Aviation Accident Summaries

Aviation Accident Summary ERA13LA018

Yorktown, NY, USA

Aircraft #1

N443FD

SIKORSKY S-55B

Analysis

During cruise flight, the pilot heard an unusual noise and, after circling while attempting to determine the source of the noise, he elected to perform a precautionary landing to a nearby farm field. During the approach to land with a quartering tailwind, the pilot used the collective to arrest the descent rate; however, after having used the full travel of the collective with no appreciable reduction in the descent rate, the helicopter landed in the soft ground, all four landing gear sank, and the helicopter rolled over and came to rest on its left side. No preimpact mechanical malfunctions or anomalies were noted that would have precluded normal operation. A nearby weather recording station recorded the wind about the time of the accident as being from the north-northwest at 12 knots, gusting to 16 knots. According to the pilot, the helicopter was moving forward at a speed of about 10 knots at touchdown. Considering the tailwind and the helicopter's low airspeed, it is likely that the airspeed slowed to the point where the helicopter lost translational lift and began to settle with power.

Factual Information

HISTORY OF FLIGHT On October 12, 2012, about 1800 eastern daylight time, a Sikorsky S-55B, N443FD, was substantially damaged during an off airport precautionary landing near Yorktown, New York. The commercial pilot and passenger were not injured. The helicopter sustained substantial damage to the main rotor and left side of the fuselage. The helicopter was operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a ferry flight. Visual meteorological conditions prevailed and no flight plan was filed for the flight destined for the Igor I Sikorsky Memorial Airport (BDR), Bridgeport, Connecticut. The flight originated from Newton Airport (3N5), Newton, New Jersey, approximately 30 minutes prior to the accident. According to the pilot, while in cruise flight, with a quartering tailwind, an unusual noise was heard. He elected to perform a precautionary landing to a farm field. As the helicopter descended for the precautionary landing, the pilot utilized the collective to arrest the descent rate beginning about 30 feet above ground level. However, utilizing the full travel of the collective the helicopter continued with no noticeable reduction in descent. The helicopter landed in the field, all four landing gears sank into the soft ground, and the helicopter rolled over and came to rest on the left side of the fuselage. PERSONNEL INFORMATION The pilot, age 59, held a commercial pilot certificate for airplane single-engine land, multiengine land and sea, helicopter, and a second-class airman medical certificate issued July 24, 2012. The pilot reported about 6,800 total flight hours with approximately 4,800 total flight hours in rotorcraft and approximately 800 total flight hours in the accident helicopter make and model. AIRCRAFT INFORMATION The six-seat, four-wheeled helicopter was powered by a Wright R1300-3D, 800-hp 7-cylinder radial engine. According to the pilot, the helicopter's most recent annual inspection occurred on September 14, 2008, with a recorded time of 2,594 total hours. METEOROLOGICAL INFORMATION A review of the recorded data from the Westchester County Airport (HPN), White Plains, New York, located about 15 miles to the northwest of the accident location, revealed at 1756 conditions indicated wind 350 at 12 knots with gust of 16 knots, visibility of 10 miles, cloud conditions were scattered at 3500 and 7500 feet above ground level, temperature was 10 degrees C, dewpoint was minus 1 degrees C, and the barometric altimeter was 30.23 inches of mercury. WRECKAGE AND IMPACT INFORMATION Initial examination of the wreckage by a Federal Aviation Administration (FAA) inspector revealed buckling of the structure along the tail section. In addition, the main rotor blades and the left side of the helicopter sustained substantial damage. Fuel was observed at the accident location. Several ground scars, consistent with the forward and aft wheels, were noted at the accident site. The ground scars were several feet in length, approximately 1-foot in depth, and were in line with the landing direction. According to the FAA inspector who interviewed the pilot, the helicopter was moving in a forward direction at the time of touch down about 10 knots. ADDITIONAL INFORMATION The engine data monitoring (EDM) system was examined by the Safety Board's Recorders Laboratory. The examination revealed that the exhaust gas temperature was between 1,000 and 1,500 degrees F and the cylinder head temperature was indicating between 275 and 325 degrees F. According to the FAA Rotorcraft Flying Handbook, vortex ring state (settling with power) describes an aerodynamic condition where a helicopter may be in a vertical descent with up to maximum power applied, and little or no cyclic authority. The term "settling with power" comes from the fact that the helicopter keeps settling even though full engine power is applied. Among the conditions listed which were conducive to settling with power were: attempting to hover out of ground effect without maintaining precise altitude control, and downwind or steep power approaches at low forward airspeed.

Probable Cause and Findings

The pilot's improper decision to perform a downwind precautionary landing and the helicopter’s resultant settling with power and impact with terrain.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports