اصطدام الطيور (Bird Strike)

What Is a Bird Strike?

A bird strike (also called a bird ingestion when involving a jet engine, or BASH — Bird and Airport Strike Hazard) is a collision between an airborne bird or flock of birds and an aircraft in flight or during ground operations. Bird strikes are one of the most common wildlife hazards in aviation, occurring thousands of times annually worldwide. The majority are minor events causing little or no damage, but high-energy strikes — particularly multi-bird ingestions into jet engines at critical phases of flight — can cause catastrophic engine failure and present life-threatening scenarios.

How It Works

The energy transferred in a bird strike is proportional to the relative velocity between bird and aircraft — at typical takeoff and initial climb speeds of 250–300 km/h, even a relatively small bird (1–2 kg) strikes with an energy equivalent to a heavy rifle round. Engine certification standards (FAA 14 CFR Part 33 / EASA CS-E) require engines to demonstrate continued operation or safe shutdown after specified bird ingestion events — including single large birds (up to 3.6 kg for large turbofans) and multiple medium-sized birds. Windshields are tested for birdstrike resistance per 14 CFR Part 25.775. The most dangerous phase is low altitude: takeoff and climb, when altitude is insufficient for a safe glide in the event of total power loss.

Types and Standards

• Small birds: Starlings, sparrows — individually minor but dangerous in large flocks (the 1960 Boston Electra crash killing 62 was caused by starling ingestion).
• Medium birds: Gulls, geese — the primary risk category at coastal and inland waterway airports.
• Large birds: Geese, eagles, vultures — capable of causing catastrophic engine failure or windshield penetration. The "Miracle on the Hudson" (2009) involved a flock of Canada geese.
• Wildlife hazard management: Airport wildlife management programmes use radar tracking, habitat modification, trained falconers, pyrotechnics, and distress calls to deter birds from aerodrome movement areas.

Interesting Facts

• US Airways Flight 1549 in January 2009 — the "Miracle on the Hudson" — is the most famous modern bird strike incident, with both engines disabled by a Canada goose strike at 850 ft during climbout from LaGuardia.
• The FAA Wildlife Strike Database contains over 260,000 reported strikes since 1990; actual strike rates are estimated to be ten times higher due to significant under-reporting.
• Vultures soaring on thermals can reach altitudes exceeding 11,000 metres — a Rüppell's griffon vulture was struck by a commercial aircraft at 11,300 metres over Côte d'Ivoire in 1973.
• Military low-flying operations have recorded bird strikes at speeds over 900 km/h; at these velocities, even a small bird can penetrate the fuselage or damage control surfaces.