NTSB Factual Report

On September 12, 2017, about 1630 mountain daylight time, a Cessna R182 airplane, N1835R, was substantially damaged during a forced landing following a loss of engine power near Worland, Wyoming. The pilot was not injured. The airplane was registered to and operated by Meridian Flying Service as a 14 Code of Federal Regulations Part 91 aerial observation flight. Visual meteorological conditions prevailed. The flight was not operated on a flight plan. The flight originated from the Sloulin Field International Airport (ISN), Williston, North Dakota and was destined for the Worland Municipal Airport (WRL), Worland, Wyoming.

On the day of the accident, the pilot intended to continue a pipeline surveillance patrol that began the previous day. The initial flight of the day was from the Sidney-Richland Regional Airport (SDY) to ISN to pick-up a passenger. After departing from ISN, two sections of the pipeline system near ISN were observed and then the flight proceeded to the Stanley Municipal Airport (08D) to obtain fuel. After fueling, the pilot departed for ISN to drop off the passenger. After departing ISN again, he planned to fly directly to the next pipeline system near WRL. However, smoke from forest fires prevented a direct flight as planned. He deviated as required, ultimately arriving at the start of the pipeline patrol route.

About 1620, approximately halfway through the patrol, the engine lost power. The pilot turned toward a road in the area in preparation for a forced landing. The engine regained power momentarily, but it quit again. He turned toward a highway and during that time the engine regained power and quit three or four more times. He recalled thinking that plenty of fuel should have been onboard as he attempted to determine the source of the problem. When he was unsuccessful restoring engine power, he setup for a forced landing to a dirt road. To clear a set of power lines, he "stretched" the glide causing the airspeed to decay and the airplane began to stall. He ultimately executed a forced landing to the dirt road with the landing gear retracted.

The pilot noted that the airplane fuel gauges were unreliable. Attempts to repair the gauges in the months before the accident were not successful and replacement of the entire gauge cluster was required; however, the airplane owner reportedly did not have the financial resources to complete the work. To compensate, the pilot had adopted the practice of completely filling the fuel tanks during each refueling and tracking the intervening flight time. Two days before the accident an individual refueling the airplane informed the pilot that the left fuel cap seal was torn. The pilot was in the process of obtaining a new fuel cap seal but had not been able to have one installed.

The pilot stated that the airplane was fueled at SDY the preceding night. He assumed that the fuel tanks were full upon his departure from SDY the morning of the accident. The airplane fuel capacity was 75 gallons useable. When the airplane was subsequently fueled at 08D, the self-service fuel pump required prior input of the desired amount of fuel. As a result, he decided to dispense 40 gallons based on the anticipated burn that morning. However, he did not recall visually confirming the fuel level. The pilot reported that the flight time from SDY until refueling at 08D was 2.7 hours. An additional, 4.1 hours elapsed from the time the airplane was refueled at 08D until the accident.

A Federal Aviation Administration inspector reported that the airplane sustained firewall and fuselage damage. The upper surface of the left wing exhibited fuel staining aft of the fuel cap. The upper surface of the right wing was clean. The left and right fuel tanks appeared to be empty; no fuel was present when the sump drains were opened. The left fuel cap seal was worn; the right fuel cap seal appeared to be intact. The fuel selector was set to both tanks at the time of the examination. No other anomalies consistent with a preimpact failure or malfunction were observed.

FAA regulations (14 CFR 91.205) required an operable fuel gauge indicating the quantity of fuel in each tank for any powered civil aircraft with a standard category airworthiness certificate.

NTSB Probable Cause

The pilot's decision to operate an airplane with unreliable fuel gauges and the worn fuel cap seal that allowed fuel to siphon from the left wing fuel tank, which ultimately resulted in a total loss of engine power due to fuel exhaustion.