Aviation Accident Summaries

Aviation Accident Summary WPR19LA097

Newberg, OR, USA

Aircraft #1

N119T

MD HELICOPTER 369

Analysis

The pilot and his passenger were enroute to an airport to refuel when the engine lost all power. The pilot performed a forced landing in an open field, during which the helicopter landed hard and rolled over. No fuel was found inside the helicopter’s fuel tank following the accident. During an engine test run, the engine started normally and operated through all power settings with no evidence of a mechanical anomaly. The helicopter was fueled to capacity about two weeks before the accident and, at the time of the accident, had flown a total of about 2 hours, 44 minutes since it was fueled. The pilot reported that the helicopter’s fuel consumption rate was between 14 and 16 gallons per hour (gph); however, the owner’s manual performance charts indicated a consumption of 21 gph, and during the postaccident test run, the engine consumed about 26 gph at approximate cruise power demands. At these fuel consumption rates, the helicopter’s fuel endurance with full fuel was between 2 hours, 35 minutes, and 2 hours, 54 minutes. It is likely that the pilot miscalculated the amount of fuel needed for the flight using incorrect fuel consumption rates, which resulted in fuel exhaustion and a subsequent total loss of engine power.

Factual Information

On March 17, 2019, about 1605 Pacific daylight time, an MD Helicopters Inc 369HS helicopter, N119T, was substantially damaged when it was involved in an accident near Newberg, Oregon. The private pilot and his passenger were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that he and two passengers departed South Lewis County Airport (TDO), Toledo, Washington, with about 170 pounds (gallons) of fuel on board. He arrived and landed at a private property about 38 minutes later. After a two-hour delay, he departed with one passenger for McMinnville Airport (MMV), McMinnville, Oregon, where he had planned to refuel the helicopter. About 6 minutes into the flight, the engine began to lose power. The pilot initiated an autorotation and cycled the fuel boost pump in an effort to regain power. He performed a 180° turn during the autorotation to an open field. Upon touchdown, the helicopter's left skid dug into the ground and sheared off, and the helicopter rolled onto its right side. The pilot stated that the engine was not producing a sound at touchdown. The pilot and the passenger exited the helicopter unassisted. The pilot stated that he did not think he ran out of fuel, because the low fuel light illuminated, which indicated about one hour of fuel remaining. The pilot estimated the helicopter’s fuel consumption rate as between 14 and 16 gallons per hour. The helicopter came to rest in an open field. The debris field was small and localized around the helicopter. There was no post-impact fire, and the pilot stated there was no mechanical anomalies that would have precluded normal operation. The helicopter was recovered from the accident site to a secure facility by the pilot, who stated that during recovery, he cleaned up about 10 gallons of fuel-soaked dirt located beneath the fuel filler port. Post-accident examination of the engine and airframe did not reveal any anomalies that would have precluded normal operation. The engine was further examined, and a test run was performed at the facilities of Keystone Turbine Services, Coatesville, Pennsylvania, under the supervision of the Federal Aviation Administration. The test run was nominal and uncovered no anomalies that would have precluded normal operation. During examination, while the helicopter was resting on its side, access to the interior of the fuel tank was gained by removing the fuel quantity indicator assembly. A borescope was inserted into the fuel cell, but fuel was not visible. The helicopter was then placed in the upright position, and again no fuel was observed in the fuel cell. A test of the low fuel system was conducted using water as a substitute for fuel. The helicopter was placed in a level attitude and 24-volt DC power was applied to the helicopter. The low fuel light illuminated. 15 gallons of water were then placed into the fuel cell, and the low fuel light extinguished. The water was then drained via the fuel drain located on the bottom of the fuselage and with 7 gallons remaining in the tank, the low fuel light illuminated. Fuel Consumption The Owner's Manual indicated that the maximum fuel quantity was 416 lbs. (about 61 gallons). According to the supplemental type certificate data sheet for H3WE, the total of trapped and unusable fuel was 3.66 pounds, or about ½ gallon unusable. The Owner's Manual indicated that the low fuel light illuminated when approximately 35 lbs. (about 5.2 gallons) remained. It also stated that, at low fuel levels, side slip angle may cause the fuel tanks outlet to become uncovered, causing fuel starvation. According to the pilot, the helicopter weighed about 1,814 pounds at the time of the accident. The Owner's Manual indicated a fuel flow of 142 lbs. (about 21 gallons) per hour at 20°C, sea level, and a gross weight of 1,800 lbs. During the postaccident test run, the engine’s fuel consumption was about 174.4 pounds (26 gallons) per hour at power demands consistent with cruise flight. Using the fuel flow rates from the Owner's Manual with a full tank (61 gallons) provided an endurance value of 2 hours, 54 minutes. Based on the fuel consumption observed during the postaccident test run, the helicopter’s endurance with full fuel was about 2 hours 35 minutes. The pilot stated that he refueled the helicopter on March 2, 2019, and at that time the fuel tank was filled to capacity. After that fueling, the helicopter flew a total of about 2 hours and 44 minutes.

Probable Cause and Findings

The pilot's improper fuel planning, which resulted in fuel exhaustion and a subsequent total loss of engine power.

 

Source: NTSB Aviation Accident Database

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