History of Flight
On July 1, 2015, about 2215 Pacific daylight time, a Schweizer 269C helicopter, registration N2096W, was destroyed by impact forces and postcrash fire during a hard landing following an emergency autorotation near the Chelaham Airpark (17S) in Newberg, Oregon. The helicopter was operated by Precision Aviation Training, LLC, and owned by Precision Flight Training Incorporated. Visual meteorological conditions prevailed, and the local instructional flight operated under 14 CFR Part 91 without a flight plan. The flight departed 17S about 2200 for student night orientation, according to the company's Director of Operations.
A mechanic/witness observed the helicopter take off and climb to about 500 feet above ground level before hearing the engine roll back, followed by an autorotation. He then heard the engine rpm increase and drive belts squeal, then a loud thud. Another witness reported the helicopter passed very low with a rough engine sound and a high-pitched whining/squealing, then silence, followed by impact and fire. A third witness, also an employee, heard a high-pitched noise like ungreased belts and a loud sound similar to a backfire.
The accident site examination revealed the helicopter was on a left downwind leg for the departure airport when the crew experienced an inflight anomaly, leading to an emergency descent and hard landing. The helicopter impacted a harvested wheat field on a magnetic heading of about 173 degrees, coming to rest on a heading of about 355 degrees, about 0.75 nautical miles northwest of the departure airport. The first point of impact was about 27 feet north of the main wreckage. A postcrash fire consumed the helicopter.
Personnel Information
The certified flight instructor (CFI), age 31, held commercial and flight instructor certificates with rotorcraft-helicopter and instrument ratings. His most recent flight review was on March 13, 2015, and his second-class medical certificate was issued August 28, 2014, with a limitation for corrective lenses. He had accumulated 354.6 total flight hours, 278.1 hours in the same make and model, and 123.7 hours of instruction given. He began flight instructor duties on April 22, 2015.
The student pilot (PUI), age 29, received his student pilot certificate on April 17, 2015, with no limitations. He had logged 41.6 total flight hours, including 38.4 hours in helicopters and 35.8 hours in the accident make and model.
Aircraft Information
The helicopter, a 2004 Schweizer 269C, serial number S1865, was powered by a Lycoming HIO-360-D1A engine rated at 190 horsepower. The engine had accumulated 3,729.2 hours total time, with 21.9 hours since its most recent inspection on June 22, 2015, and 849.8 hours since major overhaul. The most recent 100-hour inspection was on June 2, 2015, at an airframe total time of 3,757.5 hours.
Meteorological Information
At 2253, the weather reporting facility at McMinnville Municipal Airport (MVV), about 8.5 nautical miles south-southwest of the accident site, reported wind 260° at 4 knots, visibility 7 miles, clear sky, temperature 22°C, dew point 14°C, and an altimeter setting of 29.94 inches of mercury.
Wreckage and Impact Information
Postaccident examination revealed severe fire damage. The frame tubing had multiple fractures, kinks, and bends. The tail boom was separated but intact with no blade strikes. The landing gear and crossbeams were severely damaged. The main rotor blades remained attached at the root ends, with two exhibiting thermal damage. The belt drive assembly was largely consumed by fire. The engine cooling fan disk and starter ring gear were found about 20 feet south of the main wreckage. The engine crankshaft prop flange was cracked. No evidence of a catastrophic in-flight engine failure was found.
Medical and Pathological Information
Autopsies on both occupants, performed on July 2, 2015, determined the cause of death for each as blunt force chest trauma. Toxicology tests for the CFI were negative for carbon monoxide, ethanol, and tested drugs; acetone was detected but not quantified. For the student, tests were negative for carbon monoxide and ethanol; pheniramine was detected in urine but not blood. Cyanide testing was not performed.
Tests and Research
Components including the impeller, drive adapter, drive shaft assembly, and grease sample were examined at the NTSB Materials Laboratory. The impeller showed overstress separation with no pre-existing cracks. The drive adapter had heat exposure and severe deformation on inner spline teeth. The drive shaft's forward spline exhibited severe wear and deformation with no grease, while the aft spline showed minor wear and had grease. The grease sample contained solid particles. The drive shaft material and hardness were consistent with specifications.