What happened
On April 3, 2008, a Cessna 210L, registration PT-KOZ, departed from the Redenção Aerodrome (SNDC) in Pará, Brazil, bound for Marabá. The aircraft was operating a private flight carrying a pilot and one passenger.
Shortly after takeoff, upon reaching 40/ft, the pilot heard an abnormal noise coming from the engine. At 800ft, the pilot initiated a left turn to return to the runway for an emergency landing. During the approach, the pilot failed to extend the landing gear, resulting in a gear-up landing. The aircraft sustained light damage, but both occupants escaped without injury.
The investigation
CENIPA investigators examined the engine and the aircraft's maintenance records. The investigation focused on the source of the abnormal noise and the reasons why the landing gear was not deployed.
Technicians inspected the Teledyne Continental IO-520-L engine and discovered an internal crack in the combustion chamber of cylinder number two. This crack had begun prior to the flight and ruptured during the climb phase, causing the loud noise.
Regarding the landing gear, the investigation found that the pilot did not use the aircraft's checklist during the emergency. Furthermore, a GPS unit was mounted on the control yoke in a position that obstructed the view of the landing gear position lights. While an audible warning for the gear position was triggered, the pilot could not hear it due to the intense noise from the engine malfunction.
Maintenance records revealed significant discrepancies. Although the pilot believed the engine cylinders had been replaced during a previous maintenance interval, investigators could not trace the origin or installation records of the current cylinders. Additionally, while the aircraft's airworthiness certificate was valid, the engine logbook was not up to date.
Findings
- The primary cause of the engine noise was the rupture of an internal crack in the cylinder number two head.
- Mandatory inspections required by Service Bulletin M91-6 (visual inspection of cylinders every 35 hours) and SB03-3 (internal borescope inspection every 100 hours) had not been documented or performed.
- The pilot failed to use the aircraft checklist during the emergency procedure.
- The installation of a GPS unit on the control yoke obstructed the pilot's view of the landing gear indicator lights.
- The audible gear warning was inaudible due to the high noise levels produced by the engine failure.
- There was a lack of traceability regarding the installation of the engine cylinders.