The first thing to know is that it is legal. It’s regulated by the FAA under Part 101 Subpart D of their regulations.
If you read the whole Part 101 regulation you’ll notice at the very start that the regulation only applies to unmanned balloons with payloads heavier than 4 pounds. Note that you should still follow all of the rules in Subpart D to make the experience as smooth as possible.
I was a little worried about talking with the FAA. Especially since I was not sure of the phone number and requirements.
If you were to send a big balloon to Near Space, you would have to contact the right ATC (air traffic control) office. But in our case, the ATC office doesn’t actually have anything to do with small unmanned balloons.
What you need to do is create a NOTAM (Notice To Airmen).
NOTAMs are notifications issued for hazardous reasons, such as:
- Parachute jumps
- Closed runways
- Erupting Volcanos
Who do I need to call?
The ATC office I talked to gave me the phone number for Prescott Flight Service Station (877-487-6867).
I believe that they handle all the NOTAM reporting for the West side of the US. Where does West start? No idea, you should call your ATC office to make sure. I know that many people launching balloons from different states (CA, UT, NV, …) called that specific office.
What does the FAA need to know?
What they ask you differs from one person to another.
What they asked me was:
- Date and time of the launch ?(You need to notify the FAA between 24 hours and 6 hours before the launch)
- Location of the launch? (City, States + GPS coordinates in both Decimal Degree and DMS formats). Converter can be found here.
- How far it is from any major city, airports, air force base? (It needs to be 5 miles away from everything)
- What is the ascent rate?
That was it for me. It was pretty straightforward.
However depending on who you talk to, be prepared to be asked:
- At what time will it reached 60,000ft up?
- At what time will it reached 60,000ft down?
- At what time will it land?
- Where will it land?
Theoretically, you should also notify the NOTAM station when you actually reach 60k feet up and down, if you lose communication with your balloon, and when your payload has landed. Realistically, no one cared when I called and that was fine by me.
Why 60,000ft? Because most of the air traffic flies below this altitude.
How to choose your launch location and predict the flight’s trajectory?
When looking for your launch site, you need to think about 3 main factors:
- You must not have any fence, phone pole, electric pole, tall tree around you.
- You must take into consideration the winds (when you fill the balloon and during the flight) which can carry your payload up to 200 miles away.
- You must take into consideration the estimated landing area.
- You must take into consideration the estimated flight path.
1) You really do not want all your work to end up stuck in a tree or attached to a 100ft high electric line.
3 & 4) Remember that you need to be able to recover the payload quickly (Batteries might die) and be able to receive signals from the landing location. Avoid highly populated areas or areas with lakes, mountains or dense vegetation.
Note that you need to make sure your launch site is more than 5 miles away from any airport/AFB.