According to the Cessna 172 pilot, she was conducting an aerial photography flight. She departed Laredo International Airport (KLRD), with about 40 gallons of fuel, and the fuel selector valve selected for both fuel tanks.
During straight and level flight, she switched the fuel selector valve to the slower-burning tank, and then after about two hours she switched it back to both. She monitored the difference in consumption for the remainder of the flight, changing tanks as needed to keep it balanced. She added that based upon experience, she had fuel for about 5.5 hours of flight on full fuel tanks.
The airplane was at an altitude of 5,300 foot mean sea level when it began shaking and the engine rpm dropped to about 900. She recalled that she moved the fuel selector valve from one side to both and attempted to restore engine power by adjusting the fuel mixture control and the engine throttle control, with no improvement.
She pitched the nose of the airplane down for best glide speed and prepared for a forced landing to a gravel road near Aguilares, Texas. During the forced landing, the airplane bounced and veered off the road and into a field. As the nose landing gear came down, it stuck in the grass, and the airplane nosed over and came to rest inverted. Both wings and the fuselage were substantially damaged.
The first responders reported to the FAA inspector that immediately after the accident, fuel was leaking from the right fuel tank but not the left fuel tank. After the airplane was righted, about four gallons of fuel were recovered from the right fuel tank and the left fuel tank was empty. It is unknown how much fuel, if any, leaked out while the airplane was inverted.
According to the Cessna Pilot Operating Handbook for the Cessna 172P, the fuel tanks have a total capacity of 43 gallons of fuel, with three gallons of unusable fuel. It also noted under Cruise Performance that, if properly leaned, the fuel consumption is between 6.4 and 7.3 gallons of fuel per hour.
Probable Cause: The loss of engine power due to fuel starvation.
This January 2019 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.
The oft-recommended one hour reserve (although the FARs only require a 30 minute reserve for VFR flights) makes lots of sense. Why stretch it? Gas is cheap by comparison to airplane repairs or replacement.
In straight and level flight , those 4 gallons should be available…not a good plan but they’re there…
AIR CONTAMINATION IN FUEL LINES IS A COMMON PROBLEM ON IMPROPER PRE-FLIGHT PLANNING.
Not following. Why would you have air in a fuel line unless the tank was empty? And how is other than sufficient fuel for the trip part of a preflight planning?
Sounds more like one tank vent plugging, failure to return to the airport to address a problem and poor fuel burn time management.
I think he is making a satirical comment on running out of fuel due to poor preflight planning. When the fuel lines become “contaminated” by air the engine usually does not run very well as it is difficult to burn air..
Thanks, I hope so!…lol
It’s a joke “the fuel system had air contamination “. Meaning only air in the fuel system, meaning no fuel in the fuel system.
I appreciate that. It’s just so many things pilots say should be jokes but aren’t!
And with a 1700+ hours on the engine, it would be wise to add 10% to the fuel burn rate.
More stupid pilot tricks , planning on using all of the fuel for a flight, and not using a reasonable reserve for returning to refuel.
This pilot had sufficient time in a C172 to know the endurance.
My Cessna 175 has 51 gallons usable, and I never plan on more than 4 hours of flight before refueling.
You don’t fly, do you?