What happened
On April 2, 2016, at 14:12 UTC, a Cessna 172G, registration PT-CTB, departed from the Barreirinhas Aerodrome (SSRS) in Maranhão, Brazil, for a scenic flight. The aircraft was carrying one pilot and three passengers.
Immediately after takeoff, the engine experienced successive power fluctuations. As the aircraft reached the final third of the runway, a partial engine failure occurred. The pilot attempted a recovery by executing a right-hand turn followed by a left-hand turn to return to the runway. During this maneuver, the aircraft lost lift and collided with the ground near the side of runway 29. The impact resulted in substantial damage to the aircraft, including a severed tail section, though the engine was still producing power at the time of impact. All four occupants sustained serious injuries.
The investigation
CENIPA's investigation examined onboard video footage, aircraft wreckage, and maintenance records. Analysis of the video showed that the pilot intentionally reduced power at approximately 70 feet due to the engine oscillations. The aircraft's airspeed was recorded at approximately 58 mph before the first turn, which is near the stall speed for this model.
Investigators also reviewed the aircraft's maintenance history and found that the aircraft's logbooks had been outdated since before the most recent Annual Inspection. Furthermore, the investigation identified that the installed battery was an automotive type, and critical components—specifically the carburetor and magnetos—lacked identification, making traceability impossible. Additionally, it was noted that a similar engine failure had occurred one week prior, but no formal maintenance intervention was performed; instead, the pilot attempted an informal procedure to clear the engine by running it at high RPM.
Findings
- The aircraft experienced successive power fluctuations and a partial engine failure during the takeoff roll.
- The aircraft entered a stall during the attempt to return to the runway due to improper control inputs and low airspeed.
- Inadequate aircraft maintenance was a primary contributing factor, evidenced by outdated logbooks and untraceable engine components.
- The use of an automotive battery instead of an aviation-grade battery was identified.
- The pilot's decision to use an informal procedure to address a previous engine failure rather than seeking professional maintenance contributed to the mechanical instability.