe you ought not to get airborne as it will be more "sporting" upstairs!
When isend a student solo the flying conditions usually take over the taxiing conditions, so is not normally a factor. If he / she will find it difficult to taxi, then he will find it difficult to take off and land too.
172 has a bigger keel area than a 152 and so is affected more.
KK

[boofhead]

yeah but,, what wind will flip a 152/172 over if the controls are not held the right way, and what wind will do the damage if they are?

[Keygrip]

I always remember overhearing an extremely experienced instructor/examiner/airline pilot (FO at the time) saying that a good "rule of thumb" was never to taxi in any surface wind that was greater than 50% of the stall speed of the aircraft.

[FlyingForFun]

In a C152, I find that anything over 40kts becomes difficult to taxy in, with brakes frequently needed to keep the aircraft going in a straight line when taxying cross-wind. This is on a hard surface. I wouldn't let a student taxy in more than about 30kts without me sat next to him.

It is my experience, in a C152, that they don't have any tendency to tip over if the controls are used incorrectly - but directional control is made more difficult by not having ailerons held correctly. Incorrect use of elevators doesn't seem to have any noticable effect whilst taxying, but I'm sure the engineers would disagree!

I find that controls should normally be held as if for a head-wind (back-pressure, and ailerons into wind) even in a tail-wind of up to about 30kts, because the propwash means that the controls are experiencing a headwind even if the actual wind is from behind. I tend to find that the elevators start becoming reversed with about 25kt of tailwind (need to hold them forwards in more than this) and the ailerons with about 35kt (need to hold them away from wind rather than into it). I can't explain why the ailerons reverse after the elevators - logically, they should reverse first as they are not affected by propwash. Maybe someone else can explain? Of course this will vary from one type to the next.

As for damage, assuming you can stay on the taxyway, the thing which will damage your aircraft is not keeping a tight hold of the controls. They will bang around in the wind, especially a tailwind, and it's the banging against the stops which will do the damage.

The most extreme wind I've ever experienced in a C152 (well, I was outside actually) was 50kt. We realised the wind wasn't going to die down, so we went to put the aircraft back in the hangar. It was parked facing into wind, which was fine, but we needed to turn it 90 degrees to back it into the hangar. We turned it, but as soon as we started pushing it backwards the wind caught the fin and tried to turn it back into wind again, even with the nose-wheel pointing fully in the oposite direction. In the end the only way we could get the aircraft into the hangar was to have one person pushing on the downwind side of the tail, stopping the aircraft from turning, while another person pushed the aircraft backwards into the hangar.

FFF
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[flybymike]

I raised an eyebrow at flying a 152 in 30 knots, I spluttered when I saw 40 knots mentioned, and finally breathed a sigh of relief when it went back in the hangar at 50 knots!

[Centaurus]

Some years ago a keen grade 3 flying instructor inveigled a TIF (trial instructional flight) student to part with some cash to go for a flight. Winds were 25 gusting 40 knots and several wiser pilots watched this clown trying to taxi to the runway. He had one hell of a job taxiing but full marks for perseverence he made it to the runway. He was cleared to line up and hold then carried out a flight controls full and free movement check. With full back stick applied and a 40 knot gust the C152 got airborne in half a loop and crashed behind the threshold. An expensive but remarkably good demo of effects of controls.

[Sleeve Wing]

Whilst reading FFF's contribution to this thread, I just wondered where would one want to go in a 150 if it was 30-50kts. on the deck ?
Doesn't that make it about 70kts. at 2000ft ?

For what its worth, I once came into LHR when it was blowing 40, gusting 57, about 10deg. off.
All the little ones ( Saab 340,SD 360, F27 etc.) all sensibly went back from whence they came.
I wouldn't want to do it again.

Sleeve.

[FlyingForFun]

I just wondered where would one want to go in a 150 if it was 30-50kts. on the deck ? Doesn't that make it about 70kts. at 2000ft ?Just to clarify, my personal limit is 40kt. The experience I related regarding 50kt I was outside the aircraft, and the engine was not running!

There are two reasons why I fly in this weather. The first is to show my students (who are at a suitably advanced stage of their training) what it is like. The second is when I have particularly obstinate trial lessons who, when I explain that it's possible to fly but I recommend they wait for a day when it's less windy, decide to ignore my advice and go anyway. (Incidentally, these trial lesson students have, without exception, enjoyed it - I assume that's because the kind of people who would not enjoy it are more likely to follow my advice!)

It's true that you don't get very far. From an instructor's point of view, when doing a trial lesson which is supposed to last a particular length of time, it's a little challenging. A 30 minute lesson might involve something around 20 minutes into wind, followed by 10 minutes downwind, but you can be pretty sure that you'll mis-judge it by at least 5 minutes one way or the other!

FFF
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[Centaurus]

Flying for Fun.
There are two reasons why I fly in this weather. The first is to show my students (who are at a suitably advanced stage of their training) what it is like. The second is when I have particularly obstinate trial lessons who, when I explain that it's possible to fly but I recommend they wait for a day when it's less windy, decide to ignore my advice and go anyway

My guess that one of the reasons why you choose to fly in high winds is because you can fleece some poor bastard of his cash and you see yourself as ace of the base. Your second reason beggars belief. Are you saying that if a students insists on flying then you will go along with his wishes despite your misgivings about the weather? Are you in command of the aircraft or is the student? I can just see the legal eagles descending upon your estate if something deadly went wrong.

[FlyingForFun]

Oh dear, I wish I hadn't started now.

I am most definitely in command. If it's not safe, then we don't go.

On the other hand, if it is safe, the next question is whether the student will get any benefit from it. In many - even most - cases, the answer in the kind of conditions we are talking about is no they won't, so we don't go. In a very few cases, the answer is yes - the student will benefit from experiencing it, or the trial lesson student will have an enjoyable experience. In this case, since it is safe, within my personal limits, and within my club limits, I'm quite happy to fly so long as the student has confirmed that what they are trying to get out of their experience can be achieved in the conditions on the day.

To say that I will "go along with his wishes despite your misgivings about the weather" is nonsense, because I have no misgivings about these kinds of weather conditions. I thought I'd made that clear?

FFF
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[Centaurus]

Flying for fun. Sorry about the spray old chap - I was quite wrong and should not have replied in such a boorish manner. Having said that the problem is that a brand new potential student eager for a trial flight, lacks the experience to know if his flight will be a bumpy windy one or just a nice pleasant day with a lovely view. He may say he still wants to fly but is this just bravado or simply loss of face to pull out? It is entirely the instructors responsibility to take care of his well being. Once airborne your student is captive audience to whatever the weather dishes up and in the worse case he may heave his guts out and never want to fly a light plane again.

Many years ago I was offered a ride in a yacht. The yachtsman (a qualified airline captain, no less) assured me that 30 knots surface wind on the bay was absolutely no sweat. Despite misgivings I was too embarrassed to say no thanks as I was the one who had asked him for the ride. Foolishly I went along with his undoubted enthusiasm. Of the 23 yachts that entered the race, 20 withdrew after an hour due to appalling seas. My captain was a yachtsman of some international fame and he stuck it out and won the four hour race.
I just about died of sea-sickness and nothing will ever entice me into a bloody yacht again - ever! Don't put an inexperienced but enthusiastic student pilot in the same boat - geddit!

[FlyingForFun]

No problem - no offence taken. I do see your point, though.

With regards to new students, I totally agree that strong winds are not the right conditions to get them started. But the vast majority of trial lessons I've done have not been people who are planning on learning to fly. A quick chat with them before the flight will very quickly reveal exactly what it is they are trying to get out of the flight.

It's not just the wind which might make it unsuitable for a particular student to go flying. Sticking with trial lessons, if the weather is generally poor, but there's a clear bit around your home airfield (seems to happen quite a bit at Blackpool), it's not suitable weather for someone who wants to fly over their house in Blackburn, or who wants a scenic view of the Lake District. But it's perfectly acceptable for someone who wants to learn to fly, or even someone who's not planning on going on to take lessons but is more interested in experiencing being at the controls rather than seeing the sights. It all depends on the individual - but if there's any doubt, there's no doubt, you stay on the ground.

FFF
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