Introduction
On May 13, 2012, at approximately 1454 Pacific daylight time, a Schweizer 269C-1 helicopter (registration N61482) sustained substantial damage during an off-airport landing near Hillsboro, Oregon. The helicopter was registered to and operated by Hillsboro Aviation Inc., of Hillsboro, Oregon, under Title 14 Code of Federal Regulations Part 91 as an instructional flight. The certified flight instructor (CFI) and the private pilot receiving instruction were not injured. Visual meteorological conditions prevailed, and a company flight plan was filed. The local flight originated from Portland-Hillsboro Airport (HIO) at about 1415.
Flight Details
According to the CFI's written statement to the National Transportation Safety Board (NTSB), after departure he located an off-airport landing area at an elevation of about 1,000 feet mean sea level (msl) to practice off-airport landings. After circling the area, the pilot receiving instruction initiated an approach from the south. Following an uneventful landing and takeoff, the pilot circled the area and initiated a second approach from the west to a hover over the intended landing area. The CFI observed the engine revolutions per minute (RPM) at the bottom of the green arc, about 2,500, and asked the pilot to bring the RPM back to the top of the arc. The pilot reported they were at full throttle, and the CFI took control. About 30 seconds later, the CFI turned the helicopter to the north and initiated takeoff. As the helicopter transitioned through effective translational lift (ETL), the CFI observed the RPM drop to about 2,300 to 2,400 and the helicopter began to descend. The CFI maneuvered toward a level road but was unable to reach it. The helicopter then landed on sloping terrain, and the tail rotor struck the ground.
Pilot Receiving Instruction's Account
The pilot receiving instruction reported that the first off-airport landing was performed to the north and was uneventful. He initiated a second approach to the same landing area to the east and maneuvered to an approximately 1- to 3-foot hover. The CFI told him to roll on throttle because the engine RPM was at the bottom of the green arc. The pilot stated that the CFI took over the controls, verified the gauges, and initiated a takeoff to the left. The CFI accelerated the helicopter over the ground as it sloped downhill, but the engine RPMs were "drooping." The pilot last observed the engine RPM needle indicating between 2,200 and 2,300 RPM and heard the engine "drooping." As the CFI attempted to land on a road, he heard the engine and rotor RPM dropping as the helicopter landed in a clear area just below the road.
Both the CFI and the pilot did not recall hearing a low rotor RPM warning or seeing an illuminated warning light during the accident sequence.
Post-Accident Examination
Review of the Pilot's Operating Handbook for the accident make and model helicopter revealed that the green arc for engine RPM is from 2,530 to 2,700 RPM. Examination by a Federal Aviation Administration (FAA) inspector found that the helicopter sustained structural damage to the tailboom, and the vertical stabilizer was separated. After recovery and a brief inspection, the engine was started and ran uneventfully with no anomalies noted.