Was it or not?

LUIS MARTINEZ · Dec 5, 2019

A news helicopter was struck by a suspected drone over Los Angeles, causing substantial damage | CNN

The object ripped a hole through the helicopter’s tail and dented and scratched the craft in other spots – damage too severe to be caused by a bird, crew said.

edition.cnn.com

BigAl07 · Dec 5, 2019

My $$ would be UAS.

R.Perry · Dec 6, 2019

Personally I find it hard to believe that a drone did that damage. If it weren't for the other scratches I would have guessed a bullet hit that thing. While in the Navy I seen many aircraft with bullet holes, and a bullet hitting at a glance can cause that kind of damage. However it would'nt cause other superficial damage.
I could see a don't causing that kind of damage if it were a high speed inpact, but that had to be a glancing impact and obviously wasn't a head on impact.
Interesting question, I just love how CNN wrote the article, obviously like most CNN reporters he was clueless.

dronecyclops · Dec 6, 2019

UAS its not even close to looking like a bird strike

LUIS MARTINEZ · Dec 6, 2019

dronecyclops said:
UAS its not even close to looking like a bird strike

Can't see blood or body debris so perhaps. Guess I don't want to believe it...

Dave Pitman · Dec 6, 2019

R.Perry said:
Personally I find it hard to believe that a drone did that damage. If it weren't for the other scratches I would have guessed a bullet hit that thing. While in the Navy I seen many aircraft with bullet holes, and a bullet hitting at a glance can cause that kind of damage. However it would'nt cause other superficial damage.
I could see a don't causing that kind of damage if it were a high speed inpact, but that had to be a glancing impact and obviously wasn't a head on impact.

My thoughts, exactly. Most all of the speed of impact would have had to come from the uas coming from the side. I don't think a consumer uas could be traveling fast enough to make that penetration.

Head on is a different matter.

PatR · Dec 6, 2019

We might want to remember a helicopter does not have to be flying in the direction the front is facing.

Dave Pitman · Dec 6, 2019

PatR said:
We might want to remember a helicopter does not have to be flying in the direction the front is facing.

Very true. But I doubt a news copter would be flying sideways at high speed, why would they even if they could? Any rotory guys in here?

R.Perry · Dec 6, 2019

Dave Pitman said:
Very true. But I doubt a news copter would be flying sideways at high speed, why would they even if they could? Any rotory guys in here?

ya, their called drone pilots. I've heard the Apache can fly 60 mph sideways.
That impact is a good one for the NTSB to spend a million or so dollars trying to figure out what hit it. Even as heavy as the Inspire is I don't see that kind of damage, but could be wrong.

spamgnome · Dec 7, 2019

Dave Pitman said:
I don't think a consumer uas could be traveling fast enough to make that penetration.

As most of us (I suspect) use commercial drones, that's what we tend to picture, but there are a lot of other pieces of hardware out there that might have more weight and sharper edges than a DJI drone.

spamgnome · Dec 7, 2019

One has to look at this probabilistically. What else occupies the skies with helos? Planes, other helos, balloons, Drones, and stray bullets. Given this was in L.A. area, we probably have to put the odds of it being a bullet a but higher than in other places (that was a joke.) Given that the pilots didn't report a collision with another manned aircraft, the most likely scenario is a drone. Was it flying sideways? Probably not completely sideways, but keep in mind that in a crosswind situation, a helicopter (plane, too) has to crab into the crosswind to travel in a desired direction. In the case of a helicopter, the crab angle will be larger when compared to a plane due to the helicopter's lower airspeed. So, yes, some element of "sideways" travel is not just possible, but rather likely.

Damage: The aluminum skin on these types of aircraft are rather thin, so I don't see that gouge as unlikely at all especially if the drone was accelerated due to the downwash of the main rotor.

I get the desire to defend drone operators, but as we learn daily, most drone operators are not professional pilots.

In summary, I think when you start to eliminate all of the unlikely scenarios, the most likely is a drone.

PatR · Dec 7, 2019

spamgnome said:
I get the desire to defend drone operators, but as we learn daily, most drone operators are not professional pilots.

Nor do they understand the construction materials and techniques used for full scale aircraft.

Depending on what those in the helicopter were looking at or trying to film, it’s very possible the helicopter was being crabbed to keep something on the ground in view of a reporter or cameraman. The pilot does not fly the camera, others do.

Philztoy · Dec 7, 2019

It looked like the strike was on the front of the horizontal stabilizer to me. If that is the case the helicopter was moving forward at a hundred knots when the leading edge of the stabilizer ran into something. Wouldn’t take a lot to damage it at 100 kts.

R.Perry · Dec 7, 2019

I would like to know what if anything will be found inside that tail section. The other issue I see that makes a drone strike problematic is the rotor wash could easily blow a drone under the helicopter. Reality is we can arm chair and guess all we want but the reality is they may never know what hit it. Just making an assumption that it was a drone without any proof is typical CNN journalism.

Dave Pitman · Dec 7, 2019

R.Perry said:
Reality is we can arm chair and guess all we want but the reality is they may never know what hit it.

For sure.

Looking at the photo again, notice a single clear puncture with nothing around it. You would think there would be some scratching or at least some scuff marks around the puncture if a drone died there. It looks more like something small, blunt, and hard.

Maybe we'll know, someday.

Philztoy · Dec 7, 2019

Will be interesting to read the NTSB report.

CNN reporting is suspect.

Mavic Mac · Dec 7, 2019

R.Perry said:
I would like to know what if anything will be found inside that tail section. The other issue I see that makes a drone strike problematic is the rotor wash could easily blow a drone under the helicopter. Reality is we can arm chair and guess all we want but the reality is they may never know what hit it. Just making an assumption that it was a drone without any proof is typical CNN journalism.

Wouldn't be the first time a drone collide with a copter. Sept 21, 2017 a drone collided with a Blackhawk over Staten Island, NY
Story HERE

One statement from the article states
Arterburn says the Black Hawk, being a military helicopter, is built to withstand significant damage, and that a civilian helicopter would probably have faired much worse.

Pilots occasionally file reports claiming to have struck a drone, but such collisions don’t typically leave much evidence behind, as the small parts fall to the ground, and so have been impossible to confirm.

Fred Garvin · Dec 7, 2019

Bullet Holes:

BigAl07 · Dec 7, 2019

R.Perry said:
............The other issue I see that makes a drone strike problematic is the rotor wash could easily blow a drone under the helicopter. ........

This should help....

(Not my calcs I'm copy/pasting from a post on another forum but these are realistic #'s )

*********** Start Quotation ************
Take an arbitrary helicopter - I'm choosing a Sikorsky UH-60, which has a maximum takeoff weight of 10,000 kg and a rotor diameter of 16.4 m, sweeping an area of 211 m².

To support its weight the downthrust has to be 100,000 N, and so the downward pressure below the rotors needs to be of the order of 500 N/m².

The cross-sectional area of a Phantom is around 0.25 m², and so the downward force on the Phantom would be, at most, 125 N.

Acting on a mass of 2 kg, that will yield a downward acceleration of 62.5 m/s².

The UH-60 flies at 150 knots (78 m/s), and so the time taken for even a stationary Phantom to pass the 16.4 m under the rotors, front to back, would be 0.2 s.

Applying the standard equations of motion, vertically, to the Phantom, it will be deflected downwards by 1.4 m in that time, not even nearly the height of the aircraft.

But, since the fuselage is positioned such that only around one half the length of a rotor blade extends ahead of it, the time that an incoming Phantom would be exposed to the downforce before striking the aircraft would be roughly one quarter of the estimate above - i.e. 0.05 s. In that time the deflection will be around 7 cm. Barely noticeable - it's still hitting the windshield.
*********** End Quotation ************