The dual APUs provided allow normal operation as long as one APU is operating. However, certain equipment not required for safe flight will be lost.
Note: The SAS emergency hydraulic system automatically provides hydraulic power for the SAS pitch and roll servos in the event of a No. 2 hydraulic system failure.
LOSS OF |
RESULTS IN COMPLETE LOSS OF |
NECESSITATES USE OF |
APU No. 1 |
Ball nose and SAS yaw |
Mission abort may be required. |
APU No. 1 & 2 |
All hydraulic power |
Emergency battery to attempt to restart APU. |
APU No. 1 & 2 |
All electrical power |
If restart fails, ejection is mandatory. |