FAA Question

[Bradfo69]

So... I get this silly idea last year to offer to do lasers at a local Halloween attraction place as all the money raised goes to lukemia. A good friend (and the idiot that got me into this hobby) is the house DJ for this event which runs Fri, Sat, Sun for the month of October. He typically runs music videos and plays music for the people in line for the haunted hayride. Anyway, I filled out all of the FAA paperwork and we had a rehearsal last week and I took some final measurements so I could send the paperwork in but, in past years, it's terminated on plywood. THIS year, they decided to build some sort of a screen/scrim thing. And, it ain't solid obviously. I couldn't see any light traveling beyond it when I walked around back that night but, how on earth do I determine if anything going beyond this thing presents a hazard to any random aircraft cruising around at 30,000 feet? I'm only going to be able to do this maybe one night on Sunday the 28th but, I gotta get the paperwork in fast since they want it a month in advance.





Thoughts?

[Steve Milani]

You will play a laser show over a screen. This is what You will declare to authority, so Authority will be informed about this. You know, they know.
If there were some nearby airport, I think authority should have to inform airport about lasershow. If authority fail to inform airport, then they should be a really foolish people.....
You are a "simple citizen" and you could not know nothing about airport/aircraft/laser and its problem/regulations. Authority MUST know all about this problem. They MUST to inform all people needed (you and airport staff).

Anyway...
30,000 feet = 10,700 meters = 10,7 kilometres = 6,64 miles.

Have your laser modules such small divergence and so high power to be a danger for aircraft flying at that distance?
And then.... how long and how many times your "escaping rays" can hit exactly aircraft cockpit? ( to be clearest: to hit pilots eyes).
Weather will be fine or will be cloudy/foggy/etc. etc.???
Too much factors have to be considered.... your brain will burn thinking about how much safety factors you should have to consider..

I think you have less than 1/1,000,000,000 of bad chances...

I well know that in USA regulations about laser are very severe (maybe too much...). But I also think we all live on Earth, not on Mars..... We have to think in "real life way" and not like "science-finction movie way"

I think you can sleep safe.

[flecom]

We have to think in "real life way" and not like "science-finction movie way"

no you have to think angry greedy lawyer way

[Displaser]

Brad,

Is covering the frame with a different material an option? As a scrim, I'd wonder if this meets the criteria as a beam termination?

[flecom]

or maybe put plywood behind the screen?

[Bradfo69]

I fully realize that the chances of anything happening or even anyone saying anything are a bazillion to one but, I am trying to do things in the right way and if nothing else, get "in the system" so if the occasion ever arises that I do want to do something else outdoors, I have started and established a worthy track record.

Yes, I could potentially get something and climb up and put it behind the frame on the night(s) we're doing a laser show. I gave that some consideration and may be the route I go. It's pretty heavy material as I saw it originally laying on the ground. It's almost like webbing for a beach chair and doesn't allow much transmission but... could something sorta get through? I suppose so.

I'm sort of wondering if it's even worth it because, as you can see in the photo, the square I have to work with in terms of a projection zone is about 7 feet by 7 feet and, wasn't overly impressive when I did a test run. The one thing I thought about doing was also hitting the screen with a lumia effect as well and play the graphics over top of the lumia.

Edit: The night we tested, you could "see" the beam from the projector to the screen because of the natural humidity in the air but, as I mentioned I saw nothing at all in the air space behind the screen. Even a cheesy 5mw pointer would have made a distinct visible beam and with this, I saw absolutely nothing leaking through.

[Steve Milani]

no you have to think angry greedy lawyer way

I absolutely agree.
But if you inform also airport authority about a laser show from hours XX to YY in the evening/night, I think there should be not any safety problem.
In the worst case, if an aircraft is approaching while lasershow is running, flight control operator can (better to say: MUST) communicate to pilots: "Warning! There is a lasershow near to airstrip! Watch out for laser rays!"... Or something like this...

I think this should be the easiest and most logical solution: local authority and airport authority both know about lasershow. So... problem should be cleared

[flecom]

well the way it works over here is you request permission from the FAA and they will grant or deny it

[Darcean]

Sorry to hijack your thread.. but i pose a what if question..


What if you were contacted to do a laser show within 3-4 weeks of the event, under the 30 day deadline..(21-28 days before show start), and turned in a FAA form 3 weeks before show.. Would the FAA still consider the form, with it being a terminated show with suitable termination points? Just a thought on my head if I ever come into that situation.

[blowfly]

With a scrim screen i think you have to start with the assumption that the beams will basically be unterminated. The FAA doesn't have the expertise to get into what material you are projecting through, they only want to know when, where, projection frustum, and beam characteristics. You can always call them and ask this question though.