Flying Training

Lesson 9: Circuits

Sunday 11 December 2005 at 6.30am with Niall Higgins in Citabria VH-RRW

Weather: cool and misty, clearing slightly as the lesson went on.

Now for the nitty gritty - taking off and landing. This lesson was originally booked for 2.30pm yesterday, but (a) Brendan's concert was at 2pm and (b) it was too windy anyway. Early morning is much better for circuits - no crosswinds or gusts. I was up at 4.45am and left at ten past five, arriving to a very quiet Camden at 6am on the dot. Jim turned up with fresh rolls, and Niall shortly afterwards. There was time for a cup of tea before the preflight inspection and briefing.

For the briefing Niall had drawn up a typical Camden circuit, for runway 06-24, with the reference/turning points (church/building on hill to the east; old folks home to the west). Runway 06 has the traditional left hand circuit, but 24 is a right-hand circuit (to keep away from the glider field). Circuit height for Camden is 1300 feet, and the circuit sequence is:


  • Take off - keep in line with runway using a reference point well ahead
  • Climb at best rate of climb - which Niall defines as 80 knots, because this will also work for other aircraft types such as a Cessna 182, and because it gives plenty of engine cooling.
  • At 700 feet (officially 1000 feet following recent CTAF changes) begin a climbing turn onto crosswind - no more than 15° of bank.
  • On crosswind leg continue climbing to circuit height - 1300 feet. Keep at 90° to runway, correcting for drift if necessary.
  • At 45° fom the runway, make a level turn onto the downwind leg (30° of bank).
  • Maintain heading, speed, height and spacing (HSHS) on the downwind leg, and do the downwind checks (BUMFISH - below). Keep a lookout for traffic.
  • I'm sure there's also a downwind radio call when the tower is not operating, but I don't remember making it.
  • Just before turning base, make a radio call. When the tower is not operating, this might be, "All stations Camden, Romeo Romeo Whisky, Citabria, turning base, runway zero-six, touch and go."
  • At 45° fom the runway, make a descending turn onto the base leg (up to 30° of bank).
  • On the base leg, descend aiming to reach 800 feet for the turn onto final.
  • Make a descending turn onto final, aiming to roll out on the runway centreline.
  • Aim for the runway numbers, keeping the runway centreline vertical in your viewpoint, and reducing speed from 80 to 60 knots. Use power to maintain the aimpoint at 1/3 up the windscreen.
  • Over the aimpoint, flare to a level flying attitude just above the runway, and keep the nose straight down the runway using a reference point at the opposite end of the runway.
  • As flying speed reduces, raise the nose to maintain level flight.
  • As the speed reaches the stall, the stick should be full back for a three-point landing.
  • For a touch and go, open the throttle smoothly, stick forward and keep the nose straight (hah! Easy to say).

While flying the downwind leg, repeat this mantra:

Downwind Leg


Heading - compass, reference point, gyro (not in RRW or MWY)
Speed - 90-100 knots, 2400 rpm
Height - 1300 feet
Spacing (from the runway) - jury strut on runway

Downwind checks:

Downwind Checks


Brakes OFF
Undercarriage DOWN (as they always are on a Citabria, unless they've fallen off)
Mixture - FULL RICH
Fuel - ON (including the electric fuel pump on in some aircraft)
Instruments - NORMAL (especially oil pressure and temperature)
Switches - ON (ie both magnetos)
Hatches and harness -SECURE

On final approach:

Final Approach


Aimpoint - the runway numbers are at 1/3 in the windscreen, and should stay there till the flare. Use power.
Line - the runway should be vertical in the pilot's view.
Performance - speed and height. Speed is 80 knots reducing to 60 knots.

So out we went to the plane, and taxiied out. I don't know why, but this was my worst attempt at taxiing since lesson 1. I seemed to have no rudder authority and I believe we had the wheels on the grass at a couple of points. I also overcooked the turn into the run-up area, and stopped with our nose pointing right and over the line.

On the take-off I found it impossible to keep the nose straight with the rudder, and Niall had to contribute significantly to keep us on the tarmac. On the initial climb I drifted off the centreline somewhat. The actual circuit was OK, but the "Heading, Speed, Height, Spacing" disappeared from my mind as soon as we were airborne, and Niall had to remind me.

The base leg and approach seemed OK, but we ended up a little high and fast on the first few circuits. It's amazing just how low and slow a correct approach seems. On one circuit Niall took over and made a late sideslip to lose some height.

The flare was difficult to judge - it's a very small movement on the stick, and too much means the aircraft starts to float higher, while still bleeding off speed and approaching the stall - not good. The idea is to be just above the ground, where the speed becomes unimportant, and to gently raise the nose so that the tailwheel contacts the ground at the same time as the mains.

By far the most difficult part was keeping the nose straight when the throttle was opened again for takeoff. I found myself always correcting too late and too much so we zig-zagged down the runway with Niall making corrections to my corrections, or where I failed to provide any useful input. In an effort to give me more time to get my feet doing the right thing, Niall kept the throttle at around 50% until the last possible moment before lift off, and there were a couple of later circuits where he said, "That's much better," but to be honest I didn't feel confident at all by the end of the lesson.

After the lesson we had a debrief where Niall ran me and Daniel (the next student) through the various factors affecting the aircraft's direction on takeoff. They are:

Factors Affecting Direction on Takeoff

The following factors tend to push the aircraft nose to one side on takeoff: torque, slipstream, p-factor and gyroscopic effect. In more detail:

  • Torque - tends to twist the nose left (and up when in flight) for clockwise propeller rotation when viewed from the cockpit). This pushes the left wheel into the tarmac so the aircraft wants to turn left. The effect is constant for a given throttle setting, ie over the whole takeoff roll.
  • Slipstream - corskcrews down and left, spiralling around to hit the tail and push the aircraft left. This effect reduces as the speed increases and the slipstream straightens out.
  • p-factor - when the tail is down, the angle of attack of the right propeller blade is greater than the left (again for clockwise rotation). This contributes to the tendency of the aircraft to head left, but only until the tail is raised. With the tail level and the thrustline straight ahead, the p-factor disappears.
  • gyro effect - when a force is applied to a spinning disc (ie the propeller) to make it change its plane of rotation, there's a resulting force at 90° to the applied force, and against the direction of rotation. Guess what? This also means a nose-left tendency, but only as the tail is raised. With the tail up and steady in a flying attitude, this effect too disappears.
  • Not a turning effect, but it's important to note that the rudder becomes much more powerful as the speed increases, so the corrections are smaller.

Niall says not to think about all these effects during takeoff, but it appears that the corrections need to be early, and should be less as the take-off roll progresses. I'm just hoping something will click.

[Later comment: Jim Drinnan said to raise the tail as the throttle is pushed forwards, not afterwards. This, in combination with making the throttle and stick changes slower, is now allowing my feet to catch up. And Neil Tucker's contribution was "keep your feet moving - small changes, then return to neutral". It's coming together - thanks guys! (6 Jan 2006)]