Engine failure during training flight leads to excursion in Belo Horizonte

Casualties unknown • BELO HORIZONTE, MG, BR

A Cessna 150F experienced a catastrophic engine failure shortly after takeoff during a local instruction flight, resulting in a landing on the grass beside the runway.

What happened

On August 11, 2011, a Cessna 150F, registration PT-CNG, departed from Carlos Prates Airport (SBPR) in Belo Horizonte, Brazil, for a local flight training mission. The aircraft was carrying two crew members. Shortly after takeoff, the engine began to vibrate and suffered a significant loss of power.

Upon recognizing the engine failure, the instructor decided to execute a return to the runway. During the approach, the aircraft landed on the grass area located on the left side of the runway. After the initial touchdown on the grass, the pilot managed to maneuver the aircraft back onto the paved runway surface, where it eventually came to a stop. Both occupants of the aircraft were uninjured, though the engine sustained internal damage.

The investigation

The investigation focused on the mechanical cause of the power loss and the maintenance practices of the operator. Investigators identified a catastrophic failure of cylinder number 3, caused by the seizure of an exhaust valve.

Technical analysis revealed that the engine was not equipped with an external oil filter. According to the aircraft's maintenance manual, specifically section 2-20, the oil change interval must be performed every 25 hours when an external oil filter is not present. However, records showed that the oil was being changed every 50 hours of operation.

Findings

  • The primary cause of the engine failure was the catastrophic failure of the third cylinder due to an exhaust valve seizure.
  • Improper maintenance intervals regarding oil changes contributed to the engine failure, as the 50-hour interval used by the operator exceeded the 25-hour limit required for engines without external oil filters.

Safety action

Following the investigation, SERIPA III issued a safety alert (DIVOP 01/2012) to operators utilizing the Teledyne Continental O-200A engine. The alert instructed operators to strictly adhere to the oil change intervals specified in the manufacturer's maintenance manual, noting the critical differences in requirements based on the type of oil filter installed.

Probable cause

The engine failure was caused by a catastrophic failure of the number 3 cylinder due to an exhaust valve seizure, resulting from maintenance intervals for oil changes that exceeded the manufacturer's requirements for engines without external oil filters.

Frequently asked questions

What happened in the 2011-08-11 aircraft accident near BELO HORIZONTE, MG, BR?

A Cessna 150F experienced a catastrophic engine failure shortly after takeoff during a local instruction flight, resulting in a landing on the grass beside the runway.

What aircraft was involved and where did it happen?

The accident on 2011-08-11 involved a aircraft, registration PTCNG, at BELO HORIZONTE, MG, BR.

What was the probable cause of the accident?

The engine failure was caused by a catastrophic failure of the number 3 cylinder due to an exhaust valve seizure, resulting from maintenance intervals for oil changes that exceeded the manufacturer's requirements for engines without external oil filters.

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