Managing Flying Risk – Winch launching
It is important that all pilots who winch launch are aware of the detail contained on the ‘Safe Winch Launching’ web page.
Cartwheeling Accidents
Cartwheeling accidents – predominantly to experienced pilots – happen as a result of not releasing the cable if the wing drops during the ground run. If the wings cannot be kept level before take-off, release before the wing touches the ground.
Launch Point Controller
A suitably experienced Launch Point Controller (LPC) should be appointed to co-ordinate safe launching. The LPC should be positioned so that launch signals, the launching wires or ropes, and all aircraft approaching to land are in sight.
Strop/Shock Rope
The strop/shock rope positioned between the launching cable parachute and the launching rings should be long enough to minimise the risk of the cable parachute fouling the glider and should be sheathed in a semi-rigid covering – such as plastic hose – to minimise the risk of the rope fouling the glider wheel or structure. The Winch Operators Manual provides guidance.
Weak Link
A weak link designed to protect the glider from excessive loads is required for all winch launches. The weak link maximum breaking strain is detailed by the glider manufacturer or type certificate holder.
Guidance for all pilots
If you are the PILOT;
Start the launch with your hand on the release
If you cannot keep the wings level, release IMMEDIATELY.
“Release IMMEDIATELY” means BEFORE the wing touches the ground.
Why hand on the release? Because you need to pull the release within half a second of taking the decision to release.
Why immediately? Because the cartwheel that may follow a wing drop onto the ground can be so rapid that no recovery by releasing or other means is possible.
After take-off, maintain a shallow climb until adequate speed is seen with continued acceleration. Then allow the glider to rotate at a controlled pace. If power is lost near the ground, immediately lower the nose to the appropriate recovery attitude.
After a power loss in mid-launch, adopt the recovery attitude, wait until the glider regains a safe approach speed, and land ahead if it is safe to do so.
Instructors additional guidance
If you are the INSTRUCTOR;
Start the launch with your left hand on the release and your other hand very close to the control column.
If you or your student cannot keep the wings level, release IMMEDIATELY.
Why hand on the release? Because you need to pull the release within half a second of taking the decision to release.
Why immediately? Because the cartwheel that may follow a wing drop onto the ground can be so rapid that no recovery by releasing or other means is possible.
If your student does not react correctly and promptly during the launch, take control.
Wing Runner and Signaller Guidance
If you are the WING RUNNER;
Ensure that you have been trained before taking on the task.
Stop the launch if you are resisting an up or down force at the tip.
Run with the tip while holding the wings level.
Why stop the launch? Because most wing drops occur immediately after the wing tip runner lets go.
Note to CFIs: the responsibilities of the wing tip runner make this a safety-critical task.
If you are the SIGNALLER;
Ensure that you have been trained before taking on the task.
If the wing drops to the ground at or near the beginning of the ground run IMMEDIATELY stop the launch by sending a STOP signal to the winch by every available means.
Do not wait for one or two seconds to see if the pilot picks the wing up.
The purpose of sending a STOP signal is to avoid a potentially fatal cartwheel.
Launch signals can be visible or audible.
It is highly desirable for the signalling system to allow the signaller to trigger an unmistakeable audible and visual STOP command to the winch driver.
Note to CFIs: the responsibilities of the signaller make this a safety-critical task.