Incident Sequence
During landing, the left main landing gear exhibited asymmetric braking: the inboard wheel applied a high level of braking while the outboard wheel did not brake. This caused the aircraft to depart the runway, where it impacted runway lighting, resulting in minor damage.
Maintenance Issues
The reversal of the left main landing gear's inboard and outboard anti-skid tachometer wiring occurred during scheduled maintenance at a vendor. The vendor reported that their personnel were unaware that the built-in test equipment used did not verify cross-wiring of tachometers. A different test, specified in the aircraft maintenance manual and an operator reference document, was designed to detect such a condition but was not performed.
Post-Incident Findings
Examination of the aircraft and brake components after the incident revealed no further anomalies. The operator noted that the reference documentation for the scheduled maintenance involving the left main landing gear tachometers was unclear, and the procedure was subsequently revised.