CS 26.201 Tyre inflation pressure

Compliance with point 26.201 of Part-26 is demonstrated by complying with CS 25.733(f) of CS-25 or its equivalent, or with the following:

(a)‘Minimum serviceable inflation pressure’ means a tyre inflation pressure specified by the aeroplane type certificate holder below which damage to the tyre, potentially leading to a tyre failure, may occur.

(b)The operator ensures that one, or a combination, of the following means is (are) used:

(1)A task is incorporated in the aeroplane maintenance programme (AMP) that requires tyres inflation pressure checks to be performed at a suitable time interval.

(2)The aeroplane is equipped with an installed system that monitors the tyres inflation pressures and that:

(i)provides an alert to the flight crew whenever a tyre inflation pressure is below the minimum serviceable inflation pressure, or

(ii)allows the tyres inflation pressures to be checked prior to the dispatch of the aeroplane, and a tyre inflation pressure check task is included in the pre-flight procedures of the operations manual.

(c)Tyre inflation pressure checks in the AMP A ‘suitable time interval’ is the maximum time interval between two consecutive tyre inflation pressure checks. These pressure checks are conducted daily in order to ensure that the elapsed clock time between two consecutive tyre inflation pressure checks does not exceed 48 hours. Time intervals longer than 48 hours may be used if they are substantiated and agreed by the competent authority. This substantiation includes at least an analysis of the expected loss of tyre pressure during operation, taking into account environmental and operational factors, including the potential for pressure loss at a rate that exceeds the normal diffusion resulting from damage to or degradation of the tyre/wheel assembly. If available, statistical data related to pressure losses gathered from the service experience of aeroplanes equipped with equivalent wheel designs may also be used. The substantiation is made in cooperation with the tyre manufacturer(s). In addition, the operator may take credit from an installed system monitoring the tyre inflation pressures. The time interval does not exceed the applicable value provided by the type certificate holder in the instructions for continued airworthiness.

(d)Tyre pressure monitoring system If a tyre pressure monitoring system is installed, its development assurance level is commensurate with the potential consequences of an alert not being provided, as well as with the consequences of false alerts. If the system includes the indication of tyre pressure levels, the consequences of a false indication are also taken into account. The assessment of these consequences includes the effects of the failure of one or more tyres (including simultaneous tyre failures) that may be caused by the operation of the aeroplane with under-inflated tyres. Tasks are included as necessary in the AMP (taking into account the instructions for continued airworthiness provided by the design approval holder) to ensure that the calibration of the tyre pressure monitoring system is maintained.

[Issue: 26/4]