Proper Procedures for Using an Aircraft Towbar

A fundamental weakness present in any aircraft is its limited independent ground maneuverability. That's why when aircraft are required to change location for maintenance purposes, replacement due to defects or transport from the runway to its designated spot on the flightline, aircraft towbars and tugs are used to perform towing and pushback procedures. An aircraft towbar is a valuable piece of equipment that allows a tug operator to maneuver a grounded aircraft independently to any designated location. However, without a proper understanding of how to use a towbar, towing aircraft can quickly become a dangerous operation. Proper safety procedures must be put in place and regularly used before every tow or pushback. By implementing the proper guidelines for using aircraft towbars in aircraft towing, you'll prevent potential injuries, accidents and fatalities.

In this article, we'll discuss the proper procedures for using an aircraft towbar so your ground crew can perform aircraft towing operations safely and effectively. But keep in mind: this list is not exhaustive. For complete operating instructions, you should always refer to your operation and service manual.

1. Use the Proper Aircraft Towbar & Head

Before every use of an aircraft tug, it's essential that ground operators first verify they're using the correct aircraft towbar and towbar head for the specific aircraft being transported. Aircraft towbars and towheads are aircraft specific, to ensure they can meet or exceed the weight and stress produced from pushing or pulling operations. If the incorrect equipment is put to use when towing aircraft, it can damage planes or injure operators. Operators should also check all linkages and moving parts for signs of wear and tear.

In addition, it's also important to check the body or tube of the aircraft towbar for cracks and straightness. Taking the time to inspect equipment thoroughly before each use can save on costly repairs that can cause trouble down the road. If a crack is discovered, contact Tronair or an Authorized Service Center for evaluation. If the aircraft towbar appears to be bowed from end to end, it should be taken out of service immediately.

2. Inspect the Lift Mechanism

Most wide-body aircraft towbars are typically quite heavy, so a lift mechanism is used to raise the head to meet the nose gear during towbar connections. This mechanism is also used to lift the towbar wheels above the ground once connected to the aircraft.

Check the manual pump to make sure the fluid is at a proper level and that there aren't any leaks. Operators should also inspect the lift cylinder for leaks, cracks and a deteriorating outer sleeve. If anything looks amiss, the lift mechanism should be repaired or replaced before use.

3. Examine the Wheels & Carriage

Before every use, operators must examine aircraft towbar wheels to ensure they don't break off during aircraft towing procedures. Inspect the hardware for tightness and the wheels themselves for straightness, dents and cracks in and around the lug holes. It's also critical to examine the rotating carriage and axle shaft for cracks, straightness and tightness.

If any loose lug nuts are found, they can be tightened back down with a torque wrench. For any other visible damage to the wheels or carriage, the aircraft towbar should be repaired or replaced before use.

Operators can check the owner's manual for all other general maintenance guidelines, such as when wheel hubs should be disassembled and cleaned, bearings should be inspected and repacked with grease and wheel seals should be replaced.

4. Verify The Right Type Of Coupler Is In Use

An aircraft towbar coupler should always match its intended purpose and parameters. Damage to the towbar or the aircraft can occur when towing aircraft with the following types of couplers: lift head, swivel hook, vertical side switch latch and standard duty latch. Using incorrect or damaged couplers can result in issues ranging from a minor inconvenience to severe financial loss or operator injury. These incorrect couplers are known to cause binding and failure in the eyebolt. The two common indicators of eyebolt binding are:

1. Wear on the Outside Diameter of the Eye
2. Indentations on the Inside Diameter of the Eye

Typically, eyebolt failure will begin at the head of the eye. Tronair recommends using an E-style hitch with a properly sized pin to eliminate eyebolt binding during aircraft towing procedures.

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.

Choose Tronair for Your Aircraft Towbars

Now that you know how to connect and use a towbar for safe aircraft towing procedures, you'll need the equipment that can help you get the job done. Tronair has the aircraft towbars to benefit your specific operations, whether you're operating a large or small aircraft tug. We also carry aircraft towbars for both commercial and non-commercial aircraft designed and engineered to optimize safety and efficiency, so whether you're a private or large-scale operation, you'll be able to find the equipment you need. Have a question or need more information? Reach out to our customer service department to talk to a Tronair expert today.

Contact Tronair About Aircraft Towbars Today