NTSB Factual Report

On April 15, 2003, at 1305 Pacific daylight time, a homebuilt Herb Six Northstar, N606HS, registered to and being flown by a private pilot, sustained substantial damage when the right main landing gear collapsed on takeoff roll at Medford, Oregon. The pilot was uninjured. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was personal, was operated under 14CFR91, and was destined for a local airstrip in the Medford area.

The pilot reported (refer to NTSB Form 6120.1 attached) that after his pre-takeoff checks he was cleared for takeoff on runway 32 from the A-5 intersection (refer to attached diagram). He stated that "...I made a wings level left turn onto runway 32, advanced [the] throttle [and] raised the tail. At that moment the right front of the fuselage dropped. I thought I had blown my right main tire. I cut power [and] tried to keep straight on [the] centerline. [I] slowed to 5-10 mph [and] ground looped to [the] left...."

Additionally, he reported in part in the "recommendations" section of his submitted NTSB Form 6120.1 (attached), that "...cause was [the] failure of [the] r[igh]t gear leg strut that failed in compression...."

Post-accident examination revealed the right main landing gear shock strut cross tube (refer to graphic images 1 and 2) buckled in two locations: 1) at the wheel axle attach bolt and 2) several inches outboard of the shock strut fairing outboard edge. The buckling was characteristic of compression rather than tensile loading. The right main landing gear (wheel and "vee" strut) was observed folded under the aircraft's center fuselage with the weight resting on the outboard circumferential surface of the tire (refer to graphic images 3 and 4).

NTSB Probable Cause

The compressive buckling and collapse of the right main landing gear.