Round and round like a merry-go-round
Wednesday, August 29th, 2007Time flown today: 1h 05m
Total time so far: 23h 50m
Today was my first time away from the circuit in over three months! The detail was steep turns, and the overhead join. The departure was straightforward, although the instructor later pointed out that I incorrectly set the DI in the pre-takeoff checks: apparently, I set it to 200 (one notch to the left of the 210 numbers, the same as the compass) when I meant 220. I have a hazy recollection that I might have initially set it correctly, thought it was incorrect, and then gone and broken it… and I recall a generally superior sense of being in control at the time. It’s a dangerous state of mind!
We departed towards Banbury, and soon found fairly dense haze, which with the low sun rendered westwards flight visibility fairly marginal for VMC, if my recollection of Air Law is correct. It also completely obscured the horizon, which would make learning steep turn technique tricky: but we climbed up to 4500ft at the top of the haze layer, and suddenly it gave us a well-defined horizon to practice with. So, the procedure for the steep turn:
- Good lookout: direction of turn, ahead, opposite direction, ahead, direction of turn again, back ahead, and go…
- Roll into turn, and add a bit of throttle when rolling past 30 degrees of bank
- Add and maintain substantial back pressure to keep the nose at a good attitude, check the balance and adjust rudder, check the altimeter, check the DI, check the ASI
- Look out, to maintain external orientation and check for traffic.
- Repeat 3 and 4 until about 20 degrees from the desired heading, checking a different instrument each time you look inside the cockpit. If the aircraft is descending, add a bit more power and/or increase back pressure.
- Roll out and promptly reduce power while doing so.
It’s easier than I expected. It needs a hell of a lot of back pressure to avoid descending, a great deal of careful attention to attitude and instruments, it tends to roll out of the bank and I need to make more of an effort to lean forward and look out into the direction of the turn for traffic. But other than that, I pretty much nailed it first time - lacking finesse but essentially correct. And it’s *loads* of fun, especially holding it on at 60 degrees. With the fairly marginal view of the ground, the brilliant low sunshine illuminating the haze and cloud-layer I was level with the top of, it was a beautiful and fundamentally alien environment to be whizzing around in, one that I’ve only viewed before from a window-seat in an airliner. It’s flying.
Next up, the instructor demonstrated what happens when it’s done wrong. If the nose drops, the speed increases, and increasing back-pressure just tightens it and pulls the nose lower… the airspeed increases past 100 knots, the engine (with a fixed propeller) speeds towards the redline, and the altimeter rapidly unwinds… it’s a spiral dive! Recovering incorrectly from this may result in the aeroplane reaching the ground without its wings, so it’s important (but easy) to get it right:
- Throttle to idle
- Wings level, rudder neutral
- Gently level off (pulling back too firmly could cause a dynamic stall), and put the aircraft into a gentle climb
- As the airspeed drops through 100 knots, apply cruise power and stabilise it in the cruise attitude
Since I did this in my first ever trial lesson in Cornwall last year, it’s familiar and easy. The PA28 seems much more benign and gentle to recover than a C152: without any back pressure, the aircraft had levelled itself by the time I’d rolled the wings level, presumably a consequence of neutral trimmer position at a very high airspeed.
Nonetheless, it was still plenty of fun, especially once the instructor put us into a more extreme spiral dive. I have a hunch that I could develop an aerobatics habit.
So back towards the field, for an overhead join. I recall getting confused about this when doing them in Microsoft Flight Sim one time, but Richard presented a brilliant and simple method to avoid getting it wrong:
- When a few miles out, make the call to Approach and request an overhead join. Note the runway and circuit direction. Let’s say we’re given 01 right-hand circuit.
- Descend to the joining height (typically about 1000ft above circuit height, above the ATZ). At Oxford it’s 2300ft QNH. The circuit is right-hand, so we must keep the airfield on the right, and make every turn to the right. Aim roughly to fly along the perimeter of the airfield, just far enough away to be able to see the runways (more tricky in a right-hand circuit if you’re sat on the left).
- Make the overhead call, and fly the perimeter of the airfield at joining height. This implies right turns.
- When we see the runway numbers for our runway - 01 in this case - the correct way up in front of the wing (i.e. we’re flying perpendicular to the desired runway near the threshold), it means we’re entering the dead-side, so it’s time to descend.
- Descend to circuit height while making a gentle 180 degree turn to bring us back over the opposite threshold. Unless ATC has specifically asked us to report downwind, call “descending dead-side”. Have a good look at the airfield, the signals, the runways, and the circuit traffic. Plan out over the ground where the rest of the circuit is going to be, pick some landmarks as aiming-points for downwind and base legs. Watch out for any fast-climbing traffic taking off that might conflict when crossing the upwind threshold.
- Level off at circuit height, cross the upwind threshold, and pick an aiming point to make sure that the wind doesn’t blow us downwind. Keep a good eye out for the line of the downwind leg, and make a nice sharp 90 degree turn onto it.
- As a circuit: call downwind, downwind checks, base, configure descent, final and land.
And it all went well, fairly straightforward. I put my thumb on the flaps lever button when deploying them (car handbrake-style) and wasn’t sure whether I’d deployed one or two stages: took a couple of seconds of looking out the window to decide it was two stages. If uncertain, I could always have retracted them and done it again - I had loads of time and height. Approach was bang-on, landing was 8/10: great flare, great hold-off, just dropped it fractionally too firmly when it finally stopped flying. As Jonathan pointed out yesterday, I could have added a nudge of power to mitigate that.
That was the most fun and least demanding lesson I’ve had in ages! Next up: practice forced landings. Time to get the book out…