EASA issued an emergency airworthiness directive (EAD 2010-0063-E) regarding ATR-72 flight controls.
During flight control checks prior to take-off (cockpit pre-flight preparations), abnormal motion of the rudder pedal was observed in two ATR72-212A aeroplanes, the affected pedal staying stuck on its stop end position. Subsequent inspection showed that in both cases, one of the rudder pedal rods, Part Number (P/N) S2728116400000, was broken.
Further investigation revealed that an error has occurred during the manufacturing process of the affected rods. As a result, some of the rods (which have been identified as belonging to production batch numbers CC 2109699 and
CC 2118930) may have an outer diameter which is smaller than the minimum value as specified in the original design drawings.
The rods belonging to these batches were installed in the rudder pedal assemblies of certain aeroplanes. Most of the related rods have been checked and found to be in conformity with acceptable dimensions; those that were not
have been replaced while still on the production line, prior to delivery of the affected aeroplanes. However, seven (7) aeroplanes already in service have been identified that are likely to have the affected rods installed.
This condition, if not corrected, could lead to failure of the rudder pedal rod, possibly resulting in reduced control of the aeroplane. In combination with an engine failure or during a landing or take-off under crosswind conditions, such a failure could lead to loss of control of the aeroplane.
For the reasons described above, this Emergency AD requires inspection of the four rudder pedal rods, to detect a lower than acceptable outer diameter at each rod end, and replacement of any rods that fail the inspection criteria.