Class D is no longer cleared for passenger aircraft — Page 167, Lesson 259

I want to walk you through the classification of fire zones in aircraft and the requirements for crew protective breathing equipment. Let's start with the fire classes. Class D is no longer cleared for passenger aircraft. That's a simple but important point — if you're studying for a passenger-carrying operation, Class D is off the table. Class E applies to cargo aeroplanes only. For a Class E cargo compartment, there are several specific requirements that must be met. First, there must be a separate approved smoke or fire detection system that gives a warning at the Engineer or Pilot station — so the flight crew gets an alert specifically for that cargo area. Second, there must be a means of shutting off the airflow into that compartment without affecting the flight deck — so you can isolate the cargo hold's ventilation while keeping the cockpit's air supply normal. Third, there must be a means to exclude smoke, flames, and noxious gases from the flight deck — so the cockpit environment stays protected. And fourth, the crew emergency exits must be accessible under all loading conditions — meaning no matter how the cargo is arranged, the crew can still get to their exits. Now, the subsequent actions associated with any fire or instance of smoke in an aeroplane will be defined in the Operations Manual, or OM. So the specific procedures you follow are laid out by your airline, not by this regulation alone. Let's move on to Crew Protective Breathing Equipment, or PBE. The regulation applies to: unpressurised aeroplanes with a maximum take-off mass, or MTOM, greater than 5700 kilograms, or with more than 19 passenger seats — and all pressurised aeroplanes, regardless of size. So if you're flying a pressurised aircraft, you need PBE. If it's unpressurised, you need it only if it's above that weight or seat threshold. What must the PBE do? It must protect the eyes, nose, and mouth of each flight crew member whilst they are on flight crew duty. And it must provide oxygen for a period of at least 15 minutes. That oxygen supply may come from the supplemental oxygen supply as required by EU-OPS 1.770 — so it doesn't have to be a separate bottle; it can be tapped from the crew's existing oxygen system. Sufficient PBE must also be carried for each cabin crew member, stowed at the cabin crew member station. Additionally, one set of PBE is to be stowed at or adjacent to the stowage of the hand-held fire extinguishers. And where a fire is possible in the cargo area, the PBE is to be stowed outside that area but adjacent to the entrance — so you can grab it before entering the cargo compartment. Finally, a critical operational point: whilst using PBE, normal communications must not be prevented. The equipment is designed so you can still talk to the other crew members and use the intercom or radio without obstruction.