What happened
On April 5, 2002, a Cessna 152, registration EC-FGP, departed from Reus airport for a local pleasure flight. While flying near the town of Sant Carles de la Rapita at an indicated altitude of 1,300 feet, the pilot initiated a descent to 800 feet along the coastline. During this maneuver, the pilot engaged the carburetor heat and reduced engine power to approximately 1,700 RPM. Upon attempting to increase power to reach the target altitude, the engine power dropped significantly, nearly stalling.
After several unsuccessful attempts to restore engine responsiveness by manipulating the throttle, the pilot identified a suitable landing site on the beach near the port of Les Cases d’Alcanar, specifically choosing a section of the beach near the breaking waves to ensure a smoother surface. The aircraft performed an emergency landing on the beach, striking the right wing edge first, followed by the nose wheel. The aircraft sustained damage to the engine, propeller, right wing, and landing gear, but the one occupant of the aircraft remained uninjured.
The investigation
The investigation examined the aircraft at the accident site and at an authorized maintenance center. Technical inspections of the fuel and electrical systems revealed no anomalies. The aircraft had more than 80 liters of fuel on board, and the engine was still operational at the moment of impact.
Prior to takeoff, the pilot had performed standard pre-flight checks, including checking oil levels and draining fuel sumps, finding no signs of contamination. The investigation also reviewed the aircraft's flight manual and standard operating procedures for similar aircraft. It was noted that while the manual suggests using carburetor heat during the "before landing" phase, it advises against its use during "balked landing" maneuvers. Furthermore, standard practice for similar engines suggests that carburetor heat should only be used in icing conditions, which were not present during this flight.
Findings
- The primary cause of the accident was that the engine was unable to provide the required power due to the activation of the carburetor heat.
- The use of the carburetor heat caused the air entering the carburetor to increase in temperature and decrease in density. This resulted in an excessively rich fuel mixture, causing the engine to stumble and fail to respond to increased throttle.
- The use of carburetor heat was unnecessary given the ambient temperature of approximately 20 degrees Celsius and the lack of icing conditions.
- The pilot's decision to perform an emergency landing was appropriate given the low altitude and the lack of engine response.