EMF and interference for drones

Format

Electromagnetic interference (EMF/EMI) is an A2 and STS exam topic covering the effect of radio disturbances on the control link and GPS signal. Questions test whether the pilot understands the causes, signs and safety responses to interference.

Exam questions typically present a scenario: the drone begins behaving unpredictably, the control signal drops intermittently — what should you do? The correct answer is always to return the aircraft and land at the nearest safe location as soon as possible.

Preparation

The EMI topic must be studied at several levels: 1) what causes interference (proximity to electrical infrastructure, other radio sources, 2.4 GHz vs 5.8 GHz spectrum), 2) how interference manifests, 3) how to minimise exposure.

High-voltage power lines, broadcasting towers and densely built urban areas are locations where EMI risk is elevated. Before flying in such zones, conduct additional equipment checks and plan an emergency return route.

Mocks

In A2STS, EMI questions appear at different difficulty levels: from theoretical definitions to scenarios where you must decide the correct pilot action.

Study this topic alongside batteries and meteorology — all three form the A2 technical question block. The SRS system will ensure adequate review time for all three.

Frequently asked questions

Does a 5.8 GHz control system protect against interference?

5.8 GHz has less congestion than 2.4 GHz in urban areas but is not immune to interference. Different frequency bands have different advantages and disadvantages — understand both for the exam.

What should I do if the drone loses GPS signal during flight?

Switch to manual/attitude flight mode (if available) and return the aircraft to a safe area. Waiting for GPS to restore while the drone is airborne is unsafe.