What happened
During a flight intended to prepare a student pilot for a commercial pilot licence flight test, an Aquila AT01 with registration VH-OIS was performing precautionary searches at the Coombing Park Aeroplane Landing Area (ALA) in New South Wales. After completing three search patterns, the crew performed a touch-and-go maneuver.
Following the take-off, the aircraft climbed toward rising terrain. To avoid obstacles, the pilot executed a climbing left turn toward a less wooded area. During this maneuver, the aircraft likely descended and accelerated slightly while flying over a small dam. The aircraft subsequently struck an embankment bordering the dam and the open area.
The investigation
Investigators examined the wreckage and assessed the aircraft's performance, finding no mechanical defects, sudden loss of performance, or evidence of pilot fatigue or medical issues. The investigation focused on the operational decisions leading to the accident.
It was determined that the Coombing Park ALA was not an approved landing site under the operator's manual, as it was not listed in the ERSA. While the instructor contacted the ALA manager to request permission for the touch-and a go, the call lasted only 24 seconds, representing a missed opportunity to receive a detailed briefing on local hazards. Furthermore, the investigation found that the instructor had not previously performed precautionary searches or landings at this specific location, which limited their ability to assess the terrain hazards.
Findings
- Pre-flight planning failed to confirm that the take-off area was clear of obstacles, as required by the company operations manual.
- The precautionary search was conducted at altitudes and positions that made it difficult to effectively identify the rising terrain hazard.
- The decision to perform a touch-and-go rather than a standing take-off reduced the margin of safety, as the aircraft was forced to climb toward rising terrain.
- The take-off was performed on an uphill slope, likely with a tailwind, toward terrain that exceeded the aircraft's climb capabilities.
- The combination of a loss in climb performance during the turn and the presence of trees and rising terrain necessitated an uphill forced landing that the aircraft could not complete.
Safety message
- The operator's sample operations manual, which allowed the use of any aerodrome listed in the ERSA for training, did not ensure those sites were suitable for such operations.
- Current CASA guidance regarding obstacle clearance may result in aircraft being required to maneuver at unsafe heights or being unable to clear terrain beyond the runway end.