The answer, according to a recently released report, is 500 feet or less above the ground—but collisions that did more damage to aircraft tended to occur higher up.
That and many other safety pointers about collisions between wildlife and aircraft were gleaned from 30 years of data crunched in Wildlife Strikes to Civil Aircraft in the United States, 1990–2019, issued in February by the FAA and the U.S. Department of Agriculture Wildlife Service—a document worth perusal by any pilot.
The report holds special interest for the flight training community: It cites National Wildlife Strike Database data indicating that 82 percent of bird strikes occur at or below 1,500 feet above ground level—encompassing the altitudes at which we practice ground reference maneuvers and fly most general aviation airport traffic patterns.
As for surface operations, the report addresses the where and- when of collisions with terrestrial animals: Evidently, they are more likely at night, and more probable on arrival than on departure, and with some seasonal concentration.
Student pilots can review basics about wildlife hazards and reporting procedures in Chapter 7 of the Aeronautical Information Manual and should note that wildlife is among the collision-hazard risks they will be expected to manage on a practical test.
How? A tip from AIM Section 7-5-4 recommends that “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.”
A collision with a large bird 1,200 feet above the ground forced a return to the home airport from a training flight to another field and proved quite a learning experience—for the CFI aboard.
“In the future, I will instruct students to be very proactive in avoiding birds, and make quick changes in the flight path in order to avoid a bird strike, especially if I do not appear to see the bird,” the CFI resolved in an Aviation Safety Reporting System filing.
“Also, considering the amount of damage, I should have landed at the first airport,” the instructor wrote.