Accident Details
On February 1, 2015, at about 0030 Pacific standard time, a Robinson R44 II helicopter, registration N510KJ, performed a forced landing following a partial loss of engine power approximately 5 miles east of Calexico, California. The commercial pilot was not injured, and the helicopter was substantially damaged. The helicopter was registered and operated by John Reed Aviation as a 14 Code of Federal Regulations Part 137 aerial application flight. Night, visual meteorological conditions prevailed, and no flight plan was filed. The local flight originated at Calexico International Airport, Calexico, California, about 0025.
Pilot Information
The pilot reported in a written statement that the pilot who flew the helicopter on the previous flight stated to him prior to the accident flight that there was a "feeling and increasing vibration on the pedals." A subsequent examination of the helicopter revealed no anomalies. The pilot started the accident helicopter and performed a hover control check to ensure everything was working properly, then took off for a high reconnaissance of the field. After reaching the field and during the first turn, the engine experienced a partial loss of power. The pilot described that during a turning maneuver at the conclusion of a spray pass, the rotor RPM decreased. He lowered collective and rolled on throttle, turned west to avoid power lines, and flared near the ground. The helicopter landed hard and rolled onto its right side, resulting in substantial damage to the forward fuselage and tailboom.
The pilot reported a total flight time of 583 hours in rotorcraft, with 40 hours in the last 90 days and 85 hours of night flying experience.
Weather Conditions
United States Naval Observatory data indicated that sunset and end of civil twilight at the accident site were at 1714 and 1740, respectively. The moon was in a waxing gibbous phase, with 96% of the moon's visible disk illuminated.
Wreckage Examination
Examination of the helicopter was performed by the National Transportation Safety Board (NTSB) and a Federal Aviation Administration (FAA) inspector. The agricultural sprayer assembly was removed from the fuselage prior to examination. Main rotor blades, tail boom sections, drive shaft, tail rotor assembly, and four transmission drive belts were removed from the helicopter prior to examination and found with the main wreckage. The four transmission drive belts were cut to facilitate their removal and revealed normal wear. A section of the tail rotor pitch control rod, about 3 feet in length, separated from the aft control rod end and was not found during examination. Examination of the fuselage revealed that the windshield separated from both left and right sides and was buckled in several locations. The main rotor blades remained intact and were buckled in several locations. The tail rotor assembly was intact, and the stinger separated near the aft attachment. The tail rotor blade pitch movement moved freely by hand. The engine cowling and fan shroud were undamaged. The instrument panel was undamaged. Control continuity was established from the cabin controls to the swashplate and damaged tail rotor control rod. Examination of the Lycoming IO-520-AE1AA engine revealed no anomalies. The helicopter was set up for a test run, and the engine started with little hesitation. The engine ran smoothly for several minutes, and a magneto check was performed. Several throttle bursts were applied, and the engine was shut down normally.