Downwind landings present special hazards and should be avoided when an into-the-wind landing is available. However, factors like gliderport/airport design, obstacles, or high terrain at one end of the runway, and runway slope may dictate a downwind procedure takeoff and landing procedures. Emergencies or a launch failure at low altitude can also require a downwind landing. The pilot must use the normal approach airspeed during a downwind landing. Any airspeed in excess only causes the approach area and runway needed for approach and landing to increase.
A tailwind increases the touchdown groundspeed and lengthens the landing roll. The increased distance for landing can be determined by dividing the actual touchdown speed by the normal touchdown speed, and squaring the result. For example, if the tailwind is 10 knots and the normal touchdown speed is 40 knots, the actual touchdown speed is 50 knots. This touchdown speed is 25 percent higher than the normal speed (10 divided by 40 = .25 × 100 = 25 percent), a factor of 1.25. A factor of 1.25 squared is approximately 1.56; the landing distance increases 56 percent over the normal landing distance.
On downwind approaches, a shallower approach angle should be used, depending on obstacles in the approach path. Use the spoilers/dive brakes and perhaps a forward slip, as necessary, to achieve the desired glidepath.
After touchdown, use the wheel brake and all available drag devices to reduce groundspeed and stop as soon as is practical. This is necessary to maintain control of the glider. Landing with a tail wind means a loss of control at a much higher ground speed and requires more braking action.
Common errors during downwind landing include:
- Improper glidepath control.
- Improper use of slips.
- Improper airspeed control.
- Improper correction for wind.
- Improper procedure for touchdown/landing.
- Poor directional control during/after landing.
- Improper use of wheel brakes.
After Landing and Securing
After landing, move or taxi the glider clear of all runways. If the glider is to be parked for a short interval between flights, choose a spot that does not inconvenience other gliderport/ airport users. Protect the glider from wind by securing a wingtip with a weight or by tying it down. Consult the manufacturer’s handbook for the recommended methods for securing the glider. Remember that even light winds can cause gliders to move about, turn sideways, or cause the higher wing in a parked glider to slam into the ground. Because gliders are particularly vulnerable to wind effects, the glider should be secured any time it is unattended.
When the glider has finished flying for the day, move it to the tiedown area. Secure the glider in accordance with the recommendation in the GFM/POH. The tiedown anchors should be strong and secure. Apply external control locks to the glider flight control surfaces. Control locks should be large, well marked, and brightly painted. If a cover is used to protect the pitot tube, the cover should be large and brightly colored. If a canopy cover is used, secure it so that the canopy cover does not scuff or scratch the canopy in windy conditions.
If the glider is stored in a hangar, be careful while moving the glider to avoid damaging it or other aircraft in the hangar. Chock the main wheel and tailwheel of the glider when it is in position in the hangar. If stored in a wings-level position, put a wing stand under each wingtip. If stored with one wing high, place a weight on the lowered wing to hold it down.
If the glider is to be disassembled and stored in a trailer, tow the glider to the trailer area and align the fuselage with the long axis of the trailer. Collect all tools and dollies required to disassemble and stow the glider. Secure the trailer so that loading the glider aboard does not move or upset the trailer or trailer doors. Follow the disassembly checklist in the GFM/POH. Stow the glider components securely in the trailer. When the glider has been stowed and secured, collect all tools and stow them properly. Close trailer doors and hatches. Secure the trailer against wind and weather by tying it down properly.