Bird Strike and FOD

Bird strike and FOD (Foreign Object Damage/Debris) are common operational risks — from minor paintwork damage to catastrophe.

Source: FAA AC 150/5200-32B Reporting Wildlife Aircraft Strikes; ICAO Annex 14 Volume I Chapter 9; NTSB Wildlife Strike Database.

Bird strike — statistics

FAA Wildlife Strike Database:

USA: about 13 000–16 000 reported strikes per year (2020s).
80 % of all strikes below 500 ft AGL (take-off and landing).
97 % at or near the airfield.
Main species: gulls, pigeons, sparrows, falcons, raptors.

Energy of a bird encounter

Kinetic energy: E = ½ × m × v²

Example: 1 kg bird × (130 m/s)² / 2 = 8450 J on the aircraft part.
Larger birds (geese, pelicans 4-8 kg): up to 50 000 J — engine destruction possible.

Bird strike — a risk for general aviation too

Bird strike is also a risk for GA aircraft — not only for transport aircraft. In a GA light aircraft the greatest risk is:

Penetration of the windshield by a larger bird (goose, raptor, heron) at higher cruise speed.
Consequence: the pilot is injured or knocked unconscious by the impact and glass shards.
Outcome: the aircraft is out of control because the pilot can no longer fly it.
Secondary damage: bird in the cockpit, cabin pressure (at higher altitudes), strong wind, feathers and blood obscuring vision.

A bird in the engine intake can also cause power loss or fire, and a bird strike on the wing leading edge damages the airfoil.

→ PPL consequence: avoid bird-active times (dawn/dusk, migration); avoid low flight in bird hotspots; on visual contact with birds dodge carefully (typically downward — birds tend to fly up/outward in fright).

Damage patterns

Windshield: cracking, breakage with large birds — largest risk in GA due to direct pilot threat.
Engine: birds in engine inlet → blade damage → flameout.
Wing leading edge: dents, cracks.
Pitot/static: clogged → false indications.
Antennas: ripped off.

Case study — US Airways 1549 ("Miracle on the Hudson")

15 January 2009, A320 after take-off LaGuardia.
At ~2900 ft AGL: flock of Canada geese → both engines flameout.
Captain Sullenberger landed on the Hudson River.
155 souls, all survived.
Source: NTSB AAR-10/03 Loss of Thrust in Both Engines After Encountering a Flock of Birds, US Airways Flight 1549.

Avoidance in flight

Increased attention during take-off and landing in bird-rich regions.
Dawn/dusk: birds especially active.
Migration seasons (spring/autumn): more birds on routes.
On bird sighting: slight altitude change or descent (birds usually flee downward).
On bird strike: continue flight with safety manoeuvre, ground inspection after landing.

Wildlife hazard management at airfields

ICAO Annex 14 Chapter 9 requires airfields to:

Wildlife hazard assessment.
Wildlife management programme (active deterrent — falconers, acoustic devices, habitat management).
Reporting to State Authority and ICAO.

FOD (Foreign Object Damage / Debris)

Definition: any loose object on the movement area that can damage an aircraft (screw, stone, tool, loose materials).

Famous FOD accidents:

Concorde Flight 4590 (25 July 2000, Paris CDG): metal strip on runway → tyre burst → fuel leak → fire → crash, 113 dead.

Prevention:

FOD walks: regular runway inspection by staff.
FOD containers on the apron.
Hand-sweeping after maintenance.
Wing walker during towing.

What to do on bird strike / FOD encounter

Maintain aircraft control — AVIATE above all.
Watch engine gauges: vibrations, RPM drop, oil-temp rise → engine handling per POH.
Structural damage: inspect visually before landing (co-pilot or tower).
Mayday for severe damage — especially with injured pilot or breached windshield.
Emergency landing for engine issues.
Reporting after landing: FAA Form 5200-7 in USA, comparable in EU (EASA wildlife reporting).