While safe ground handling is primarily the responsibility of the pilot-in-command of the glider, all members of the ground crew also need to be knowledgeable of these procedures. Safe movement of a glider requires special procedures, especially during conditions of high or gusty winds. To provide the knowledge necessary to accomplish this operation safely, this course will describe the sequence of moving a glider from a hangar or tie-down to the flight line. This chapter will provide the information necessary to conduct this operation safely.
The glider is typically repositioned on the ground by pushing or pulling on specific areas of the airframe. The glider may also be moved with the assistance of a surface vehicle. Some parts of a glider are fragile and may be damaged by careless contact. Examples include pushing on the trailing edge (rear surface) of a wing or applying excessive pressure on both wingtips simultaneously to move a glider. Pushing or pulling on critical areas of the airframe can damage control surfaces or wing attachment fittings.
Accordingly it is important to learn which parts of the glider can be used for handling before the glider is moved. If the ground crew member is not familiar with a specific model of glider, it is important to first determine the proper method to use in repositioning it. Ground crew members should seek advice from the pilot-in-command or operator before attempting to reposition an unfamiliar glider. Glider cockpit canopies are very susceptible to damage. Normally the canopy should be kept closed and locked anytime the glider is moved or remains unattended. However, this may be impractical during certain operations. In this case, the canopy frame should be held firmly so the canopy is not jerked open or slammed shut as the glider is moved.
Preparation and planning before moving
Before a glider is untied or first moved out of the hangar, it is necessary to first ensure there are people available to assist in moving it safely. The number of helpers required will depend on the size of the glider, the wind (if strong or gusty, more help will be required), and the conditions in the areas through which it is to be moved. For example, significantly sloping terrain will require additional help to maintain control of the glider while being moved; a restricted space will require helpers to be positioned close to the parts of the glider nearest the obstructions. If a glider is to be towed by a surface vehicle, a minimum of one helper at the wingtip to assist in steering the glider and a second assistant walking at the nose of the glider would be required. If there is any doubt whether there are sufficient helpers, the decision to move the glider must be made by the pilot-in-command, or the operator.
Moving the gliderWhether a glider is pushed, pulled or towed, it should not be moved faster than a slow walk.
Positioning the Helpers
One helper should always hold a wingtip, and be responsible for steering the glider. To steer the glider, moving the left tip forward towards the nose will make the glider turn to the right. Moving the wingtip to the left will have the opposite effect. On level ground, it is not necessary for both wingtips to be held. When a glider is being moved up or down a gentle slope, a helper needs to be at each wingtip to restrain it; for a steeper slope a helper, or helpers, should also be placed down the slope from the glider to assist in restraining the glider as needed. When a glider is being towed forward by a vehicle, another helper should walk ahead of the wing, close to the cockpit, in a position to hold the glider back if the glider begins to over-run the tow vehicle. This individual would also be positioned to release the towrope in the event this became necessary.
Strong and gusty winds
When the wind is strong or gusty, more helpers are required to keep the glider from being damaged during ground movement. The flight controls should be locked or otherwise restrained to prevent the control surfaces being blown against their stops. The airbrakes should be opened if possible. Depending on glider design, this may not be possible without operating the wheel brake. The cockpit should be occupied to increase the weight of the glider. If the cockpit is occupied, the occupant should always be restrained using the glider seatbelts and shoulder harness.
Turning the glider
When a glider is turned on the spot or with a short radius, ground crewmembers should be aware of the need to prevent damage to glider nose-skids, tail-wheels and other components. This can typically be accomplished by ensuring that the component in question is well clear of the ground. For example, pressing down on the rear fuselage of the glider will help to keep the nose-skid clear of the ground. However, care must be taken to avoid lifting on or pressing down on parts that could be damaged. In strong or gusty winds, particular care is necessary. The upwind wing should always be held low to prevent the wind picking it up and flipping the glider on its back. As the glider is turned around through the wind, helpers must "change wings" so that a helper is always holding the upwind wing and keeping it low. In addition to keeping someone in the cockpit, it may also be necessary to have a helper lift the tail as the nose of the glider is turned into the wind, thus reducing the lifting force generated by the wings.
Things to watch on the way
The glider should be moved along a planned route to its destination so as to avoid potential obstructions such as bad ground, tight spaces, and moving hazards like taxiing aircraft. Also be aware of the prop or jet blast moving rearwards from powered aircraft. When the glider arrives at the launch point (unless lined up for the pilot to enter and take an immediate tow) it needs to be parked safely clear of all aircraft and vehicles that are expected to be moving. (See section on 'Parking and Tie Down') In either case, the glider should not be left unattended unless it is properly configured and it is safe to do so. If the glider cannot be tied down or otherwise restrained, at least one ground crewmember should remain in position.
These principles, of course, apply similarly to a glider being returned to its hangar or tie-down.
Problems During Glider Repositioning
Although a number of problems can occur during the repositioning of a glider, the most typical relate to the ground crew not being able to adequately control the glider's path. For example, the surface vehicle may over-speed the glider during ground movement. The solution is almost always to release from the tow vehicle and stop the glider. It may be necessary to turn the glider around to prevent it from colliding with the tow vehicle or other obstruction. It is important to take appropriate action to prevent a recurrence of the problem. Remember most ground movement incidents are caused by excessive towing speed. The glider should not be towed faster than a slow walk.
Parking and Securing the Glider
Except in light wind conditions and in locations where the glider is unlikely to be affected by prop or jet blast, a glider should not be left unattended unless it has been tied down or otherwise safely restrained. In any case, it should be parked safely clear of other aircraft and vehicles. If there are fixed tie-downs (ropes or chains) at the location, these are normally attached to the tie-down points on the glider. Different models of glider have different restraint mechanisms. If unfamiliar with a particular glider, obtain specific instructions from the pilot-in-command or operator.
Orienting the Glider and Keeping it Safe on the Airport
While on the field, the glider must always be properly safeguarded. If permanent tie-downs are already there, they should be used. If removable pickets are available, these should be installed and used. If neither are available, the glider should be secured by other means (see next section "Methods of Securing the Glider"), otherwise helpers should remain beside the glider to keep it secure if wind conditions require it. Only in very light winds should a glider be left unsecured and unattended.
When not dictated by the location of permanent tie-downs, the orientation and placing of the parked glider are important in ensuring its safety. If fixed tie-downs are not used, the glider should be parked crosswind, with the wind angling from the rear. Wherever possible, the controls should be restrained (e.g. by seat belts or installation of control locks) and the airbrakes should be locked open. Except in the case of light/high winged gliders, which should be parked with the into-wind wing on the ground, gliders should be parked with the downwind wing on the ground and, if the canopy is hinged at the side, with the glider oriented so the hinge is on the upwind side. The canopy should always be locked. Doing this is the most stable way of parking a glider. By not pointing the glider into wind, the wings generate minimal lift; and by having the wind angling from the rear, the control surfaces, if not locked, are held by the wind against their stops.
Methods of Securing the Glider
Where there are no permanent tie-downs, removable pickets may be anchored into the ground and attached to the glider by ropes or chains. Alternatively, gliders may be secured by straps attached to tie-downs or weighted bags or weights (often old tires) placed on the wingtip and restricting the nose and/or tail from moving. Parachutes should not be used as damage to the parachute may result. In any case, if the ground crewmember is not familiar with the specific glider, or the method of restraint to be used, the proper procedure can be obtained from the aircraft flight manual or from the owner or operator. The glider can be damaged if incorrect procedures are used.
- Before moving the glider, plan a route and ensure that there are enough helpers to move the glider safely.
- Know where to push or pull on the glider to avoid damaging the airframe.
- Do not move the glider faster than a slow walk.
- Take special care and precautions (including extra helpers) in strong or gusty winds.
- Be ready to stop in case of emergency.
- Do not leave the glider unattended unless the glider is secured and it is safe to do so.
- Park and secure the glider in a safe manner considering the surface wind and other aircraft and vehicles.
- If in doubt, ask!
Further reading: SSA Soaring Flight Manual, Chapter 11.<