Encounters of the feathered kind

Is there any pilot who hasn't at some point gazed up, with curiosity or envy, at birds in flight? For most of us, this was probably well before we were old enough to join the flying fraternity. Fascination with creatures of flight as well as the profound yearning to join them has transcended civilizations and cultures throughout history.

Whenever we ourselves are flying and we realize we're sharing the skies with feathered wings, that's when things suddenly become very different. At some point almost all of us have seen at least one bird (and often many more) from the cockpit of a general aviation airplane, while in flight. What might happen, should our flight paths ever coincide?

Possibly the first documented bird strike was recorded by none other than the Wright brothers, about a century ago, near Dayton, Ohio. At that time, it may not yet have dawned on airmen that birds don't have perfect reflexes and avoidance skills. A few years later in late 1911, a brave and ambitious pilot named Calbraith Rogers completed the first transcontinental flight from New York to California in the Vin Fiz, a Wright biplane. Then, about five months later, he flew into a flock of gulls off Long Beach, California, and drowned in the surf under the wreckage of that same famous airplane. The danger of midair collisions with birds doubtless became more apparent.

This map shows the four major migratory flyways in North America: Pacific, Central, Mississippi, and Atlantic.

As recently as the 1970s reported bird strikes were still relatively uncommon. But because of several factors, including expanded conservation efforts; the quadrupling of migratory bird populations; suburban sprawl into their habitats; and bigger, quieter, and faster airplanes, things are getting worse. While most bird strikes are not catastrophic for the pilots concerned, some are quite serious--as you can see.

It may surprise you to learn that within the past decade, wildlife strikes in general have cost U.S. civil aviation almost a half-billion dollars a year. Although birds aren't the only problem--deer as well as coyotes and other creatures (even alligators) have wandered onto runways--they still outnumber mammals by at least 30 to one. The U.S. Air Force reported more than 3,000 bird strikes in a single year (taking the year 2000 as an example), and almost 6,000 bird strikes were reported for U.S. civil aircraft in that same year. More than 400 people have been killed by bird strikes, and many more have been injured. About 90 percent of the fatalities have occurred since 1960, and hundreds of aircraft have been destroyed.

Although more than 600 bird species live in or migrate through the United States, the types of birds primarily involved in strikes are gulls and waterfowl (each a bit under one-third), and raptors (about 15 percent). Note this as well: About 80 percent of bird strikes go unreported, so this problem is actually greatly underestimated. (Birds that roost or nest in the airport environment also cause damage to aircraft and equipment. You check closely for evidence of bird nests during your preflight, don't you?)

Consider this: A 12-pound Canada goose, when it strikes an aircraft traveling at 130 kt, hits with the energy of a thousand-pound weight dropped from a height of nine feet. Could your aircraft take that? Granted, the majority of North American bird strikes involve birds weighing four pounds or less. Yet a four-pound bird can cause quite a bit of damage (see "Learning Experiences: Out of Nowhere," December 2005 AOPA Flight Training). Because of simple physics, the greater the mass, the greater the likelihood that any damage during chance encounters will be hazardous, messy, and expensive. According to FAA statistics, if you do experience a bird strike, there is about a 15-percent chance that it will negatively affect your flight. (And two-thirds of those involve either an aborted takeoff or precautionary landing.)

Nonetheless, the first thing that one might worry about is immediate personal injury, should a bird of any size happen to strike the windshield. For the average aircraft, there is coincidentally also a 15 percent chance that this would happen to be the point of impact.

Almost three-quarters of all bird strikes involve commercial aircraft. You might think that the average size of Transport-category aircraft would render any bird strike a trivial matter. But here are some records from the history books: In 1960, a departing Lockheed Electra ingested a small flock of starlings into all four engines at Logan Airport and crashed into Boston Harbor, killing 62 people. In 1973 a Learjet taking off from Atlanta struck a flock of birds and crashed, killing eight people. In 1995, a Concorde ingested one or two Canada geese while landing at John F. Kennedy International. The Concorde landed safely, but the damage was more than $7 million. Also in 1995, a four-engine U.S. Air Force jet the size of a Boeing 707 ingested Canada geese into two engines during takeoff from Elmendorf Air Force Base in Alaska and crashed, killing all 24 on board.

During the next 10 years, there is about a 25-percent probability that a large jet transport will be involved in a fatal bird-strike-related accident in the United States or Canada, according to the Bird Strike Committee USA, a government/industry coalition created to study responses to the problem.

Here are some other strike statistics related to flight regime, locality, and season. First, 80 percent of all strikes occur within the airport environment, below 1,500 feet agl. Almost half occur under 100 feet agl; two-thirds under 500 feet. While bird strikes may occur at any airport, those adjacent to wetlands or wildlife preserves are at higher risk of having a significant bird strike hazard. But guess where many airports are? By far the greatest numbers of incidents occur during takeoff/climb (35 percent) and approach/landing (50 percent).

Bird migration plays an important part in the odds that your path will cross one of theirs. (Many birds fly higher during migrations, and so strikes can occur at higher altitudes.) There are four major migratory flyways in North America--Atlantic, Mississippi, Central, and Pacific. The Mississippi flyway contains the largest number of birds, followed by the Pacific, Central, and Atlantic. There are three peak seasons for bird strikes: March and April during the spring migration; September and October during the fall migration; and July and August when inexperienced birds are present and adults molt their flight feathers. More strikes occur during fall migrations because large flocks move to wintering areas in a short time, whereas spring migrations are slower and more irregular. Ninety percent of migratory flights occur below 5,000 feet msl.

There are a few things on the plus side. First of all, air traffic controllers are required to issue advisory information to pilots on any possibly hazardous bird activity, as well as to adjacent facilities and flight service station personnel. Also, airports are getting smarter about how to make themselves less attractive to birds. Many organizations exist to exchange information, promote the collection and analysis of strike data, and develop standards to cope with bird strikes. One result is the FAA's National Wildlife Strike Database. The U.S. Air Force's Bird Aircraft Strike Hazard (note the acronym) team at Kirtland Air Force Base in New Mexico oversees the military side of strike reduction efforts. The coolest one is probably the Bird Avoidance Model--another clever acronym--that correlates bird habitat, migration, and breeding characteristics with key environmental and geospatial data. It allows you to map where the birds have been in comparison to where you are, and where you're going. Even better, the Avian Hazard Advisory System uses Nexrad radar to keep airplanes away from birds, monitoring bird activity in near-real-time for flight crews.

There are also a number of helpful things to remember:

• Check notams for bird problems at departure and destination airports.
• Familiarize yourself with local and national bird migration routes.
• Of course, have a gander (sorry!) at the Web sites I've mentioned.
• Avoid low flight along rivers or shorelines. These are navigational features for birds.
• Don't fly over sanctuaries, landfills, fish processing plants, and other bird havens.
• Fly as high as possible; only 1 percent of GA bird strikes occur above 2,500 feet agl. In fact, most bird activity commonly occurs at pattern altitude at most non-mountainous airports, according to federal wildlife scientists.
• If you must fly in a high-risk area and there are two pilots on board, discuss emergency procedures beforehand, including how to deal with windshield penetration or pilot incapacitation.
• Wear sunglasses or smoke goggles to deal with a windshield penetration.
• Up to 90 kt, birds might take evasive action, but the greater your speed, the greater the chance that they can't.
• If you see birds ahead, attempt to pass above them as birds usually break downward when threatened. Scientists have found that below 500 feet, birds exhibit a variety of behaviors, including climbing.
• If dense concentrations are expected, avoid high-speed approaches; half the speed means one-quarter the impact energy.
• If you observe bird activity on the runway, ask airport personnel to disperse them before taking off. Never use an aircraft to scare birds away.
• Exercise the utmost vigilance during takeoff and landing.
• Use landing lights during takeoff, climb, descent, approach, and landing; it makes the aircraft more visible.
• If a strike occurs on the takeoff roll, stop if there's sufficient runway remaining.
• If a collision seems likely, duck (uh, sorry again) below the glare shield to avoid being hit by the bird and flying plexiglass. Advise passengers to do the same. Protect your eyes and head.
• If the windshield is penetrated, slow the aircraft to reduce the confusion from wind blast, debris, or precipitation.
• Fly the aircraft, first and always! Don't get distracted by the blood, feathers, noise, and wind. (See "Learning Experiences: Small Airplane, Large Bird," p. 47.)
• Assess the damage and decide whether you can proceed to an airport or make an off-airport landing. Declare an emergency; it doesn't cost anything. Even if no damage is visible, consider having a mechanic look at the airplane.
• Once safely on the ground, do your share and complete the paperwork. FAA Form 5200-7 is the document for reporting bird strikes. A .pdf version can be downloaded from the FAA Web site.

Jeff Pardo is an aviation writer in Maryland with a commercial pilot certificate for airplanes, and instrument, helicopter, and glider ratings. He has logged about 1,250 hours since 1989. An Angel Flight mission pilot, Pardo has also flown for the Civil Air Patrol.