Hand catching? Unsafe practise or valuable skill?

Warning – Graphic content!

“Yer but …! “

In 2018 a rather shocking image came up on one of my social media drone pages where somebody was injured while hand launching their drone! The image was hard hitting and straight to the point. After spending some time looking on the web it turns out this isn’t a one off, across the world many pilots are being injured as a result of hand launching their drones. Is it been taught properly, or at all, or is this a practice that we should be avoided at all cost.

I contacted the individual and asked him what happened.

“A DJI Spark, one moment it was lying on my hand, the next minute I couldn’t get my hand away quick enough…! I spent hours in surgery and I’m not sure what I’ll be left with”

I wished him a speedy recovery! 8 years on I would interested to know how he is doing.

The whole situation peeked my interest, why were people doing something that had the potential to main them? So I decided to do some research.

So why do people do it?

They think it looks “pro”
On social media, especially with FPV and camera-operator content, hand catching gets framed as a skill.
Bad landing surfaces
If you’re flying from boats, long grass, rocky ground, or sand, it’s logical to want to protect the expensive toy.
Copycat behaviour
New pilots imitate what they’ve seen, not understanding the potential risks.
False confidence / muscle memory
Regular flying can breed complacency. Most hand-catch incidents happen to experienced pilots who are “comfortable” with the aircraft.
Bad advice online
There are plenty of YouTube tutorials that casually present hand-catching as normal practice without necessarily covering the safety concerns.

Before I look at the negatives lets look at the makeup of a drone and how it works.

Most drone propellers are made from lightweight, tough materials chosen to balance strength, efficiency, and safety. The most common options are:

Plastic (ABS, Nylon, Polycarbonate)

Glass filled or Carbon filled Nylon

Carbon Fibre

Wood

Most people are using DJI so I will focus on these for this example. DJI use a Polycarbonate propellor a type of high performance plastic known for being exceptionally tough, impact and heat resistant, while still being light weight and flexible. In simple terms, it’s a plastic that behaves a bit like metal in strength and rubber in toughness!

Polycarbonate is also used in Bullet proof windows, Safety glasses, Riot shields and Power tool casings, to give you an idea of strong it can be.

Most pilots fly Mode 2, where inputs from the pilot, through the controller, are past to the drone, where the flight controller manages the output to the motors to help maintain stable flight. The flight controller contains multiple sensors including the IMU (Internal Measuring Unit), the Barometer, accelerators, GPS and vision sensors.

The IMU sends a signal to the motors via a speed controller, “You need ‘this’ amount of power to hold this input”.

Now lets put your Hand into this equation:

As the blade collides with an immovable object, like your hand, it will be naturally slowed by the impact. However, the immovable object isn’t the flight controller and as a result the IMU senses a change in performance and doesn’t realise your hand is not just a gust of wind. It therefore increases the power to that motor to combat that effect, and it keeps going as it programmed to do just that.

At this point two things can happen, either the blade snaps, but remember its made out of Polycarbonate, OR you skin ends up looking like the image earlier!

So could this be a unsafe practice?

Potential Risks (The Cons)

A prop can easily slice to the tendon or bone no matter the size.
Vision systems and obstacle avoidance sensors are easily confused and can react inconsistently in fight leading to erratic movement.
Releasing a hand from the controller in order to catch the drone means you are no longer in full control of the drone.
While concentrating on the catch, you risk loosing your spatial awareness to any external risks to your flight.
Stepping into the flight path risks loose clothing, hair, or straps being inadvertently caught in the propellors, either damaging the aircraft or you.
Risk of life changing injury or extended recovery periods, preventing ongoing flight operations and the risk to your business or hobby.
As a CAA-approved pilot you already know: the human hand is not an approved landing pad. CAP722 5.2 The Remote Pilot.