Emergency Procedures, Abnormal Operations and Emergency Equipment
This domain tests what happens when things go wrong: immediate-action drills, emergency authority, distress and urgency communications, and the equipment carried on board. Items often describe an abnormal situation and ask for the correct first action or the correct call.
Immediate actions and decision making
- Memory items for time-critical events - rejected take-off, engine fire or failure, cabin altitude warning, smoke - followed by the QRH checklist.
- Emergency descent after depressurisation: don oxygen masks, establish communication, descend to 10,000 ft or the minimum safe altitude, turn off the route as required, advise ATC.
- Evacuation and ditching: the 90-second certification standard for evacuation, exit selection, crew commands, life rafts and survival equipment.
- Emergency authority: the PIC may deviate from rules to the extent necessary and must report (Annex 2, CAT.GEN.MPA.105).
Communications and signals
- Distress MAYDAY on 121.5 MHz; urgency PAN PAN. SSR codes 7700 emergency, 7600 radio failure, 7500 unlawful interference. ELT on 406 MHz and 121.5 MHz.
- Radio failure: follow the applicable procedure, squawk 7600, maintain the last assigned level for the prescribed time and attempt communication on published frequencies.
Emergency equipment (CAT.IDE.A)
- Hand fire extinguishers, protective breathing equipment, portable oxygen, first aid kits and emergency medical kit, life jackets for every person (plus infant jackets), life rafts and survival kits for extended overwater flight, megaphones, escape slides, crash axe, flashlights and ELT.
- Items are checked at intervals defined in the OM, and their stowage is briefed to the crew.
Worked example
Cruising at FL350, the cabin altitude warning sounds. The crew don masks and establish communication, then start an emergency descent at maximum practical rate to 10,000 ft or the MSA, selecting the appropriate heading away from terrain and traffic, while cabin crew deploy passenger oxygen. A MAYDAY call states the problem, intention and level. The flight then diverts to the nearest adequate aerodrome, considering passenger oxygen duration in the diversion decision.
Traps
- Using PAN PAN for a fuel situation that meets the MAYDAY FUEL definition.
- Squawking 7700 for radio failure instead of 7600.
- Assuming cabin oxygen generators last for the whole diversion.
- Forgetting overwater equipment when the route crosses water beyond the defined distance.
Communication, Navigation and Surveillance Equipment Requirements and MEL/CDL
This domain covers what equipment must be fitted and serviceable for the intended flight, and how inoperative items are managed: the required CNS fit, specific airspace requirements, and the MEL and CDL framework. Items frequently ask whether a particular defect permits dispatch.
Required equipment
- CAT.IDE.A sets the minimum for VFR and IFR: radio communication and navigation equipment appropriate to the route, altimeters, transponder, ELT and the equipment required by the airspace.
- Airspace specifics: RVSM needs two independent altitude measurement systems, an altitude alerting system, an autopilot with altitude hold and a serviceable transponder with altitude reporting; Mode S and 8.33 kHz channel spacing in European airspace; ACAS II and TAWS for the applicable masses; PBN approval for RNAV and RNP procedures; ADS-B where mandated.
MEL
- The operator's MEL, derived from the master minimum equipment list and approved by the authority, permits dispatch with specified items inoperative under stated conditions and limitations.
- Repair categories: A as stated in the item, B within 3 days, C within 10 days, D within 120 days.
- The item must be placarded, entered in the technical log and recorded; the MEL may not be less restrictive than the MMEL and never permits flight outside the airworthiness requirements.
CDL
- The configuration deviation list covers missing external parts that are not structural or critical, with the associated performance corrections applied.
Worked example
Before departure with a defective co-pilot altimeter, the MEL may allow dispatch for certain operations. However RVSM needs two independent altitude measurement systems, so the flight cannot enter RVSM airspace; it may be planned below it, with the limitation recorded, the instrument placarded and the defect entered in the technical log. If the intended route leaves no non-RVSM level available, the aircraft does not go.
Traps
- Believing the MEL can defer an item that the flight rules or airspace require.
- Using the MMEL directly instead of the approved operator MEL.
- Treating CDL items as having no performance effect.
- Forgetting the placard, technical log entry and crew notification.