AN AIRBUS A320-231: A US Airways A320 at San Diego Airport
Image: David Mueller, via Wikimedia Commons
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US Airways Flight 1549 took off from La Guardia Airport in New York City at 3:03 P.M. Eastern time on its way to Charlotte, N.C., with 150 passengers and five crew members on board. As it gained altitude, it reportedly ran into a "massive flock of birds," according to The New York Times, and the jet engines began making noises—and lost power.
Heading north without engine power, the pilot of the Airbus A320 changed course and—in what some are describing as a heroic but calm act—glided to a watery landing in full view of buildings on Manhattan's west side. "The pilot got on and said, 'You guys got to brace for a hard impact,'" passenger Jeff Kolodjay told the Times. "That's when everyone started to say their prayers. I got to give it to the pilot, he did a hell of a landing." When the pilot, Chesley Sullenberger, emerged from the plane, he had not even donned a life vest, according to the Times of London.
A flock of eight-pound (3.5-kilogram) geese had apparently brought down a plane, plunging it and 155 people into the frigid waters of the Hudson River.
A group of rescue boats soon plucked shivering passengers from the wings. They have been taken to area hospitals, and only minor injuries have been reported so far.
But not every bird-struck flight has been so lucky. The first fatal strike was recorded in 1912, just nine years after the Wright Brothers first flight in Kitty Hawk, N.C. The space shuttle Discovery pulverized a bird during a launch in 2005, although no damage to the spacecraft was recorded.
With soaring air traffic and migratory birds recovering from DDT and other pesticides, the number of bird strikes has been rising over the last 20 years, from about 1,500 in 1990 to about 8,000 last year.
In Thursday's crash, investigators believe geese may have been sucked into both engines during take-off, an unusual situation that is simulated, but not tested, during "bird strike" certifications by aircraft engine manufacturers.
To find out more about the dangers of bird strike, we spoke with Richard Dolbeer, a wildlife biologist and expert on bird strikes who retired in September after working 36 years for the U.S. Department of Agriculture in Sandusky, Ohio.
[An edited transcript of the interview follows.]
Why are birds such a threat to aircraft?
It basically comes down to the physics equation for kinetic energy: Energy is proportional to mass times velocity squared. The velocity of the aircraft allows for the impact of this feathered bird to generate enough force to cause an engine to malfunction. (A 12-pound, or 5.5-kilogram, Canada goose struck by an aircraft traveling 150 miles, or 240 kilometers, per hour at liftoff generates the force of a 1,000-pound, or 455-kilogram, weight dropped from a height of 10 feet, or three meters, according to Birdstrike USA.—Editor's Note)
When a plane is taking off, it is going 170 miles (275 kilometers) per hour and accelerates to several hundred mph. The engine's fan blades during taking off—like this plane today—are going 3[,000] to 4,000 rotations per minute, and the tips of those turbofan blades are actually at the speed of sound or greater—700 to 800 mph (1,125 to 1,285 kilometers per hour). When a bird hits one of those fan blades, there's a tremendous energy transfer from the bird to the engine, and that's basically why a bird can cause serious damage to an aircraft engine.
We do know that for this flight today, Canada geese would be the most likely species. They typically weigh eight to 10 pounds (3.5 to 4.5 kilograms). They are a large bird so you can imagine the force that's generated.
What is the typical outcome of a bird strike?
Since 1990 the FAA (Federal Aviation Administration) has compiled statistics on bird strikes. I'm the author of a report showing that 12 percent to 15 percent of the strikes result in some damage to aircraft. In the majority of strikes, 85 percent or more, nothing happens: The bird bounces off the plane or a small bird…just goes through the engine and there's no discernible damage [to the plane]. In a small percentage you get damage, and in a smaller percentage you get catastrophic damage.
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21 Comments
Add CommentOperational bird radars are available and in use. The USAF has six specialized bird radars and NASA has two it uses for monitoring space shuttle launches. Foreign airports such as Calgary IAP and the Durban IAP also have systems in use. These systems are low cost, automatic, proven and for what the Airbus we just lost cost, we could have these systems at most every airport today.
Reply | Report Abuse | Link to thisYou have got to be kidding me. Bird populations are nowhere near historic (define properly), levels. Citing a rise in bird population as a scapegoat is absurd.
Reply | Report Abuse | Link to thisThe previous comment of radar is a good example of technology that isn't used here, due to "it cost money".
How about placing a simple screen in front of the turbine that turns big birds into smaller bird "pieces", before it enters the turbines. Again, it might cost a CEU his bonus for a year to implement that.
How about realizing that the more planes we put in the air, the more accidents are going to happen. Airline travel is so safe today compared to driving a car, that I can't believe we are talking about this issue. Except, news channels put forth their crap and we all eat it up, even though it stinks.
This is a very very well designed aircraft and full credit to the pilot also.
Reply | Report Abuse | Link to thisdid DDT do something to birds?
Reply | Report Abuse | Link to thisNo, DDT did not do anything to birds - those claims were based on seriously flawed studies. That didn't stop the environmentalists from pushing to get it banned though - an action that has cost perhaps 100 MILLION lives to malaria.
Reply | Report Abuse | Link to thisWe should all be grateful to God for saving the life of pilot and his passengers. He must have been divinely inspired to take the action he took.
Reply | Report Abuse | Link to thisIf God is responsible for saving everyone, why didn't God just divert the birds away from the plane in the first place?
Reply | Report Abuse | Link to thisI'm sure the birds being sucked into engines and pulverized would disagree that no major damage is being done.
Reply | Report Abuse | Link to thisThe question should be how to keep birds safe from planes.
I don't see why a piece of equipment similar in concept as the old "cow catcher" on locomotive can't be designed for a jet engine. A simple conical devise "grating" formed in front of the engine intake could either deflect or "cheese cutter like" shred a bird into smaller pieces allowing them to bounce off or pass through a turbo fan without major damage.
Reply | Report Abuse | Link to thisI don't see why a piece of equipment similar in concept as the old "cow catcher" on locomotive can't be designed for a jet engine. A simple conical devise "grating" formed in front of the engine intake could either deflect or "cheese cutter like" shred a bird into smaller pieces allowing them to bounce off or pass through a turbo fan without major damage.
Reply | Report Abuse | Link to thisInstead of testing engines by tossing chicken carcasses into them, maybe they should switch to pigeons and sea gulls. I can't remember the last time I heard of a jet passing through a flock of chickens. :)
Reply | Report Abuse | Link to thisWhat can't a grille be put over the engine intakes? This would absorb all or part of the energy of bird stikes and reduce the impact on the compressor blades.
Reply | Report Abuse | Link to thisA problem with screens or grating like you've describe is that they a) cut down on airflow into the engine and b) have the potential for ice to collect on them.
Reply | Report Abuse | Link to thisAirplanes have quieter engines than they had in the past and many times the birds can't hear the aircraft. Maybe a device that emits a signal that birds can hear (similar to a dog whistle) could be place on aircraft to warn the birds to GTF outta the way.
Much can be done and should be done to avoid hitting birds.
Reply | Report Abuse | Link to thisWhy is that if this plane had gone down in flames and everyone died, we'd be looking at the pilot for cause? But, because it came down safely, one of the gods is responsible. Sorry, I prefer to give ALL of the credit to Captain Sully. It was his experience and skill only that kept his passengers safe. If you want one of your gods to get the credit, I'll need proof...not to mention an explanation as to why that god didn't just not put the birds in the path of the plane in the first place..
Reply | Report Abuse | Link to thisLive birds used to be used in research rather than frozen trajected ones I believe, the variety of birds both in flocks like starlings/lapwings + individual as baldheaded eagles/geese is far ranging.
Reply | Report Abuse | Link to thisI hope there is cohesive global research on this not just each country holding stats.
May I ask somebody, why the motors of a plane are not protected by a sort of a strong sieve (percolater) of a conic shape towards the direction of the flight? Thank you. Pavel Kabrt, pavelkabrt@seznam.cz, Czech Republic
Reply | Report Abuse | Link to thisPerhaps the same question others ask: does anybody know, why the motors of a plane are not covered by a strong conic sort of percolator /sieve/ with its top in front? Thank you, Pavel Kabrt, Czech Republic, pavelkabrt@seznam.cz
Reply | Report Abuse | Link to thisme and my group are in midle school we have been assined to find a solution to our problemm i agree with furgus we should be finding a way to keep the birds and the planes safe not just the planes
Reply | Report Abuse | Link to thisThe author states "There's no magic chemical you can spray or sound you can project that is going to scare the birds away. “
Reply | Report Abuse | Link to thisHe is not only wrong he is totally wrong. There certainly is a chemical that gets rid of birds without harming them and does so very effectively. He should read what the EPA has published regarding Methyl Antrhanilate and efficacy on ALL species of birds. Now different means need to be employed to use this chemical but it's efficacy to rid areas of all birds is a fact not a supposition.
Seriously?? DDT didn't do anything to birds?? Wow, can't believe you are so naive.
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