What happened
On August 30, 2015, an EMB-721C aircraft, registration PT-EPD, departed from the Ourilândia do Norte Aerodrome in Pará, Brazil, bound for Kendjan Village. During the flight, the engine's second cylinder became loose, leading to significant oil leakage and subsequent engine failure. The aircraft failed to reach its destination and was reported missing.
On September 1, 2015, the wreckage was located in a dense jungle area approximately 86 nautical miles from the departure aerodrome. The aircraft had sustained substantial damage, including wings being ripped from the fuselage and a deformed nose. The impact occurred in a forested area where the aircraft struck large trees. The two fatalities involved were the pilot and a passenger, both of whom were found restrained in their seats.
The investigation
CENIPA investigators examined the wreckage and identified critical mechanical failures. Analysis of the engine revealed that cylinder #2 had detached from the crankcase assembly. Evidence of "mirror marks" on the cylinder skirt indicated that the component had been working loose for a period of time prior to the total failure. Furthermore, investigators discovered that the installed crankcase assembly was incompatible with the engine type; the part found was intended for turbocharged engines, representing an unauthorized major modification to the aircraft's design.
Findings
- The primary cause of the engine failure was the unauthorized installation of an incompatible crankcase assembly, which led to the loosening and eventual detachment of cylinder #2.
- Maintenance oversight failures allowed an unapproved component to be installed and remain undetected during engine reviews.
- The aircraft was operating with a major modification that had not been properly authorized or recorded according to Brazilian civil aviation regulations.
- The aircraft had taken off from an unregistered runway and was carrying unauthorized cargo (groceries) in the rear seats.