Challenger II N778H accident near Rogers City, Michigan

Probable cause

The separation of the right wing’s forward lift strut from the fuselage due to a missing nylon-insert lock nut. Contributing to the accident was the noncertificated pilot’s decision to operate the airplane even though a condition inspection had not been completed in the 13 years since the airplane received its experimental airworthiness certificate.

NTSB analysis

The noncertificated pilot was departing on a local flight. The pilot reported that about 100 ft into the takeoff roll the airplane began to swerve right, but before he could abort the takeoff, he heard a bang and the airplane pitched up and rolled. A witness reported that the airplane abruptly pitched up, rolled right, and impacted the ground in a left-wing-down attitude. The witness stated that the airplane completed about 270° of right roll when the left wing impacted the ground. The airplane sustained substantial damage to the left wing, fuselage, tailboom, and left horizontal stabilizer.

Postaccident examination of the airplane revealed that the right wing’s forward lift strut separated from the fuselage longeron. The channel bracket remained attached to the lift strut, but the attachment bolt pulled out of the fuselage longeron. The nylon-insert lock nut that normally secured the attachment bolt to the fuselage longeron was not located during the investigation. Flight control continuity was confirmed from the cockpit controls to each flight control surface.

The pilot did not maintain maintenance records for the airplane, nor had the airplane undergone a condition inspection since the Federal Aviation Administration (FAA) issued the experimental airworthiness certificate in December, 2007.

Text from the NTSB. Open the NTSB docket for CEN21LA420 for the full record.