The pilot reported that the Cessna 172 was refueled while he performed the pre-flight inspection at night, but the right fuel tank fuel cap was not secured.
He recalled that the fuel selector had been set to both, and about halfway through the flight, he noticed that the right fuel tank appeared full, but the left fuel gauge indicated that fuel was being consumed from the left tank.
He decided that he would “check the situation out” when he reached his destination.
About five miles from his destination, he noticed that the left wing tank fuel quantity indicator showed that the left tank had five gallons remaining, and that the right tank was still full.
During approach to the airport in DuBois, Pennsylvania, the airplane became “very unstable and seemed to be uncoordinated,” according to the pilot.
The stall warning horn sounded and he applied left aileron and left rudder to align the airplane’s heading with the runway heading, but was unsuccessful.
He aborted the landing, established a climb and retracted the flaps. The Low Fuel warning light illuminated, and he switched the fuel selector to the right tank. The engine lost power, and he made a right tear-drop turn back to the runway.
The airplane was about 1,000 feet above ground level, and he pitched for best glide airspeed about 70 knots, as he attempted to restart the engine, but the engine did not start.
He lowered the nose, the airspeed increased to 85 knots, and he put in 20° of flaps, and landed on the runway. The airplane bounced hard and returned to the runway before coming to a stop. The airplane sustained substantial damage to the lower fuselage longerons.
The pilot reported that there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation.
Probable Cause: The pilot’s improper fuel management, which resulted in fuel starvation and a total loss of engine power, and his subsequent improper landing flare, which resulted in a hard, bounced landing. Contributing to the accident were the pilot’s improper preflight inspection during which he failed to see that the right fuel cap was not secured.
This November 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.
Preflight inattention problem followed by incompetence in a developing situation. Pilot didn’t understand the fuel system.
This pilot had only 10 hrs in type, 100 hrs total, so he probably had no idea why the left tank was so low, besides missing the pre-flight check of the fuel cap.
With the selector on ‘both’ I can see haw the fuel could be siphoned from the selector , not allowing any fuel to gravity feed into the lines.
I had a Cessna not drawing fuel from one tank for an hour, about 10 gallons, and it was obvious that one wing was ‘heavy’, having to hold opposite aileron . Switching the fuller tank for an hour brought the wings level again.
BTW, from the form 6120, who refuels an aircraft inside a hangar ? In California that’s illegal.
Both is the normal setting in cruise flight, but either left or right can be selected in cruise per the POH to address balancing issues which per the POH can occur even when the wing is not maintained exactly level. Selecting right earlier in the flight at a safe altitude when the imbalance was becoming obvious would have hopefully helped to evaluate the airplane condition and helped decide on a safe strategy, and prevent either tank from reaching a critically low level.
Same story with different names.
Pilot places fuel selector on BOTH. This is NORMAL Operations for that Cessna. And the NTSB rubber stamps “The pilot’s improper fuel management, which resulted in fuel starvation and a total loss of engine power,” Unless one has specific reasons to only use left or right, BOTH is the way this is to be done. At least that was true back when I did a lot of C172 flying in the early 2000s before going to Pipers.
This was not improper fuel management. What was the problem was failure to properly pre-flight. That fuel cap problem is the whole cause of this in my non-professional opinion.
On Hi-Wing Cessnas, the cross over venting can get disturbed such that one can’t get fuel out of one of the tanks (was more a problem w/ C15x in my experience). And in that situation when one sees the fuel drop on one tank and not the other, it is time to make a precautionary landing to find out why — ask an A&P familiar with Hi-wing Cessnas about the issues with the venting on various models.
And this was a case of you have to make this landing work, this is not a TOGA thing, because you already have a fuel problem. Just add enough power to recover this landing. As he found out, he had just enough to get to altitude and then engine out. So he just turned an urgent situation into an emergency.