Boeing 737 Passenger Jet Damaged in Possible Midair Drone Hit | Hacker News Reader

Boeing 737 Passenger Jet Damaged in Possible Midair Drone Hit

bloomberg.com

65 pointsAnimats63 comments

Unless they found pieces of bird or drone, I don't understand why there's speculation yet either way.

At jet speeds, you don't need a man-made object to explain a huge hole. Here's an example of a bird strike in a 737: https://www.stuff.co.nz/travel/travel-troubles/97238940/mass...

There's speculation because bird strikes occur constantly (>13,000 reported to FAA in 2014) and they aren't newsworthy, but a hypothetical drone strike will light up social media. And Bloomberg has no journalistic integrity.

https://aviation.stackexchange.com/questions/23420/how-many-...

Maybe the drone had a Chinese spy chip in it...

To be accurate:

Boeing 737 Passenger Jet Damaged in Midair UFO Collision

Aliens are using drones now?! /s

It could be that because they didn't find bits of bird it makes it more likely to be a drone. I'd expect (and I have no experience here so someone with more please say if this is wrong) there to be bits of gooey, squishy or sticky bird still stuck to the plane.

I’ve had two bird strikes on piston-engine airplanes; your instinct that they leave recognizable bits is spot-on.

>Unless they found pieces of bird or drone, I don't understand why there's speculation yet either way.

Clickbait. If it's being talked about here, that article has likely (or likely will be) shared all over social media.

The nose cone of passenger jets would have to be fairly thing / weak I guess? Because that's where the forward-looking radar is right?

If a bird hit anywhere else on the plane the cross sectional area of the impact zone would be fairly small in comparison to the nose cone, and probably a fair bit stronger, so we could probably expect to see less damage on a wing or tail fin as at 700 odd kilometers per hour the bird would probably be cut in two by the leading edge of a wing or tail fin?

I'm not aircraft engineer, though.

Bloomberg are good at speculative reporting!

You can run so many more stories! (just need to make sure the prediction algorithm is good)

I wonder what is behind that damaged section of the plane. Passenger seats?

That damaged section is called the nosecone; there's a weather radar behind it.

Do you mean this in an ironic way or in an actual "construction of a Boeing 737" way? Because while larger airplanes do have seats directly in the front of the plane (with the cockpit being on a higher floor) the Boeing 737 doesn't.

The Academy of Model Aeronautics has done some amazing research on pilot interactions with drones using FAA data [1].

One of the things they found was that only 3% of drone reports from pilots are actual "close calls", the rest are observations of drones operating legally below 400 ft or cases where done is used as a catch all term (weather baloons, etc).

Another interesting thing I read from them (my bookmark is 404ing now, will try to find the link), is that of the actual incidents they investigated of drones acting recklessly in controlled airspace, all of the offending drones were operated by the military or DHS.

1. https://www.modelaircraft.org/sites/default/files/UASSightin...

The pilots did not specifically witness a drone, just a lack of birds: https://www.youtube.com/watch?v=1Fts9u5ND24

Front shot of the dent shows no signs of small/sharp sub-dents or deep scratches within the main dent that would've been caused by hard object such as drone. Which kind of steers thinking toward heavy and soft object that planed collided with.

"Is goose going to be okay?"

"... can’t be tracked on radar ..."

Can I voluntarily strap a transponder to my own drone if I buy one? How small can transponders be?

Looks like tiny ADS-B transponders are readily available: https://uavionix.com/

Measures 3x9x11cm, so likely too bulky for many drones.

Check these ones out, they're the ones designed for drones:

https://uavionix.com/products/ping2020/

20g, 25mm x 39mm x 12mm

The electronics for your typical GA transponder are primitive by modern standards and can be very small, but it would probably need to be paired with a radar reflector or else it would either remain undetected or appear as noise.

After watching a Defcon talk about the idea that transponders self-indicate their position without signature, so it would be possible to clutter ATC and make the panic, I was under the impression that rogue transponders couldn’t safely be dismissed, just in case it were actually the 747 it claims to be.

>After watching a Defcon talk about the idea that transponders self-indicate their position without signature

Older style (I forget the proper name) transponders don't indicate their position, only ID and altitude. Newer ADS-B transponders include GPS position.

It's an interesting point though. Assuming for a moment that a bunch of drone operators equipped their drones with ADS-B transponders, I speculate that there could be a chance of overwhelming an airport approach radar's ability to track targets. Could potentially overwhelm the electronics, or the operators.

While we’re still using secondary radar (which gets an azimuth and range return from the radar site), it’s trivial to ID fake ADS-B outputs. I don’t know if they have filtering in place now or not. The effective bandwidth of ADS-B is limited as well, serving as an effective cap on number of targets created.

Do that and keep doing it, and it would not be hard to find your transmitter.

Which has more mass, a goose or a drone? My bet is on the goose.

Which has more mass, a pigeon or a 5.56? Which would you rather have bump into you at it's typical flight velocity?

are you trying to suggest a drone is flies significantly faster than a goose?

An African goose, or a European goose? The African goose is non-migratory.

Yes, but which can cause more damage to a fuselage? Mass isn't the only factor

This was at the Tijuana airport which is right next to the US border. While drones have been know to be used to smuggle contraband across the border, looking at this flight path for landing [1], the plane actually circles around over the US and then back into Mexico. It's possibly that the the strike occurred in US airspace. yikes

Note: I'm not certain that this is the flight in question. The other approach is solely in Mexico airspace. I'm also not trying to rope in drones/contraband to an already unclear situation.

[1] https://flightaware.com/live/flight/AMX770/history/20181213/...

Could someone correct me if I'm wrong: but I assume this is why we have altitude restrictions on consumer drones, right? Other than the technological challenges of going that high up, but it's also so we don't become burdensome on the air traffic.

Do not overestimate the technological challenges of going high up. An autonomous drone that can work at all in Denver, must also be able to operate at a mile high in Los Angeles.

I just want to throw out there that you're not wrong but keep in mind that there's a pretty big difference between operating 100ft off the ground in Denver and operating 1 mile above Los Angeles.

Know why?

You need enough battery/fuel to climb 0.99 miles minus 435ft in L.A. (and presumably safely descend) through progressively thinner atmosphere, in Denver you need need enough battery/fuel to climb 100 ft in thinner atmosphere.

The amount of planes flying 100ft above the terrain is considerably less than those that are operating between 100ft and 0.99 miles above the terrain.

There are good reasons that I said "autonomous" and "operate" as qualifiers. Both direct control from the ground and getting a mile high are potential additional challenges in Los Angeles.

DJI drones all have altitude restrictions, but even those can be overcome without a lot of modification.

It is easy to purchase or even build a drone without any altitude or other restrictions. The vast majority of cheap drones do not have altitude restrictions.

The collision happened shortly before landing, so the plane may not have been that high.

Perhaps we should install the equivalent of dashcams into airplanes ...

Something a bit more complicated than a dashcam, something that record all the sensors data and all the inputs as they are applied... maybe also the cockpit conversations....

And we could make it really bright orange and boxy!

And call it "black"!

If this were an drone should we expect burns? It seems feasible for a small lithium ion battery to be damaged by an such an impact. If a damaged lithium ion battery got stuck in the nose cone things could get dramatically worse dramatically quickly.

Look at the picture. Something punched a sizable hole in the nose. That plane hit something much harder than a bird.

Nonsense. At 300-500mph, hardness doesn't really matter, mass is the killer. There's no reason to suspect from the damage alone that it was a drone.

https://duckduckgo.com/?q=jet+bird+strike&t=brave&iar=images...

The plane was on landing approach, during which it isn't traveling 300-500mph.

Also, notice how in every single one of the pictures in your link there are blood streaks. This is pretty much universal in a bird strike, as a strike hard enough to damage aircraft skin is also hard enough to severely injure any bird, leaving at least some feathers behind. The photo in the OP doesn't have either blood or feathers. That doesn't totally rule out a bird strike, but it does make it less likely.

For anyone else. The landing speed of a 747 is around 166mph-172mph [1].

[1] http://lmgtfy.com/?q=747+landing+speed

Approach speed is anywhere between landing speed and cruising speed. They don't slow to 170mph before descending or entering a landing approach, for example.

They have to be at or below 250 knots below 10,000 ft unless they're in a special control zone.

Here's a bird strike with no blood or feathers: https://www.upi.com/Top_News/US/2016/04/28/Bird-strike-leave...

High or moderate speed would even blow the blood, like spraying windshield fluid on car at 70 MPH

If they flew through rain it might wash the blood away.

Feathers may not be seen on damaged surfaces, relative wind speed on nose(after hit) would mostly blow the feathers away from surface, however feather may be found deep inside of broken places where wind could not take feathers on escape.

Birds can cause the same damage. Here are just two examples, the second creating a much bigger hole than the supposed drone strike:

https://www.aviationcv.com/aviation-blog/2016/bird-strike-de...

EDIT: Here's one with a "drone" still hanging from the nose cone: https://www.miamiherald.com/news/local/community/miami-dade/...

There is some previous of a bird hitting a 737 on the nose and doing a lot of damage [1]. As well as the speed factor mentioned by sibling comments, the nose cone is typically made of thinner and lighter material to avoid blocking, well, RADAR.

1: https://www.telegraph.co.uk/news/aviation/12192721/Bird-stri...

> That plane hit something much harder than a bird.

Something like a drone? That's what the article says. It's even what the headline says.

Must have been a big ass drone. That's a huge hole.

That said, the headline is speculation. All we know is that the pilots heard a loud bang and there is a hole in the nose. It might be a drone or it might be something else.

> Must have been a big ass drone. That's a huge hole.

Small things at (relative) high velocity make big holes. It's physics.

This is theoretically the entry hole though, it typically does not get larger with velocity.

When you see bullet impacts on a target the entry hole is typically bullet size while the exit hole can be much larger.

I'm not saying I'd expect the perfect outline of a drone like on a cartoon, but the hole should be roughly the size of whatever hit it unless something subsequently exploded inside or collapsed the support structure and allowed the airflow to further damage the skin.

It does, but to a point (as you pointed out), but no commercial plane is going to hit a bird as fast as a bullet impacting a target. Aircraft skin is relatively thin and easy to tear, and may fragment leaving a much larger hole than the object that hit it.[0][1][2]

0. https://www.telegraph.co.uk/travel/news/Bird-strike-rips-blo...

1. https://www.nydailynews.com/news/national/bird-bash-leaves-g...

2. https://www.dailymail.co.uk/travel/travel_news/article-34900...

Speed can cause outsized damage. Meteor Crater in Arizona (1200 meters in diameter) was caused by a relatively small meteorite (50 meters across).

No need to get aggressive. The article also says that we don't actually know yet what hit the plane; OP was simply saying they agree that a drone strike is plausible.

Three months ago, a military jet fighter Saab JAS 39 Gripen crashed here in Sweden after a mid air collision with a flock of large birds.

The Swedish military has five to ten of such incidents per year, through almost all ends with the pilot doing an successful emergency landing. The crash sparked discussion that a bird warning system should be in place in order to prevent accidents in the future.

Those crashes are often caused by engines ingesting birds.

Here's one that happened to a BAe Hawk in Moose Jaw, Saskatchewan a while back:

https://www.youtube.com/watch?v=GuLcVkW4YVg

The on-board video shows it crashing into a corn field not long after the crew ejects.

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