History of Flight
On July 11, 2008, at 1050 eastern daylight time, an Agusta A109E, registration N109DU, operated by AirMed, Incorporated, experienced a partial loss of engine power after takeoff from Doctors Hospital Heliport (8GA4), Augusta, Georgia. The helicopter sustained minor damage during a subsequent forced landing. The certificated commercial pilot and two crew members were not injured. Visual meteorological conditions prevailed, and a company flight plan was filed for the positioning flight conducted under 14 CFR Part 91, destined for Brevard, North Carolina.
The pilot reported that after ascending to a hover over the helipad and conducting a power check, the helicopter departed in a northwesterly direction, climbing to about 30 feet, where both engines lost power. The pilot executed a right pedal turn and maneuvered back toward the helipad, but landed short, straddling a fence separating the pad from an adjacent road. The main landing gear sustained minor damage, and the helicopter's skin was punctured in a non-structural area.
Personnel Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine land, rotorcraft helicopter, and instrument airplane and helicopter. His most recent FAA second-class medical certificate was issued on October 24, 2007. He reported 6,400 total flight hours, including 6,000 hours in rotorcraft, 950 hours in the Agusta 109 series, and 18 hours in the Turbomeca-powered Agusta A109E, all in the accident helicopter.
Aircraft Information
The helicopter had accrued 2,800 total aircraft hours. It was maintained under a manufacturer's continuous inspection program, with the most recent inspection completed on April 17, 2008.
Meteorological Information
At 1053, the weather at Augusta Regional Airport (AGS), 8 miles southwest, included scattered clouds at 2,300 feet, wind from 310 degrees at 4 knots, visibility 10 miles, temperature 28°C, and dew point 23°C.
Tests and Research
The digital engine control units (DECUs) from both engines were removed and examined. The number 2 DECU revealed a "Stepper Motor Channel Fault." After reinstallation and troubleshooting, a fault was consistently produced on the number 2 engine when power was reapplied. The number 2 hydro-mechanical unit (HMU) was replaced, after which no faults were noted. Further testing in France under BEA supervision found that the DECU and HMU functioned normally. However, inspection of the regulation harness revealed moisture deposits, corrosion, and cracked, burned insulation on wire 3.
Data from the DECUs showed that the stepper motor fault on the number 2 engine was recorded 98 seconds after power-up with the engine mode switch in idle, causing the HMU fuel metering needle to freeze at 65% N1. The number 1 DECU recorded a level 1 "collective pitch channel fault" 209 seconds after power-up, which did not affect control and was not displayed. The parameters showed the limit override button was off, and the 102% NR switch was not activated before takeoff, as required by the flight manual.
Additional Information
A subsequent review identified a 17-second one-engine-inoperative (OEI) event that occurred on May 7, 2007, prior to the accident flight. The helicopter was not equipped with an optional "Engine Out Kit" offered by the manufacturer.