NPA 2020-05

Tyre pressure monitoring

The objective of this NPA is to decrease the risk of a hazardous or catastrophic tyre failure of a large aeroplane that is caused by inadequate tyre inflation pressure.
This NPA proposes to amend CS-25 to require applicants to provide a means to ensure that no tyre is below its minimum serviceable inflation pressure during operation. This can be achieved either by providing a task in the instructions for continued airworthiness (ICA) that requires operators to perform tyre pressure checks at a suitable time interval (i.e. daily or at another substantiated interval), or by installing a tyre pressure monitoring system that alerts the flight crew in the case of a tyre with an unsafe pressure. It also proposes to amend Part-26 and CS-26 to require the same objective to be implemented by operators of large aeroplanes, i.e. either by including in the aeroplane maintenance programme (AMP) tyre inflation pressure checks at a suitable time interval, or by installing a tyre pressure monitoring system.
The proposed changes are expected to increase safety without any significant economic impact, and with no environmental or social impact.