Lufthansa 787-9 with RAT deployed

A Lufthansa Boeing 787-9 was photographed in flight with its Ram Air Turbine (RAT) visibly deployed, an event confirmed by a ground observer who noted the aircraft produced a loud, propeller-driven sound audible from below — a characteristic acoustic signature of RAT operation. The RAT is a small propeller-driven emergency power unit that extends automatically or manually from the aircraft's fuselage into the airstream when primary electrical or hydraulic power generation is lost or critically degraded. Its deployment is an abnormal event by definition and indicates the flight crew was operating under emergency or abnormal checklist conditions at the time of the photograph.

The significance of a RAT deployment on the 787 is amplified by the Dreamliner's unique "More Electric Architecture," which replaced traditional bleed-air-driven hydraulic and pneumatic systems with electrically powered equivalents. Unlike legacy widebody aircraft that carry conventional hydraulic systems as primary power sources, the 787 relies on six generator channels — two per engine plus two APU-driven — feeding a high-voltage AC electrical bus architecture. The RAT on the 787 is designed to supply emergency electrical power to flight-critical systems when those primary generation channels are unavailable, making its deployment a signal that multiple layers of the aircraft's power generation redundancy have been compromised or declared inoperative by the crew.

For flight crews operating the 787, a RAT deployment triggers a cascade of checklist actions involving load shedding, system prioritization, and — in most scenarios — a diversion to the nearest suitable airport. The aircraft remains controllable with RAT power supplying flight controls and essential avionics, but operational capability is substantially curtailed. The audible whine described by the ground witness is consistent with the RAT spinning at high RPM to generate the necessary electrical output in the ram airflow, a sound that can carry considerable distance in certain atmospheric conditions and is distinctive enough to be recognized even by non-aviators as anomalous.

This incident, while specific details of cause and outcome remain unconfirmed from the limited source material, reflects a broader operational reality for Part 121 operators flying next-generation widebodies: the shift toward all-electric architectures introduces failure modes and emergency scenarios that differ meaningfully from those on earlier-generation aircraft. Training departments at airlines operating the 787 and A350 — both of which employ advanced electric power architectures — invest significant simulator time in power loss and electrical abnormal scenarios precisely because the crew response and system behavior diverge from what pilots transitioning from 777, 767, or A330 fleets would expect. The visual confirmation of a deployed RAT on a revenue Lufthansa flight serves as a real-world reminder that these systems, engineered as last-resort backups, do activate in line operations.