5. Check the Shear Pins
Shear pins carry the bulk of the load when towing aircraft. These pins are specifically designed to break once they reach a specific PSI limit to lessen the potential for damage to the plane. Shear pins are most commonly found on the aircraft towbar head but can sometimes be located in the towbar shock assembly.
Remove the shear pins and check them for straightness, cracks and indentations before use. If a pin looks in any way suspicious, it should always be replaced. Next, inspect the shear pin bushings. If the bushings are chipped or cracked, operators must replace them. Only manufacturer-approved shear pins and bushings should be used. It is also recommended that spare shear pins are readily available for rapid replacement to improve operational efficiency during aircraft towing procedures.
6. Use Proper Eyebolt & Hitch Pins
Verify that the proper eyebolt and hitch pin size is in use before pushing or towing aircraft. A correct size eyebolt should only make contact with the hitch pin. Operators will be able to see a gap between the outside diameter of the eyebolt and the coupler faceplate. If this is not the case, please contact Tronair.
7. Check the Towbar Connection
To avoid any possible damage, aircraft towbars should always be attached to the aircraft first. Once an operator has successfully verified the aircraft-side towbar connection is secure, they can connect the other end to the tug.
Once the towbar connections are secure on both sides, ensure that the towbar is as horizontal as possible. The angle between the tug and towbar should be about 90 degrees. Damage to the towbar or aircraft can occur from an excessive towbar angle during aircraft towing procedures. If needed, operators can use pintle hooks to ensure the towbar is as level as possible during aircraft towing and pushback. These hooks help prevent contact of towbar wheels with the ground during towing.
The maximum angle between the ground and the aircraft towbar should only be five degrees. Keep in mind that damage to the towbar can occur from pushing the aircraft with the towbar jackknifed to the tug.
8. Maintain a Correct Towing Angle
When transporting an aircraft with a towbar, it is recommended that the towing angle not exceed 45 degrees. Damage to the towbar or aircraft can result from towing or pushing an airplane while maintaining too sharp of an angle between the tug and towbar. When making turns, operators should always use a large sweeping radius.
Understand that each towbar has its own owner's manual and guide for proper procedures and upkeep for using and maintaining the towbar. Operators must follow these instructions carefully during all aircraft towing procedures.