What happened
On April 13, 2008, a Beechcraft Be-76 Duchess, registration CS-DCS, was conducting a local instructional flight for multi-engine propeller (MEP) instructor qualification at Cascais Municipal Aerodrome (LPCS). The flight was operated by GESTAIR Flying Academy.
During the landing phase, while flying in a tailwind, the pilot in command (PIC) was preparing to land after completing the pre-landing checklist. The instructor, however, noticed an abnormality and decided to execute a go-around procedure. During this maneuver, the propeller tips made contact with the runway surface, causing minor damage to the propeller tips. Upon attempting to retract the landing gear during the go-around, the crew discovered that the gear was already in the retracted position. Following the incident, the crew performed a subsequent circuit and landed the aircraft normally. The aircraft subsequently taxied to the parking area, where the damage to the propeller tips was confirmed.
The investigation
The GPIAAF investigation established that although the crew reported following the checklist, the landing gear had been left retracted during the approach. The investigation noted that there was no mention of the landing gear warning horn activating, which may have been due to the throttles not being fully reduced or the warning being silenced. Additionally, the crew failed to notice the landing gear position lights, which may have been obscured by ambient light intensity.
Investigators determined that the instructor felt an unusual aircraft attitude, which prompted the decision to abort the landing. The investigation also found that the landing gear system, including the hydraulic operation and warning lights, was fully functional, as the gear deployed and locked normally during the subsequent landing attempt. The investigation concluded that the gear was likely retracted during the approach, suggesting a breakdown in flight discipline.
Findings
- The landing gear was not placed in the down position prior to landing.
- The pre-landing checklist was performed, but it failed to detect the retracted gear status.
- The crew failed to effectively apply Crew Resource Management (CRM) principles and task distribution during the multi-pilot operation.
- The propeller tips sustained minor damage due to contact with the runway surface during the aborted landing.
- The crew's familiarity with repetitive maneuvers likely led to a reduction in alertness and a failure to verify critical flight configurations.
Safety action
Following the investigation, the GPIAAF issued a safety recommendation (PAP Nº 04/2008) to GESTAIR Flying Academy, urging the following:
- Increased emphasis on the practical application of CRM concepts, particularly for two-pilot operations.
- The implementation of self-discipline mechanisms to ensure that all procedures in the Operating Manuals are followed strictly, specifically ensuring that checklists are read aloud using the physical lists provided on board rather than relying on memory.