On October 28, 2018, about 1645 eastern daylight time, a Piper PA-28-161, N8132X, was substantially damaged after a runway excursion and collision with a ditch at Simsbury Airport (4B9) Simsbury, Connecticut. The commercial pilot and pilot-rated passenger were not injured. The airplane was operated by Interstate Aviation, Inc. under the provisions of 14 Code of Federal Regulations part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the flight that originated at Bradley International Airport (BDL), Windsor Locks, Connecticut, about 1635.

According to pilot, he was in the traffic pattern at 4B9 practicing approaches and touch-and-go landings. After touchdown on runway 21 for a full stop landing, the brakes "failed." He elected to steer the airplane to the right in an effort to avoid a fence and slow the airplane in the grass. The airplane departed the runway surface and collided with a ditch. The pilots exited the airplane and were met by first responders. The pilot also reported that, during taxi out for takeoff, the wheel brakes were "sluggish."

An inspector with the Federal Aviation Administration responded to the accident site and examined the wreckage. He reported that the left wing sustained structural damage during the landing. The left main landing gear separated and was found adjacent to the wreckage. The inboard and outboard brake pads exhibited normal wear. The brake assembly was attached in its normal position by two AN bolts. The brake assembly puck to brake pad and the brake supply hydraulic line also showed evidence of leaking hydraulic fluid.

An examination of the right main landing gear wheel brake assembly revealed that it was missing from its proper mounting position on the right gear trunnion. The assembly was not installed onto the main wheel brake rotor with the required AN bolts. The hydraulic fluid line and elbow fitting were also not attached to the brake assembly.

A review of the airplane maintenance records revealed that a 100-hr inspection was completed on October 10, 2018, or 18 days before the accident. The inspection entry included the following: "Serviced all tires, wheels, brakes, brake reservoir fluid." The main landing gear tires were also replaced during this inspection. The last maintenance entry where brake parts were replaced was on October 16, 2017.