Introduction
On October 4, 2023, at approximately 2347 Eastern Daylight Time, FedEx Flight 1376, a Boeing 757-236, experienced a left hydraulic system failure shortly after departing from Chattanooga Metropolitan Airport (CHA). The flight crew attempted to return to CHA, but encountered a landing gear malfunction that prevented normal and alternate extension. The airplane landed with its landing gear retracted, resulting in substantial damage. The two flight crewmembers and a jumpseat occupant onboard were not injured.
Flight History
The flight was a non-scheduled domestic cargo operation under 14 CFR Part 121 from Chattanooga to Memphis International Airport (MEM). The aircraft had no preflight maintenance issues. The captain was the pilot flying, and the first officer (FO) was the pilot monitoring. After an uneventful push-back, engine start, and taxi, the flight was cleared for takeoff on runway 20 at 2221:54 EDT. Approximately 11 seconds after gear retraction, the left hydraulic system fluid quantity and pressure began to decrease, triggering a master caution. The crew noted a left hydraulic quantity warning and later a trailing edge flap disagree message after selecting flaps up. They executed checklists, set alternate flap modes, and decided to return to CHA.
Hydraulic System and Gear Extension
The Boeing 757 has three independent hydraulic systems (left, right, and center). The left system normally powers landing gear extension and retraction, flap/slat operation, and nose wheel steering. A power transfer unit (PTU) can transfer pressure from the right system to the left, but it cannot be manually controlled. Following loss of left system fluid, the PTU was expected to shut off. When the crew attempted to lower the landing gear, a gear disagree indication appeared. The alternate extension system, which uses a dedicated circuit to release uplocks, also failed to deploy the gear after several attempts.
Accident Sequence
After the gear disagree warning, the crew broke off the approach and attempted alternate gear extension multiple times, including cycling circuit breakers advised by a FedEx maintenance technician. A low pass over the runway at about 150 feet allowed tower personnel to confirm that the gear was not down. The crew then prepared for a landing with the gear retracted. The airplane touched down at 2347:10, with initial contact marks consistent with the left engine. The aircraft slid off the end of runway 20, impacting localizer antennas and coming to rest about 830 feet beyond the pavement.
Postaccident Findings
Postaccident inspection of the cockpit revealed that the left engine and electric hydraulic pump switches were in the OFF position, while the right and center pump switches were ON. The landing gear control lever was down, the ALTN GEAR EXTEND switch was OFF with its cover open, and the ALTN FLAPS knob was at 20. Hydraulic fluid quantities measured 0.32 (left), 0.95 (center), and 0.95 (right) on the EICAS. When maintenance personnel attempted to service the left system, fluid leaked from the left landing gear door actuator retract hose. The failed hose was removed and replaced; no other leaks were found. The landing gear remained retracted until the aircraft was lifted for recovery.
Evacuation and Damage
After the aircraft stopped, the jumpseat occupant attempted to open the L1 door, but it only rotated halfway and the slide did not deploy. The R1 door was then forced open, and the slide deployed normally. All three occupants exited via the R1 door and slide, uninjured. The incident was classified as an accident due to substantial damage to the aircraft.