Understand the roles of the AAIB and CAA, the steps for reporting an accident or airprox, and the legal duty to preserve evidence under Article 13
How the UK handles aircraft accidents and serious incidents
The Air Accidents Investigation Branch (AAIB) leads formal investigations into aircraft accidents and serious incidents in the UK. It sits within the Department for Transport and operates a 24-hour phone line and online portal for immediate notifications.
If you witness or are involved in an event that meets the legal threshold for an accident or serious incident, contact the AAIB right away.
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring.
In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.
Who must report and what to preserve
Anyone who sees, is involved in, or learns about an accident, serious incident or an Airprox (near-miss) has two immediate duties: alert emergency services and notify the AAIB without delay.
Article 13 of (EU) 2010/996 (as retained in UK law) requires taking reasonable steps to protect physical and digital traces until investigators take custody. That includes wreckage, recordings, flight data, and any other material relevant to the inquiry.
Think of the site as evidence: restrict access, stabilise conditions and record everything that happens. The same principles apply to cockpit voice and flight data recordings, maintenance records, and digital telemetry.
Immediate actions checklist (do this after ensuring safety and emergency response)
- – Secure the scene: allow access only to authorised personnel. – Preserve fragile items: avoid moving wreckage or components unless it’s necessary for safety. – Isolate electronics: do not power down devices unless preservation requires it, and record any action taken. – Protect recordings and data: leave memory cards and flight recorders in their original state whenever possible. – Document everything: log entries and exits, timestamps, actions taken and observed damage. – Collect witness details: capture names, contacts and short initial statements while memories are fresh. – Notify authorities and operators: give concise facts — location, nature of the event, injuries and immediate hazards.
Examples of reportable events
Report anything that creates a meaningful safety risk. Common examples include:
- – Loss of control or structural failure. – Bird strikes that cause significant damage. – Runway incursions with potential for collision. – Major system failures or unexpected flight-control behavior. – Airprox events where separation or collision risk was compromised.
Preserving digital evidence
Digital files are often decisive. Avoid altering originals. Create authenticated copies for analysis and keep originals on secure, read-only media. Maintain a written chain-of-custody log for every transfer or access and note device identifiers and timestamps.
Near-misses and Airprox
Near-misses deserve the same careful treatment as incidents that cause damage. Record precise times, positions, callsigns and altitudes. Photographs, radar screenshots and witness statements strengthen the investigative picture. If an event meets the Airprox definition, notify the UK Airprox Board (UKAB) in addition to any MOR submissions required by the CAA.
Who to contact and how
- – For accidents and serious incidents: contact the AAIB immediately via its 24-hour number or web portal. Prompt contact preserves investigative jurisdiction and critical evidence. – For regulatory reporting: submit a MOR to the CAA when required; use a VOR for non-mandatory, supplementary information. – For Airprox: notify UKAB in addition to any MOR or AAIB contact, when applicable.
Keep a single, auditable file of all communications, originals and authenticated copies. Expect investigators to request originals, metadata and maintenance records during the initial liaison.
Legal duties and practical evidence protection
Statutory obligations require retention of operational records, recordings and physical traces until authorities say otherwise. Practical steps for frontline staff and operators include:
- – Isolate the scene and avoid non-essential handling. – Make verified digital copies of flight data and voice recordings as soon as possible. – Compile witness statements promptly and record who collected them. – Preserve maintenance logs, recent service records and related documentation. – Secure metadata for photos and videos (device IDs and timestamps).
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.0
Special categories: drones, recordings and whistleblowing
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.1
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.2
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.3
Airprox reporting and UKAB
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.4
A practical reporting template
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.5
- – Incident classification (accident, serious incident, Airprox) – Exact location and time (UTC and local) – Aircraft type(s) and operator(s), registration/callsign(s) – Number of people on board and injuries (if any) – Brief factual sequence of events (no speculation) – Immediate safety actions taken – List and location of preserved evidence (recorders, photos, logs) – Witness names and contact details
Why prompt, accurate reporting matters
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.6
Where to find guidance
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.7
- – AAIB website: reporting contact details, forms and procedural guidance. – CAA occurrence reporting guidance: MOR and VOR submission instructions. – UKAB website: Airprox guidance and reporting forms.
Final practical reminders
- – Notify the AAIB immediately for accidents and serious incidents. – Follow CAA guidance when preparing MOR and VOR submissions. – Preserve evidence under Article 13 obligations and keep originals intact. – Use whistleblowing channels for sensitive disclosures. – For Airprox events, submit reports to both the CAA (MOR) and UKAB as needed.
The Civil Aviation Authority (CAA) offers complementary guidance on reporting routes. It also operates the Mandatory Occurrence Report (MOR) and Voluntary Occurrence Report (VOR) systems for regulatory and safety monitoring. In short: the AAIB conducts safety investigations; the CAA provides regulatory oversight and additional reporting channels.8
