CS-E 890  Thrust Reverser Tests

ED Decision 2007/015/R

(See AMC E 890)

(a)     Applicability. CS-E 890 is applicable to thrust reversers intended to be installed on turbine Engines.

(b)     The thrust reverser must be fitted to the Engine for the whole of the endurance test of CS-E 740 and a representative control system must be used.

(c)      Thrust reversers intended for ground use only. The following specific tests must be performed as part of the tests of CS-E 740:

(1)     150 cycles from an Engine rotational speed in the forward thrust range not greater than that which will be achieved in a representative aeroplane under typical landing conditions to the declared maximum reverse thrust conditions, sustaining the maximum reverse thrust conditions during each cycle for the period for which approval at these conditions is sought.

(2)     25 cycles from the Engine rotational speed for rated Take-off conditions to the declared maximum reverse thrust conditions.

(3)     One cycle to the declared maximum reverse thrust conditions, from each of ten Engine rotational speeds in the forward thrust range (except Take-off rotational speed and idling), these speeds being such that the forward thrust range is divided into approximately equal increments.

(4)     One cycle to the Take-off maximum rotational speed from each of 15 speeds in the declared reverse thrust range, these speeds being such that the reverse thrust range is divided into approximately equal increments.

(d)     Where approval is sought for ground and in-flight use, in addition to the tests prescribed under CS-E 890(c), a test of at least 5 hours must be performed, as part of the tests of CS-E 740, at the maximum reverse thrust conditions declared for in-flight use divided into equal periods each not less than the maximum permitted for in-flight use and including at least 30 operations into reverse thrust.

(e)     (1)     During the tests of CS-E 890(c) and (d), the time to complete each scheduled thrust operation must be recorded.

(2)     The power control lever movement into reverse thrust must be initiated from the conditions indicated in the schedule, reverse thrust being selected in accordance with the recommended procedure. Immediately the thrust reverser is indicated as being in the reverse thrust position, the power control lever must be moved from the minimum idling position with reverse thrust to the position appropriate to the maximum with reverse thrust in a time not greater than 1 second. During decelerations the power control lever must be moved from the position appropriate to the declared maximum with reverse thrust to the minimum idling position with reverse thrust in a time not greater than 1 second.

(f)      After the completion of the tests specified in CS-E 890(c) and (d), the Engine and the thrust reverser must comply with the specifications of CS-E 740(h).

(g)     Engine tests must be performed as required under CS-E 890(b), (c) and (d) unless it is agreed that alternative evidence may come from the Applicant’s experience on Engines of comparable size, design, construction, performance and handling characteristics, obtained during development, certification or operation, supported by analysis and tests as appropriate.

[Amdt No: E/1]