When calibrating an aircraft towbar, it’s essential to ensure all moving part are accounted for. This means being conscious of each needed step is a necessity in order to guarantee aircraft towbar accuracy and reliability. To help you get a better idea of each step needed in aircraft towbar calibration, we have created a brief calibration checklist below.
Check towing eye for bending, excessive wear and deformity Inspect towing eye mounting bolts. Make sure that all fasteners are not loose or missing and tighten bolts to 25 ft-lbs or replace if required. Check towing eye should for turning movement – If the towing eye can turn chances are the centering pin within the shock assembly may be broken. Check the shock assembly for preload on the spring – This can be done by pulling on the towing eye. If the shock can be moved by hand, the spring is worn out. Inspect the towbar tube for cracks, gouges greater than 1/16 inch, and bends or deformities. Check the casters – Swivels should operate freely and the bearings should not be missing. Inspect caster mounting fasteners – Fasteners should not be loose or missing. Check the caster mounting plate and channel – If bent or broken, repair before calibration. Inspect the lifting handle at the towing eye end – Mounting fasteners should not be loose or missing. Check the towbar undercarriage – Pneumatic tires should be inflated to the proper pressure. Air leaks should be fixed or tires should be replace if needed. Wheels should rotate freely, wheel rims should not be bent, and tire axle is not bent. Mounting fasteners should not be loose or missing. ***Grease the tire axle every 90 days to 6 months. Inspect towing head attachment ball lock pin – Verify the correct ball lock pin is used (should be the factory supplied pin).