Attempted Takedown with Shotgun?

[John235]

Good handling of that situation!

Im really curious about the prop damage- it was obviously hit by a gun, had you ever hit anything, it wouldn’t have been on the trailing edge of the prop. Has anyone else seen this type of damage on the trailing edge?

It is possible that the guy is holding a .22
cal pellet gun and not a shotgun- both are pump action, and you would not have heard that go off as easily as a shotgun Also, they could do that type of damage if its a lucky shot.

Of the three times I have found a damaged prop on my MP, all three times it was a chip out of the trailing edge. Each time, it looked much like your photo. I know for certain it has never been shot at. Once, I believe it was a late manifestation of a previous encounter with an end table while experimenting indoors. I think it was a hairline crack I missed. Once, I think it was due to landing in grass. The last time, I saw what happened. I was correcting a landing while OA was disabled and accidentally hit a thin tree branch instead. In each case, I believe the leading edge skidded over the obstacle, exposing the most fragile part of the prop to the damage. I do not find trailing edge - only damage to be particularly strange.

 

[AMann]

Of the three times I have found a damaged prop on my MP, all three times it was a chip out of the trailing edge. Each time, it looked much like your photo. I know for certain it has never been shot at. Once, I believe it was a late manifestation of a previous encounter with an end table while experimenting indoors. I think it was a hairline crack I missed. Once, I think it was due to landing in grass. The last time, I saw what happened. I was correcting a landing while OA was disabled and accidentally hit a thin tree branch instead. In each case, I believe the leading edge skidded over the obstacle, exposing the most fragile part of the prop to the damage. I do not find trailing edge - only damage to be particularly strange.

I stand corrected, that is an interesting observation. The stress to do that then is upwards against the bottom of the blade?

 

[John235]

I stand corrected, that is an interesting observation. The stress to do that then is upwards against the bottom of the blade?

Yes. I do think that is what happened. Now, hitting a branch or wire head on of course would break the leading edge. In the OPs case, it does not seem his drone was shot. A shotgun would do far more and a .22 or pellet would probably cut the blade in two. At least I hope he was not so attacked.

 

[Nickalo]

If he threaten you and you have prop damage and said he was going to shoot it down, then I would notify the local police, FAA and FBI. By doing so the matter will be investigated and he will not be threating any other drone operator trying to do things by the law. Just my advice.

 

[kidologist]

Police report filed?

I would still file a police report. It puts that nut on thepolice radar in case of a future incident. Hard to explain away that hole in the prop if you didn't crash and it wasn't there pre-flight. He may not have fired, but he might next time. He also might have used a BB/Pellet gun that you didn't get a picture of. I would report, especially in CA where they are much stricter with guns.

 

[Nickalo]

I would still file a police report. It puts that nut on thepolice radar in case of a future incident. Hard to explain away that hole in the prop if you didn't crash and it wasn't there pre-flight. He may not have fired, but he might next time. He also might have used a BB/Pellet gun that you didn't get a picture of. I would report, especially in CA where they are much stricter with guns.

I agree.

 

[johnsctt78]

THAT RIFLE IS A .22
Hatsan Mod 125 Vortex .22 Caliber Pellet Gun

 

[Madmax229]

By the way- in California, state law prohibits negligent shooting of a gun in the air (excludes hunting), so he could have faced a misdemeanor charge for doing it if he had (Negligent Firing of Firearm Penal Code 246.3 PC). Just something to keep in mind if anyone encounters the public and police in a situation like that.

Also discharging a weapon near a dwelling is against the law. Had it been a shotgun, you would have heard it.

 

[Dano]

He was probably upset you might discover his marijuana operation..

 

[Racin8de]

To me if it was any type of weapon I would say it was a pellet gun, definitely wouldn't have heard it. The damage looks more like a pellet or BB than pellets from a shotgun the whole arm minimal of the drone would have been blown off. I would still report it man, you earned & paid for your part 107 to be legal. You did nothing wrong, people cannot go around making threats especially with you're business having nothing to do with them. I mean, you're not delusional and would have known if your prop made contact with something that would have caused the jagged hole.... I'm not saying it was, but it's not cool going around making threats involving firearms... You're a legit victim PERIOD

 

[Chip]

My takeaway from this, is that in the future, I will make an effort to inform neighbors of the activity. However, I think the attempted takedown of the drone crossed the line....

Wow this is scary. But, it sounds like you handled it great. "De-escalated" a potentially dangerous situation with a cool head. Nice work and thanks for posting. If you talked to the guy and reached understanding after the possible shot, why do the police report? I would have no question if you knew he took the shot after the conversation.

In this case the probability of a .22 pellet, on that trajectory, hitting a prop rather than passing between them is approximately ⅓.

brett, very cool video of propeller v machine gun test. I have been fascinated by that issue for many years as well. SAR, I dont know how you get 1 in 3 but forget the flight logs I will take your word for it!

 

[Norb_DAIS]

Police report filed?

I didn't file a police report. I don't have any conclusive evidence.

 

[Norb_DAIS]

An interesting perspective, but I can say with a degree of certainty that I inspected the blades preflight, and did not find any visible or obvious defects.

Of the three times I have found a damaged prop on my MP, all three times it was a chip out of the trailing edge. Each time, it looked much like your photo. I know for certain it has never been shot at. Once, I believe it was a late manifestation of a previous encounter with an end table while experimenting indoors. I think it was a hairline crack I missed. Once, I think it was due to landing in grass. The last time, I saw what happened. I was correcting a landing while OA was disabled and accidentally hit a thin tree branch instead. In each case, I believe the leading edge skidded over the obstacle, exposing the most fragile part of the prop to the damage. I do not find trailing edge - only damage to be particularly strange.

 

[Norb_DAIS]

I thought we ended on a good note. Seeing the damaged prop and the photos got me a little upset.

I am trying to provide and perform a legitimate service without infringing on anyone's rights (to privacy or otherwise.) If there was more damage to the drone, I would consider contacting the police immediately.

However, I think it's another learning opportunity. I can see his point of frustration with a drone flying near or over his property even if I have every legal right to do so. I get it - the paranoia of someone spying on them with a tool like the Mavic 2 Pro or similar product.

I'm thinking that with some advanced scheduling, and about $7 worth of postage and cardstock, I could print a notification to inform people in the immediate area of upcoming drone activity.

Thoughts?

To me if it was any type of weapon I would say it was a pellet gun, definitely wouldn't have heard it. The damage looks more like a pellet or BB than pellets from a shotgun the whole arm minimal of the drone would have been blown off. I would still report it man, you earned & paid for your part 107 to be legal. You did nothing wrong, people cannot go around making threats especially with you're business having nothing to do with them. I mean, you're not delusional and would have known if your prop made contact with something that would have caused the jagged hole.... I'm not saying it was, but it's not cool going around making threats involving firearms... You're a legit victim PERIOD

 

[kilomikebravo]

In Caliornia, negligent discharge like firing in the air is a 1 year misdemeanor.

In Texas, it would be...

"Didja get him?"

You did do the right thing. Too many crazies around with guns these days

Brett: I resemble that remark.

THAT RIFLE IS A .22 Hatsan Mod 125 Vortex .22 Caliber Pellet Gun

JohnS: I'm SUPER impressed with your eyesight and pellet rifle knowledge. I zoomed into that tiny image and compared it to a photo of a real Hatsan and it DOES look like it might be one of those.

All: Personally, I would have been more worried about his wife kicking my butt than the measly pellet rifle. <chuckling>

 

[sar104]

SAR, I dont know how you get 1 in 3 but forget the flight logs I will take your word for it!

It's a very simple calculation based on the width of the prop at that radius, w, diameter of the pellet, d, motor speed, m, pellet speed, v, and pellet length, l. It turns out that at 5000 rpm and 900 ft/s the rotation rate is a second order effect, and so it reduces to the ratio (w + d)/πr.

 

[JAW]

I didn't file a police report. I don't have any conclusive evidence.

Always file a police report when it comes to firearms usage. It's not your job to come up with conclusive evidence. There's a reason why police have a report category named Police Information.

ps It's still not too late.

 

[johnsctt78]

In Texas, it would be...

"Didja get him?"






Brett: I resemble that remark.





JohnS: I'm SUPER impressed with your eyesight and pellet rifle knowledge. I zoomed into that tiny image and compared it to a photo of a real Hatsan and it DOES look like it might be one of those.

All: Personally, I would have been more worried about his wife kicking my butt than the measly pellet rifle. <chuckling>

thank you kilo

 

[brett8883]

It's a very simple calculation based on the width of the prop at that radius, w, diameter of the pellet, d, motor speed, m, pellet speed, v, and pellet length, l. It turns out that at 5000 rpm and 900 ft/s the rotation rate is a second order effect, and so it reduces to the ratio (w + d)/πr.

Ok I’m really just curious I know better then to question your math skills sar but 900 f/s is 274.32 m/s or 274,320 mm/s. The length of a .22 projectile is about 10mm. So a projectile will clear the danger zone in about .00003645 seconds. I have a hard time understanding how the rotation of the props has anything to really do with it.

5000 RPMs is /60 seconds is 83.33 rotations per second. So in .00003645 seconds it will have rotated only .00030375 times. I can’t imagine that changes the probability of a hit in any significant way over the props being perfectly still and they cover a very little area of the possible surface are of the circle at that radius.

Again I’m probably wrong and missing something but 1:3 sounded high to me too.

 

[sar104]

Ok I’m really just curious I know better then to question your math skills sar but 900 f/s is 274.32 m/s or 274,320 mm/s. The length of a .22 projectile is about 10mm. So a projectile will clear the danger zone in about .00003645 seconds. I have a hard time understanding how the rotation of the props has anything to really do with it.

5000 RPMs is /60 seconds is 83.33 rotations per second. So in .00003645 seconds it will have rotated only .00030375 times. I can’t imagine that changes the probability of a hit in any significant way over the props being perfectly still and they cover a very little area of the possible surface are of the circle at that radius.

Again I’m probably wrong and missing something but 1:3 sounded high to me too.

That's exactly correct - so I think you misunderstood my explanation. I said that the rotation rate is a second-order effect - in mathematical terms that means that it has little effect on the result. The rotation contribution to the probability is ml/30v, which comes to 0.01 at those rotation rates and speed - insignificant compared to the geometric contribution.