What happened
On April 14, 2022, an EMBRAER EMB-110P1, registration PT-OCW, was performing a passenger transport flight from Santa Rosa do Purus to Rio Branco, Brazil. The aircraft was carrying two crew members and eight passengers.
As the aircraft began its approach to Plácido de Castro Airport (SBRB), the "DOOR" warning light illuminated on the instrument panel. Upon realizing the door was unlatched, the co-pilot attempted to close and secure the door, but was unable to engage the latch due to the effects of relative wind. To mitigate the risk, the pilot in command performed a preventive shutdown of the left engine. The crew proceeded to complete the approach and landed the aircraft in a single-engine configuration. There were no injuries to the ten people on board, and the aircraft sustained no damage.
The investigation
CENIPA's investigation focused on why the door unlatched during the critical phase of flight. The investigation found that the aircraft's maintenance records, airworthiness certificates, and the crew's licenses and medical certificates were all valid. The aircraft was operating within weight and balance limits, and weather conditions were favorable.
Investigators identified a latent condition involving a portable cooler containing water, which was placed in the forward section of the cabin near the main door to allow passengers easy access. Because there was no flight attendant on board, passengers frequently moved to this area during the flight. The investigation concluded that a passenger likely inadvertently operated the door unlatching lever while accessing the cooler. Additionally, the investigation noted that the co-pilot's attempt to manually hold the door closed during the landing phase was not a procedure outlined in the aircraft's flight manual and violated regulations regarding crew duties during critical phases of flight.
Findings
- The primary cause of the incident was the inadvertent unlatching of the main door by a passenger.
- A latent hazard existed due to the placement of a water cooler near the door mechanism, which facilitated accidental activation of the latch.
- Management oversight contributed to the failure to identify and mitigate this operational risk within the operator's Safety Management System (SMS).