The hawk has landed: Braking mid-air to prioritize safety over energy or speed:
Researchers at the University of Oxford have found that hawks control their flight to ensure the safest landing conditions when perching, even if it takes longer and more energy to do so. Understanding how birds optimise their landing manoeuvres through learning may help in developing small aircraft capable of perching like birds.
In new research published in Nature, four Harris' hawks wearing tiny retroreflective markers were tracked flying back and forth between two perches. Their precise movements were recorded by 20 motion capture cameras positioned around the room, allowing the research team to reconstruct their flight paths on over 1,500 flights. The research team then used computer simulations to understand why the birds chose their particular path to the perch.
Aircraft have the luxury of using a runway for braking after landing to reduce speed. In contrast, birds must brake before they arrive at the perch -- however slowing down to a safe speed while in flight risks stall, leading to a sudden loss of flight control. The researchers discovered that the hawks follow a flight path that slows them down to a safe speed but minimises the distance from the perch at which they stall.
To minimise stall, the hawks dived downwards while flapping, before spreading their wings into a gliding posture as they swooped up to the perch. By selecting just the right speed and position from which to swoop up to the perch, the birds were already within grabbing distance of the perch when they stalled, keeping their landings as safe and controllable as possible.
Co-lead author Dr Lydia France, Department of Biology, University of Oxford said: 'We found that our birds weren't optimising either the time or energy spent, so their swooping trajectories were neither the shortest nor cheapest options for getting from A to B. Instead, our birds were reducing the distance from the perch at which they stalled and were even better at limiting stall than our simplified computer model.'
[...] Landing is a critical manoeuvre, and stalling has been the cause of many aircraft accidents. Looking at birds and asking how they solve the problem of safe landing might help us find new bioinspired design solutions for our own technologies, including small aircraft capable of perching like birds.
Journal Reference:
KleinHeerenbrink, Marco, France, Lydia A., Brighton, Caroline H., et al. Optimization of avian perching manoeuvres [open], Nature (DOI: 10.1038/s41586-022-04861-4)
(Score: 2, Interesting) by fustakrakich on Monday July 04 2022, @05:47PM
Airplanes land like ducks [youtube.com], not hawks
hail hail freedonia...
La politica e i criminali sono la stessa cosa..
(Score: 2, Funny) by Anonymous Coward on Monday July 04 2022, @06:23PM
What a useless waste of R&D dollars. Instead, they should develop aircraft capable of slithering like snakes.
(Score: 2, Insightful) by Anonymous Coward on Monday July 04 2022, @06:41PM
When failing to "ensure the safest landing conditions" means instant downgrade from hunter to cat food, the choice is obvious.
(Score: 3, Interesting) by Opportunist on Monday July 04 2022, @07:23PM
Hawks are pretty much the bleeding edge tech air fighter jets of the animal kingdom. They have very few safeguards and reserves, both when it comes to their stability and their survivability if they cannot hunt. OF COURSE they have to make absolutely sure to not break any part of their airframe because they are effin' DEAD if they do. And any hawk who failed to do that landed well 100 times, broke a bone the 101st landing and died without passing on his genes.
The difference is maybe that we can repair our airplanes and if they break down, hey, as long as the passengers are fine, it's not a death sentence. We can afford to do the calculation whether it's more reasonable to "waste" energy and time every time we land or whether we accept the risk that we have to replace a landing gear it every 1000 flights.
(Score: 3, Interesting) by Anonymous Coward on Monday July 04 2022, @09:02PM (2 children)
A family member worked at several different aircraft companies in the 1930s and through WWII. He worked in wind tunnels, flight test, and stability & control (analysis--with slide rules back then). He clearly knew a lot about aircraft behavior.
One day at the beach he decided to feed the sea gulls, and demonstrate the problems of low speed flight...at the birds' expense. At arms length he held out a piece of bread, and as a gull came in to snatch the treat, he would slowly step back, so the bird would have to fly one or two feet further. The birds were already in "full flaps and open slats" on their slow approach (very dramatic), and this little extra flight was more than they could manage. They stalled, one wing dropped and they tumbled in the least graceful manner imaginable. It was only 3-4 (~1 meter) feet to the ground, so no harm done. But I had the impression that the gulls were very embarrassed (or confused) as they picked themselves up and slunk away.
I would not mess around like this with a hawk, those talons don't look friendly!
(Score: 4, Interesting) by FatPhil on Monday July 04 2022, @09:36PM
"their swooping trajectories were neither the shortest nor cheapest options for getting from A to B"
Dear academics, congratulations - your "cost" metric is wrong.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Tuesday July 05 2022, @08:22AM
I think other people have seen this too ...
https://anchor.fm/andrew-grillet/episodes/Its-a-birds-life-e1kos7r [anchor.fm]
(Score: 3, Interesting) by aliks on Monday July 04 2022, @09:15PM (1 child)
Great timing for this article - as I was drinking champagne with one of the authors yesterday!
To err is human, to comment divine
(Score: 3, Funny) by Anonymous Coward on Monday July 04 2022, @10:19PM
I thought they would celebrate *after* getting published on SoylentNews.
(Score: 2, Insightful) by Anonymous Coward on Tuesday July 05 2022, @02:31AM
I'm of two minds.
A - no shit this is what birds (and trapeze artists, and kids dismounting swings, and...) do. Hardly novel. And sad that some folks have never seen a bird perch!
B - I guess it's good to have it documented and analyzed numerically
(Score: 0) by Anonymous Coward on Tuesday July 05 2022, @08:27PM
Birds have extremely variable aspect wings which is what makes extremely difficult manoeuvres like perching possible. A mechanical equivalent [wikipedia.org] would be expensive, high maintenance, and ultimately less safe than any fixed or rotary wing aircraft, because gliding in to a long runway is the safest possible landing method and even helicopters can autorotate in an emergency. Perching is probably the hardest way to safely land any aircraft because the margins are so tight.
(Score: 2) by legont on Wednesday July 06 2022, @01:49AM
General aviation - what press usually call small - airplanes do exactly the same. The idea of safe landing is to stall your airplane as vertically close to the runway as possible. The only difference with birds, birds have much lower stall speeds. One could watch birds that have relatively high stall speeds such as geese and swans. They actually often do the whole pattern - downwind, base and final - for exactly the same reason as pilots. They need to estimate wind speed and direction (and check the landing spot) to minimize the touch down speed as well.
Note that commercials - big jets - typically land differently. Jets don't stall over the runway. They simply slam the runway letting the landing gear do the work.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.