History of Flight
On November 12, 2008, at 1431 Atlantic standard time, a Robinson Helicopter R44, registration N452JM, was substantially damaged when it impacted a runway after a loss of control while hovering at Fernando Luis Ribas Dominicci Airport (TJIG), San Juan, Puerto Rico. The certificated commercial pilot received minor injuries, while the passenger was seriously injured. On January 10, 2009, the passenger died from his injuries. Visual meteorological conditions prevailed, and a visual flight rules flight plan was filed for the flight, which departed Cyril E. King Airport (TIST), Saint Thomas, U.S. Virgin Islands, about 1300. The personal flight was conducted under 14 Code of Federal Regulations Part 91.
The pilot stated that he completed his approach to runway 9, abeam the U.S. Customs facility on the north side of the runway. He was then instructed by the tower controller to hover-taxi to the U.S. Customs parking ramp. The pilot initiated a hovering turn to the north, when the helicopter pitched up, rolled left, struck the main rotor on the ground, and eventually came to rest on its left side.
Personnel Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine land, airplane multiengine land, instrument airplane, and rotorcraft-helicopter. His most recent FAA second-class medical certificate was issued in June 2008. The pilot reported 1,700 total hours of flight experience, 800 hours in helicopters, and 530 hours in the Robinson R44.
Aircraft Information
According to the pilot and FAA records, the helicopter was manufactured in 2000 and had accrued 510 total aircraft hours. Its most recent annual inspection was completed July 17, 2008, at 497.5 aircraft hours. During that inspection, the left lateral servo was removed and replaced for a leak repair.
The mechanic who performed the pre- and post-inspection stated that he would itemize discrepancies for correction during the annual inspection and then re-inspect. He noted a wiring repair using automotive electrical tape near the battery or starter relay, which he wrote up as a discrepancy. The mechanic stated that he did not know who performed maintenance between annual inspections. He described the removal of the left lateral cyclic servo as requiring disconnection from the bottom of the vertical push-pull tube, and that the maintenance manual prescribed removal only at that point. The mechanic stated that the flight controls were secure and marked with torque seal after the annual inspection.
Meteorological Information
At 1456, weather conditions at Luis Munoz Marin International Airport (TJSJ), 6 nautical miles east, included few clouds at 3,200 feet, visibility 10 miles, temperature 30°C, dewpoint 22°C, altimeter 29.82 inHg, and winds from 070° at 13 knots.
Wreckage and Impact Information
Examination of photographs taken by the FAA inspector revealed that the forward right, forward left, aft, and fixed scissor attachment points of the non-rotating swashplate were visible. All control tubes and scissor rod-ends were attached except the forward left. The forward left attachment ear had no corresponding attachment hardware, and the rod-end was separated from the top of the control tube. The fracture surface appeared consistent with overload. A search of the wreckage and crash site did not produce the rod-end. A court-ordered search on January 25, 2010, also did not recover the rod-end.
Detailed examination showed flight control continuity throughout, except at the left lateral servo control tube separation. The interior bore of the left lateral servo attachment ear had marks consistent with the dimensions and spacing of the attachment bolt threads.
A consultant hired by the owner inspected the wreckage on August 12, 2009, under FAA supervision. The swashplate and support assembly were examined at McSwain Engineering in Pensacola, Florida, on March 11-12, 2010. Photographs revealed thread marks consistent with rotational scoring and multiple impacts. A swab of the interior bore recovered metal filings. An NTSB senior metallurgist concurred with the examination.
Additional Information
Examination of the Robinson Helicopter maintenance manual showed that removal of the left lateral cyclic servo did not require disconnection of the C121-31 (upper) control tube from the swashplate; only the C121-28 (lower) control tube needed to be removed with the servo. Inspection and maintenance items performed during the most recent annual inspection included no procedures that required disconnection of the upper left lateral servo push-pull tube rod end at the swashplate attachment ear.