4. LESSON 12 - CIRCUIT IN STRONG WINDS
Key points:
- Use a steeper angle when judging the circuit
- Correct for drift on the base leg
- Use a higher airspeed
A strong wind will require adjusting your circuit; you will need to use a steeper angle (height and distance) to the landing area: fly closer and/or higher.
On a windy day it takes much less time to fly down the downwind leg. It is therefore a good idea to place your high key area further upwind than usual, so you have a little longer on the downwind leg and don’t feel rushed. Don’t allow the glider to drift downwind before you start your circuit. It is much easier to fly down-wind to high key than to struggle upwind trying to work out the best place to turn to start the circuit. On the diagonal and especially on the base leg, you will have to correct for drift. Angle your heading into the wind, in order to keep your track over the ground the right distance back from your landing area. If you do not apply the drift correction on the base leg, you risk being blown back too far and not making it to the airfield. Keep in mind that a strong headwind will cause your ground speed on final approach to be a lot lower, so your approach is a lot steeper and your ground run shorter. Make sure your final turn is close to the landing area if it’s very windy.
Near the ground, the headwind will decrease due to the wind gradient (explained in Lesson 4.20). For that reason, you need a higher airspeed on the final approach.
A good rule of thumb is to increase your normal approach airspeed by adding half the wind speed at ground level. For example, with 20 kts of headwind on the ground, you will need to increase your airspeed during final approach by at least 10 kts. You need to gain this extra airspeed in good time, well before you enter the wind gradient. It can help to be trimmed for approach speed by the time you get to low key. This frees you to concentrate on your flying, and also means that your left hand can be placed ready on the airbrake lever in good time.