Accident Details
On March 2, 2013, at approximately 1500 Atlantic Standard Time, a Robinson R44 II helicopter, registration N834RC, operated by a private individual, was destroyed when it collided with powerlines and terrain while performing an autorotation. The incident occurred near Ciales, Puerto Rico, following a reported loss of main rotor RPM. The private pilot, who held a private pilot certificate with a rotorcraft-helicopter rating, received minor injuries. The flight departed from a field near Yauco, Puerto Rico, at about 1420, destined for Fernando Luis Ribas Dominicci Airport (TJIG) in San Juan. Visual meteorological conditions prevailed, and no flight plan was filed. The flight was conducted under 14 CFR Part 91.
While en route at approximately 700 feet above ground level, the pilot observed a decay in rotor RPM and immediately initiated a 180-degree autorotation. The helicopter subsequently struck high-tension wires and then impacted terrain. A postcrash fire consumed a significant portion of the helicopter.
Pilot Information
According to Federal Aviation Administration (FAA) records, the pilot held a private pilot certificate with a rating for rotorcraft-helicopter. The pilot’s most recent FAA third-class medical certificate was issued on February 19, 2013. The pilot reported 239 total hours of flight experience, with 73 hours in the R44 helicopter.
Aircraft Information
The single-engine, single-rotor helicopter, serial number 11616, was powered by a Lycoming IO-540 engine producing 260 horsepower. The most recent annual inspection was completed on October 1, 2012, at 743 total aircraft hours.
Witness Accounts
Witnesses reported seeing a low-flying helicopter making exploding noises and emitting black smoke. The helicopter then collided with power lines, caught fire, and crashed beneath the power lines.
Engine Examination
Examination of the engine by an FAA inspector revealed no external impact or fire damage to the cylinders or manifolds. The engine was free to move when examined. Compression was confirmed on all six cylinders using a compression tester. The magnetos were not tested due to fire damage. Examination of the lower spark plugs showed normal wear on all six plugs. The fuel injection servo was removed and examined by an NTSB investigator on April 15, 2013, in Ashburn, Virginia; no anomalies were noted.
Weather Conditions
At 1550, the weather observation at Mercedita Airport (TJPS) in Ponce, Puerto Rico, located 20 miles south of the accident site, included wind from 150 degrees at 10 knots, visibility of 10 miles, few clouds at 3,000 feet, temperature 29°C, dew point 21°C, and an altimeter setting of 29.99 inches of mercury.