Beech U-8F N62069 accident near Goodland, Kansas

Probable cause

Maintenance personnel’s inadequate inspection of the airplane, which failed to detect and correct chafed electrical wiring and a degraded fuel bladder with holes, which resulted in ignition of fuel vapor and a right wing explosion.

NTSB analysis

The pilot heard a loud bang while starting the right engine and noticed flames exiting the right wing. An airport surveillance camera captured a wing explosion that lasted about 1 second, which substantially damaged the right wing.

Examination revealed that the right wing outboard aft fuel bladder was brittle, with several holes due to age-related oxidation, and electrical wiring to the navigation lights was chafed in two locations, with evidence of electrical arcing. Review of maintenance records indicated that the airplane was inspected about 50 hours before the accident; the inspection included checking the fuel tanks for leakage, and electrical wiring for chafing. Based on the condition of the fuel bladder and wiring, it is likely that the most recent inspection was inadequate.

About 2 years before the accident, the airplane’s left wing exploded due to ignition of fuel vapor. Following the most recent wing explosion accident, the operator instituted several maintenance protocols to aid in detection of a fuel leak, including top-off of the fuel system in conjunction with the wing inspection procedure checklist or unscheduled fuel system maintenance.

Text from the NTSB. Open the NTSB docket for CEN21LA274 for the full record.