What happened
On February 1, 2012, an Embraer E170-200 was performing a takeoff from Warsaw Chopin Airport (EPWA). Shortly after the aircraft became airborne and rotated, the crew attempted to retract the landing gear but found it impossible to move the landing gear lever to the "Up" position.
Despite the mechanical difficulty, the Engine Indication and Crew-Alerting System (EICAS) did not display any specific failure messages or warnings regarding the landing gear system. Due to the inability to retract the gear, the crew decided to abort the flight and returned to the departure airport, where they performed a landing without further complications.
The investigation
Following the incident, the aircraft was handed over to technical maintenance crews for inspection. Maintenance personnel conducted comprehensive landing gear tests to identify the source of the malfunction. The investigation focused on the electronic and mechanical components of the gear deployment and retraction sequence.
Findings
- The investigation established that the primary cause of the incident was a malfunction of the Weight-on-Wheels (WOW) sensors located on the right main landing gear.
- The faulty sensors prevented the landing gear lever from being moved to the retracted position.
Safety action
- The operator's maintenance teams performed tests and replaced the defective WOW sensors in accordance with the Aircraft Maintenance Manual (AMM) procedure 32-62-03-400-801A. Following the repair, the aircraft returned to service.