What happened
The aircraft was conducting an FAA certification flight under experimental rules. During the recovery phase of the maneuver, a non-type-rated FAA pilot occupied the left seat while the pilot in command (PIC) sat in the right seat. As the aircraft descended, warning lights for duct failure and leading edge overheat illuminated; the PIC took corrective action. The FAA pilot then initiated an instrument landing system approach to runway 22, which was wet. The approach was conducted with the left engine at high idle, and the thrust reversers were not armed for landing. Touchdown occurred approximately 2000 feet down the runway, and spoilers were deployed. When the FAA pilot realized reverse thrust was unavailable, he attempted to slow the aircraft using brakes, but the left brake was inoperative. The PIC took control and cycled the anti-skid system, yet still experienced no left braking action. The aircraft subsequently ran off the end of the runway, and the nose gear collapsed in muddy terrain.
The investigation
An examination of the aircraft revealed that during previous maintenance, the speed sensor harnesses for the left main gear were reversed. This installation error eliminated any braking capability to the left brake while the anti-skid system was engaged.