Icon A5 N83BA accident near Wheeling, Illinois

Probable cause

The pilot’s decision to operate the engine above its maximum continuous speed for most of the flight, which led to fuel exhaustion and a subsequent total loss of engine power.

NTSB analysis

The pilot was conducting a personal cross-country flight when the airplane had a total loss of engine power while on a 3-mile base leg for the runway at the intended destination. The airplane collided with trees and terrain during the forced landing, which resulted in substantial damage to the composite fuselage and wings.

Based on recorded engine data, most of the flight was flown above the maximum continuous engine speed of 5,500 rpm and, as a result, the actual fuel consumption rate during the flight exceeded the fuel consumption rates listed in the Pilot Operating Handbook performance section. The engine operates between two modes, economy and power, which have significantly different fuel consumption rates. Although the airplane was equipped with an analog tachometer and analog fuel quantity indicator, it was not equipped to display instantaneous fuel flow rate, total fuel used, or the engine operating mode (economy vs. power).

Postaccident fuel consumption calculations, based on the engine running in power mode for 68.4% of the flight and economy mode for the remaining 31.6% of the flight, suggest that the engine likely used at least 15.2 gallons of fuel.

The pilot reported that the airplane’s fuel gauge indicated 17 gallons before the flight, but postacccident testing revealed that the fuel gauge consistently indicated 1.0 to 1.5 gallons more than the amount in the fuel tank. The airplane likely had 15.5 to 16.0 gallons of fuel before engine start; as such, the pilot likely departed with less fuel than he thought was on board. However, the airplane would likely have had enough fuel to complete the flight had the pilot operated the engine at or below the airplane manufacturer’s maximum continuous speed limit.

Text from the NTSB. Open the NTSB docket for CEN19LA220 for the full record.