Professional investigator concludes - "what's the fuss about?"

[Marko9219]

If you have an example make it a *pertinent* example

On July 25, 2000, an Air France Flight 4590 departing Charles de Gaulle International Airport ran over a piece of titanium debris from a Continental DC-10, shredding a tire and slamming rubber debris into the plane’s fuel tank. The subsequent leak and fire caused the Concorde to crash, killing 100 passengers, nine crewmembers, and four people on the ground.

Yup... pertinent...Surprise! A 200 gm piece of metal did fatal damage to a jet. Who cares about the mechanics of the damage? We have people arguing that something as small as our Mavic just couldn't be a real threat.

 

[Brojon]

Anecdotal response by "some jockey"? That's pretty funny, considering that "jockey" is a wing safety officer.

So ask him how many aircraft on his watch are lost to FOD. Answer - zero.
That's not to say there is no FOD *damge* mertely that they did not result in aircraft failure.
THEN ask what was the most common objects ingested.
Fact of the matter is about 60% of FOD happens near the terminals - crap on the runway such as the Concorde accident.
I think it was the French that have a scanning system that can photo ID FOD and classify it - I think their results were something like 80% was rubber.
Chunks of rubber coming off the tires is very common - I'd heard they use retreads extensively and we've all seen the tire carcasses along the highways.
Nope - a very small amount of FOD happens in the air and the vast majority of takeoff and landing FOD is runway debris.

Foreign Object Debris (FOD) - SKYbrary Aviation Safety

 

[Brojon]

Yup... pertinent...a 200 gm piece of metal did fatal damage to a jet. Who cares about the mechanics of the damage? We have people arguing that something as small as our Mavic just couldn't be a real threat.

Oh fer goshsakes give it up - they had to physically run over a broken off piece of rigid titanium on the runway! That popped the tire which threw rubber into the gas tanks setting them on fire.
200 g of titanium could actually be quite large structurally as it is a very light but rigid metal. It's also only used in high temperature areas so the likelihood is an engine cowling, turbine blade or something like that. I guess if someone strapped a titanium samurai sword to the Mavic it could be a hazard.

 

[lisadoc]

So, my bias is based on my past experiences and part of those experiences are seeing first-hand what a small object can do instantly to jet turbines. It was too funny actually, an hour ago as I was typing the above response and in walked Capt. Walz, the F-35 pilot. Talk about great timing! I said "Hey...Read this thread and tell me your thoughts about hobby drones and the threat to you guys." He actually laughed when he read it. He said they have briefings on this exact topic very frequently.

He literally said "They pose a huge threat if they are anywhere near our take-offs or landings."

Again, I must point out that no one is arguing that drones striking an aircraft pose no threat to the aircraft. The issue here is of risk and the appropriate level of response with risk mitigation tactics designed to avoid such risk.

First of all, I'm shocked that an F-35 pilot would consider drones to be such a risk. I can't get F-35 pilots, or F-16, or F-18 pilots to take seriously the risk posed by flocks of large birds, let alone a singular tiny drone, so I applaud that pilot who has acknowledged the risk to their aircraft. I guess it's because they're a FSO, not only a pilot. I'm also surprised that they have frequent briefings on this topic, as to date, there have been no incidents with drones striking fighter aircraft and the AF has refused on the whole, to broach this specific topic with much enthusiasm.

But we must be wary of equating the risk of a drone strike to a small fighter aircraft to the risk of a drone striking a large commercial plane. Or for that matter to a KC-10, or a C-17, or a KC-135, or a C5, or even a C-130. Fighter aircraft have a much different risk assessment as it relates to FOD, as well as to birds/drones flying at very low altitudes. The speeds of those planes and the flight profiles nowhere resemble the flight profiles of AMC aircraft or commercial traffic. Even military flight profiles, with their constant touch-and-go practicing, does not resemble in any fashion the typical commercial air traffic. For example, the risk of FOD at an airfield and on the apron for fighter aircraft (basically very powerful vacuum cleaners) is quite different than the FOD risk at a commercial or AMC airport.

But let's deal with the facts, as that is the only way to make a scientifically-based determination of the true threat. First, it should be noted that approximately 825,000 drones (weighing more than 250 gms) were sold in the US in 2016 alone. Combined with the recent sales of drones from 2015 and 2014, that number swells to well over 1.5 million drones in operation around the US (likely even more, adding in those pre-dating 2014 still in use). If you add in the smaller hobby drones that kids/novices fly, this number balloons to roughly 4 million. But let's stick with the number of hobby drones that are equivalent to the Mavics, Phantoms, and Inspires of the world, etc.

If a person only uses their drone for 2 hours a year (a very conservative number), that means that there have been more than 5.5 million flight hours by drones in the US during the period of 2014-2016. During that same period, there were exactly zero confirmed drone strikes to aircraft. (And, yes I know I'm not counting the very recent strike to the Army Black Hawk helicopter or the strike in Canada). By most accounts, 5.5 million flight hours without a single incident/failure for any flight aspect is a pretty remarkable feat. Was the risk zero? - absolutely not. But the incident rate was zero, and with that truly high number of hours (and remember, that's a very low estimate of total flight hours), I would propound that the strike risk is significantly low.

So, is the reaction of the media, the general public, the regulatory authorities (heck even DJI) proportionate to the risk posed by the hobby UAS industry to civilian (or even military) aircraft? I would argue that in light of many other flight safety hazards that remain unaddressed or poorly mitigated today, that the reaction to the UAS hobbyist is unnecessarily alarmist or at least very disproportionate to their efforts to mitigate the other risks.

But reasoned argument (not based solely on anecdotal evidence) is welcome on the subject and should be encouraged. I am always happy to learn more on the issue and be enlightened to evidentiary positions that I didn't consider, so I am pleased to read how others broach this topic and their perspectives on the risk drones pose to aviation.

 

[Marko9219]

So ask him how many aircraft on his watch are lost to FOD. Answer - zero.
That's not to say there is no FOD *damge* mertely that they did not result in aircraft failure.
THEN ask what was the most common objects ingested.
Fact of the matter is about 60% of FOD happens near the terminals - crap on the runway such as the Concorde accident.
I think it was the French that have a scanning system that can photo ID FOD and classify it - I think their results were something like 80% was rubber.
Chunks of rubber coming off the tires is very common - I'd heard they use retreads extensively and we've all seen the tire carcasses along the highways.
Nope - a very small amount of FOD happens in the air and the vast majority of takeoff and landing FOD is runway debris.

Foreign Object Debris (FOD) - SKYbrary Aviation Safety

Yeah...true. So? Because pieces of rubber are more common threats, doesn't make our Mavics less lethal. The point is, our Mavics could be deadly to a jet. It doesn't matter one bit what usually causes the damage. We're talking about the threat our Mavics pose to aircraft, and it's just indisputable that they are potentially lethal. I just find it amazing that so many people are denying it.

 

[Brojon]

Yeah...true. So? Because pieces of rubber are more common threats, doesn't make our Mavics less lethal. The point is, our Mavics could be deadly to a jet. It doesn't matter one bit what usually causes the damage. We're talking about the threat our Mavics pose to aircraft, and it's just indisputable that they are potentially lethal. I just find it amazing that so many people are denying it.

Well I find it pretty amazing that folks think they're flying a 100% lethal projectile capable of taking down a jumbo jet with deadly accuracy.
Fly the dang thing into a tree if you want to see how tough it is.

 

[sar104]

Well I find it pretty amazing that folks think they're flying a 100% lethal projectile capable of taking down a jumbo jet with deadly accuracy.
Fly the dang thing into a tree if you want to see how tough it is.

Is there any chance that you might actually discuss the subject at hand, rather than creating ridiculous straw man arguments to knock down?

 

[Brojon]

At the strain rates involved the hardness of ice is not a significant factor and, in very high-speed impacts, such as with turbine blades, its behavior is largely hydrodynamic. That's not true of some of the component materials in a UAV. I'd suggest that you read more papers and watch fewer videos. The survivability of turbine blades under ice ingestion is a poor indicator of survivability with other materials.

Good to know all those high paid engineers and flight safety people are wasting their time testing then.
You'd have thunk they'd use something that's - I dunno - dangerous to aircraft to test with?
I think you should enlighten these folks to the error of their ways...

 

[Brojon]

Is there any chance that you might actually discuss the subject at hand, rather than creating ridiculous straw man arguments to knock down?

All I've heard is Chicken Little arguments.

 

[Pathogen]

If drones are this deadly to aircraft they can be used to defend skyscrapers from aircraft strikes!

Make no mistake, The Mavic Pro is a deadly weapon in the right hands!

 

[Marko9219]

Well I find it pretty amazing that folks think they're flying a 100% lethal projectile capable of taking down a jumbo jet with deadly accuracy.
Fly the dang thing into a tree if you want to see how tough it is.

Please elaborate about the 100% lethal projectile and jumbo jet and deadly accuracy thing a bit more please. That all seemed like some gigantic leap of reasoning.

 

[Marko9219]

The denial of fact here is simply amazing.
"The little Mavic under my control would never hurt a flea! It's not capable! Jets are waaaay bigger and waaaay tougher than my little Mavic."
It's like someone insulted your wife and your pick up truck and your dog, all at once.
Too funny.

 

[Brojon]

The denial of fact here is simply amazing.
"The little Mavic under my control would never hurt a flea! It's not capable! Jets are waaaay bigger and waaaay tougher than my little Mavic."
It's like someone insulted your wife and your pick up truck and your dog, all at once.
Too funny.

And you are persisting - why? Your arguments make it seem like anyone flying anywhere near an aircraft is cause for panic.
I disagree. Should people be flying drones around aircraft? Of course not.
But what we have is a situation where people are absolutely losing their minds over supposed drone strikes.
On the "civilian side" we have people screaming "you (gvmt) has to DO SOMETHING! Think of the children!".
On the other side we have dronies that start screaming "Idiot! These &%$*&^%!! people are going to get my drone banned! They could have destroyed that aircraft and all the people on it would have been killed - HANG THEM!"
Meanwhile the Foxbat that got clipped is nursing his wing in a tree cursing the fact the idiot humans have built a runway with those *things* chasing away his bugs.
We already know there have been substantially more false alarms than actual cases of drones striking an aircraft - two to be exact. The media of course doesn't care sine they have ripe fodder for revenue - "killer drones! Fly at your own risk!".
Neither incident resulted in significant damage to either aircraft, one being a relatively flimsy Army helicopter. The Army released no photos of actual damage so we don't have a clue what the actual score was. With all the fuss I hope those birds never see combat.
So I post an article from a reputable source by a guy with skin in the game saying "look! your worst fear just occurred and NOTHING HAPPENED!" The naysayers come out of the woodwork with the notion this guy and his article are full of bovine fecal matter. Then we have the overly-proud-of-the-fact actual pilots that start pontificating on how dangerous it is and OMG I can't believe you people aren't taking the situation seriously!
Then we have a couple of qualified as-in-I-do-this-for-a-living people that spoke in a highly articulate manner about actual real world risk mitigation and how low the risks are and y'all either take a pass or ignore them.
Then I'm accused of bias. lol. Pot meet kettle.

 

[Meanee]

I think I lost few brain cells reading some of this. Are we seriously considering a ******** article from random person writing for Forbes to be a statement that drones are not dangerous to a plane? I guess I will go fly my MP in JFK now...

 

[Brojon]

I think I lost few brain cells reading some of this. Are we seriously considering a ******** article from random person writing for Forbes to be a statement that drones are not dangerous to a plane? I guess I will go fly my MP in JFK now...

Lack of brain cells notwithstanding I don't think you really gave much thought to the message.
He's not a random - unlike you he's a trained professional - as are several members here who have weighed in with similar conclusions.

 

[Meanee]

Lack of brain cells notwithstanding I don't think you really gave much thought to the message.
He's not a random - unlike you he's a trained professional - as are several members here who have weighed in with similar conclusions.

Trained professional would not make such nonsense assessment. Granted, I am not an airline pilot. But if I fly around on my rented C172, I would rather not hit a drone with my prop, damaging it and making me do emergency landing. But hey, awesome for you to point out that "Unlike you" which shows your maturity quite well.

 

[Brojon]

Trained professional would not make such nonsense assessment. Granted, I am not an airline pilot. But if I fly around on my rented C172, I would rather not hit a drone with my prop, damaging it and making me do emergency landing. But hey, awesome for you to point out that "Unlike you" which shows your maturity quite well.

Sorry if the truth hurts - as you pointed out you are NOT any of the positions qualified to quibble about what a professional asserts.
I presume your level of maturity has you believe you're opinion is somehow more valuable?

 

[Meanee]

Sorry if the truth hurts - as you pointed out you are NOT any of the positions qualified to quibble about what a professional asserts.
I presume your level of maturity has you believe you're opinion is somehow more valuable?

Oh, trust me, it does not hurt at all. I tend not to take attempted insults personally, especially from some random internet person who decided that he is somehow better than others. And while I usually take all opinions into consideration, some are just way out there. Like yours.

Truth is, when hard object collides with another hard object, something will be damaged. It could be a scratch, it could be a dent, or it could be turbine that will shred itself after it becomes unbalanced. Is the risk of it worth it? Or should we just start flying drones anywhere we would feel like, and let planes run (fly?) them over?

 

[Brojon]

You're right - I should not have stooped to the level you established.
You totally and absolutely missed the point. I suspect you just jumped in both feet and don't hold out hopes you could try again without jumping to conclusions.
Hint: this is about risk mitigation and reality based concerns - not pointless speculation.

 

[Meanee]

You're right - I should not have stooped to the level you established.
You totally and absolutely missed the point. I suspect you just jumped in both feet and don't hold out hopes you could try again without jumping to conclusions.
Hint: this is about risk mitigation and reality based concerns - not pointless speculation.

You have a skyscraper to climb to get to my level. But hey, keep at it, whatever makes you comfortable.