ASSISTING THE PILOT WITH PRE-FLIGHT PREPARATIONS
Before the pilot is ready to climb into the glider for takeoff, a number of preparations and safety checks must be completed to ensure that the glider is in an airworthy condition. The pilot may require assistance to accomplish some of these checks and the ground crewmember may be asked to assist in completing them. The following sections review typical pre-flight tasks in which the ground crewmember may be asked to assist.
Where Pre-Flight Preparations should be Carried Out
The glider is not safe to fly until all necessary pre-flight preparations and checks have been completed. Consequently, the glider should be kept clear of, and not obstruct, the launching area while pre-flight preparations are being accomplished.
Assembling the Glider
Gliders that are not used on a daily basis are often disassembled and stored in specially designed trailers. Enclosed trailers protect the airframe from exposure to the natural elements when not being used. These trailers also allow the pilot to relocate the glider easily. The assembly of a glider typically requires the pilot and at least one helper. To ensure the glider is assembled correctly, pilots and other persons assisting in the assembly should adhere to the manufacturer's assembly checklist.
Critical Assembly Check
Whether a glider has just been assembled, or merely towed out from its hangar or tie-down spot, it needs to be carefully checked before flight (sometimes called a "Pre-Flight" Check). This should involve the pilot ensuring that all critical assembly items are checked for correct assembly, security, and proper operation.
Four causal factors have been identified to be prevalent in assembly related accidents:
- Distractions during the assembly process,
- Failure to follow manufacturer's recommended assembly procedure,
- Failure to conduct a positive control check,
- Rushing the procedure to get into the air.
To enhance safety in the assembly procedure, the Soaring Safety Foundation recommends that a Critical Assembly Check be conducted after the glider has been assembled. The pilot-in-command should enlist another person to assist in examining critical assembly components to ensure proper installation. This person does not necessarily need to be familiar with a specific aircraft or manufacturer, but should have a basic understanding of the factors involved in a properly assembled glider. This can be achieved by the Pilot-in-Command explaining to his/her helpers how each part is installed and attached securely. The ground crewmember may be asked to serve in this capacity.
The following list, though not totally inclusive, offers items that should be checked prior to flight. Failure to have these items correctly assembled may result in difficult or impossible flight characteristics. The check by the Pilot-in-Command and an assistant can normally be performed by simply walking around the aircraft, starting and ending at the cockpit area.
With the help of an assistant, check each of the following items for proper installation and security.
After check of these items is complete, a Positive Control Check should be performed.
- Main wing pin(s) installed
- Drag spar pin(s) installed
- Control rods attached
- Hotellier connectors attached
- Spring-loaded connectors engaged
- Locking collars engaged
- Safety pins installed
- Safety collars installed
- Outer wing panels installed
- Control rods attached and properly secured
- Horizontal stabilizer properly installed
- Elevator control rod attached
- Rudder cables attached
Positive Control Check
In the assembly process, not only do the wings and horizontal tail surfaces (and any other parts which have been attached) require to be properly attached to the glider but the flight control surfaces on these components (the ailerons, flaps and airbrakes on the wings, the elevator on the horizontal tail surfaces) need to be properly connected to the controls in the cockpit. Pilots have been injured and killed as a result of failure to properly connect flight controls.
A positive control check is conducted with one person manipulating the flight control in the cockpit and another person holding the flight control surface to be checked. The person in the cockpit moves the control to be checked (control stick, airbrake lever, flap handle, etc.) while the other person firmly resists the movement of the surface being checked. Normally the pilot will place the control to each end of its travel in turn then, while the other person resists the movement of the flight control surface, attempt to move the control away from that position. To prevent damage to the control surface, excessive pressure should not be applied. If the pilot is able to move the cockpit control while the surface is being held, then the flight control is not properly connected. The ground crewmember may be asked to assist with a positive control check.
Checking the Towline
Prior to the first flight of the day, a check of the integrity of the towline is necessary. It is also a responsibility of the ground crewmember to monitor the condition of the towline during launch operations. To check the integrity of the towline, it first must be laid out on the ground - a proper inspection cannot be made if the towline is coiled up.
The towline needs to be checked to ensure that it is undamaged. A thorough check must include the following -
- The steel rings at either end must be securely attached to the rope, and not be distorted.
- The rope should show no signs of distress or fraying at any point, particularly where there are splices, and where it goes around the rings.
- There must be no knots in the rope itself.
- No strands of the rope should be broken.
- The rope condition should be generally good without frays, kinks, oil stains or other discontinuities.
Particular care should be taken with the inspection of the weak link(s) and any part that has been 'protected' from wear by attachment of tape, thimbles, tennis balls, or other items. If there is any doubt as to the serviceability of any part of the towline, a final determination should be made by the glider pilot or tow operator.
It is not possible here to include all the areas in which the pilot may require help with pre-flight preparation. The ground crewmember should inquire what assistance the pilot may need. These areas include:
Glider Tow Hitch
It is essential that the tow hitch on the glider functions correctly, and neither causes the towline to hang up, nor release prematurely. While inspection of the tow hitch is part of the glider pilot's Pre-Flight Check, a functional check of its operation also needs to be carried out. The wing runner may be asked to assist in this check by attaching the towline to the tow hitch and pulling on it to keep it under tension while the glider pilot operates the release handle in the cockpit. (See Connecting Towline for details of how the towline should be attached.)
The pilot often requires help in fitting and/or closing the canopy, particularly if the canopy is designed to detach completely from the cockpit (no hinge). If the pilot requires assistance, the wing runner should be familiar with proper operation of attaching the canopy before the glider is moved on to the flight line. This will prevent operations from being delayed when the canopy is secured immediately prior to launch.
Tow Out Equipment
To assist in moving the glider around the field, glider pilots often attach special towing out equipment to the glider. This may include a tail dolly, a wingtip wheel, and other special purpose items. The glider pilot may require help in attaching or removing such equipment. If asked to assist, the wing runner must know how such equipment is attached and removed. In particular, the tail (which is usually heavy) must be raised to permit the attachment of the tail dolly. The wing runner needs to know where it is safe to lift the tail or rear fuselage for this purpose, and whether it is safe to press down on the nose of the glider to assist in the process.
- While pre-flight preparations are being made, make sure the glider is parked safely in a location that does not obstruct the launch area.
- If helping with the rigging, the wing runner should know ahead of time what is required, and where to hold glider components to prevent damage to the airframe.
- The wing runner should know how to assist in a Critical Assembly Check and the Positive Control Check.
- The wing runner should know where the glider can be safely lifted before helping to attach or remove a tail dolly.
- When checking the towline, it must be laid out so that any imperfections affecting its integrity can be readily identified.