U.S. Study suggests Drone Collisions with Airliners may not be Fatal

[DooKey]

A recent FAA study showed that an airliner traveling at 250kts (max allowed speed below 10K ft) was likely to only cause minor damage to the airliner. This study is in conflict with one that the British government conducted that purported to show more damage is caused by a drone striking an airliner. If you look at this older article you'll see the Brits used components that would never be in a real drone. I tend to think the FAA study looks to be a more likely case study and I'm glad to know some idiot using a drone in the wrong spot isn't likely to get me killed.

Computer simulations carried out by Assure found that a 1.2kg quadcopter striking the windscreen of a commercial jet airliner travelling at 250 knots simply bounced off, leaving a few marks or chips on the windscreen.

 

[M76]

A drone? Very thorough study I have to say considering a drone can be anything up to 25kg in weight.

 

[Elios]

no but it's going to causes millions in damages at the lest and if it happens at critical stage of flight ie takeoff or landing shit happens fast it's really only a matter of time till you have a hull loss

 

[Elios]

how about engine ingestion? 100% 1.2kg drone goes in an engine at landing bad things will happen fast

 

[dgingeri]

There are certain people who will do anything, including flat out lie about possible outcomes, in order to control other people, and they make up a large portion of governments. They also happen to be the least trustworthy for power, but most people who vote don't seem to want to see that.

 

[dgingeri]

how about engine ingestion? 100% 1.2kg drone goes in an engine at landing bad things will happen fast

That depends on how hard the components are and how big the hardest components are. If a drone is made out of mostly plastic with only a few steel parts, like all consumer drones, then the turbines will just chop it to pieces and the small steel parts will pass right through the engine without harming it, or at most with very little harm. If it is a government drone with large steel parts and heavy motors, it would shatter the turbine and the engine would likely tear apart and catch fire.

 

[Elios]

That depends on how hard the components are and how big the hardest components are. If a drone is made out of mostly plastic with only a few steel parts, like all consumer drones, then the turbines will just chop it to pieces and the small steel parts will pass right through the engine without harming it, or at most with very little harm. If it is a government drone with large steel parts and heavy motors, it would shatter the turbine and the engine would likely tear apart and catch fire.

lol no a bird half that size will fuck an engine

 

[focbde]

lol no a bird half that size will fuck an engine

Untrue. It takes several very large birds to really do any damage or pose a risk - if you look up the bird ingestion testing they do you'll see that one chicken-sized bird won't pose a problem in the slightest.

 

[Verge]

Untrue. It takes several very large birds to really do any damage or pose a risk - if you look up the bird ingestion testing they do you'll see that one chicken-sized bird won't pose a problem in the slightest.

When they were doing that test on the new 787 engines, i believe they were using frozen birds as well.

 

[Guarana [BAWLS]]

When they were doing that test on the new 787 engines, i believe they were using frozen birds as well.

THAW YOUR CHICKENS!

 

[dgingeri]

lol no a bird half that size will fuck an engine

Think about that for a second. The turbine is made of titanium. It would turn a bird into cold cuts in half a second. It might chink the metal a little, bit not near enough to fail. It took an entire flock of geese (about 12-14, as I heard) to take out the engine of the plane that went into the Hudson a while back, and that was because it clogged the works behind the turbine.

Plastic is more fragile than bird bones and titanium is hard stuff. Being under stress of the revolutions of the engine and as thin as they are, steel components could do some damage, but not near as much as to take an engine out. If they're small enough, they'd just go right between the blades.

If birds caused as much damage as you say, we'd have plane crashes daily, and it would be more dangerous to fly than to drive.

 

[dgingeri]

THAW YOUR CHICKENS!

lol, mechanically separated chicken.

 

[RipperMac]

Birds (soft tissue mostly) will not just pass through an engine so don't kid yourself about minor plastic parts. A small standard 10/32 screw will and can cause major and potentially catastrophic damage and all drones have metal of some kind (to include batteries). I see minor and massive damage from tiny objects in engines all the time but lets not forget aircraft engines are finely balanced and a tiny imbalance creates a larger imbalance and beget huge problems quickly.
This bird

Caused this damge

 

[Dead Parrot]

There is a difference between damage and "We will be in the Hudson" damage. What the FAA study indicates is the most likely outcome of a drone-airliner collision is the airliner survives and lands/takes off normally. Of course, the older British study did highlight that things can go wrong with damage studies when the cat wondered into the chicken launcher during lunch and totally screwed up the engine.

 

[travisty]

I know how much air is sucked in by those engines. A light drone will be sucked in easily. If a bird can disable an engine I can only imagine a drone can too

Edited: Replaced 'destroy' with 'disable'

 

[dgingeri]

I know how much air is sucked in by those engines. A light drone will be sucked in easily. If a bird can destroy an engine I can only imagine a drone can too

"Destroy" is a relative term. It would damage the blades, sure, but not to the point of shattering the fan and causing a crash. The engine would have to be turned off, and the fan some other small components replaced, but it would not be destroyed. When someone says "destroyed", I'm thinking that no parts would be reusable, and that would take a LOT of damage.

 

[lcpiper]

That depends on how hard the components are and how big the hardest components are. If a drone is made out of mostly plastic with only a few steel parts, like all consumer drones, then the turbines will just chop it to pieces and the small steel parts will pass right through the engine without harming it, or at most with very little harm. If it is a government drone with large steel parts and heavy motors, it would shatter the turbine and the engine would likely tear apart and catch fire.

Exactly, small steel parts are not going to simply pass through the engine doing no damage.

And then, the next assumption you are making, "like all consumer drones". Are you imagining that whatever controls we put in place are only going to be for small consumer drones vs custom built drones?

https://www.nbcnewyork.com/news/loc...rs-Drone-Hit-NYC-Staten-Island-446994923.html

Tell me what you think of this one. And this happened to a pair of Blackhawk helicopters. Now Blackhawks aren't as armored as Apache's are, but these are still fairly rugged aircraft.

 

[dgingeri]

Exactly, small steel parts are not going to simply pass through the engine doing no damage.

And then, the next assumption you are making, "like all consumer drones". Are you imagining that whatever controls we put in place are only going to be for small consumer drones vs custom built drones?

https://www.nbcnewyork.com/news/loc...rs-Drone-Hit-NYC-Staten-Island-446994923.html

Tell me what you think of this one. And this happened to a pair of Blackhawk helicopters. Now Blackhawks aren't as armored as Apache's are, but these are still fairly rugged aircraft.

Yeah, exactly. This isn't major damage. I have more damage on my car on the passenger side door from a traffic cone. As far as "forced the helicopters to land" is standard procedure after a collision of any type (unless in combat) to check for crippling damage, which there was none. Those Blackhawks were able to take off again right after that and continue operating normally, and head back to base and get repairs. They could continue operating with damage like that indefinitely. It's just cosmetic. (The military likes things perfect, so of course they do repair it, but not because it would interfere with operations of the aircraft.) This news crew blew the whole thing out of proportion.

 

[travisty]

"Destroy" is a relative term. It would damage the blades, sure, but not to the point of shattering the fan and causing a crash. The engine would have to be turned off, and the fan some other small components replaced, but it would not be destroyed. When someone says "destroyed", I'm thinking that no parts would be reusable, and that would take a LOT of damage.

Yeah destroyed was not the correct word to use. Disable would probably be better.

Sure an aircraft can fly with one engine down, still it adds danger to what should be easily preventable

 

[pgaster]

And they thought there was no way foam would hurt the space shuttle.

 

[lcpiper]

Yeah, exactly. This isn't major damage. I have more damage on my car on the passenger side door from a traffic cone. As far as "forced the helicopters to land" is standard procedure after a collision of any type (unless in combat) to check for crippling damage, which there was none. Those Blackhawks were able to take off again right after that and continue operating normally, and head back to base and get repairs. They could continue operating with damage like that indefinitely. It's just cosmetic. (The military likes things perfect, so of course they do repair it, but not because it would interfere with operations of the aircraft.) This news crew blew the whole thing out of proportion.

And if that damage had been the engine? Yes a Blackhawk has two engines, many passenger liners have more. Now I get that you are trying to say that the risk of actually losing an aircraft is really low. But let's not regulate airspace and keep drones out. Because the risks of catastrophic damage is low. So just let the drones fly around and the insurance will sort it out. Nobody actually needs to be at their destination on time.

But while all those drones are flying around the airspace, what are the odds that a plane that is already in some sort of trouble, could hit the drone that broke the camel's back?

We can't control bird strikes though they do try. But we can try and reduce the risks of damage and even the slim chance of catastrophic damage so why wouldn't we?

 

[Elios]

"Destroy" is a relative term. It would damage the blades, sure, but not to the point of shattering the fan and causing a crash. The engine would have to be turned off, and the fan some other small components replaced, but it would not be destroyed. When someone says "destroyed", I'm thinking that no parts would be reusable, and that would take a LOT of damage.

loss of power even fractional from 1 engine at takeoff or landing is major emergency ....

 

[focbde]

loss of power even fractional from 1 engine at takeoff or landing is major emergency ....

No, it isn't. Even twinengine jets are able to take off with one engine fully disabled. No idea where you got THAT from.

 

[kju1]

Sure an aircraft can fly with one engine down, still it adds danger to what should be easily preventable

Not always. It really depends upon several factors: Aircraft loading, phase of flight, airspeed, etc. Below Vmc a multi engine aircraft will lose control if the critical engine is lost. There can be multiple Vmc for aircraft with more than two engines. Additionally with one, or more, engine(s) out your ceiling (the max height at which you can fly) is limited. You may not be able to maintain sufficient altitude to clear obstacles - which means you cant climb in many cases. In some cases the aircraft does not have sufficient power remaining with one engine out to maintain level flight at any altitude (depending on conditions and loading) and the remaining engine(s) will simply delay the inevitable. For example in a twin engine aircraft (of any sort) you lose about 80% of your climb performance when you lose one engine.

loss of power even fractional from 1 engine at takeoff or landing is major emergency ....

Landing? Fuck no. Who gave you that idea? If you lose ALL engines on landing you become a glider and then you just glide into the runway. Thats just silly to think otherwise. Use your noggin.

No, it isn't. Even twinengine jets are able to take off with one engine fully disabled. No idea where you got THAT from.

Not necessarily true for takeoff, I addressed landing above. WIth a twin engine jet you lose about 80% of your climb performance if you lose an engine. With aircraft loading you might not have sufficient power to climb out enough to avoid obstacles. Jets are certified under takeoff segments with climb gradients that specify required minimum performance numbers. They say nothing about obstacle clearance. So lets do a little example. You are flying a Hawker 800XP - a twin engine jet at max gross weight full fuel and all your friends on board departing from Aspen Colorado which is a field elevation of about 8,000 feet. Lets say its a nice summer day at 15 Celsius (cuz thats what we use in aviation) this number is important because it affects our take off performance. The minimum safe altitude (MSA) to avoid the mountains on take off is 13,000 feet to 16,000 in the area. Sounds easy for a jet that can climb at ~2,000 fpm right?

Anyway the departure at Aspen requires up t o 840 feet per nautical mile (about 2,000 fpm which is our max) all the way to 16,000 feet. Now looking at the performance charts for the 800xp I see the single engine performance is ~500 fpm. Um...oops? We cant safely take off if a single engine fails and while we would be airborne we would hit the mountains. That sounds painful to me.

TLDR; take off is about more than getting off the ground. Its about safely getting to altitude where you can maneuver and avoid the obstacles (if any). That is not guaranteed with an engine out.

 

[focbde]

Not necessarily true for takeoff, I addressed landing above. WIth a twin engine jet you lose about 80% of your climb performance if you lose an engine. .

To be fair, I didn't elaborate enough in my statement. I wasn't saying they're expected to be able to climb to cruising altitute, but that they can safely take off to be able to land. All twinjets are certified to be able to continue with a takeoff procedure even fully loaded if they lose an engine after V1. Before V1 of course the takeoff would be aborted. This means they've had both engines up until this point providing thrust which, of course, makes the difference. Let's not forget also that on takeoff, full thrust is never used anyway. So between V1 and V2, having only one engine, but at max power, will be sufficient - that's what all jets are certified to be able to do, irrespective of temperature and altitude. I can imagine that some airports climb-out would prove to be a bit botty-clenching though - really depends on how distant any obstacles are and if they present a barrier to a quick return and landing.

 

[focbde]

Anyway the departure at Aspen requires up t o 840 feet per nautical mile (about 2,000 fpm which is our max) all the way to 16,000 feet. Now looking at the performance charts for the 800xp I see the single engine performance is ~500 fpm. Um...oops? We cant safely take off if a single engine fails and while we would be airborne we would hit the mountains. That sounds painful to me.

TLDR; take off is about more than getting off the ground. Its about safely getting to altitude where you can maneuver and avoid the obstacles (if any). That is not guaranteed with an engine out.

True, but you're not limited to going in a straight line. In your scenario above, you wouldn't continue to climb, intending to proceed with your trip - you'd immediately plan to return and land. The point there is, you have enough thrust to be able to continue to climb safely - sure, you wouldn't get over the mountains, but if you were even thinking of doing so at that point, then you'd be a moron.

 

[kju1]

True, but you're not limited to going in a straight line. In your scenario above, you wouldn't continue to climb, intending to proceed with your trip - you'd immediately plan to return and land. The point there is, you have enough thrust to be able to continue to climb safely - sure, you wouldn't get over the mountains, but if you were even thinking of doing so at that point, then you'd be a moron.

Sure, I know you can get it "off the ground" with one engine. My point was, and I shouldve been a little more clear on that, you might not be able to comply with an ODP. So while a twin jet can fly with one it is not always safe to take off at high density altitudes at max gross weight. Because your climb performance can degrade quite suddenly to the point where you cannot comply with an ODP and if youre IFR you really need to comply with an ODP . I think we can both agree going from capable of doing a 500fpm to just under 200fpm would be a significant drawback in clearing the obstacles and could put you in a situation you cant get out of....making you wish you never took off.

Like I said my point was you should make that decision before you start the takeoff roll....can I safely depart with one engine. I assume every take off will result in an engine failure and plan accordingly. With a single that means I am looking for the best place to abort or commit to a landing in the trees. With a twin it means I am doing the math to make sure i have sufficient climb performance should I lose an engine. I can and have refused to fly at max gross weight simply because if an engine failed we would not survive. Never had anyone question my decision once I explained the math. Left fuel off and made an extra stop for gas .

 

[travisty]

Not always. It really depends upon several factors: Aircraft loading, phase of flight, airspeed, etc. Below Vmc a multi engine aircraft will lose control if the critical engine is lost. There can be multiple Vmc for aircraft with more than two engines. Additionally with one, or more, engine(s) out your ceiling (the max height at which you can fly) is limited. You may not be able to maintain sufficient altitude to clear obstacles - which means you cant climb in many cases. In some cases the aircraft does not have sufficient power remaining with one engine out to maintain level flight at any altitude (depending on conditions and loading) and the remaining engine(s) will simply delay the inevitable. For example in a twin engine aircraft (of any sort) you lose about 80% of your climb performance when you lose one engine.

Thanks. I had really never thought about it but i'm sure all those bragging point boing/airbus make about 'flying on one engine' is in ideal conditions. I remember a city counsel meeting where a storage place was being designed in the flight path our local airstrip and it was just into the FAA guidelines as unsafe as an obstacle for takeoff landing. The FAA deemed it acceptable. It plays into those ideal conditions though.
Living in Colorado i had a friend who was an armature flyer and he explained some of the mountain airstrips and the crazy approaches they have

 

[focbde]

[QUOTE="travisty, post: 1043361165, member: 289807"
Living in Colorado i had a friend who was an armature flyer and he explained some of the mountain airstrips and the crazy approaches they have[/QUOTE]

I'm from NZ and I can personally testify to this one being a VERY fun airport to fly in/out of...

https://en.wikipedia.org/wiki/Milford_Sound_Airport

 

[focbde]

Sure, I know you can get it "off the ground" with one engine. My point was, and I shouldve been a little more clear on that, you might not be able to comply with an ODP. So while a twin jet can fly with one it is not always safe to take off at high density altitudes at max gross weight. Because your climb performance can degrade quite suddenly to the point where you cannot comply with an ODP and if youre IFR you really need to comply with an ODP . I think we can both agree going from capable of doing a 500fpm to just under 200fpm would be a significant drawback in clearing the obstacles and could put you in a situation you cant get out of....making you wish you never took off.

Like I said my point was you should make that decision before you start the takeoff roll....can I safely depart with one engine. I assume every take off will result in an engine failure and plan accordingly. With a single that means I am looking for the best place to abort or commit to a landing in the trees. With a twin it means I am doing the math to make sure i have sufficient climb performance should I lose an engine. I can and have refused to fly at max gross weight simply because if an engine failed we would not survive. Never had anyone question my decision once I explained the math. Left fuel off and made an extra stop for gas .

Your approach regarding safety is commendable - but there are few scenarios where losing an engine would mean you wouldn't at least be able to return safely. Not saying they don't exist of course.

That's all very true above , except you would only be expected to comply with ODPs if continuing on, and not when performing an emergency return/landing in the event of an engine failure on takeoff?