Jump to content
sectrix

FPV, RPV and the law; best practices

Recommended Posts

Hi everyone,

Ever since I was a kid I've always loved planes. My ultimate fantasy was to build my own and fly it around. Recently, I started to think about how model aircraft could fill this void. It seemed the ultimate experience would be to pilot the plane in the first person, with video and sensor feedback. A virtual cockpit. The only limiting factor would be range of the radio equipment. It seemed too grand an idea to not have been done before, so I started a search. I soon found the RC aircraft industry more or less followed the regulations set forth by the AMA, which prohibits beyond-line-of-site flying. Devastated, I began an exhaustive search to find the laws governing model aircraft, to see if it is illegal or simply not recommended. To facilitate the learning of others I'm recording what I've found here.

The systems of RC aircraft flying we are concerned with here involve the aircraft and its operation, the Radio Control signals sent to the plane, and the video/data signals sent from the plane. The FAA governs the aircraft and its operation. The FAA says it has no specific regulations for small remote controlled aircraft. It offers a single advisory, AC 91-57, for a guide. This states basically:

1)Do not operate over populated areas, or noise-sensitive areas.

2)Do not operate unproven aircraft around spectators.

3)Stay less then 400' AGL, and notify ATC when within 3 miles of an airport.

4)Give way to full scale aircraft.

5)Don't hesitate to ask for help when complying.

So it seems FPV and RPV aircraft are not expressly prohibited by the FAA, as long as you follow the rules. The FAA also "encourages voluntary compliance with industry developed safety standards". For signal transmission, the FCC is a little more clear. There are basically four options for controlling RC craft (as per 47CFR95.210 and 47CFR97.215):

1)27 MHz band (Channels 1-5): 4 watts

2)27 MHz band (Channel 6): 25 watts

3)72 MHz band: .75 watts

4)Amature radio bands: 1 watt

The other portion controlled by the FCC is the transmission of the video and sensor data. There are a plethora of video and data frequencies available in the Amateur Radio bands. A cursory search reveals these types of emissions (video and data) are limited to certain frequencies (per 47CFR97.305), and some frequencies have additional power limitations (per 47CFR97.313). So, when designing your own FPV or RPV aircraft, keep those things in mind.

But I also have a few questions still. What is best for long range radio control? The crowded (but powerful) 27 MHz band? A nice, quiet amateur radio band somewhere? For that matter, what is the best (for long distance) live video and telemetry solution? Am I going to be ostracized by the RC airplane community for being a FPV flyer? (I saw crashergs from RC-Universe get flamed pretty bad for asking about autopilot systems) In practice, is it really that big of a deal with the law to operate RC aircraft from long distances? This is the most exiting thing I've gotten interested in in years. Any comments would great.

Share this post


Link to post
Share on other sites
For that matter, what is the best (for long distance) live video and telemetry solution?

How do you define long distance?

Dan

Share this post


Link to post
Share on other sites

Beyond line of site, certainly. I don't know really what kind of range is possible, so when I say long distance, I guess I mean anything in excess of a mile. This is a gray area for me right now; I dont know what methods are used to transmit telemetry and video data, their regulations and ranges.

Share this post


Link to post
Share on other sites

Depending on altitude, you can get 2 to 3 miles out of a stock RC system. The higher the better. If you have a fairly clear area I consider it safe only as long as you use a spotter. Once you're that far out you need a Video link to see what is going on. The spotter helps by scanning for other approaching aircraft. I live in the Idaho High Desert so on a still day you can hear full scale planes when they're farther than 10 miles out. You just have to be able to respond if one starts heading your way. I use a GPS device with a co-pilot stabilizing unit as well as a BP altitude lock. If I need to I can get the plane a couple hundred feet agl and enable it to return to me.

Dan

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×