Drone Laws - 1:1 Rule

In this blog we are going to be taking a look at the 1:1 rule that applies to operations within the Open category and specifically those that are flying in the A2 and A3 Subcategories

This is also one that has a big impact on those that hold an A2 CofC and are flying a drone or model aircraft within the A1 Sub category under the transitional provisions, as no horizontal separations distances are stated but the 1:1 rule will want to be used as a guide to determine how far away you would want to be from an uninvolved person.


Before we get into the 1:1 rule it would be worth taking a look at the separation from uninvolved persons that we need to maintain within the OPEN Category.

So, for the most part within the A3 subcategory and the A2 With a non C classed drone under the transitional provisions (The likes of DJI Mavics 2, DJI Phantoms under 2kg) We need to maintain a horizontal separation distance of 50m from uninvolved persons. To help ensure their safety during a UAS Operation. (*Distances will reduce once C2 aircraft become available)

This should be viewed as a cylinder around the uninvolved person and they cannot be overflown at any height. Unless you have a privately built drone with a weight below 250 g or a drone purchased on the market with a class identification C0 or C1 mark. Even then you should try to minimise the time during which you fly over people.

The other option if overflight is needed is to look at conducting flights within the Specific category and not the Open but this would require a GVC (General VLOS Certificate) and a operational authorisation granted by the CAA (Civil Aviation Authority)

Further information on the GVC can be found - HERE


While called the 1:1 rule its important to understand that's its a principle as apposed to an exact rule in law, this is more of a quick to action safety measure than a hard and fast rule, and is to be used to help quickly work out if a drone or model aircraft separation from an uninvolved person is enough.


The one-to-one rule comes into play for most people when your flying with a height greater than 50m if something was to go wrong and the drone or model aircraft was to fall out of the sky from a height of say 120m or 400ft it could potentially expose people that are a distance away to a greater risk and potential impact as it may not fall straight down.

So, this is where the one-to-one rule comes into try and keep things safe no matter what height you are flying at.

The 1:1 rule is based on the relationship between the height and the distance your drone or model aircraft is from the uninvolved person and states that you should aim to have a similar horizontal distance from uninvolved persons to the height that you are flying at.

Horizontal distance is equal to Height of Drone/Model aircraft.

So, if you are flying at 70m you should aim to keep 70m horizontally away from uninvolved person.

If an uninvolved person were to come within your operational areas (the area where you are flying) you need to maintain that 50m horizontal separation distance.

How you choose to deal with this might differ depending on the situation and the location you are flying in You might choose to increase your horizontal distance so that you are further away from the uninvolved person to comply with the 1:1 rule

or you might choose to reduce your height so that you come back in line with the 1:1 rule.

For the 1:1 rule to work you need to have good situational awareness. Understanding distance and heights and how to find this information on your equipment will help to make implementing this much easier.

Don't forget that the INFRATEC Drones website has a wealth of further training, guidance and materials that are available to you to help ensure you have a safe and positive time when flying your drone or model aircraft.

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