Synopsis
On 12 September 2022 at 12:50 UTC, a Grumman American AA-5B Tiger (registration AA5B-0197) was cruising at 1500 ft AMSL in airspace class G near Itegem, a submunicipality of Heist-op-den-Berg, Belgium. The aircraft had departed from Grimbergen Aerodrome (EBGB) at approximately 12:38 UTC and was en route to Zwartberg/Genk Aerodrome (EBZW). During the flight, a herring gull weighing 800 g struck the aircraft, shattering the windshield and entering the cockpit. The bird impacted the pilot's head, tearing off the headset and smearing the pilot's goggles. The pilot declared a PAN PAN and returned to EBGB, where the aircraft landed safely. Both occupants exited without injury. The aircraft sustained substantial damage.
Occurrence
According to the report, the aircraft was flying level at 110 KIAS at 1500 ft AMSL between Herenthout and Heist-op-den-Berg when the bird strike occurred. The gull shattered the windshield, entered the cockpit, and landed on the rear seat. The impact on the pilot's head caused the headset to be torn off and goggles smeared. The pilot declared a PAN PAN to Brussels Info, but communication was difficult due to wind and prop wash noise. Brussels Info initially understood the pilot to report a fire in the cockpit. The aircraft landed uneventfully at EBGB. The passenger reported that the bird came from above. The propeller showed no impact damage. The flight path was reconstructed using FlightAware data.
Aircraft Information
The aircraft involved was a Grumman American AA-5B Tiger, built in 1975, with serial number AA5B-0197. It was powered by a Lycoming O320-A4M engine and equipped with a fixed-pitch two-blade McCauley propeller. The type certificate was based on US FAR 23, which is similar to European CS-23. CS-23.2320 requires protection of occupants from serious injury due to windshield breakage, but only Level 4 aeroplanes (with 10-19 passenger seats) must withstand a two-pound bird impact at approach flap speed. The AA-5B is not a Level 4 aeroplane.
Bird Strike Context
The bird was identified by the Research Institute Nature and Forest (INBO) as a first calendar year herring gull. INBO noted that flying at 1500 ft AMSL is unusual but possible, as gulls can use thermal updrafts. Gulls are common inland, especially in autumn and winter, with many migrating from northern breeding areas. The report also provides statistics on bird strikes in Belgium from 2019 to 2023: of 50 reports involving aircraft with MTOW under 2.25 tonnes, only two occurred en route (including this incident). Canopy damage was reported in three cases, with two broken canopies. The herring gull is one of several species involved, with mass ranging from 700 to 1500 g. The period of the year shows peaks in bird activity, consistent with the September date.
Conclusion
The investigation determined that the aircraft windshield was damaged by the bird strike, and no other technical or operational issues were identified. The pilot's response and landing were successful. The report does not assign a probable cause.