Incident Summary
Following takeoff, the flight crew encountered a landing gear malfunction. When the gear was retracted, the left main gear indicated an unsafe condition, and an unsafe door indication also appeared. The crew attempted to recycle the gear, but the same indications persisted. The gear handle was then placed in the neutral position, and the left main gear extended to a down and locked position. The captain decided to return to Memphis for a precautionary landing. After the gear extension cycle, all gear indicated down and safe, and tower personnel confirmed that the gear appeared to be down.
Sequence of Events
Upon touchdown, the left wing began settling, but the crew was able to keep the aircraft on the runway. An emergency evacuation was initiated; however, the slide at the left forward door did not inflate. No pressure was found in the inflation bottle for that slide, and no reason could be determined for the loss of pressure.
Investigation Findings
An investigation revealed that the left main landing gear outer cylinder, part number 65-57901-19, had failed from fatigue. A stress corrosion crack had initiated on the outer diameter of the strut cylinder, where a strap had obscured the corrosion. There was no history of a hard landing.