Airports are complex, high-occupancy environments with unique fire safety requirements. We examine the regulatory framework, engineering challenges, and operational considerations.. Critical National Infrastructure UK airports — from Heathrow processing 80 million passengers annually to regional airports serving vital domestic and international connections — are designated Critical National Infrastructure. Their fire safety requirements reflect this status, combining standard building fire safety regulations with aviation specific safety requirements that create one of the most complex regulatory environments in the built environment. Airport terminal buildings present extraordinary fire engineering challenges: vast open volumes, complex passenger flows, multiple occupancy types under one roof, high value retail and catering operations, critical security infrastructure, and the imperative for business continuity that makes any disruption extraordinarily costly. Regulatory Framework Airport fire safety operates under multiple overlapping regulatory frameworks: Regulatory Reform (Fire Safety) Order 2005 — applies to all airport buildings as workplaces and public venues Civil Aviation Authority (CAA) regulations — CAP 168 (Licensing of Aerodromes) includes fire safety requirements ICAO Standards and Recommended Practices (SARPs) — international aviation fire safety standards NFPA 415 — Airport Terminal Buildings (often referenced alongside UK standards) Building Regulations — apply to all new construction and significant alterations Health and Safety at Work Act 1974 — overarching workplace safety legislation Terminal Building Fire Engineering Structural Fire Protection Large span roof structures — often unprotected steel relying on fire engineering analysis Mezzanine and multi level retail areas — compartmentation within open plan terminals Baggage handling systems — fire risks in concealed conveyor routes Jet bridges — connecting terminal to aircraft, requiring fire rated construction Detection and Alarm Beam detection across large terminal volumes Aspirating detection in concealed spaces and baggage areas Voice alarm systems for controlled evacuation messaging in multiple languages Integration with security systems — fire alarm activation must not automatically open security barriers Suppression Sprinkler protection throughout terminal buildings Enhanced suppression in retail, catering, and baggage handling areas Gas suppression in IT/comms rooms and ATC facilities Foam systems in fuel handling areas Airside Fire Safety Beyond terminal buildings, airports have extensive airside fire safety requirements: Aircraft Rescue and Fire Fighting (ARFF) CAA mandated ARFF category based on aircraft size Response time requirements (operational within 3 minutes) Specialist ARFF vehicles with foam and dry chemical agents Airport fire service staffing and training requirements Fuel Storage and Distribution Aviation fuel farm fire protection — foam systems, bunding, separation distances Hydrant fuel distribution systems Refuelling operations — procedures and equipment COMAH/DSEAR compliance for major fuel storage Evacuation Complexity Airport evacuations present unique challenges: Security implications — evacuated passengers may need re screening Airside/landside separation — maintaining security boundaries during evacuation International passengers — language barriers, unfamiliarity with building Reduced mobility — passengers with disabilities, elderly, families with children Scale — Heathrow Terminal 5 can accommodate 30,000+ people Business continuity — flight disruption costs of £millions per hour Phased Evacuation Most large terminals adopt phased evacuation strategies: Fire zone evacuation first Adjacent zones prepared for evacuation Full terminal evacuation only if fire escalates Staff managed evacuation with PA guidance Emerging Challenges Sustainable Aviation Hydrogen fuel infrastructure — new fire and explosion risks Electric aircraft charging — lithium ion battery risks at scale Sustainable Aviation Fuel (SAF) storage — different fire characteristics Security Threats Fire as a component of security incidents Integration of fire safety and counter terrorism planning Hostile vehicle mitigation affecting fire service access Climate Resilience Increased frequency of extreme weather events Flooding affecting below ground infrastructure and fire systems Heat stress on fire safety systems and materials For airport and aviation facility fire engineering, contact Magnus Opifex.