What happened
On 29 September 2005, a Jabiru SP aircraft, registration ZU-DAX, was conducting a training flight near George Aerodrome when the crew encountered a critical mechanical failure. During the flight, the instructor and student pilot discovered that the elevator control system was malfunctioning, specifically failing to respond to nose-up inputs while still allowing nose-down movement. To maintain pitch control, the instructor had to manually manage the aircraft's attitude by adjusting engine power. This emergency maneuver resulted in a hard landing on runway 11, which caused the nose landing gear to collapse and the propeller to sustain significant damage. No injuries were reported for the two occupants.
The investigation
An investigation by the SACAA AIID examined the aircraft's maintenance history and the mechanical state of the flight controls. Technical inspections of the aircraft revealed that the rear capture of the elevator push-pull cable had moved or was incorrectly installed. While initial manufacturer findings suggested a specific clamp failure, further testing indicated that the elevator control cable likely shifted due to improper installation. The investigation also scrutinized the maintenance records of the operator and the maintenance organization, uncovering several regulatory discrepancies regarding inspection intervals and personnel ratings.
Findings
Several contributing factors and regulatory failures were identified during the inquiry:
- The loss of elevator control was attributed to the elevator control cable moving because the anchor point clamp was not properly installed.
- The aircraft was being maintained at irregular intervals that did not comply with the required 25-hour inspection mandate for this aircraft type.
- Maintenance was performed by an engineer who was not appropriately rated for this specific airframe and engine type.
- There was no documented evidence of required maintenance for the altimeter, airspeed indicator, or compass swing.
- The instructor had been operating the aircraft type for 68 hours without the proper type rating being officially endorsed on his license.
- The incident was not reported to the CAA until eight days after the occurrence.
Safety action
Following the investigation, several recommendations were made to improve oversight:
- The CAA Airworthiness Division should conduct more rigorous document assessments before issuing Authority to Fly Certificates to ensure maintenance compliance.
- The Licensing Department should implement stricter checks on pilot licenses to prevent unauthorized type-rating operations.
- The CAA Safety Promotions Department should emphasize the necessity of immediate accident and incident reporting to the Air Safety Investigations Division.