Since I last posted, I've had a few more lessons, all training for flying in the circuit. Since I've now described the circuits itself in great detail (maybe too much?), I'm going to change focus a little. Instead of trying to tell the narrative of each lesson, I'll write some shorter posts, each about one aspect of what I'm learning. I'll start with something I've noticed a lot more while hanging around the airport: traffic.
Lots of people think that it must be very rare to get close to other aircraft. Even very experienced pilots have a name for this: the Big Sky law. The sky is big and aircraft are small. If aircraft were evenly distributed about the sky, at different heights and different horizontal positions, you might never see another one. But aircraft tend to congregate, and the busiest places are aerodromes. You need to be over an aerodrome at least twice every flight. Lots of people practise flying circuits like I've been doing, so they'll spend the whole flight at the aerodrome. As I've mentioned before, at Cambridge, we even get airliners practising there sometimes, because the airport's unusual instrument landing system (ILS) set-up and short runway let them get the feel of London City Airport.
Where there's traffic, there's a collision risk, and there have already been a couple of occasions where I wasn't entirely comfortable with what other pilots were doing.
A couple of weeks ago, we had a controller in the tower who was not entirely on the ball. It seemed like he was new to the area, he was working single-handed in another controller's break period, and the aerodrome had got busy quite suddenly. I think for a while his workload had just increased too much to deal with. Normally, I try to keep an ear open on the radio to listen to what all the other aircraft are doing: it's a good habit because you can hear aircraft you haven't spotted yet. Because the radio was so busy, I wasn't able to keep track of everyone. When I was on the downwind leg, I became aware of a single-engine utility airplane on my right at the same height, over the runway and coming straight towards me. I had the impression he was being vectored by the controller, but because I'd lost track of the radio, I couldn't be sure.
I pointed him out to my instructor, who didn't seem very concerned at first. I was unsure of what I should do. Normally, if you have the other aircraft on your right, you should give way to it, but as I was in the circuit already and he seemed to be joining, I thought that he should be merging with the existing traffic.
"I'm going to climb to avoid," I said on the intercom.
"Good idea," replied my instructor, but I'd only climbed a hundred feet or so before the other aircraft turned away. When we discussed it afterwards, he guessed that either the aircraft was performing an overhead join and had descended too early, or that ATC had instructed them to orbit for spacing (it was a very busy day), and the orbit had been a bit larger than intended. It could well have been another student flying the other aircraft. We never found out for sure what was going on. It was pretty unnerving seeing the thing coming towards me while I was supposed to be flying a neat circuit.
There's a helicopter flying school at Cambridge, and they have to cross the grass runway to get to the helicopter training area, so they often cause traffic problems for me. This time it was again on the downwind leg that I saw a helicopter ahead of and below me, passing left-to-right. Its path took it into the blind spot below the nose cowling, and I didn't know if it would be flying level or climbing, flying straight or turning towards me. Again I expressed my concern to the instructor (a different instructor to last time), and told him I was going to make a small clearing turn. The turn didn't help much at first, but eventually I saw the helicopter pop out behind my right wing. He was still heading away at the same level as before, so I was able to resume the circuit satisfied that there was no collision risk.
In the debriefing, the instructor said I needn't have worried. The helicopter circuit at Cambridge is at 700 ft, so it would have remained well below us. Even so taking actions like these two is a part of what some instructors at the Group call captaincy: taking command of the situation, and learning to be in charge of the aircraft instead of doing what the instructor tells us.
The helicopters aren't just a nuisance. One of the best moments of yesterday's lesson was when a helicopter overflew the runway while I was taxying along it. It was less than a hundred feet up, so I could see it clearly, and watch the student pilot manipulating the controls. Its shadow followed shortly behind it: a nice crisp outline of a helicopter "flying" along the surface of the grass. I don't know why, but the shadow itself was a reminder of just how fun aviation is. It's not just the flying itself, but meeting other pilots, and simply being around all the aircraft, knowing that in each is another pilot doing much the same as me.