Summary
On July 19, 2009, about 0840 Eastern daylight time, a Robinson R44 II helicopter, registration N25VH, was substantially damaged during a forced landing near Silver Spring, Pennsylvania. The student pilot, the sole person on board, was not injured. The flight was conducted under Part 91 as an instructional flight in visual meteorological conditions without a flight plan.
Flight History
The pilot departed Frederick Municipal Airport (FDK) at about 0745 for Lancaster Airport (LNS). She cruised at 3,000 feet msl at 110 knots. After establishing communication with LNS tower, while beginning descent, she noticed the vertical speed indicator showed a descent of about 1,000 fpm and airspeed of 120 knots. Manipulating the collective, cyclic, and throttle did not stop the descent. She decided she could not reach LNS and selected a field for landing. Although the engine was operating, she performed an autorotation. The helicopter landed hard in a soybean field, remained upright, and the engine continued running until she shut it down normally.
Personnel and Aircraft Information
The pilot held a private pilot certificate with airplane single-engine land rating and a senior parachute rigger certificate. She had about 212 hours of fixed-wing and 64 hours of rotary-wing experience, 62 in the R44. The helicopter, manufactured in 2004, had a Lycoming IO-540 engine. It was owned by a corporation, leased to an FBO at FDK, and rented by the pilot. Total time was 898.9 hours. The most recent 100-hour inspection was on May 30, 2009. On June 23, 2009, three rebuilt hydraulic servos were reinstalled, and service bulletins SB 69 and SB 388C were complied with.
Meteorological Information
The 0856 LNS weather observation recorded wind from 310 degrees at 9 knots, 10 miles visibility, clear skies, temperature 21°C, dew point 13°C, and altimeter 30.11 inHg.
Wreckage and Impact
The helicopter landed about 8 miles west-southwest of LNS. Landing skids were deformed upward; right side and underside of fuselage buckled; one engine mount deformed, another fractured. Fuel was clear and bright. Control checks showed full travel with no binding. On-scene examination found no pre-impact failures or anomalies explaining the inability to maintain altitude. The insurer deemed the helicopter damaged beyond economical repair; it was disassembled after follow-up tests.
Post-Accident Examinations
Four days after the accident, FAA and NTSB personnel examined the helicopter. Main drive V-belts were good; hydraulic reservoir full; spark plugs clean; intake air filter clean; fuel servo throat clean with correct throttle movement; fuel strainer clean; injectors clear. The engine was test-run and operated smoothly up to 90% rpm for about 5 minutes. It was then shipped to Lycoming for further testing.
At Lycoming on October 14, 2009, the engine appeared undamaged. Oil suction screen had three small black flakes (presumed carbon); oil filter was not opened; magneto timing was within limits (left 22°, right 23°); spark plugs showed normal wear. The engine was run under a production test program for about 50 minutes, achieving target rpm. No further disassembly was warranted.
Hydraulic System
The R44's main rotor controls are hydraulically boosted. The hydraulic system toggle switch was on the cyclic control panel. Normal procedures require hydraulics on for all flight; the POH states hydraulic failure is indicated by heavy controls. The helicopter had no annunciation for hydraulics off. The pilot had practiced hydraulics-off operations. She stated the system was operating throughout the flight. Post-accident examination found no evidence of hydraulic malfunction or that the switch was turned off.