ATR One Engine Out

Following engine failure procedure:

In any case, the maximum continuous power (MCT) is set to the remaining engine.

• If no obstacle limitation (condition 1)
If the engine failure occurs during the cruise, a 200 kt descent is performed until a vertical speed of 500ft/mn is reached.
If the engine failure occurs during climb, climb is continued at VmLB0° or VmLB15° depending on the atmospheric conditions,
until the single engine ceiling.

• If obstacle limitation (condition 2)
If the engine failure occurs during cruise, over a mountainous or a restricted area, the drift-down procedure is
followed.

The minimum manoeuver speed in flight is VmLB flaps 0° in normal conditions and VmLB flaps 15° in icing conditions. This
speed ensures the highest altitude versus the distance in climb, and the best lift-to-drag ratio speed during descent.

This speed is selected when an engine failure occurs in flight and that the vertical profile has to be optimised.

This procedure consists in:
– deciding at the decision point whether to continue, divert or return.
– then decelerating to VmLB0° or VmLB15° depending on the atmospheric conditions, called in this case drift-down
speed, and descending to the gross ceiling, where, if the obstacle is cleared, a single engine cruise is initiated.

NOTE: Procedures are detailed in the FCOM 3.09.03, One engine inoperative procedure - in flight.