Accident Summary
During approach to Washington National Airport, the flight crew discovered that the right main landing gear would not extend. The landing was aborted, and the crew attempted to rectify the situation but were unsuccessful. An emergency gear-up landing was subsequently performed at Dulles International Airport. All crew members and passengers evacuated the aircraft without injury.
Post-Accident Examination
Following the incident, a detailed examination of the landing gear system was conducted. The investigation identified that the right downlock link bearing, Boeing part number BACB10B107J, had corroded and seized. This condition prevented the gear from locking into the extended position.
Maintenance Findings
The downlock link bearing was found to have no external provision for lubrication. Additionally, there was no requirement for disassembly to inspect or lubricate the bearing during routine maintenance. The bearing was subject to an 'installed' inspection during 'A' checks, which occurred every 130 flight hours, and during 'C' checks, performed every 36 days. The most recent 'A' check had been completed on October 28, 1985.