The airline transport pilot was relocating the CubCrafters CC19 to the owner’s private ranch.
He noted that, before the flight, he ordered fuel for the airplane. But when the fuel truck arrived, he checked the fuel levels using the fuel quantity sight gauges inside the airplane and “realized it was full,” so he declined to have the airplane refueled.
He added he did not visually verify the fuel levels in each fuel tank or use a dipstick.
He also told investigators that before the flight, he was dealing with a malfunctioning hangar door when he received a telephone call from work. After the call ended, he conducted his preflight inspection of the airplane and again attempted to close the hangar door.
When he attempted to start the engine, the battery was dead, so he charged it, started the engine, and then took off.
About 45 minutes after departure, during cruise flight over mountainous terrain, the engine began to lose power. As he turned the electric fuel pump on, he noticed a slight increase in power, however shortly after, the engine lost all power.
He initiated an off-airport landing to an open area near Hyrum, Utah. However, when he realized that the airplane would be unable to reach it, he maneuvered toward another suitable landing area.
During the landing, the plane hit trees and terrain before it came to rest upright, which resulted in substantial damage to the right wing and fuselage. The pilot was seriously injured in the crash.
First responders and wreckage recovery company personnel independently confirmed that no fuel was recovered from the wing tanks. Recovery personnel also reported that there was no fuel in the engine inlet fuel line during disassembly.
Post-accident examination of the airplane revealed no evidence of any preexisting mechanical malfunctions or failures with the engine or fuel system, including the fuel quantity sight gauges, that would have precluded normal operation.
It is possible that, due to the distractions the pilot reported experiencing while preparing for the flight, he did not correctly read the fuel quantity sight gauges during the preflight inspection. It is likely he departed with insufficient fuel onboard to complete the flight, which led to a loss of engine power due to fuel exhaustion.
Probable cause: The pilot’s improper verification of the fuel quantity during the preflight inspection, which resulted in fuel exhaustion and a subsequent loss of engine power. Contributing to the accident was the pilot’s distraction due to a malfunctioning hangar door and a telephone call while preparing for the flight.
NTSB Identification: WPR18LA199
This July 2018 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Seems more and more of these reports start with “an ATP pilot”.
Perhaps checklist and CRM dependency is taking it’s toll.
I have a PA-18 with similar sight gauges installed. They are marked for both level flight and ground attitude. The problem is that with the 18 gallon tanks the little floating ball indicator will disappear into the fitting on the top and bottom of the gauge when the tank is full or at about 1/4 full when sitting on the ground. When the tank is full the little ball float is hidden in the top fitting and the sight glass is full of fuel so there’s no color indication to show the fuel level. Same situation when less than 1/4 tank and the gauge will look almost identical unless there’s more fuel in one tank than the other. Simple and reliable gauges but not fool proof. The report doesn’t indicate that he switched tanks but unless this aircraft has a BOTH position, most don’t but some do, it’s likely there was some fuel in the opposite tank from the one selected.
The report says he verified the fuel quantity using the fuel sight gauges and determined that the tanks were already full so he declined having the aircraft refueled. I did a little bit of checking and found a picture of that type aircraft that showed what the sight gauge looked like and as per its description, it is a simple length of clear tube that lets you visually see what the level in the tank is. This is a foolproof system, no electricity needed and no calibration to get skewed so how is it possible for the pilot to have checked the level as full and yet run out of fuel 45 minutes later. Either he lied or there was a significant fuel leak that developed in the air.
Sight gauges can be misleading too. The level of fuel seen depends on whether one is on the ground or in the air. For a tri-gear it’s not a big difference, but the difference for tailwheel planes is considerable. For the CubCrafter, it seems 1/4 full tanks will indicate empty on the ground. Safe? Not necessarily. From experience, the only secure way to read these type of sight gauges is to clearly identify the meniscus boundary between air and fuel. Empty or full, it can’t be seen! Not to mention reports of CC gauge tubes fogging and becoming less transparent with time.
So, harried pilot, probably unfamiliar with that airplane, glances at fuel level gauge on the ground. Plane had less than 1/4 fuel, so there was none in the tube. Tube was foggy pilot assumed it was full of gas, but it was really devoid of it. Pilot takes off, doesn’t bother to twist around to see the fuel level in flight because he knows it’s full.
No system is so simple as to eliminate every possible screwup!