The long winding road

I was excited as I arrived at the aerodrome. For a start, I'd looked at the weather beforehand, and it was the first chance for a real flying day so far this year. On top of that, we'd been warned about some large aircraft operations, and it's always fun to see a 787 taking off from Cambridge's modest runway. I wasn't disappointed on either account. (But to make sure you're not disappointed, I'll warn you now that this is a two-parter.)

A spectator sport

A B787 lines up at a slightly larger airport. It looks a lot smaller close up. Photo courtesy Flickr user hitachiota, licensed CC-BY.
I thought I was to have the first flight of the day, but one of the instructors went out for a solo flight first. While he was out, we saw the 787 pulled out by a tug to the far end of the main runway. The Tiger Moth was turning to come back as the 787 commander called ready to start his engines. "No, don't point that thing at me!" was the Moth pilot's reaction (he confessed to me later). The backwash from those turbofan engines might blow the tiny biplane all the way to Addenbrokes.
The tower were sensible, and let the Tiger Moth complete his base leg and land before allowing the 787 to start up. I heard the sound of its mighty engines, and it wasn't long before I could see it gather speed and then lift itself from the runway. No matter how much air travel I do, or how much I learn about flying, I still find a certain magic in the way the wings flex and then pick the aircraft off the ground, supported by thin air.
The supposedly perfect weather wasn't as great as all that. The clouds had been closing in all morning, and once I finished my briefing the earlier pilot told us that the cloudbase was as low as 1000 ft. This gave us a problem. You can only fly through cloud under special conditions which completely exclude Tiger Moths, and you can't leave the area of the aerodrome flying that low. This knocked our planned training on the head, restricting us to flying in the circuit of the aerodrome.
My instructor even suggested cancelling the lesson. Circuit flying is about 12 lessons ahead of where I was up to, so he thought I wouldn't get much out of it, and was worried I might find it disheartening. I was having none of it. I'd have been much more disheartened by not flying in the best weather so far this year.

Inside the cockpit

Tiger Moth G-AOEI taxying at Cambridge Airport
CFG's other Tiger Moth, G-AOEI, shown taxying on the grass runway in this 2006 photo by Terry Joyce. CC-BY-SA
Once we'd completed our pre-flight checks and started the engine, there was an opportunity for a lot of taxying practice. Taxying a Tiger Moth is a bit like sailing into the wind: you can't just go straight in the direction you want. You can't see straight in front of you, because the engine is in the way (and the instructor, if you're in the rear cockpit). To make sure you're not going to hit anything, or get a wheel stuck in a rabbit hole, you need to zig-zag along the taxiway. You turn to the right, and look "ahead" by leaning out the left side of the cockpit. You turn to the left, leaning out the right side, and so on. The wind was blowing the opposite direction to normal today, so once we reached the runway, we'd be taxying all the way along it to the far end.
But I get ahead of myself. To even enter the taxiway, a few metres from our start point, we'd need to get permission from the tower. Even before that, we had to listen to the ATIS on the radio. Automated Traffic Information Service is a special radio frequency that continuously plays a recorded message giving aerodrome information (such as which runways are in use), weather, and other useful information. It used to be a continuously looping tape that was re-recorded  by the controller every so often, but nowadays it is computer-generated with a text-to-speech system. Each time it's updated it gets a new letter identifying the particular version. You have to listen to the message to get the necessary information, then when you call the tower, confirm to them which version of the recording you heard. We listened to the ATIS, checked the wind and set our altimeters correctly, and then changed to the tower frequency.
The instructor knew I'd been swotting up on radiotelephony procedures, so he told me to make the radio call, after confirming what I would have to say. First I had to wait for an opportunity to speak. Only one person can talk on the frequency at a time, and there was a long exchange between the tower and another pilot, so I had to wait for nearly a minute before I could press the transmit button and speak. (I've coloured the radio transmissions to make it more obvious who is saying what. The Tiger Moth is yellow, of course, and the tower is grey.)
"Cambridge Tower, Golf Alpha Hotel India Zulu. I have information echo, QNH 1032. Request taxi."
"Golf India Zulu, cross runway 05 main, backtrack and line up runway 05 grass."
I had to read back the instruction, to confirm I'd heard it correctly. It would be bad if I misheard and thought it was OK to cross a runway just as another aircraft was trying to take off or land, so all important instructions and information have to be read back.
"Cross runway 05 main, line up runway 05 grass, Golf India Zulu."

It's not often we get cleared all the way to the grass runway at once. Usually we have to wait at the holding point before the main runway, and then call the tower again to get permission to cross it. Tiger Moths aren't designed for tarmac, so it can be hard to steer across the main runway. I straightened our path, and we reached the other side fine. From there it was only a couple of wiggles before I turned right to snake my way down the grass runway. My wiggling was a little too enthusiastic, and at one point the instructor was afraid that I would run over one of the markings. They are made of chalk, so the aerodrome authority don't like it when you run over them. I had it all under control, though, and we were a good metre from getting chalk dust everywhere.
My legs were a little tired from working the rudder pedals by the time we got to the other end for our pre-take-off checks. Flying involves a lot of checklists. You might think that we should have sorted everything out before getting to the runway, but there's an outside chance something will come loose while bouncing across the rough grass, so we re-check that the controls still work, and there are one or two things to adjust too. It was only a moment's work, and then the instructor prompted me to make the next call.
"Golf India Zulu, ready to depart."
"Golf India Zulu, wind 030 degrees 10 knots. Clear to take off runway 05 grass." (If you remember my post on radio procedures, you've already read that to yourself as "zero three zero degrees one zero knots".)
"Clear to take off runway 05 grass, Golf Alpha Hotel India Zulu."
My instructor told me off for not abbreviating my callsign G-AHIZ when the tower had already abbreviated it to GIZ. In the heat of the moment I had misremembered my radiotelephony manual. I thought that you shouldn't abbreviate your callsign when giving or reading back a clearance, but in fact that only applies to ATC route clearances. All the same, it was probably the least embarrassing possible mistake to make.
For the first time, I'd successfully taxied us all the way to the end of the runway, negotiating with the tower all the way. The instructor took control, we picked up speed, and we were soon climbing away from the very same grass I'd just been weaving along.

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