Aeronautical Information Manual (AIM), page 527

Index   526 -- Page 527 -- 528

Section 4. Bird Hazards and Flight Over National
Refuges, Parks, and Forests

7-4-1. Migratory Bird Activity

a. Bird strike risk increases because of bird

migration during the months of March through April,

and August through November.

b. The altitudes of migrating birds vary with winds

aloft, weather fronts, terrain elevations, cloud

conditions, and other environmental variables. While

over 90 percent of the reported bird strikes occur at or

below 3,000 feet AGL, strikes at higher altitudes are
common during migration. Ducks and geese are
frequently observed up to 7,000 feet AGL and pilots
are cautioned to minimize en route flying at lower
altitudes during migration.

c. Considered the greatest potential hazard to
aircraft because of their size, abundance, or habit of
flying in dense flocks are gulls, waterfowl, vultures,
hawks, owls, egrets, blackbirds, and starlings.
Four major migratory flyways exist in the U.S. The
Atlantic flyway parallels the Atlantic Coast. The
Mississippi Flyway stretches from Canada through
the Great Lakes and follows the Mississippi River.
The Central Flyway represents a broad area east of the
Rockies, stretching from Canada through Central
America. The Pacific Flyway follows the west coast
and overflies major parts of Washington, Oregon, and
California. There are also numerous smaller flyways
which cross these major north-south migratory


7-4-2. Reducing Bird Strike Risks

a. The most serious strikes are those involving
ingestion into an engine (turboprops and turbine jet
engines) or windshield strikes. These strikes can
result in emergency situations requiring prompt
action by the pilot.

b. Engine ingestions may result in sudden loss of
power or engine failure. Review engine out
procedures, especially when operating from airports

with known bird hazards or when operating near high
bird concentrations.

c. Windshield strikes have resulted in pilots
experiencing confusion, disorientation, loss of

communications, and aircraft control problems.

Pilots are encouraged to review their emergency

procedures before flying in these areas.

d. When encountering birds en route, climb to

avoid collision, because birds in flocks generally

distribute themselves downward, with lead birds

being at the highest altitude.

e. Avoid overflight of known areas of bird
concentration and flying at low altitudes during bird
migration. Charted wildlife refuges and other natural
areas contain unusually high local concentration of
birds which may create a hazard to aircraft.

7-4-3. Reporting Bird Strikes
Pilots are urged to report any bird or other wildlife
strike using FAA Form 5200-7, Bird/Other Wildlife
Strike Report (Appendix 1). Additional forms are
available at any FSS; at any FAA Regional Office or
at http://wildlife-mitigation.tc.faa.gov. The data
derived from these reports are used to develop
standards to cope with this potential hazard to aircraft
and for documentation of necessary habitat control on

7-4-4. Reporting Bird and Other Wildlife


If you observe birds or other animals on or near the
runway, request airport management to disperse the
wildlife before taking off. Also contact the nearest
FAA ARTCC, FSS, or tower (including non-Federal
towers) regarding large flocks of birds and report the:

a. Geographic location.

b. Bird type (geese, ducks, gulls, etc.).
c. Approximate numbers.

d. Altitude.

e. Direction of bird flight path.

Bird Hazards and Flight Over National Refuges, Parks, and Forests 7-4-1

Page 527 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   526 -- Page 527 -- 528