An airplane tire experiences centrifugal force within the tire body that increases with the wheel’s rotation rate as an airplane accelerates for takeoff. The structural design of the tire limits it to some maximum rolling speed on the ground, and this limit speed is provided by the tire manufacturer. Exceeding the tire’s speed restriction could result in failure of the tire during takeoff or landing, with possible safety implications.
A tire’s greatest rotation rate occurs at the point of liftoff from the runway. Liftoff speeds can be very fast, particularly at high weights and small flap settings, and under high altitude hot day conditions in which the airplane’s true speed is considerably greater than its indicated speed. The airplane’s weight must be such that liftoff will occur before its ground speed reaches the limit value, this requirement can impose a weight limitation on the takeoff.
The rated speed is marked on the sidewall of the tire in Miles Per Hour (mph).
The highest speed limit for tires in present-day use is 235 mph or 204 knots, for A320 Tire speed limit is 225 mph (195 kts)
As a matter of fact, the flight crew has no mean to know exactly the speed that is actually reached during take-off and landing phases. In case there is a suspicion of “over speed” during take-off or landing phases, the primary source and most valuable information to determine whether or not a tire over speed has been experienced will be the Wheel Speed data (Provided by the Tachometers to the Braking Control System) to be correlated to the wheel on ground signal (Landing gear compressed signal). This involves retrieving and analyzing the DFDR data.
In case of confirmed Tire overspeed, YOU MUST IMMEDIATELY:
1. REMOVE THE APPLICABLE WHEEL(S) FROM THE AIRCRAFT
2. SEND THE RELATED TIRE(S) BACK TO THE TIRE MANUFACTURER TO MAKE SURE THAT IT/THEY IS/ARE SERVICEABLE
if any one deal with tire overspeed event, please share your experience
Author – Zinhom Mahmoud
