TAMPA -- On May 24, Royal Canadian Air Force Capt. Andrew Wetmore was preparing to land at MacDill Air Force Base in a Challenger jet when he saw three large birds ahead of him.
What happened next highlights a problem for military and civilian aviation worldwide, causing about 300 deaths and more than a half-billion dollars since the dawn of aviation, according to figures compiled by U.S. and Canadian military officials and a civilian pilots organization.
Shortly after Wetmore noticed the birds, the aircraft hit one of them, later identified as a vulture.
"Immediately there were multiple warning lights and complete avionics loss on left side," according to an email from the Canadian Air Force. "Both engines appeared to be working, however extensive electrical systems were off line. There was noticeable wind noise from the hole in the front of the aircraft."
The jet landed safely. But U.S. Air Force Capt. Thomas Sayers, safety officer for the 927th Air Refueling Wing at MacDill, said birds pose a constant problem to aviation at MacDill.
Birds hover over the airfield in what Sayers called a "meat tornado."
A few large birds or a large number of smaller ones can be so severe they prohibit takeoffs and landings.
Under the condition known as "bird low," planes can take off and land at will, he said. "Bird moderate" allows pilots to take off or land, but not make repeated attempts. And "bird severe" prohibits any coming or going.
During certain times of the year, the base plans no landings before or after sunrise and sunset, he said.
MacDill's airfield undergoes inspection for bird hazards at least once a week, Sayers said. The base also has a bird hazard working group that meets quarterly to find ways of dealing with the problem. It's a challenging task, he said, because of all the water and grass around the peninsular base -- prime bird habitat -- and because areas nearby also attract birds. What's more, a solution sometimes creates another new bird habitat.
Base personnel, for instance, are changing the times and places they cut grass because it kicks up bugs that attract birds. Also, mowing the grass can create ruts, which can fill with water, which can also attract birds.
So, among other things, the base is looking at applying grass inhibitors and using bigger tires on mowers, Sayers said.
The Canadian jetlanded safely en route to its mission of collecting Brig. Gen. Denis Thompson, head of Canadian Special Operations Forces Command, and his Australian counterpart.
But the right side of the nose of the aircraft was damaged. The crew remained in control of the aircraft and the engines were working, but "extensive electrical systems were off line right side of the cockpit," according to the Canadian Air Force."
The jet, which also ferries dignitaries including military personnel, politicians and the Royal Family, returned to service last month.
Since 1987, U.S. military aircraft have suffered more than a half-billion dollars damage from 10 species of birds measured, according to a master's thesis written by U.S. Air Force Maj. Jason Trudel.
Airports with large populations of waterfowl and other species present a challenge. But Trudel's thesis shows that of the five airports with the most aircraft-bird collisions, only JKF in New York is directly on the water and Chicago-O'Hare Airport is near the water.
Airports in Atlanta, Dallas-Fort Worth and Denver, also in the top five, are not near significant bodies of water. The American white pelican has caused the most expensive damage among military aircraft, at $257 million, according to Trudel's thesis.
The black vulture and turkey vulture come in at numbers three and four, causing more than $100 million in damage each, according to the report.
Horned larks, perching birds, American mourning doves, barn swallows and eastern meadowlarks hit military aircraft most often, according to Trudel's thesis.
Wildlife has taken a toll on civilian aircraft as well, according to the Federal Aviation Administration, with nearly 120,000 collisions at more than 1,600 U.S. and more than 500 foreign civilian airports between January 1990, and December 2011, according to the FAA.
The numbers are drawn from just a third of all strikes, according to the FAA.
One of the most famous aircraft crashes from a bird strike took place Jan. 16, 2009, when U.S. Airways Flight 1549 landed safely in the Hudson River after hitting a flock of geese. It made a hero of pilot Chesley "Sully" Sullenberger.
Sayers, a KC-135 pilot with more than 2,000 flying hours, said nearly all pilots have hit birds.
"There's nothing you can do short of going around with laser beam in front of your jet," he said.
The birds that hit the Canadian jet "typically tuck their wings in and dive. These bigger airplanes can't respond instantaneously. You hold your breath and hope you miss."