What happened
On December 7, 2000, an EMB-721C aircraft, registration PT-EKX, departed from the Jataí aerodrome (SWJW) for a local flight with three people on board. Shortly after climbing through 500 feet and entering a left turn, the engine suffered a sudden failure. The pilot attempted to restart the engine but was unsuccessful.
Seeking an emergency landing site, the pilot identified an open field near a river. During the approach, the pilot encountered a group of trees approximately 15 meters in height. In an attempt to clear the obstacle, the pilot performed a maneuver that caused the aircraft to lose airspeed and lift. Consequently, the aircraft entered a stall and collided with the ground in a level attitude. The impact caused severe damage to the engine, propeller, landing gear, fuselage, and left wing. The three occupants sustained serious injuries.
The investigation
CENIPA investigators examined the engine and fuel system, discovering that the fuel injector was failing to provide fuel to the distributor unit. The investigation revealed that a self-locking nut (PN 1SG344) had detached from its seat, causing the diaphragm to displace and sealing the fuel passage. While the exact cause of the nut's detachment could not be determined, investigators noted it may have resulted from improper maintenance or material failure. Additionally, it was found that the magneto had not been updated in accordance with Airworthiness Directive AD nº 96-12-07.
Regarding the occupants, investigators noted that the pilot and one passenger were not wearing safety harnesses, which likely contributed to the severity of their injuries. The investigation also noted that the aircraft's maintenance records were up to date, with a 100-hour inspection performed only five hours prior to the accident.
Findings
- Engine failure caused by the detachment of a self-locking nut in the fuel injector, which interrupted the fuel flow.
- Improper judgment by the pilot regarding the selection of the landing site and the approach trajectory.
- Limited flight experience in this specific aircraft type, which contributed to the loss of control during the obstacle avoidance maneuver.
- Potential maintenance deficiencies regarding the securing of engine components and failure to comply with relevant Airworthiness Directives.