Casualties unknown

2021-05-01: Piper Seneca II PA 34 (ZS-PBV) — Runway 25 Port Alfred Aerodrome, Eastern Cape, ZA

Runway 25 Port Alfred Aerodrome, Eastern Cape, ZA

On May 1, 2021, a Piper Seneca II PA 34 (registration ZS-PBV) was involved in an aviation accident near Runway 25 Port Alfred Aerodrome, Eastern Cape, ZA. Investigators recorded the probable cause as: The left gear down lock mechanism had a FOD in the form of a rivet stuck in the grease between the machined faces of the truss and the link assembly, preventing the down lock from engaging. This led to a gear collapse during landing roll. This summary draws on records from the South African Civil Aviation Authority (SACAA) Accident and Incident Investigations Division.

Sourcesthe South African Civil Aviation Authority (SACAA) Accident and Incident Investigations DivisionPrimary reportUpdated 1785104676Data APIEditorial standards

During circuit training, the left main gear of a Piper Seneca (ZS-PBV) failed to lock down due to a CherryMAX rivet lodged in the truss-link assembly. The gear collapsed on landing roll; no injuries and minor damage.

Accident Overview

On 1 May 2021 at 1148Z, a Piper Seneca II (PA34) with registration ZS‑PBV was conducting circuit training at Port Alfred Aerodrome (FAPA), Eastern Cape Province, under Part 141 of the Civil Aviation Regulations. The aircraft was crewed by an instructor and a student pilot. The flight was performed in visual meteorological conditions during daylight. After five uneventful circuits on Runway 28L (RWY 28L), the green indicator light for the left main landing gear did not illuminate while on the base leg. The instructor initiated a go‑around and requested the tower to visually inspect the landing gear. The tower confirmed that the left main gear was not in the normal down position. The instructor then declared an emergency landing on Runway 25 (RWY 25). As a precaution, the left engine was shut down and feathered on short final.

During the landing roll, the left main gear collapsed, causing the aircraft to veer left off the runway and come to rest on the left side of RWY 25. Neither the instructor nor the student pilot was injured. The damage was limited to the left‑side main gear flap.

Post‑Accident Findings

Following the accident, the aircraft maintenance organisation (AMO) inspected the left main landing gear. A foreign object debris (FOD) was discovered: a CherryMAX rivet lodged in the grease between two machined faces of the truss and link assembly. This obstruction prevented the gear down lock from engaging. The rivet likely dislodged from the nacelle and entered the left main gear. The dislodged rivet was replaced, and the landing gear was tested for serviceability according to the Piper Maintenance Manual 753‑817 (revision dated 30 November 2019).

Safety Actions

The FOD was removed, the rivet replaced, and the landing gear successfully tested for proper operation.

Safety Recommendations

Maintenance organisations are encouraged to ensure proper housekeeping before and after maintenance to reduce the risk of similar occurrences.

Probable cause

The left gear down lock mechanism had a FOD in the form of a rivet stuck in the grease between the machined faces of the truss and the link assembly, preventing the down lock from engaging. This led to a gear collapse during landing roll.