Le Sueur, MN, USA
N9005T
CONTINENTAL COPTERS INC. TOMCAT MK5A
The commercial pilot stated that, during the preflight inspection of the helicopter before the agricultural flight, there were about 23 gallons of fuel onboard, which he determined was sufficient to complete the 45- to 60-minute flight to his destination. The pilot stated that, before departure, the helicopter fuel gauge indicated "close" to 3/4 full. Based on the helicopter's total fuel capacity (41 gallons), a 3/4-fuel quantity indication would have equated to about 30 gallons. About 50 minutes into the flight and 7 miles from the destination airport, the engine lost power. The pilot performed an autorotation to a field, during which the helicopter impacted terrain and sustained substantial damage. During postaccident examination of the helicopter, no usable fuel was found; however, the fuel gauge indicated a little over a 1/4 tank of fuel remaining. The examination revealed that the fuel transmitter's resistive element was corroded. The fuel transmitter was tested, and the resistive values were uncorrelated to the transmitter's float position. A new fuel transmitter from the operator's parts department was tested, and the resistive values corresponded to the float position no anomalies were noted. Although the fuel gauge was indicating that a sufficient amount of fuel was onboard for the flight, the pilot should have visually checked the fuel quantity in the tanks before takeoff to ensure that a sufficient amount of fuel was onboard for the flight, which he did not do. His improper preflight fuel planning and his dependence on erroneous fuel gauges led to the subsequent fuel exhaustion and total loss of engine power.
On July 26, 2018, at 2100 central daylight time, a Continental Copters Inc. Tomcat MK5A, N9005T, experienced a total loss of engine power during cruise flight. The pilot performed an autorotation to a field and impacted terrain about six miles east of Le Sueur, Minnesota. The commercial pilot received minor injuries, and the helicopter sustained substantial damage. The helicopter was registered to and operated by Scotts Helicopter Service Inc under Title 14 Code of Federal Regulations Part 137 as a ferry flight that was not operating on a flight plan. Dusk visual meteorological conditions prevailed for the flight that departed from Hastings, Minnesota at 2009 and was destined to Le Sueur Municipal Airport (12Y), Le Sueur, Minnesota. The pilot stated that during preflight inspection of the helicopter, there was about 23 gallons of 100 low lead fuel aboard, and he thought that was enough fuel to complete a flight to 12Y. He stated the helicopter would consume 15-17 gallons of fuel per hour and it usually took 45 minutes to an hour to complete the flight. He said that prior to departure, the fuel gauge indicated "close to ¾ full." About 5-10 minutes after departure, he remembered that he forgot to sump the fuel tank and landed the helicopter to sump the fuel tanks. He then continued the flight and about 7 miles east of 12Y, about 400-500 feet above ground level and at 60 knots, the engine sputtered, regained power for a second, and then quit. He performed an autorotation to a field, and the helicopter impacted terrain. The type certificate for the helicopter was held by the operator. According to the type certificate data sheet for the helicopter, the fuel capacity for the helicopter was 41 gallons. The last annual inspection of the helicopter was dated February 14, 2018 and was performed by the operator's maintenance personnel. Postaccident examination of the helicopter by a Federal Aviation Administration inspector revealed no useable fuel aboard and the fuel gauge indicated a little over ¼ tank of fuel. The fuel transmitter was of the resistive type manufactured about 1974 by Stewart Warner. The fuel transmitter's resistive element was corroded. The fuel transmitter was tested using an Ohm meter, and the resistive values were uncorrelated to float position. The inspector stated the operator had a new fuel transmitter in their parts department, which he tested, and found that the resistive values corresponded to float position and had no anomalies. According to the inspector, the owner/operator stated, "pilots don't depend on those gauges – but they always stick the tank before departing so they know what they've got!"
The pilot's inadequate preflight and in-flight fuel planning, during which he did not visually check the fuel quantity in the fuel tanks and instead relied on the fuel gauges that were showing erroneous fuel quantity indications, which resulted in fuel exhaustion and the subsequent loss of engine power during cruise flight.
Source: NTSB Aviation Accident Database
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