When you read the words mountain flying, you probably think of the Alps, the Rockies or a French 
‘altiport’. But there are some mountain considerations even flying in the UK.
Firstly the rules – there is an EASA Mountain Rating – and you must hold it to use some of the high altitude ‘altiports’.
Secondly, no qualification is needed to fly over mountains., just a bit of knowledge and common sense. Today I flew over Wales to Llanbedr, and this prompted me to write down some tips for flying over mountains which I first learnt in Colorado:
- MSA – take this very seriously! Aim to be at least 1000 ft above the peaks, and preferably 2000 ft for reasons that are revealed below. Remember that you should base your MSA on peaks on- and off- track. In poor visibility it is easy to wander. Granite hurts!
- Updrafts, downdrafts and turbulence – You can expect updrafts on the windward side of mountains, and downdrafts and turbulence on the leeward side. Today, that meant that -with an easterly wind- I found myself reducing power to avoid gaining height as I approached Snowdonia, and encountered a lot of turbulence in the descent in towards Llanbedr. Conversely on the return trip, it was mightily bumpy even at 4000 ft (1000 ft above the highest peaks of Cadair Idris at 3000 ft) but much smoother at 4500 ft.
- Fly the valleys or over the peaks? This depends how much you want to climb and how comfortable you feel flying up a valley with rocks on both sides. Fortunately, most UK mountains are low enough that we can generally fly over them – not the case in the Rockies!
- Plan your climb and descent – on the way in to Landbedr, I needed to desc
end from 4000 ft to circuit height – this needs to be gradual to avoid over-cooling the engine. A straight line direct routing may create a very abrupt descent. A slightly circuitous sightseeing route is maybe a good plan. Likewise on departure – I needed to get back up to 4000 ft before heading for the hills. - Know your aeroplane – what climb rate can you expect at 4000 ft? Will a climb from sea-level to 4500 ft cause over-heating? I decided to remove my oil cooler baffle plate for the return journey.
- Keep your back-door open – in other words: know which way you will turn and what heading you will fly if something does not go according to plan – poor visibility, reduced climb performance, engine over-heating, severe turbulence etc.
And the by way, it was a great trip.