Boeing 737 Passenger Jet Damaged in Possible Midair Drone Hit

Paul_Johnson said:
Well, that would be correct. Mostly. Three holers are certified on two and four holers on three. Twins are certified on one. All of the above also have to be able to to takeoff down to the certified minimum number of operative engines and are committed if an engine out event happens after V1 (14 CFR 25.121).
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Yes...but there’s one very important thing they don’t cover: obstacle clearance. They touch on it with climb gradient but the simple fact of the matter is that under some circumstances (high density altitude at max gross weight for example) you might not have sufficient performance to meet the required obstacle clearance for a particular departure procedure. Which would make your day a very bad one...

But chances are your pilot did their job and planned for that on takeoff right ;).

Paul_Johnson said:
Sudden asymmetrical thrust while losing altitude and approaching terrain? I'd go with that is a bad time. Maybe not #1 (which would be right after you lost the OTHER engine), or #2 (right after hitting that TO/GA button/switch), or #3 (right at V1) but probably #4. About the only "good" time is during cruise at altitude with fuel and a diversion airport right under you.



Well, seeing how each contract gets better and better these days are better than yesterdays.



Noise is a weird thing in planes. If it hit the tail they would never hear it up front. Hit the flaps (which unless you had a pretty aggressive flap setting would be.....interesting) probably not going to hear it either
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Actually on final you’re pretty much at zero thrust if you’ve been on the ball. So no assymetrical thrust there. Earlier in the approach maybe.

And the best time to lose an engine is on the ground at the terminal .

Elios said:
if it was during approach you bet your ass it would low power setting and losing an engine is not good time go try it in a sim
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See above.
 
kju1 said:
Actually on final you’re pretty much at zero thrust if you’ve been on the ball. So no assymetrical thrust there. Earlier in the approach maybe.
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Descent rate would be far to high if you had pulled the throttles to (approach) idle well before flare. A little before flare in some sure, during flare in some sure, but just once you are on final...not really.
 
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I'm thinking they'll do tests of the residues left on the nose cone and find out soon enough if it was a drone
 
Airliners are NOT at idle on approach. Descent rate would be far too high. Just listen next time you're on a plane... the engines are cut to idle at the flare just before touchdown, when you're 5-15 feet off the runway.
 
kju1 said:
Yes...but there’s one very important thing they don’t cover: obstacle clearance. They touch on it with climb gradient but the simple fact of the matter is that under some circumstances (high density altitude at max gross weight for example) you might not have sufficient performance to meet the required obstacle clearance for a particular departure procedure. Which would make your day a very bad one...

But chances are your pilot did their job and planned for that on takeoff right ;).



Actually on final you’re pretty much at zero thrust if you’ve been on the ball. So no assymetrical thrust there. Earlier in the approach maybe.

And the best time to lose an engine is on the ground at the terminal .



See above.
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They don't pull back to idle because 1. too fast descent rate, and 2. they need the ability to quickly spool up the engines in case of an emergency. Pulling back to idle means that it would take a few seconds for the engines to start providing thrust again, in which case it might be too late.
 
sooooooooooooooooooooo, they never saw or recovered the 'drone', but assume it was a 'drone'?
 
mnewxcv said:
sooooooooooooooooooooo, they never saw or recovered the 'drone', but assume it was a 'drone'?
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no blood and feathers it wasnt a bird... cant think of any thing else they could hit in clear air that would do that
 
kumquat said:
They are. If that's not sufficient, the next step is going to be an outright ban on drones period.
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And how would that make things better? It would only make it worse for people legitimately using drones. The people flying at airports already demonstrated that they're not affected by a ban. Hell DJI drones won't even take off near airports and certain locations, as is. So an outright ban would solve absolutely nothing.
 
Arcygenical said:
That likely wouldn't drop a 7 series jet though.
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Good friend of mine is into jet engine testing for a well known company. He has to certify the engine and they test, among many other things, what happens when a bird enters a jet engine...

... yeah, you DON'T WANT TO be in a plane if that happens. The plane should be able to make it to landing but the engine would be total'ed.

So no, the plane won't drop because of that (even when both engines fail, the plane is able to drop slowly) but it will destroy the engine. A bird. Something with metal parts is much more problematic.
 
Dekoth-E- said:
Honestly, yes I am. A consumer level drone at 35,000 feet? I'm more than a little skeptical. There are few to no consumer radios I know of capable of even close to that range.
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It was on final, not FL35. You shouldn't be surprised.
 
M76 said:
And how would that make things better? It would only make it worse for people legitimately using drones. The people flying at airports already demonstrated that they're not affected by a ban. Hell DJI drones won't even take off near airports and certain locations, as is. So an outright ban would solve absolutely nothing.
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Way way fewer people will buy drones if they're banned.
 
Tsumi said:
They don't pull back to idle because 1. too fast descent rate, and 2. they need the ability to quickly spool up the engines in case of an emergency. Pulling back to idle means that it would take a few seconds for the engines to start providing thrust again, in which case it might be too late.
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It takes 8 seconds for a jet engine to develop thrust. Also I said "pretty much at zero thrust" not idle. Which jets do you fly?

In the jets I have flown we set to flight idle on final as part of the checklist and adjust to maintain descent rate from there. Depending on the airport and conditions sometimes we dont even have to adjust.
 
Mega6 said:
Your kidding, right?
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Considering the last two planes I've been on were either C130s or bushmasters not particularly. One is too heavy to do anything out of power and the other is a lawnmower that flies. For some stupid reason, my brain did not equate people weight to cargo weight.
Why? Are you just surprised I'd admit to a bad assumption on my part? I'm a bloody scientist. I'm wrong on a daily basis.
 
Elios said:
no blood and feathers it wasnt a bird... cant think of any thing else they could hit in clear air that would do that
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literally could've been anything. UFO possibly. Maybe rear ended Santa's sleigh doing a test flight. I don't see all signs pointing to drone. Really feels like they just wanted to make an article about drones, since that what the article is about, and the incident is hardly discussed after the first paragraph. They also fail to mention what altitude this occurred at.
 
It will only get worse, as stupid people are having more kids than smart people. Stupid people go a long way to make the world suck. Train travel, for example. Growing up, I loved trains. I wanted to travel cross country.
And this year, I did. All night, the engineer was blowing the damn horn, at every single crossing. Why? Because stupid people can't be bothered to stop and check to see if a train is coming, and would walk onto the tracks or drive onto them right in front of a train. So it's impossible to get a decent sleep on an over night train.
As drones get cheaper, more and more stupid people will be flying them into other vehicles, both flying and on the ground.
 
kju1 said:
Actually on final you’re pretty much at zero thrust if you’ve been on the ball. So no assymetrical thrust there. Earlier in the approach maybe.
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Actually on final you are under power, especially in transport category aircraft. Power is not brought back to idle until crossing the numbers and the 50' / 100' call (depends on the large airframe type). Then its a smooth transition into the flare and idle thrust. If you cut power too early the pax in the back will get to experience a carrier landing.

727 was 3000lbs fuel flow at flaps 30 after crossing the outer marker. That kept reference speed plus 10 knots assuming no wind.

737 we used 55%N1 (2200 lbs) at flaps 30. So no where near idle.

So losing an engine in the 737, even in short final, is not a fun experience and you will see the sudden yaw from asymmetrical trust.

Drones are a nuisance in aviation and pose a bigger hazard to smaller airframes including corporate jets and helicopters. A small drone is capable of crushing 3-4 feet of a light aircraft's leading edge and pushing the leading edge back to the spar. It is also capable of shattering or delam'ing a rotor blade.

I think all drones need to be capped at a 500' max altitude. That would prevent a ton of issues with drones and aircraft.
 
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Cr4ckm0nk3y said:
Actually on final you are under power, especially in transport category aircraft. Power is not brought back to idle until crossing the numbers and the 50' / 100' call (depends on the large airframe type).
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I'd just like to point out that he didn't say "brought back to idle", he said "you're at zero thrust". As I'm sure you're aware, there is a big difference between the two, idle being, well, idle, and zero thrust meaning the engines are still spooled up enough to maintain speed, without increasing it.
 
-Anomie- said:
I'd just like to point out that he didn't say "brought back to idle", he said "you're at zero thrust". As I'm sure you're aware, there is a big difference between the two, idle being, well, idle, and zero thrust meaning the engines are still spooled up enough to maintain speed, without increasing it.
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Do you want to try that again?
 
-Anomie- said:
I'd just like to point out that he didn't say "brought back to idle", he said "you're at zero thrust". As I'm sure you're aware, there is a big difference between the two, idle being, well, idle, and zero thrust meaning the engines are still spooled up enough to maintain speed, without increasing it.
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Zero thrust means either rapid descent or rapid loss of airspeed. If you're using engine power to maintain speed, you're not at zero thrust. If you're not slowing down or descending as fast as friction dictates you would be doing, you're not at zero thrust.
 
I call bullshit on this. Planes are regularly tested against chickens, here is a video where mythbusters are shooting frozen chickens out of a cannon to compare vs thawed chickens. The damage was about the same. Now it is true that a bird will destroy an engine, but too much here just seems strange. And yeah there may be metal parts in a drone but all the same they are mostly plastic.

 
jiminator said:
I call bullshit on this. Planes are regularly tested against chickens, here is a video where mythbusters are shooting frozen chickens out of a cannon to compare vs thawed chickens. The damage was about the same. Now it is true that a bird will destroy an engine, but too much here just seems strange. And yeah there may be metal parts in a drone but all the same they are mostly plastic.

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Yep, you're right

636089510410085161-AP-Plane-Splashdown.5.jpg


Mythbuster's>actual science
 
If you people actually think that planes were not designed with bird collision in mind then... :banghead:
Because bird sightings are so rare.
Birds won't bring down planes. Nor will medium-sized drones.
Still not ok to fly near airports.
 
Nebell said:
If you people actually think that planes were not designed with bird collision in mind then... :banghead:
Because bird sightings are so rare.
Birds won't bring down planes. Nor will medium-sized drones.
Still not ok to fly near airports.
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Then why have birds brought down planes?
 
Paul_Johnson said:
Then why have birds brought down planes?
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Dual engine failure. Flocks of birds. Fortunately, rare. Still scares me a bit to know about when I fly.

In reality (and thankfully), single engine failure is far more common and dealt with by skilled pilots. Engine failure scenarios at take off and landing are probably one of the most practiced events. Airplane manufacturers and airlines do not get certifications unless they can pass criteria for single engine scenarios. A single drone is not likely to damage both engines simultaneously. That being said, anyone that flies a drone near an airport is a complete moron.
 
Space debris is not impossible either. But I am going to go with micro-singularity was the cause.
 
For anyone genuinely interested in how often bird strikes occur on commercial aircraft, head over to avherald.com and type in bird strike in the search field. Happens multiple times per week.
 
ewb302 said:
Dual engine failure. Flocks of birds. Fortunately, rare. Still scares me a bit to know about when I fly.

In reality (and thankfully), single engine failure is far more common and dealt with by skilled pilots. Engine failure scenarios at take off and landing are probably one of the most practiced events. Airplane manufacturers and airlines do not get certifications unless they can pass criteria for single engine scenarios. A single drone is not likely to damage both engines simultaneously. That being said, anyone that flies a drone near an airport is a complete moron.
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You might want to re read all of my post in this thread. ;)

And single engine out event can lead to crashes/ Accidents as well.
 
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