What happened
On October 17, 2011, a Learjet 3/1A, registration PR-JJV, was performing a private passenger flight from Goiânia, GO, to Palmas, TO. While climbing under instrument flight rules (IFR) in instrument meteorological conditions (IMC), the aircraft experienced simultaneous failures in its navigation systems and both the primary and standby attitude indicators.
These malfunctions caused the flight crew to experience spatial disorientation, leading to an abnormal aircraft attitude and a subsequent loss of altitude. The aircraft descended through several flight levels before the crew successfully regained control. The flight crew managed to perform an emergency landing at Brasília International Airport (SBBR). While all 6 occupants (two crew members and four passengers) escaped without injury, the aircraft sustained substantial damage to its lower fuselage structure.
The investigation
The investigation by CENIPA faced significant challenges due to the actions taken by the operator following the event. The aircraft was moved from Brasília to Viracopos International Airport in Campinas, SP, without the knowledge or authorization of the investigating authority. Furthermore, the aircraft underwent repairs in Campinas before investigators could examine it. This unauthorized movement and subsequent repair resulted in the loss of critical physical evidence that could have identified the specific contributing factors to the component failures.
Additionally, the occurrence was not reported to the regional investigation office (SERIPA VI) until 45 days after the incident occurred.
Findings
- The primary cause of the loss of control was spatial disorientation resulting from the failure of navigation systems and attitude indicators.
- The co-pilot was not properly qualified for the flight, as his instrument rating had been expired since November 2006, and he lacked the required type rating for the Learjet 31A.
- The co-pilot's medical certificate was also expired.
- The aircraft was operating within weight and balance limits, and its airworthiness documentation and maintenance logs were up to date.