What happened
On December 8, 2015, an Embraer EMB-202A, registration PT-VVS, was performing agricultural spraying operations at Fazenda Alto Jaguarí in Aguaí, São Paulo. The aircraft was conducting its ninth takeoff of the day, carrying a pilot and a load of 440kg of agricultural chemicals.
Shortly after passing the opposite end of the takeoff strip, the engine failed while the aircraft was at an altitude of approximately 10 meters. The pilot attempted to manage the emergency by jettisoning the chemical load and switching fuel tanks, but was unable to maintain flight. The aircraft subsequently collided with a sugarcane field at the end of the runway, resulting in substantial damage to the airframe. The pilot escaped the crash uninjured.
The investigation
CENIPA investigators examined the engine, which was a Lycoming IO-540-K1J5, and the maintenance records of the aircraft. While the aircraft was within its weight and balance limits, the investigation focused on the mechanical state of the ignition system.
During a detailed engine examination conducted months after the accident, investigators found that the left magneto was inoperable due to oxidized contact points (breaker points). Although investigators noted that this oxidation might have developed after the accident, they identified a critical discrepancy in the spark plugs: all plugs exhibited electrode gaps that exceeded the manufacturer's specifications. This condition could have caused engine roughness or an engine cutout by making it difficult for the electrical arc to jump between electrodes.
Additionally, the investigation noted that the pilot utilized a 20-degree flap setting during takeoff, a configuration not recommended by standard operating procedures for takeoff and climb, which potentially compromised the aircraft's performance during the emergency.
Findings
- The engine failure occurred during the takeoff phase of flight.
- Improper spark plug gap settings were identified, which may have contributed to abnormal engine operation.
- The pilot's use of 20-degree flaps during takeoff was inconsistent with standard procedures and reduced takeoff performance.
- Maintenance quality regarding the inspection of spark plugs during the previous 100-hour inspection remains an undetermined contributing factor.