What happened
On June 3, 2016, a Saab SF-304A operated by Sky Taxi sp. z o.o. was involved in an aviation incident within the Ostrava-Mošnov (LKMT) control zone in the Czech Republic. The aircraft had recently undergone a scheduled nose landing gear replacement at the JTS Aviation maintenance facility, which was completed on June 1, 2016.
Following takeoff on the day of the incident, the crew moved the landing gear lever to the UP position and observed that all three green landing gear position lights had extinguished, while a red TRANSITION light remained illuminated. This indicated that the gear was in an intermediate position. The crew attempted to cycle the landing gear three times, but the indication error persisted. Consequently, the crew decided to return to the departure aerodrome to troubleshoot the issue.
Upon landing, maintenance personnel performed a functional test of the landing gear extension and retraction according to the Aircraft Maintenance Manual (AMM). During this ground test, the gear operated correctly, and the cockpit indications were normal, leading to the aircraft being cleared for another flight. However, during the second departure, the exact same indication error occurred, forcing a second return to the airport. Following this second event, technicians adjusted the landing gear position indication switch. After a third takeoff, the gear cycling tests were successful, and the aircraft proceeded to its planned destination at EPWR without further issues.
The investigation
The investigation focused on the discrepancy between the successful ground functional tests performed by maintenance personnel and the recurring indication failure observed during flight. The investigation examined the maintenance actions taken following the nose gear replacement and the subsequent technical adjustments made to the landing gear signaling components.