Flying in the Snow

The road to the airfield  on a snowy day
The following was circulated at Shenington and is a useful reminder of how things can go wrong when flying in snowy conditions.

Taking to the air when there is snow on the ground offers a new and attractive perspective to our normally familiar landscape.

DGS on a snowy day. Photo from the east end of the runway looking north west
There is nothing quite like looking down on pristine white snow-covered ground on a sunny winter's day, or even not so sunny! We do have to take some extra care that we do it safely though.

K7M G-DBVB ready to launch
Here are some things to think about:

Never launch with any snow or ice anywhere on the aircraft.  Pay special attention to gaps between flying and control surfaces even if Mylar or similar sealed.  

Do not fly in falling snow, the visibility can get very poor very quickly and the snowflakes disorientating, plus the danger of accumulation on flying surfaces and the canopy.

A light dusting of dry powdery snow on the runway will not normally cause problems with the launch, though visibility for the glider pilot on the ground run during an aerotow will almost certainly be compromised -and quite possibly loose snow thrown up by the parachute in the very early part of the winch launch will do the same.

Any significant lying snow will have the above effect as well, but more serious considerations should be thought about.

The normally obvious airfield shape, layout of runways, transition between surfaces may well be obscured. 

The airfield may be "invisible" and from a surprisingly short distance, especially for inexperienced pilots (and sometimes more experienced too!).

Snow will pack into the release hook, soft snow will rapidly freeze solid, at best that will make hooking on impossible and leading up to the worst case where releasing will be impossible!

Snow will go into the critical parts of the release hook that you cannot see or get to on most gliders - cleaning out the parts you can see is not enough and just because it passes the "release checks" on the ground will not guarantee it doing so at height in the colder air!

Snow will pack into the wheel box where friction during the ground run will melt it very slightly and then it will rapidly re freeze in the lower temperature aloft, leading to a landing with the wheel jammed solid. Inconvenient when you need to tow back, causing possible damage to the landing gear, but more seriously, potentially leading to a loss of directional control on the landing run.

I would add a couple more points:

Bringing snow into the cockpit on boots and clothing will add to the humidity as it melts increasing the likely-hood of condensation on the canopy.

With a complete covering of snow on the ground and in flat light caused by a featureless stratus sky there is the possibility of a 'white-out'. This causes a loss of contrast such that it is sometimes not possible to judge where the ground is (even when walking!) Judging when to round-out would, at best, be difficult.

David Jesty

DGS Safety Officer