70% of birds fly below 1,500ft, 25% of birds fly between 1,500ft and 15,000ft, and only 5% above 15,000ft. What is the greatest height at which a bird has hit an aircraft? What species was the bird?
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1$\begingroup$ One got ingested at 37000 feet mnn.com/earth-matters/animals/photos/… $\endgroup$– DJohnMMar 21, 2017 at 21:21
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1$\begingroup$ What kind of height, or altitude? True altitude, pressure altitude, height above ground? In the upper flight levels, extremes of condition could theoretically yield variation of thousands of feet between true and pressure altitude, for example. $\endgroup$– J WMar 22, 2017 at 2:07
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$\begingroup$ What I knew (and this doesn't necessary contradict you, only helps to set more percentual boundaries) is that 90% of the birds are within 3000 ft AGL. That's why airliners try to hold the speed between 160 and 180 KIAS when taking off or landing if ATC report bird spotting or collision from previous traffic. :) $\endgroup$– Germano CavalcantiApr 10, 2017 at 10:00
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1$\begingroup$ While not at flight levels, I have during the winter somewhat frequently seen eagles over central New York, at 13,000 to 15,000. However, I do not know anyone who has hit one at those altitudes. $\endgroup$– mongoOct 29, 2017 at 23:46
3 Answers
On November, 29 1973 a bird strike occurred at an altitude of 11,300 m over Abidjan. The engine was shutdown during the collision, and was not restarted.
Altitude
The altitude is that recorded by the pilot shortly after the impact, which damaged one of the aircraft’s engines and caused it to be shut down. The plane landed safely at Abijan without further incident.
Species
It was determined the bird was a vulture:
The remains of the vulture consisted of five complete and 15 partial feathers from the wings (secondaries, lesser, and underwing coverts), tail, neck, and breast. Sufficient details arc apparent in these feathers to allow their certain identification as G. rueppellii, using comparative material in the U.S. National Museum of Natural History.
Rüppell's vulture is a specie weighting 7 to 9 kg and living 40 to 50 years:
Record
Wikipedia confirms this is the highest collision recorded in the history of aviation:
An aircraft over the Ivory Coast collided with a Rüppell's vulture at the altitude of 11,300 m (37,100 ft), the current record avian height.
Why such altitude for a bird?
This is well above Everest height, why does this bird flies so high, where there are not so many preys, pressure is only 25% of the pressure at ground level and temperature is about -57°C?
The reason suggested is that thinner air allows faster flight without much effort and saves precious energy. Flying at such a great height, vultures face almost no physiological problems with regard to breathing; they have much more efficient breathing system than other living beings, including humans.
Their flow of blood enables oxygen to be extracted from air, with far greater efficiency than any other living being. If the flight is in cloudless condition, low temperature at great heights too does not bother them.
Birds at high altitude
The previous record altitude for a bird-aircraft collision was of a Mallard (Anus platyrhynchos) at 21,000 ft (Manville, Wilson Bull., 75:92, 1963), based on feathers that I identified from the strike. That collision occurred between Battle Mountain and Elko, Nevada, on 9 July 1962.
Other high-altitude records of birds include:
sightings of migrating geese at 29,000 ft, over the Himalayas (Griffin, Bird Migration, Natural History Press, Garden City, N.Y., 1964), and
soaring Bearded Vultures (Gypaetus barbatus) at over 24,000 ft.
Vultures are a known threat to aviation, as are other birds flying high:
Images and data taken from Science Focus article
In 2010, in Scotland, a Rüppell's vulture participating to a display was caught in a wind and was lost. Aviation operators had to be notified, in case the vulture was still in the vicinity.
With a wingspan of 10ft, it could do a lot of damage to a large aircraft. But it's also half the size of some of our small training aircraft and it could take one of them, or even a helicopter, right out.
Damaged compressor after a bird strike (not the involved aircraft):
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$\begingroup$ Was this pressure altitude, or height above MSL? $\endgroup$– J WMar 22, 2017 at 2:09
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1$\begingroup$ @JonathanWalters -- I believe it was originally reported as a FL by the pilots $\endgroup$ Mar 22, 2017 at 4:09
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4$\begingroup$ How did they identify the flying object that impacted the plane? $\endgroup$– AronMar 22, 2017 at 4:23
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2$\begingroup$ @Aron: By a few feathers in the engine (the engine was shutdown during the collision, and not restarted). See the second article at the bottom of the first page. What I like in this industry is the depth of the investigations. $\endgroup$– minsMar 22, 2017 at 8:15
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3$\begingroup$ What I'd like to know is: what on earth do vultures need to do at 37'000 feet? $\endgroup$ Apr 7, 2017 at 22:51
Highest I've ever heard of is 40,000 ft.
On May 19, 2014 Atlas Air flight GTI8665, a 767-300 freighter, reported a bird strike at FL400 over Indiana. They were unable to tell what type of bird it was but the pilots reported that there were guts on the windshield. The windshield was broken and the aircraft was diverted.
Pilot: Center Giant 8665 Heavy
Controller: Giant 8665 go
Pilot: Believe it or not we just had a bird strike up here [...] left windshield, we're okay
Controller: Giant 8665 do you need any assistance there then?
...
Another flight: What altitude was that bird strike?
Controller: That was Flight Level 4-0-0
...
Controller: If you had to guess was it just one bird there, did you see any other birds in the vicinity of that hit?
Pilot: To the best of my knowledge it was a single bird sir, we do have guts on the windshield and the outer paint is cracked...
Controller: ... Definitely an anomaly I think [...] 4-0-0
Pilot: Yeah 4-0-0 he may have been on oxygen I dunno
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3$\begingroup$ Has anyone analyzed this case further? $\endgroup$ Mar 21, 2017 at 23:09
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1$\begingroup$ @UnrecognizedFallingObject I dunno. I just remember hearing that recording. I think there's only one species of vulture that is even capable of flying that high $\endgroup$– TomMcWMar 21, 2017 at 23:16
The wikipedia article on the Rüppell's vulture has an interesting footnote which leads a pdf of The Wilson Bulletin dated December 1974(!) which details the following other instances of high flying birds, including the one mentioned here:
Collision between a vulture and an aircraft at an altitude of 37,000 feet.-On 29 November 1973, a Riippells ’ Griffon (Gyps rueppellii) collided with a commercial aircraft at 37,000 ft over Abijan, Ivory Coast, western Africa. The altitude is that recorded by the pilot shortly after the impact, which damaged one of the aircrafts ’ engines and caused it to be shut down. The plane landed safely at Abijan without further incident. The remains of the vulture consisted of five complete and 15 partial feathers from the 461 462 THE WILSON BULLETIN December 1974 Vol. 86, No. 4 wings (secondaries, lesser, and underwing coverts), tail, neck, and breast. Sufficient details arc apparent in these feathers to allow their certain identification as G. rueppellii, using comparative material in the U.S. National Museum of Natural History. The previous record altitude for a bird-aircraft collision was of a Mallard (Anus platyrhynchos) at 21,000 ft (Manville, Wilson Bull., 75:92, 1963), based on feathers that I identified from the strike. That collision occurred between Battle Mountain and Elko, Nevada, on 9 July 1962. Other high-altitude records of birds include sightings of migrating geese at 29,000 ft, over the Himalayas (Griffin, Bird Migration, Natural History Press, Garden City, N.Y., 1964), and soaring Bearded Vultures (Gypaetus barbatus) at over 24,000 ft (Ah, Birds of Sikkim, Oxford University Press, London, 1962).-ROXIE C. LAYBOURNE, National Fish and Wildlife Laboratory, Bureau of Sport Fisheries and Wildlife, National Museum of Natural History, Washington, D.C. 20560. Accepted 7 June 1974.
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