What happened
On March 22, 1994, a Cessna 402B, registration PT-JHV, operated by Táxi Aéreo Kovacs, departed from Itaituba Airport, Pará, for Santarém. The aircraft was carrying two crew members and six passengers. Shortly after takeoff from runway 05, while cruising at approximately 300 feet, the pilot experienced intense vibrations in the control column and declared an emergency via radio.
The aircraft entered a right-hand turn and transitioned into a steep dive. The pilot attempted to maintain control by applying pressure to the elevator, but the aircraft eventually struck the surface of a nearby lagoon approximately one mile from the threshold of runway 23. The impact caused the aircraft to submerge. While some occupants managed to remain on the aircraft wing until help arrived, the co-pilot and two passengers subsequently drowned after entering the water. The accident resulted in three fatalities.
The investigation
CENIPA investigators examined the wreckage and the flight control systems. The investigation focused on the elevator control mechanism, specifically the connection between the elevator arm and the push-pull tube. Investigators discovered that three rivets, which secured the lower end of the elevator control arm to the push-pull tube, were missing.
Analysis of the aircraft's history revealed that on the previous flight, the aircraft had encountered severe turbulence for approximately 15 minutes. Investigators also noted that while the aircraft's maintenance was up to date, the specific component involved in the failure was difficult to access for inspection. Furthermore, the investigation found that the passengers had not received safety briefings regarding emergency procedures, and the aircraft's life jackets were not utilized during the evacuation.
Findings
- The primary cause of the accident was the loss of elevator control due to the failure of the elevator control system components.
- The loss of control was triggered by the absence of three rivets at the junction of the elevator arm and the push-pull tube.
- Severe turbulence encountered during a flight the previous day may have contributed to the structural fatigue or displacement of these rivets.
- The difficulty in inspecting the specific connection point, combined with the manufacturer's service manual not requiring the removal of these rivets during standard inspections, hindered the detection of the defect.
- The lack of passenger safety briefings and the failure to use life jackets contributed to the fatalities during the post-crash phase.