Winter Flying
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In these debates, everybody who wants to look good will always take the position of an absolutely clean airframe.
It is a bit like arguing against CRB checks for PE teachers
But, as I said, there is a world of difference between muck on the wings etc, and muck on the hull. The latter is just a bit of friction. People fly with planes covered in dead flies... The former is what is going to get you because it messes up the lift.
And different planes have different tolerances.
I don't fly a PA28 (nowadays) but a few mm as absolute maximum sounds reasonable.
This is structural ice. Carb ice is a completely different issue.
It is a bit like arguing against CRB checks for PE teachers
But, as I said, there is a world of difference between muck on the wings etc, and muck on the hull. The latter is just a bit of friction. People fly with planes covered in dead flies... The former is what is going to get you because it messes up the lift.
And different planes have different tolerances.
I don't fly a PA28 (nowadays) but a few mm as absolute maximum sounds reasonable.
This is structural ice. Carb ice is a completely different issue.
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It is not a case of looking good, it is a case of flying an aircraft with unknown propertys due to the changed wing shape.
I would agree that a small amount of hore frost on the fuselarge is not likely to result in any aerodynamic problems with the flying of the aircraft however will it result in problems with the static ports and give errors in the ASI readings ?
Older low tech wings are likely to be less effected by ice however the newer composite aircraft are using wing sections that are far more advanced and the shape is far more critical so much so that gliders are fitted with devies that clean flys from the leading edges in flight to maintain performance.
The whole ice subject is so fraught with unknowns that the only policy in my view is no ice unless the flight manual offers some advice on the subject.
I would agree that a small amount of hore frost on the fuselarge is not likely to result in any aerodynamic problems with the flying of the aircraft however will it result in problems with the static ports and give errors in the ASI readings ?
Older low tech wings are likely to be less effected by ice however the newer composite aircraft are using wing sections that are far more advanced and the shape is far more critical so much so that gliders are fitted with devies that clean flys from the leading edges in flight to maintain performance.
The whole ice subject is so fraught with unknowns that the only policy in my view is no ice unless the flight manual offers some advice on the subject.
I've been flying a lot recently and always do through the winter. Some of my tips would be:
- Fill up the tank after flying. Full tanks get less condensation in them.
- Clean the windscreen well before every sortie. Flying into a low sun with a dirty windscreen is very difficult - especially if there is poor visibility anyway.
- If you will be landing into sun late in the day you might want to have second thoughts about departing!
- Enough has been said about ice / frost on the airframe.
- If on grass it will be wet - allow for the longer landing distance.
- If muddy at the end of the day, and frost is expected, do you really want to give it a good wash and fill all the hinges and other orifices with water?
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On a PA28, you could probably get away with 1mm, maybe 2mm or even more
It does increase friction but it won't increase the stall speed
Friction? Ice increases friction- so your car stops more quickly on ice does it?
Many years ago the CFI of the Edinburgh flying school was seen to be religiously sweeping all the snow from the wings of a C152. Minutes later he spun in on take off.
Last edited by Pull what; 3rd Dec 2011 at 12:11.
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Greetings,
please check:
List of Safety Sense Leaflets | Publications | CAA
Safety sense leaflet 03 - Winter Flying
please check:
List of Safety Sense Leaflets | Publications | CAA
Safety sense leaflet 03 - Winter Flying
Thread Starter
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Thanks for all the helpful advice, see, a one liner can inspire some useful responses and also start an argument! Amazing. Further more, when I read a post I don't like I don't respond!
As for the direct criticism of my own flight training, I'm afraid you misunderstood my question, rtn11 got it. I simply wanted to know if there were any issues that the PPL syllabus doesn't cover.
I would hope that we are all calm, friendly and reasonable in the air! It seems to me a lot of the threads degenerate into a willie waving competition, with some really useful stuff thrown in!!!!
Happy days
As for the direct criticism of my own flight training, I'm afraid you misunderstood my question, rtn11 got it. I simply wanted to know if there were any issues that the PPL syllabus doesn't cover.
I would hope that we are all calm, friendly and reasonable in the air! It seems to me a lot of the threads degenerate into a willie waving competition, with some really useful stuff thrown in!!!!
Happy days
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Safety Sense Leaflet 14: Piston Engine Icing
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As for the direct criticism of my own flight training,
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Can you explain how you have come to this conclusion? I assume you have test flown a PA28 with more than 2mm of ice adhering to the airframe.
The whole point is that it is a complete unknown, noone knows how much you can get away with until it's too much and there's a serious problem.
Obviously, if it had been much more than 2mm, and we had intentionally stalled, things could of been more lively, but this was a simple IMC lesson, and picked up a small bit of ice shortly before commencing the approach, so I saw no big issue in continuing as normal knowing warmer air was only a few hunderd feet below.
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I agree with that, but let me inject a little bit of reality.
How long has the PA28 been out? A few decades. Countless tens of thousands are (or have been) flying.
I simply do not buy that 2mm is going to bring one down. I am not a 20,000hr pilot (and anyway most of those do it in a big jet) but I have seen enough IFR, and since nearly all formal IFR I do is high altitude (Eurocontrol flights) I have seen plenty of icing. Summer or winter, some icing on almost every flight, FL140+.
Most of it is just light, but 1-2mm is really easy to pick up. You can get it in seconds. I wouldn't bat an eyelid at 2mm; it is barely visible as a bit of frost in between the rivets on the leading edge, and it doesn't show up on the speedo at all. And the shape of my wings is not much different from a PA28.
If you fly a plane which will plummet at 2mm (and I am sure there are some laminar designs that will do that) you better forget all flying in IMC below 0C unless you have full TKS (£30k or so - more than most PA28s are worth) and you use it - ~ £200 per hour is what it costs. Or rubber boots, and they better be working (many aren't) but few modern and potentially ice-sensitive designs use boots.
My guess is that 2mm of rime is going to increase PA28 Vs by a few kt. So you won't be doing a max performance landing into Deanland
I am also pretty sure there is plenty of urban knowledge on this, but they are not going to be posting it here because most are renters and are going to get a bad name
What you can't do is just sit there and let it build up and up and up, with no way out (which usually means a descent into warmer air). If in IMC below 0C you have to watch it like a hawk and be considering your options. But that applies to any non-deiced plane. One cannot embark on a flight in potentially freezing IMC, for 1-2hrs, with no way out.
If you have an IR, then you would file for FL100+ and climb up through the thin layer discussed and sit there in sunshine. With the IMCR you are basically a "VFR" flight as far as ATC are concerned (declaring yourself "IFR" does not get you anything) and you get pushed down below CAS, and that is the one area where an IR is useful in the UK over an IMCR. With the IMCR, winter flying is mostly going to be below cloud unless one can be sure one can climb above it without going into CAS.
How long has the PA28 been out? A few decades. Countless tens of thousands are (or have been) flying.
I simply do not buy that 2mm is going to bring one down. I am not a 20,000hr pilot (and anyway most of those do it in a big jet) but I have seen enough IFR, and since nearly all formal IFR I do is high altitude (Eurocontrol flights) I have seen plenty of icing. Summer or winter, some icing on almost every flight, FL140+.
Most of it is just light, but 1-2mm is really easy to pick up. You can get it in seconds. I wouldn't bat an eyelid at 2mm; it is barely visible as a bit of frost in between the rivets on the leading edge, and it doesn't show up on the speedo at all. And the shape of my wings is not much different from a PA28.
If you fly a plane which will plummet at 2mm (and I am sure there are some laminar designs that will do that) you better forget all flying in IMC below 0C unless you have full TKS (£30k or so - more than most PA28s are worth) and you use it - ~ £200 per hour is what it costs. Or rubber boots, and they better be working (many aren't) but few modern and potentially ice-sensitive designs use boots.
My guess is that 2mm of rime is going to increase PA28 Vs by a few kt. So you won't be doing a max performance landing into Deanland
I am also pretty sure there is plenty of urban knowledge on this, but they are not going to be posting it here because most are renters and are going to get a bad name
What you can't do is just sit there and let it build up and up and up, with no way out (which usually means a descent into warmer air). If in IMC below 0C you have to watch it like a hawk and be considering your options. But that applies to any non-deiced plane. One cannot embark on a flight in potentially freezing IMC, for 1-2hrs, with no way out.
If you have an IR, then you would file for FL100+ and climb up through the thin layer discussed and sit there in sunshine. With the IMCR you are basically a "VFR" flight as far as ATC are concerned (declaring yourself "IFR" does not get you anything) and you get pushed down below CAS, and that is the one area where an IR is useful in the UK over an IMCR. With the IMCR, winter flying is mostly going to be below cloud unless one can be sure one can climb above it without going into CAS.
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This might also be of interest: Aircraft Icing Training - Courses
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Simple advice - if you are a newish ppl holder, dont fly the aeroplane with ice on it. Some aircraft are more tolerant than others, but why take the risk? I disagree with IO540, trying to put a figure on what is an acceptable amount of ice on a PA28 can lead to deaths, thats why its not in the POH - how do you measure the ice? where do you measure it? Those are all valid questions. Why not just follow the POH? CLEAR the ice / frost off before flight. If you are in flight and you get some ice that was not predicted, do something to change whats happening before your trying to fly a giant ice cube, climb, descend or turn back, dont blindly push on in an aircraft not equipped for ice thinking it will get better. Its too big a gamble.
If you want extreme for airflow disruption due to objects on a wing, try the Rutan Longeze, the SLIGHTEST precipitation in the air reduces cruise by 10kts, and you often feel the aircraft trying to pitch nose down with a reduction in airspeed BEFORE you even see the visible precipitation.
To say that the TB20 has a similar wing to the PA28 is even more ludicrous of IO540. Even small changes in planfom, aspect ratio, chord thicknes or most important of all airfoil section can have dramatic effect on an aircraft performance and tolerance to different things.
If you want extreme for airflow disruption due to objects on a wing, try the Rutan Longeze, the SLIGHTEST precipitation in the air reduces cruise by 10kts, and you often feel the aircraft trying to pitch nose down with a reduction in airspeed BEFORE you even see the visible precipitation.
To say that the TB20 has a similar wing to the PA28 is even more ludicrous of IO540. Even small changes in planfom, aspect ratio, chord thicknes or most important of all airfoil section can have dramatic effect on an aircraft performance and tolerance to different things.
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We are talking cross-purposes (as usual).
I didn't write that one should takeoff with any ice on the wings or the elevator.
I was referring to the hull (the cockpit exterior, etc).
My other comments on how much ice a PA28 could perhaps carry refer to in-flight icing, and decisions based on that.
I will leave this discussion now, because like I said it is like arguing against CRB checks on PE teachers.
I didn't write that one should takeoff with any ice on the wings or the elevator.
I was referring to the hull (the cockpit exterior, etc).
My other comments on how much ice a PA28 could perhaps carry refer to in-flight icing, and decisions based on that.
I will leave this discussion now, because like I said it is like arguing against CRB checks on PE teachers.
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I have experienced prop ice on a PA28 when there was no more than a hint of frosting on the leading edge of the wing. Not pleasant!
I have also had the engine breather ice up. The result was oil being pumped out of the front crankshaft oil seal over the cowling and windscreen.
Ultimately if you don't takeoff with ice on the flying surfaces and don't fly in rain or cloud when it's below zero you should be OK.
Ice often forms first around the OAT probe above the screen on PA28s.It is a good early warning.
If you do fly in cloud in winter, always have an escape plan.
D.O.
ps Not flying today. Runway covered in ice and snow.
I have also had the engine breather ice up. The result was oil being pumped out of the front crankshaft oil seal over the cowling and windscreen.
Ultimately if you don't takeoff with ice on the flying surfaces and don't fly in rain or cloud when it's below zero you should be OK.
Ice often forms first around the OAT probe above the screen on PA28s.It is a good early warning.
If you do fly in cloud in winter, always have an escape plan.
D.O.
ps Not flying today. Runway covered in ice and snow.
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IMHO this thread is beginning to degenerate from what is safe or not safe towards a potentially dangerous set of "what-you-can-get-away-with" opinions.
The Summary on the final page of the Safety Sense Leaflet 3 - Winter Flying says it all.
Please read it. Do not fly with ice or frost or snow on the aircraft and do not fly in icing conditions. It is really quite simple.
JD
The Summary on the final page of the Safety Sense Leaflet 3 - Winter Flying says it all.
Please read it. Do not fly with ice or frost or snow on the aircraft and do not fly in icing conditions. It is really quite simple.
JD
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"what-you-can-get-away-with" opinions.
I have first hand knowledge of the skill and experience of about ten PPRuNers, the rest of you are a guess to me. I will not be the one who describes something I know may be possible, albeit with lots of skill, many variables, and a big risk, to an audience of people whose skill and experience is unknown to me. It is the safe, conservative, and professional thing to do, to first say, follow the Flight Manual, and there after, generally "if you have to ask - no".
Similar to fooling around in icing, we recently had a thread inviting comments about aerobatics in non aerobatic aircraft. We do not need to "ramp up" the excitement on PPRuNe, by increasing the threshold of risk the participants should accept as normal. If anything, based upon increasing tribal knowledge, the threshold should be reducing, unless new technology is mitigating it. We have deiced aircraft, use them for icing conditions, we have aerobatic aircraft, use them for aerobatics, we have floatplanes, use them for water landings.
Some silly pilot sees or reads about water skiing wheel planes (Ok, I'm assuming), and then an a plane is up side down in the Derwent river. Apparently that pilot tried something else that did not work either. He did not know that the technique is not possible in tricycle aircraft! I sure hope the advice to attempt that was not presented on PPRuNe.
My entire job is to test and evaluate modified aircraft to assure that they do what they are supposed to, don't do what they should not, and have a margin of safety to allow for variance in pilot skill. I sure am not gong to participate here in enticing pilots of completely unknown (to me) skill and judgement, into those risky corners I spend my working day trying to keep them out of!
Contributors here would, in my opinion, do best to offer advice, which conforms as closely as possible to the approved and accepted practices usually presented in the Flight Manual, or national regulations.
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From the CAA safety booklet:
e) Ensure that the entire aircraft is properly de-iced and check visually that all snow, ice and even frost, which can produce a severe loss of lift, is cleared. This includes difficult-to-see ‘T’ tails. If water has collected in a spinner or control surface and then frozen, this produces serious out-of-balance forces. There is no such thing as a little ice.
e) Ensure that the entire aircraft is properly de-iced and check visually that all snow, ice and even frost, which can produce a severe loss of lift, is cleared. This includes difficult-to-see ‘T’ tails. If water has collected in a spinner or control surface and then frozen, this produces serious out-of-balance forces. There is no such thing as a little ice.
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I had to stop a private hirer today. He was happily sat in the aircraft, having deiced the wings, about to start up. He had completely negelected to deice the elevator, which in many ways is more serious than wing ice.
Thorough de-icing of the whole aircraft should simply be standard, even the fuselage (although good covers prevent most of this).
Thorough de-icing of the whole aircraft should simply be standard, even the fuselage (although good covers prevent most of this).