On August 15, 1997, a Cessna 550 Citation II (registration PT-LML) operated by Riana Táxi Aéreo was involved in an aviation accident near Cocal do Sul, Brazil in flight. 2 people were killed. Investigators recorded the probable cause as: It is believed that the crew failed to prepare the flight according to published procedures, did not follow the pre-departure checklist and failed to verify the position of the pressurization mode selector prior to take off. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 1 related events involving the same aircraft type or operator are linked below.
On a flight from Porto Alegre to Rio de Janeiro, the aircraft entered an uncontrolled descent from 33,000 feet, disintegrated at 1,500 feet, and crashed. Both pilots were killed. Investigation cited checklist errors and hypoxia.
Event
During a flight from Porto Alegre to Rio de Janeiro, while cruising at an altitude of 33,000 feet, the aircraft entered an uncontrolled descent. No distress call was sent by the crew. The descent rate reached 20,000 feet per minute. At an altitude of 1,500 feet, the aircraft disintegrated in the air and subsequently crashed. Both pilots were killed.
Investigation
The official investigation determined that the crew failed to prepare the flight according to published procedures. They did not follow the pre-departure checklist and did not verify the position of the pressurization mode selector prior to takeoff. At 33,000 feet, both pilots suffered hypoxia, leading to loss of consciousness and situational awareness. The report noted that possibly one of the pilots fell and inadvertently moved the control column, causing the aircraft to enter the uncontrolled descent.
Probable cause
It is believed that the crew failed to prepare the flight according to published procedures, did not follow the pre-departure checklist and failed to verify the position of the pressurization mode selector prior to take off. At an altitude of 33,000 feet, after suffering hypoxia, both pilots lost consciousness and situational awareness. Maybe one of them fell and moved the control column, causing the aircraft to enter an uncontrolled descent.