Casualties unknown

1990-07-18: Mitsubishi MU-300 (N800TJ) — Milwaukee, WI

Milwaukee, WI, US

On July 18, 1990, a Mitsubishi MU-300 (registration N800TJ) was involved in an aviation accident near Milwaukee, WI. Investigators recorded the probable cause as: THE PILOT'S DELAYED DETERMINATION OF TRACTION OR BRAKING ACTION UNTIL TOO LITTLE RUNWAY REMAINED TO GO AROUND OR TO EMPLOY ALTERNATE MEANS OF ACTIVIATING THE BRAKES. CONTRIBUTING TO THE ACCIDENT WAS THE OVERSERVICING OF THE MAIN GEAR STRUTS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A pilot reported no brake response after a soft landing on a wet runway with thunderstorms and rain nearby. The airplane overran, sustaining substantial damage. Tests found no brake system discrepancy but revealed overpressurized main landing gear struts.

Event Summary

During landing, the pilot executed a soft touchdown and commenced aerodynamic braking. After lowering the nosewheel to the runway, the pilot applied wheel brakes with anti-skid engaged. The pilot reported no response to the brakes. Subsequently, the airplane overran the runway, resulting in substantial damage.

Investigation Findings

Post-accident testing of the brake system revealed no discrepancy. However, the main landing gear struts were found to be overpressurized. The anti-skid logic circuit is designed to interrupt brake activation until load switches on the main struts sense weight on the wheels (i.e., struts less than fully extended).

Additional Details

At the time of the accident, there were thunderstorms and rain in the vicinity, and the runway surface was wet. The right main tire track was identifiable as a clean strip across the asphalt and white paint markings at the runway departure end.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X23650. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.