What happened
On September 26, 2016, a Piper PA-34-200 performing a multi-engine instrument flight training mission departed from Florianópolis, SC, with a destination of Bacacherili, PR. The flight included a stop in Lages, SC, for touch-and-go training.
Upon landing at Bacacheri Airport (SBBI) on runway 36, the crew attempted to initiate a right turn to enter taxiway C. During the application of the brakes, the pilots felt a sudden jolt and noticed the left brake pedal sink to the floor. Both the normal and emergency braking systems became completely inoperable. Consequently, the aircraft drifted right, exiting the runway and traveling 50 meters before coming to a stop in a drainage ditch. The impact caused substantial damage to the aircraft, including the failure of the nose gear and the right main gear, as well as damage to the right engine propeller. The two occupants escaped without injury.
The investigation
CENIPA investigators conducted a technical examination of the braking assembly, which revealed several critical discrepancies. The inspection found that the left brake was missing brake linings on the rear plate and exhibited excessive, irregular wear on the pressure plate linings. Furthermore, investigators discovered two unauthorized "spacers" installed between the pressure plate and the brake pistons. These spacers had been improperly installed to artificially extend the brake's travel, compensating for advanced wear. This modification was not supported by the manufacturer's technical publications or approved parts catalogs.
The investigation also reviewed maintenance records, noting that the last 100-hour inspection, performed approximately 72 flight hours prior to the accident, failed to detect these issues. Additionally, the investigation found that the aircraft's maintenance logs were not up to date and that a required 50-hour inspection had been missed.
Findings
- Deficient maintenance of the braking system, which failed to identify missing linings, excessive wear, and the presence of unauthorized spacers.
- Improper installation of unapproved components (spacers) intended to mask brake wear.
- Inadequate maintenance supervision and management oversight regarding aircraft record-keeping.
- The aircraft's pre-flight inspection procedures did not specifically require a visual check of brake lining thickness.