For decades prior to the advent of electronic instrumentation, flight instructors regularly taught pilots not to trust fuel gauges lest a failure leave them unknowingly running on empty. Despite more accurate measurement systems, fuel mismanagement still ranks number six on the NTSB’s list of GA accident categories, accounting for roughly 50 accidents each year, some with fatalities.
The human flying the airplane contributed to 95 percent of the fuel management related accidents, while equipment issues contributed just five percent to the total. The NTSB warned that 66 percent of fuel management accidents occurred on flights in which the original destination airport changed in flight.
The NTSB defines the fuel management category as an accident involving either fuel exhaustion (56 percent) or fuel starvation (35 percent). Fuel exhaustion means running the tanks dry, while starvation means the engine quits with usable fuel still on board.
A newly released NTSB safety alert, Flying on Empty, says running short of fuel is a very preventable crisis if pilots learn to not rely on fuel gauges. A thorough preflight should include visually confirming the fuel quantity in the tanks. The aircraft’s usable fuel capacity divided by the amount of fuel an aircraft burns per hour will result in how many flying hours an aircraft can be expected to remain aloft, no matter what the gauges indicate. Even after the calculations have been performed, pilots must still allow a conservative fuel reserve, usually more than the regulations demand.
Interestingly, student pilots accounted for just a tiny percentage of mishaps, about two percent. Nearly half the fuel management accidents occurred with either a private or a sport pilot at the controls with commercial and ATP aviators making up the remaining 48 percent. Fully 80 percent of fuel mismanagement mishaps occurred in daylights hours.