This set of guidelines has been put together by members of UKHAS (United Kingdom High Altitude Society) as a recommendation of how to operate high altitude balloon flights safely. They are not legally binding rules however UKHAS do recommend that people follow them as they are based on years of experience in the UK and US. Launching a balloon is your own responsibility and while these rules won't protect you if something was to happen we'd expect that by following them you reduce the risk of any incidents.

1. Permission from the CAA must be obtained for a meteorological balloon flight, this will include a NOTAM for the launch site.
2. Projects should aim to make their payload as light as possible both for safety but also as this will require less helium saving money and a finite resource. Flights with payload weights below 1Kg should be the norm and payload weights above 2Kg are discouraged.
3. Keep within the ICAO regulations for light payloads:
   1. a flight with one or more payload packages should have a combined mass of less than 4 kg.
   2. a force of less than 230 N is required to separate the suspended payload and parachute from the balloon. (See Note1)
   3. if any package is 2 kg or more the area density must be below 13 g per square centimetre. (See Note2)
4. Payloads should have insulation surrounding the equipment both for maintaining temperature but also providing 'padding' on impact.
5. Antenna elements that face down should be flexible - avoid metal rods.
6. Before launching a balloon run computer modelled flight predictions, postpone launch if there is a high chance of the payload landing in urban areas or near to airports. If the payload is predicated to pass through or near NOTAM'd airspace, Danger or Air Traffic Zones then discuss this with the operator of these areas.
7. Always get the landowners permission before attempting to recover a payload.
8. As there is a chance that your payload may not be recoverable strive to make it as environmentally friendly as possible.
9. Seek help from more experienced UKHAS members when encountering an area outside your comfort zone.
10. Follow local regulations when operating and storing compressed gases such as Helium.

Note1: The force to be applied in a direction parallel to the suspension line.

Note2: The area density is determined by dividing the total mass in grams of the payload package by the area in square centimeters of its smallest surface.