What happened
On the evening of December 10, 2022, a Cessna 1s72R, registration JA123R, was performing a sightseeing flight near Kohnan Aerodrome in Okayama Prefecture. The aircraft, operated by Okayama Air Service Co., Ltd. (OAS), was carrying the captain and three passengers.
As the aircraft was on final approach to Runway 09 at an altitude of approximately 150 feet, the pilot observed a flock of white birds illuminated by the landing lights. Shortly after this sighting, a loud impact was felt against the fuselage. Despite the collision, the pilot maintained control of the aircraft and completed the landing safely at 17:45. Post-flight inspections revealed significant damage to the leading edge of the left wing, including a large dent and deformed internal ribs, accompanied by bloodstains.
The investigation
The Japan Transport Safety Board (JTSB) investigated the incident, focusing on the circumstances of the impact and the effectiveness of local bird mitigation efforts. Investigators examined the aircraft's damage, meteorological conditions, and the airport's bird management protocols.
While the investigation confirmed the presence of blood on the wing, the specific species of bird involved could not be identified because the biological residue was not collected for analysis. The investigation also noted that the area surrounding Kohnan Aerodrome is a known habitat for various wild birds due to the proximity of Abeike Pond and Lake Kojima. The JTSB also reviewed the airport's existing bird sweep procedures and the use of pyrotechnics and lethal control measures used during certain months.
Findings
- The aircraft sustained substantial damage to the left wing's leading edge skin and ribs.
- The collision occurred during a night approach, which limited the pilot's ability to visually detect and avoid the birds in time.
- The lack of biological sample collection prevented the identification of the bird species, which is critical for developing targeted prevention strategies.
- The airport's proximity to migratory bird habitats increases the risk of such encounters.
Safety action
Following the accident, the following measures were noted:
- The operator, OAS, has instructed personnel on the importance of preserving bird remains and bloodstains for identification.
- The Civil Aviation Bureau (MLIT) has provided sample collection kits to the Kohnan Aerodrome Administration Office to assist in identifying bird species after strikes.
- The airport administration has committed to using these samples to inform more effective, species-specific bird control measures through its Safety Management Committee.