History of Flight
On November 25, 2012, at 2308 Pacific standard time, a Robinson R44 II, registration N4204A, collided with a fueling structure at Corona Municipal Airport in Corona, California. The helicopter was departing on a cross-country personal flight to Fullerton, California, under Part 91 of the Federal Aviation Regulations. The commercial pilot, who was also the owner, sustained fatal injuries, and the helicopter sustained substantial damage from impact forces and a post-crash fire. Instrument meteorological conditions prevailed, and no flight plan had been filed.
A friend reported that he picked up the pilot at French Valley Airport in Temecula around 1630, and they attended an event together. He dropped the pilot back at the airport about 2200. Fueling records showed that the pilot added 40.6 gallons of 100LL fuel approximately 15 minutes before the accident.
Security video footage revealed that the helicopter was positioned facing a fuel island, with the cabin partially under a circular metal canopy. After lift-off, the helicopter performed an immediate pedal turn to the right. As the turn neared 180 degrees, the helicopter pitched forward, causing the tail and main rotor blades to contact the canopy. The helicopter then flailed and continued turning, coming to rest after a 180-degree rotation back to its original direction. Seconds later, a fire started, followed by an explosion.
Personnel Information
The 61-year-old pilot held a commercial pilot certificate with ratings for airplane single-engine land, rotorcraft-helicopter, and instrument airplane. He also held a certified flight instructor certificate for airplane single-engine land. His third-class medical certificate was issued on October 23, 2012, without limitations or waivers. The pilot reported on his medical application a total flight time of 1,500 hours, with 50 hours logged in the previous six months.
Aircraft Information
The Robinson R44-II, serial number 12634, had a total airframe time of 133.4 hours at the last annual inspection on February 2, 2012. The engine, a Lycoming IO-540-AE1A5, serial number L33351-48E, also had 133.4 hours. Maintenance records indicated no unresolved discrepancies before the flight.
Meteorological Information
An aviation routine weather report (METAR) for Corona issued at 2256 indicated calm winds, visibility 2.5 miles in mist, an overcast ceiling at 300 feet, temperature 12°C (54°F), and an altimeter setting of 29.98 inches of mercury.
Wreckage and Impact Information
The helicopter came to rest partially under the metal canopy of the fuel island, which sustained a gash with torn metal sheets hanging. The R44's mast height was 129 inches (10.75 feet), and the rotor radius was 198 inches (16.5 feet); the canopy was 14 feet above ground. Severe fire damage extended from the mid tail boom forward, consuming most of the cabin.
The main rotor blades showed impact and thermal damage; one spar separated and was found several hundred feet away in a hangar. The main rotor gearbox separated from the airframe, with deformation and separation in frame tubes exhibiting jagged fracture surfaces. The tail rotor driveshaft disconnected aft of the intermediate flex plate, with damage consistent with severe thermal exposure. Tail rotor blades sustained minor impact damage, with rotational scoring at their tips. A semi-circular ground scar with red paint transfer was noted.
Medical and Pathological Information
An autopsy conducted by the Riverside County Coroner determined that diffuse thermal injury and inhalation of products of combustion were the causes of death. Toxicological testing by the FAA Forensic Toxicology Research Team found no carbon monoxide, cyanide, volatiles, or tested drugs.
Tests and Research
Investigators from the NTSB, FAA, Robinson Helicopter Company, and Lycoming examined the wreckage on November 27, 2012. Warning light bulbs on the annunciator panel were inspected; all surviving elements were tight except the clutch light, which was stretched. The main rotor gearbox chip detector was clean, and the gearbox rotated freely. Rotational scuff marks were noted on the upper sheave and cooling fan wheel. The sprag clutch operated properly. Flight control rod ends were accounted for, with separations attributed to thermal damage and no preimpact failure indications. The fuel valve was in the ON position; manual and auxiliary fuel pumps were partially consumed by fire. A borescope inspection of the engine revealed no mechanical deformation, and manual rotation produced compression on all cylinders. No mechanical anomalies were identified in the airframe or engine.