Do pilots ever hit birds?

Why don’t jetliners maneuver to avoid a bird strike if spotted in time?

With 75%* of the bird strikes hitting the wings and engines, why isn’t there any training to avoid such strikes by banking if a flock was spotted with enough time to react? It seems what Boeing recommends* is to ride it out then assess the damage.

Avoid or minimize maneuvering at low altitude to avoid birds. (. ) Fly the airplane and maintain flight path control.

1. Dip the right wing to move the upwash away from the flock’s path, or
2. Raise the right wing because birds are better divers than climbers.

In US Airways 1549 both engines suffered, and I don’t know if dipping one wing or the other could have saved one engine. According to the CVR transcript, from announcing «birds» to the strike there was a full second. With a typical human reaction time of 0.3 seconds to announce birds, there would have still been a complete second to roll the plane one way or the other. Enough to roll 15° in an Airbus (max normal law FBW roll rate is 15°/s).

Why is riding it out better than a bank? (Worst outcome is the same for doing nothing and doing something.)

I’m neither claiming a solution, nor discussing flight 1549 in particular, rather inquiring about the flaws in my understanding of bird strikes and the related avoidance maneuvers.

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asked Sep 26, 2018 at 17:04
user14897 user14897
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$begingroup$ That would be nice, second best thing would be any studies on avian behavior when faced with flying metal if you know any. $endgroup$

– user14897
Sep 26, 2018 at 19:28

$begingroup$ The short answer, whether flying a small or large aircraft, is that birds are better at maneuvering than you are. $endgroup$

Sep 26, 2018 at 20:06

$begingroup$ A single bird should not cause a disaster. Even the worst case of flying with one engine out is a standard drill that trainee pilots learn as soon as they progress to multi-engine aircraft, not an unknown emergency situation. But if you encounter a flock of birds (like the 1549 situation) the chances of avoiding the whole flock are negligible — therefore, don’t bother to try. $endgroup$

Sep 27, 2018 at 0:24

$begingroup$ Note that 1 second is only enough time to roll 15° if you are already rolling at 15°/s. Roll acceleration is limited, and with a fairly generous figure of 10°/s^2, one could only roll 5° in one second starting from zero roll rate — and that is assuming the pilots instantly determining the appropriate control input to make, and the control surfaces reacting instantly to the pilot’s input. $endgroup$

Sep 27, 2018 at 9:03

$begingroup$ @ymb1 , as everyone has said, you’ve just massively, spectacularly, overestimated how much time is involved! Bird strikes are «instant». A perfect analogy is, could you «dodge» an insect hitting your windscreen while driving a car — the answer is «of course not!» $endgroup$

Sep 27, 2018 at 14:04

8 Answers 8

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If you’re low, slow, and heavy (say, early in climb with full passenger and fuel load for a transcontinental or transoceanic leg), just dipping a wing can result in a stall and crash if you lose power while in a more than minimal bank.

The reasoning goes like this: the birds might not hit you. If they do, it’s unlikely you’ll lose all engine power. Even if you do lose all power, if the aircraft is level wings and not maneuvering, you have the most options for a safe landing (return to port, land on a nearby strip, land on flat ground or a road, etc.).

A sharp maneuver at that stage of a flight can itself cause a crash, never mind what will happen if you get a bird strike anyway.

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user14897
answered Sep 26, 2018 at 17:10
Zeiss Ikon Zeiss Ikon
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$begingroup$ This may be science fiction, but is there any kind of shield in existence that can be deployed to aircraft? Like, some sort of fast acting iris that will close in front of the engine intakes when birds are sighted? Or would creating an obstruction to airflow in front of the engines like that be just as dangerous as the birds entering the engine? What do war aircraft do to protect against birds? $endgroup$

Oct 5, 2018 at 6:20

$begingroup$ Close an iris in front of the engine and you’ll get an instant 100% loss of thrust, as well as possibly a fan overspeed (the turbine will still be developing power while the fan cavitates in the partial vacuum behind the iris). Then when you want thrust again, the combusters will be flamed out and you’ll have to restart — which, low/slow/heavy, is a recipe for a crash. Warplanes do the same thing airliners do, if they detect birds that might hit: grit their teeth and keep flying the airplane. $endgroup$

Oct 5, 2018 at 11:27
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Not possible to see birds in time

Incredible as it may seem, this re-enactment of flight 1549’s bird strike is actually drawn out and made twice as long as it actually happened.

The Cockpit Voice Recorder transcript, note the seconds.

15:27:10.4 HOT-1 birds.

15:27:11 HOT-2 whoa.

15:27:11.4 CAM [sound of thump/thud(s) followed by shuddering sound]

15:27:12 HOT-2 oh shit.

15:27:13 HOT-1 oh yeah.

15:27:13 CAM [sound similar to decrease in engine noise/frequency begins]

15:27:14 HOT-2 uh oh.

15:27:15 HOT-1 we got one rol- both of ’em rolling back.

1.0 seconds from calling out «birds» until the engines were ingesting them, 4.6 seconds to calling out that the engines are rolling back. That is how fast it happens.

Flight 1549 was travelling at between 210 and 220 knots when the collision happened. That is little over 100 meters per second. Unless you are looking directly at a Canada Goose (which is the kind of birds 1549 collided with), you cannot even see the bird beyond 1 km away. So in the very best of circumstances, you have less than 10 seconds to react. But if you are heading directly for the bird, then you are subject to the «blossom effect» and not very likely to notice the bird until 1-4 seconds before impact, because the eye simply cannot see something that small when travelling towards it at those speeds.

So there is no training to dodge birds, because if you are so close you can see the birds then it is already too late and there are no manoeuvres you can perform that will remedy the situation. Instead you risk exacerbating it by losing the engines and losing control at the same time.

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answered Sep 27, 2018 at 8:07
MichaelK MichaelK
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$begingroup$ OMG that video. I was like, how could you not spot the giant airlin. OH GOD. $endgroup$

Sep 27, 2018 at 10:10

$begingroup$ @Jamiec Clever, isn’t it. 😀 The video gets the point across very effectively in my opinion. $endgroup$

Sep 27, 2018 at 10:15

$begingroup$ It does indeed. The about of times I’ve been flying and spotted traffic and become a bit fixated by it, but therefore forgetting to keep scanning for other traffic. I learnt an important lesson today. $endgroup$

Sep 27, 2018 at 11:44

$begingroup$ Great answer. Ever hit a bird while driving a car? I have. I was probably going 60 mph or so. Not a snowball’s chance of seeing it in time, and that’s a much lower speed. Another example — my aunt saw a raccoon while driving, tried to dodge it, went off the road, where her car entered a ditch and flipped over. Just hit the bird. $endgroup$

Sep 27, 2018 at 22:03

$begingroup$ @Jamiec while you’re at it, do the same with trains. You watch the tail of the freight train go by with its flashing rear marker and go «yay» and start across, except the train obscured the view of another train bearing down on the crossing on the next track. $endgroup$

Sep 28, 2018 at 1:48
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The closing speeds are simply too high to be able to do anything.

A jet airliner is flying at an absolute minimum of 250km/h. Geese can fly at well over 50km/h, so you’re looking at a potential closing speed of over 300km/h. Even if you could identify a bird a kilometer away as being a threat to your plane, that only gives you less than 12s to react, and that’s under the completely unrealistic assumption that you can (a) spot a bird that’s a kilometer away and (b) instantly determine whether or not it’s going to hit you.

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answered Sep 26, 2018 at 21:05
David Richerby David Richerby
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$begingroup$ Also, the birds can fight back. There was an incident (quite a long time ago) where a 747 was approaching Anchorage, Alaska. The flight crew identified a sea eagle ahead of them, flying the same course but somewhat slower, carrying a salmon held in its talons.. At the last minute, the eagle diverted out of the path of the plane — and dropped the salmon, which scored a direct hit on the #2 engine. Some you win, some you lose. $endgroup$

Sep 26, 2018 at 23:54

$begingroup$ @alephzero — That would be a fish strike, and they knew because a grizzly went after the #2 engine after parking, bad day for that 747 😛 $endgroup$

– user14897
Sep 27, 2018 at 0:22

$begingroup$ @alephzero blog.alaskaair.com/alaska-airlines/history/flying-fish (not the engine, but a similar fish story) $endgroup$

Sep 27, 2018 at 1:02
$begingroup$ That’s sounds a bit fishy $endgroup$
Sep 27, 2018 at 8:00
$begingroup$ @DonBranson Now now Don. just swim with the stream. $endgroup$
Sep 28, 2018 at 9:16
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I think you hit the nail on the head there with the comment “if there’s time to react”. In many cases there just isn’t. Small birds are difficult to spot until they are right on top of you (generally

Add to that that a passenger jet weighing anywhere between 40,000 lbs to 1,000,000+ lbs just ain’t that agile and moving along at 200-250 KIAS at low levels gives little time available to do this in (at 200 kts you cover about 110 yards per second or a football gridiron every second). Add into this cockpit tasks and flow, ATC communication, scanning for traffic, checklists, systems operation, lack of contrast between birds and the background, etc., and you quickly find you may not have a whole lot of time available for avoidance of feathered flyers.

Pilots will alert ATC if they spot flocks of birds which might present a hazard to other pilots. I’ve notified ATC about birds before, generally hawks and other raptors circling around the departure or approach ends of runways. Airports near known migratory routes for birds may publish advisories in aerodrome NOTAMs as well.

Cactus 1549 really didn’t have a prayer and was all over before either Sully or Stiles could really inititate evasive maneuvers. They also had the shock of the strikes to deal with (Sully claimed the birds impacts with the airframe produced a physical WHAM! WHAM! WHAM! effect, like being in a car being pelted with large hailstones during a severe thunderstorm, which is shocking and disorienting in and of itself). There was no time to evade the animals once they were spotted at close range. Any other conclusion is just musing by armchair pilots.

The only evasion technique I’ve been taught about birds is to climb away from them — the theory being when a bird gets scared or spooked in flight, it tucks its wings and dives rapidly to avoid predators, etc. I have no first hand evidence that that’s an effective evasion method; it may just be another aviation old wives tale.

Explained: What are bird strikes and how they affect aviation safety?

Two planes in India — a Spicejet one bound for Delhi and an Indigo flight — were struck by bird hits on Sunday and had to be grounded. As per International Civil Aviation Organization data, airlines face an average of 34 such strikes in a day, amounting to a loss of around $1 billion annually

FP Explainers June 20, 2022 15:21:29 IST

Passengers deboard the SpiceJet plane after it made an emergency landing in Patna. PTI

Sunday was a bad day for flying in India.

Two separate flights, one involving a Patna-Delhi SpiceJet flight and an IndiGo plane flying Guwahati-Delhi, had to return back to their origin airports and were grounded for maintenance after a bird hit the planes.

The incidents will now be probed by the aviation safety regulator — Directorate General of Civil Aviation.

We take a look at what exactly are bird hits and the danger it poses to the aviation sector.

What is a bird strike?

The event of an airborne animal (usually a bird or a bat) hitting an airplane in flight is referred to as a bird strike.

Bird strikes also happen to other man-made objects on land, such as cars, power lines and wind turbines, which usually result in death for the birds.

According to scienceabc.com, the first ever case of a bird strike was reported by Orville Wright (one of the Wright brothers who is credited with inventing and flying the world’s first successful airplane) in 1905.

It was reported that Orville was flying circles near a cornfield in Ohio; he had apparently been chasing flocks of birds before he hit one. The dead bird lay on the wing of his airplane until he made a sharp turn to dump it off.

Bird strikes usually occur when an airplane is flying at low altitudes. Therefore, the most favourable conditions for a bird strike are during take-offs or landings (or other related phases) of airplanes.

A survey held by International Civil Aviation Organization (ICAO), including data from 91 countries found out that airlines face an average of 34 bird strikes in a day. The damage amounted to more than $1 billion annually. A relieving fact is that almost 92 per cent of the air strikes are without any damage.

How dangerous are bird strikes?

Bird strikes are among the most common threats to aircraft safety, and they typically occur during the take-off or landing phases of a flight.

Bird strikes occur almost every day, but some are more dangerous than others.

Arguably the most dangerous form of bird strike is one in which a bird is ingested into the aircraft’s engine; this event is referred to as a jet engine ingestion (since the bird is ‘ingested’ by the engine).

Of course, the danger in such situations increase further if a larger flock of multiple birds is involved.

The most famous incident is that of US Airways flight 1549 on 15 January 2009. The plane was scheduled from La Guardia, New York City to Charlotte, North Carolina when the aircraft hit a flock of birds (Canada geese), so significantly it obscured the pilots’ windscreen view. Both engines failed and the pilot, Captain Chesley Sullenberger – affectionately known as Sully — landed it on the Hudson River with no fatalities. This incident was then made into the famous movie Sully, starring Tom Hanks.

In the case of Sunday’s incident, SpiceJet Boeing 737 aircraft had to make an emergency landing at the Patna airport after a bird hit one of its engines. According to the DGCA, the bird hit led to the failure of engine 1 on the Patna-Delhi SpiceJet aircraft, which was forced to make an emergency landing at Bihta Airforce Station in Patna after its left wing caught fire.

A Delhi-bound SpiceJet flight returned to Patna airport after engine issues in the aircraft: Airport official#Emergency pic.twitter.com/SAvulJUOb3

— Chaudhary Parvez (@ChaudharyParvez) June 19, 2022

In the second incident on Sunday, flight 6E 6394 from Guwahati-Delhi had to return to Guwahati airport, due to a bird hit after take-off.

IndiGo A320neo engine damaged after hitting birds on takeoff from Guwahati Airport in India yesterday. This was the 2nd birdstrike incident in 24 hours. No injuries reported. https://t.co/yMGk9EW0uJ

27saurabhsinha pic.twitter.com/GTJzqrYQjh

— Breaking Aviation News & Videos (@aviationbrk) June 20, 2022

Another instance when bird strikes can be dangerous is when they hit the airplane’s exterior, which can cause significant cosmetic damage to the plane’s exterior. This can sometimes cause aircraft to be temporarily withdrawn from service.

An example of an incident that saw a bird strike result in cosmetic damage took place in November 2020. This saw a MwantJet Embraer ERJ145 have its windscreen smashed by the force of a collision with a bird that it encountered while departing from Kinshasa in the Democratic Republic of Congo.

How to avoid bird strikes?

Airports across the world have been trying various measures to prevent them from even coming close to planes.

Predatory bird sound recordings, cartridge scarers — which produce loud bangs and flashes of light — mechanical falcons, trained falcons and drones have all been used. However, experts note that these measures are short-term in nature, as the birds get used to the sound.

Airports authorities also have to ensure that bird habitats around the airport and its runway(s) are reduced. Open areas of grass and water, shrubs, trees provide food and roosting sites for birds. For this reason, airports tend to cut down trees with nests, reduce rainwater pooling, and substitute cattle grazing for grain crops.

Another suggestion to prevent such incidents is that engines should be covered with a grill. But this isn’t as easy as it sounds. The main issue is that to effectively block the bird at 800km/h, the grid has to be significantly sturdy and thick, but this will disrupt the air flowing into the engine.

Another way to avoid bird strikes was one provided by a study from Perdue University; officials found that planes painted in dark colours attract more birds. Hence, brighter shades should be used to help birds avoid the aircraft.

Amsterdam’s Schiphol International Airport, perhaps, adopted the most innovative method to avoid bird hits. A small herd of pigs was drafted in to combat the hazard of bird strikes in a pilot project.

The idea behind the plan was that the pigs would come and eat the crop leftovers, which attract birds, removing a source of food.

With inputs from agencies

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Updated Date: June 20, 2022 15:21:29 IST

• Air Safety
• Bird Strike
• Bird Strike Airplane Damage
• Bird Strike Flight Damage