What happened
On February 12, 2018, at 16:40 UTC, a Beechcraft 76 Duchess, registration CS-DCS, operated by Escola de Aviação Aerocondor S.A., was performing a flight at Ponte de Sor Airfield in Portugal. During the landing phase, the aircraft experienced an abnormal contact with the runway because the landing gear had not been extended.
The investigation
The GPIAAF investigation examined the aircraft's maintenance history, the crew's training, and the operational procedures in place. The investigation focused on the landing gear warning system, specifically the functionality of the warning horn and the pilot's adherence to checklists. The investigators also reviewed the consistency between the Pilot’s Operating Handbook (POH), Standard Operating Procedures (SOPs), and the aircraft's checklists. Additionally, the investigation looked into the effectiveness of modern noise-canceling headsets, which can sometimes prevent pilots from hearing cockpit warnings.
Findings
- The primary cause of the event was the landing gear being in the retracted position during touchdown.
- The investigation noted that gear-up landings are a recurring issue in flight instruction, often resulting from pilot distraction or interruptions to established flight routines.
- There was a lack of uniformity between the information presented in the POH, SOPs, and checklists, which could hinder efficient procedural consultation.
- Modern noise-canculating headsets used by the crew may have contributed to the pilot failing to perceive the landing gear warning horn.
- The investigation identified a need for better integration of flight plan data into the aircraft's navigation system to provide automated gear-down warnings during approach.