7.2 Emergency & Abnormal Procedures

UK CAA A2 Certificate of Competency A2 CofC

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1 Introduction & A2 CofC Pathway

1.1 Exam Facts, Format, Pass Mark & Validity 1.2 Flyer ID, Operator ID & Practical Declaration 1.3 Operating Guides, Maintenance & Safe-to-Fly Decisions

2 Open Category Air Law

2.1 Open Category A1 / A2 / A3 & 2026 Near People Rename 2.2 VLOS, 120 m Height Limit & Flight Restriction Zones 2.3 Uninvolved Persons, Assemblies & Giving Way to Manned Aircraft

3 Near People Separation Rules

3.1 UK2/C2 Separation: 30 m Normal & 5 m Low-Speed Mode 3.2 Legacy Aircraft 50 m Separation & MTOM < 2 kg 3.3 The 1:1 Rule, Height vs Horizontal Distance & Safe Distances

4 Operational Ground Risk Mitigations

4.1 Site Selection, Segregation & Pre-Flight Briefing 4.2 Reacting to Approaching People & Abort Decisions 4.3 Weather, Performance & Segregation Checks Before 5 m Ops

5 Technical & Human Ground-Risk Mitigations

5.1 Prop Guards, Parachutes, Geo-Awareness & Other Technical Mitigations 5.2 Kinetic Energy, Mass, Speed & Ground Impact Risk 5.3 Medical Fitness, Alcohol, Medication & Fatigue

6 Aircraft Eligibility & Flight Characteristics

6.1 UK0, UK1 & UK2 Class Marks and A2 Eligibility 6.2 Rotorcraft, Fixed-Wing & Hybrid Operating Envelopes 6.3 Basic Principles of Flight, Stability & Control

7 Practical Procedures, Emergencies & Decisions

7.1 Flight Procedures & Basic Practical Drills 7.2 Emergency & Abnormal Procedures 7.3 Decision-Making, Customer Pressure & Occurrence Reporting

8 UAS Flight Performance Systems

8.1 Mass, Balance, Payload Effects on Performance 8.2 Battery Terminology, Types, Charging & Storage 8.3 Failsafe Modes, Return-to-Home & Lost-Link Behaviour

9 Navigation, Compass & Flyaways

9.1 GNSS Position Hold, Drift & Loss of Positioning 9.2 Compass Errors & Magnetic Interference 9.3 Firmware, Braking Distance & Flyaway Causes

10 Meteorology for Near-People Operations

10.1 Weather Sources, Reports, Forecasts & Local Assessment 10.2 Wind Speed, Gusts & Manufacturer Limits 10.3 Wind Gradient, Masking & Urban Turbulence 10.4 Temperature, Density, Precipitation, Visibility & Icing 10.5 Clouds, Cumulonimbus, Lightning & IP43

7.2 Emergency & Abnormal Procedures

Key Takeaways Explain This Topic AI

The correct response to an abnormal event comes from the manufacturer’s guide, the configured failsafe, and the site contingency plan; no single RTH action is safe for every event.

Loss of GNSS or compass reliability may remove position hold without removing manual control, so create space, use attitude cues, and land rather than chasing automation.

Lost link, low battery, propulsion damage, flyaway, and unexpected people each require a pre-planned response and a clear landing or containment area.

Manned aircraft always receive priority; descend or land promptly as needed, and do not fly near an active emergency response unless permission has been obtained.

After a crash or serious incident, protect life first, control fire or battery risk without unnecessary exposure, preserve evidence, and follow applicable reporting routes.

Last updated: August 2026

Abnormal Versus Emergency

An abnormal condition is a degraded or unexpected state that still allows controlled response. An emergency urgently threatens people, other aircraft, or control. The boundary can change quickly.

Use the aircraft’s manufacturer procedure , actual failsafe configuration , and site contingency plan . “Press RTH” is not universal: RTH can climb into airspace, cross people, pass behind an obstacle, or land at an occupied home point.

Loss of GNSS or Position Hold

A GNSS warning can cause drift or attitude-based control. If the control link remains:

• take manual control using visual attitude and orientation;
• reduce speed and create distance from people and obstacles;
• stop precision camera work;
• move toward a clear landing area; and

land before workload or battery becomes critical.

Do not toggle modes without understanding them. Magnetic interference, poor satellite geometry, multipath, and sensor faults can look similar. Diagnose after landing.

Compass or Heading Anomaly

A compass warning, toilet-bowl motion, or unexpected yaw can corrupt automated navigation. Stop the task, maintain VLOS, avoid routes that depend on heading, and follow the guide. If stable control remains, land clear. Recalibrating in the same magnetically contaminated place is not an airborne diagnosis.

Lost Control Link

Before launch, know whether link loss causes hover, land, return-to-home, route continuation, or another action , and after what delay. Confirm home point and RTH height/path.

If the link is lost:

• scan the known aircraft area and use crew calls;
• follow the manufacturer’s reconnection procedure;
• expect the configured failsafe rather than guessing;
• keep people away from the predicted route and landing area; and

notify relevant persons if containment fails.

Choose the failsafe before take-off so its route avoids people, obstacles, and controlled airspace.

Low Battery or Power Anomaly

Battery percentage is an estimate. Cold, age, payload, wind, cell imbalance, and voltage sag can trigger earlier warnings.

At an unexpected warning, stop the task, use the shortest safe path to a clear landing, avoid a long return across people, land with reserve, and quarantine a hot, swollen, impacted, or abnormal battery.

A forced landing in an empty contingency area is better than an attempt to reach home across a pavement.

Propulsion, Vibration, or Structural Damage

Unusual noise, severe vibration, motor warning, or visible damage can precede loss of control. Reduce demand, avoid people, and land as soon as practicable at a clear location. A fixed wing must retain airspeed and use its forced-landing area. Do not perform aggressive airborne tests.

After landing, disarm, isolate power, inspect, and ground the aircraft until corrected and verified.

Flyaway or Uncommanded Flight

A flyaway is sustained uncommanded motion or inability to produce the expected path. Causes include orientation error, wind, link problems, GNSS/compass faults, wrong mode, or configuration.

Respond by identifying whether inputs work; selecting only a known appropriate mode; using visual orientation and creating distance from people; attempting safe landing or an approved termination method; and warning people without abandoning aircraft control.

Do not chase the aircraft physically while losing the airspace scan. Preserve logs and report as applicable if containment fails.

People Intrusion and Manned Aircraft

When a person enters the buffer, move laterally to restore horizontal distance or land clear. Do not count a climb as horizontal distance and do not overfly.

For a manned-aircraft conflict, give way immediately . Descend or land when safe, maintain the scan, and do not rely on the crew seeing the UAS.

Do not fly close to or inside an active emergency-response area unless the responsible service has given permission. Helicopters can arrive quickly at low level.

Fire, Crash, and Injury

After a crash:

• protect life and call emergency services when needed;
• do not touch a burning or venting lithium battery without protection;
• keep people away from wreckage and fire;
• disconnect power only if safe;
• preserve the site and evidence except for safety, rescue, or authorised movement; and

notify the operator and use applicable AAIB and CAA routes.

A damaged battery can ignite later. Isolate it safely and follow manufacturer, emergency-service, and disposal guidance.

Scenario Matrix

• Event First priority Common wrong action
• GNSS lost, link good Create space, control visually, land Continue precision filming
• Lost link Expect configured failsafe, protect route Guess every UAS returns
• Low-voltage warning Short safe landing with reserve Stretch home across people
• Manned helicopter Give way, descend/land safely Finish the shot
• Person enters buffer Lateral separation or clear landing Climb above them
• Serious crash Rescue, preserve evidence, report Quietly remove everything

Practise decision sequences safely in A3 training. Simulate faults rather than creating hazards. Competence is recognising the state, applying the right procedure, and preventing exposure to people.