Tuesday, 17 August 2010

Electric future

There's lots of talk about electric aircraft and there are a couple of experimental versions flying, but while they're on the verge of making it to market they aren't there yet. The cost/performance benefit isn't there yet, but that begs the question of what will be an acceptable balance?

For starters it'll have to have two seats - the lighter weight of a single-seat machine might appeal from an engineering point of view, but the market for single-seat aircraft is about as big as their cockpits. I don't think that high speed will be too important, but lack of speed will be a bit of a dampener. 70kt is marginal, 90kt better, 100kt ideal. Range/endurance - it has to be at least a couple of hours surely? Anything less is going to be a real pain, and three-and-a-half to four hours would be ideal. Training aeroplanes will either need a quick charge or a quick change of batteries.

So, two people, for two hours, at 90kt and that, I think, is the bottom end of the acceptable range.

I've heard people predicting that in ten years we'll have four-seaters flying for four hours at a time - and if they manage that at any decent speed (120kt at least) we'll be in for some interesting times.

Monday, 16 August 2010

High is good

I've noticed that the way I fly seems to be changing. There was time when I hardly ever ventured above 2,000' - an excursion to anything above 4,000 was unusual and anything above that was very rare indeed.

Then, because I had to on a few occasions I started flying higher. Now, when flying any distance, I find myself climbing higher. Coming back from France last week was a good example - cloud base was broken at about 3,500 with the tops at about 6,000 (or so I thought). I'd checked out the winds aloft, and although I wouldn't be picking up a great tailwind, the increase in TAS would more than compensate for the headwind component.

When it came to climbing, the tops turned out to be higher than my estimated 6k, and I had to climb to FL95 to be comfortably in the clear. The advantage of FL95 is that oxygen isn't required; on the day in question the air was silky smooth, the vast majority of the traffic was thousands of feet below and VHF reception was fantastic meaning that I could find out about D036's activity before even leaving the coast of France. Of course, that altitude also gives a few more options on the crossing between Cherbourg's MP and SAM.

Sunday, 15 August 2010

Avoiding the gliders

A check of the NOTAM for a recent flight revealed a couple of gliding competitions, one of which was local. With my route taking me within about ten miles of Lasham there was a fair chance that I'd be spending a lot of time searching out gliders which are, as you probably know, notoriously difficult to spot.

I have a PCAS traffic system that displays the position and relative altitude of any threat traffic with Mode C or S transponders, but gliders have tended to avoid transponders in favour of either nothing or FLARM, and so far there's nothing on the market that offers both FLARM and Mode C/S in the same unit. PowerFLARM, announced at Aero earlier this year (and still not available), displays FLARM but does not provide a bearing on Mode A, C or S traffic.

When there's a high chance of glider traffic, I try to reduce the possibility of running into one in a couple of ways.

1. I seek out and try to fly in controlled airspace. If there's any Class D on the way, then I call up and request a transit. Gliders can and do fly in Class D with a clearance, but many don't bother (or have a radio) and of course the controllers should know about any traffic.

2. I climb on top if I can. Being on top of cloud also reduces the potential of meeting a glider, and of course it tends to make the flight smoother and the visibility better too.

Nothing is perfect, but doing whatever you can to stack the odds in your favour has to be a good thing.