First, don’t rush any part of the preflight, including the tires. This is particularly true of rental airplanes because you do not know if the last pilot caused tire damage during the landing and rollout. Fortunately, most training and rental airplanes don’t have wheel pants, allowing for a good visual inspection of the tires, brakes, and rotor discs. If the airplane has wheel pants, roll the airplane back and forth a few feet to view the entire tread (presuming the last pilot left you some tread to look at).

As part of the tire inspection, check the tire pressure with a good-quality tire pressure gauge. The recommended tire pressure for every make and model airplane can be found in the pilot’s operating handbook or airplane flight manual published by the manufacturer. Note that the tire pressure on the sidewall is the maximum pressure for the tire, not the operating pressure for your make and model airplane.

Visually inspect tires for flat spots, uneven wear, excessive wear, and sidewall bulges. Replace tires if their tread is worn to the base of the tread groove. On some airplanes, the landing gear camber will cause one side of a tire to wear more than the other side. Any deviation from zero camber can be corrected by demounting and turning around the tire to even out tire wear.

If the cord is showing, the tire should be replaced. However, the Goodyear Tire and Rubber Co. advises that a tire with visible cord may be safe to fly—provided that only the top cord is showing, that the damaged area is no more than 1 inch wide, and that it involves no more than one-eighth of the tire’s circumference. Pilots who determine the tire is within these limits may nonetheless opt to be more conservative and replace the tire.

While inspecting the tires, also inspect the brake assemblies. Is any brake fluid leaking? Are there any grooves or rust in the brake disc? Do the brake pads have adequate thickness?

The most common cause of a flat tire, flat spots, and cord showing is touching down with brakes applied. To avoid this problem, remind yourself, “When flying, heels on the floor and brakes no more.”

For more information consult FAA Advisory Circular 20-97B, Aircraft Tire Maintenances and Operational Practices.