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DarkSoldier
27th Oct 2008, 23:08
With the winter looming upon us I am still keen to continue hour building throughout the next few months. I am new to winter flying and would like to find out more about the hazards and other things to look out for during winter.

I am aware that I should stick to flying below the freezing level, avoid precipitation, increase landing and T/O distances, de-ice the A/C before flight, check for carb icing....I have also read the CAA's guide to winter flying.

However I am keen to hear from those of you who have experience flying during the winter.

What did you find most challenging? Any other obvious things to watch out for?

Thanks

BackPacker
28th Oct 2008, 00:18
I am aware that I should stick to flying below the freezing level, avoid precipitation, increase landing and T/O distances, de-ice the A/C before flight, check for carb icing....I have also read the CAA's guide to winter flying.

No, yes, no, yes and yes, respectively.

Flying above the freezing level is perfectly fine as long as there is no visible moisture (clouds) in the air. DO NOT fly through cloud, not even just a little bit, unless you have a fully de-iced aircraft.

Precipitation is no problem when well below the freezing level (so ambient temp well above freezing) but might be a problem close to, or above the freezing level. See above. Biggest problem is that precip in general, and snow in particular, reduces visibility, so VFR pilots tend to avoid it even in summer.

T/O distances are generally shorter. Cold air is denser so more air getting into the cylinders and more air for the prop to bite. Also your TAS is slightly lower in cold air than in warm air for the same IAS, so shorter landing distances as well. Check the POH! Of course, as soon as the runway is wet or snowed/slushed/iced over, all bets are off.

Yes, the airframe needs to be deiced before take-off. Obviously. Bloody hard work too. Unless you have a heated hangar you can use for a few minutes. Do make sure that all the melted ice is swept away from hinges etc otherwise it will re-freeze there quickly, potentially jamming your controls.

Carb ice should be checked for as per normal procedure but the worst cases of carb ice actually happen at about +15C and 100% humidity - check the CAA charts. With temperatures at approximately -15C applying carb ice can actually be dangerous: without carb heat the ice crystals in the air pass through the carburetor without any influence, but if you heat them up by applying carb heat, they melt and may subsequently cause carb ice because of the venturi/evaporation.

Checking for water in your fuel is also much harder when the aircraft is cold-soaked after a freezing night. Be careful with scraping ice off your windows: they are generally much more susceptible to scratches than your car windshield.

cpl4hire
28th Oct 2008, 10:34
My two cents,,

I assume location SW= the UK but if not some of this may not apply !
De-icing light Aircraft is a drag so if you can avoid doing it by keeping the Plane in a Hanger overnight or, if the plane has to be parked outside put it in a position where the rising sun (yes we do get sun in winter, Honest) will melt the Frost. Tip, turn the Plane into the Sun so that the Windshield clears too while you go and have a cup of tea/coffee in the Clubhouse.
Brushing light snow off an airframe is not too bad but as mentioned earlier beware that any water left on the airframe may re-freeze when you begin your flight. Dont assume snow will be blown off on the takeoff run, the wind chill factor makes it freeze onto the metal. If you use deicing fluid only Aircraft de-icing fluid will work, (Car de-icers just re-freeeze after a few mins). Scraping ice off with plastic scrapers will probably damage the finish and the aircraft owner wont thank you for it.
When you finally get airborne, the low winter sun can cause visiblity problems plus dont get caught out on a cloudless afternoon when the sun is low on the horizon, its actually already nearly dark on the ground ! (hint you can see the streetlights/ car headlights coming on!). If you dont have a night rating and your home airfield does not have runway lights plan your flight to end 30mins or more before sunset.
If you fly from a grass strip beware that wet grass/mud is more slipery than ice and the Aircraft can be hard to control on the ground when taking off and landing particularly in a crosswind !
Watch the Temperature/Dewpoint difference on the TAFs /Metars if its close you could get fog/mist developing in the late afternoon.
Winter flying can be safe and enjoyable but like all things in aviation the key is in the preparation.

Rgds, Cpl4hire

will fly for food 06
28th Oct 2008, 11:05
Please remember that you should dress to survive. You could get cold very quickly if you are suffering from shock and cant move.

tuscan
28th Oct 2008, 11:46
Winter should not be seen as looming, it does in fact provide some of the best flying conditions of the year.

I have flown several winters up here in Scotland, most of the obvious traps have been covered already. I always take a plb, strobe, chocolate, mobile phone and waterproofs/warm clothing as a minimum.
I also try and fly around lunchtime to get the best of the high sun, theres nothing like the low winter sun and afternoon haze to lower your vis to uncomfortable levels.

I look forward to high pressure and gin clear winter days more than the hot and hazy days of summer.

Piper.Classique
28th Oct 2008, 20:55
What did you find most challenging? Any other obvious things to watch out for?At the risk of sounding too obvious, navigation of the map and compass variety can be a challenge if the ground is covered in snow. You will need sunglasses, maybe gloves if your cabin heat is as ineffective as mine, and you might think about changing out of wet shoes once you are in the aircraft. At least have warm clothes on board. My cub is hangared, but it is surprising how quickly hoar frost can form when I pull it out. Some wing sections can be quite unhappy about even a light coating of rime. Mostly gliders and other glass types. Out of interest, what are you flying?

Piper.Classique
29th Oct 2008, 15:49
I'm flying a Cherokee

Ah well, at least you'll have toasty toes. Yes, you are right about vanishing roads and rivers. At least coastlines stay put;)
Enjoy your winter flying.

BackPacker
29th Oct 2008, 16:17
If it's around the freezing point and there's snow/slush on the runways (more typical of grass runways than hard ones) you might want to talk to the maintenance folks about removing the wheel spats temporarily. If slush refreezes in the spats you're in for a nasty surprise on landing. It will cost you a few knots in the cruise though.

Also include a check of the OAT in your pre-start checklist. They do break occasionally, so check its readout with the ATIS or other reference.

effortless
29th Oct 2008, 18:00
Sunglasses

debiassi
29th Oct 2008, 19:56
Sun may melt the ice but as soon as you start to roll with dew rolling over the wings, the aircraft already has moisture on the airframe, in temperature close to freezing, in fact +2degrees to -20degrees, you can get ice accretions on the aircraft leading edges. This causes early flow seperation and an aircraft could lose its aerodynamic properties in around 2 minutes in severe cases. Icing isnt taught in the PPL syllabus or even the IMC and thats for good reason. STAY OUT OF ICING CONDITIONS. It really is a killer, especially to the untrained. Also flying into known icing conditions in an incertified aircraft is illegal and in the UK the forecast conditions are what determine the law, even in a foreign registered aircraft. Have a look at some of the many examples and listen to the professionals who pay testament to the dangers of airframe icing. Stay in clear air and remove any moisture from your aircraft prior to taking off and enjoy the clear winter skies as you build up your hours.