Telling the cabin
The passengers-and-cabin-safety lesson taught the normal briefing schedule; the emergency case gets one line in the acceptable means of compliance, and the line is the point: in an emergency during flight, passengers should be instructed as appropriate to the circumstances. The elements are the ones the normal briefings already carry, now made specific: seat belts fastened and the cabin secured, seatbacks and tray tables in position, the exits and which will be used, hand baggage left behind in an evacuation, and for a ditching the life-jackets, where they are and when to inflate. Time decides the depth: a precautionary landing can brief calmly; an emergency landing briefs what matters in the minutes there are.
After the aircraft stops
An evacuation begins only when the aircraft has stopped and the engines are shut down, and the reasons are mechanical: a moving aircraft turns evacuees and slides into casualties, a running engine's intake can ingest and its blast can injure the people leaving by the very exits the slides serve. Behind the procedure sits the certification requirement the syllabus names: each crew and passenger area must allow rapid evacuation in crash landings, gear extended or retracted, fire considered, and for aeroplanes seating more than 44 passengers it must be shown that the maximum seating capacity, crew included, can be evacuated to the ground within 90 seconds under simulated emergency conditions. After the landing, the crew's work is the reasoning this course has been teaching all along: the commander decides and commands the evacuation, the crew work their stations per the type, the passengers are led clear and upwind of fuel and fire, everyone is accounted for, and the alerting and search-and-rescue machinery the air-law course taught takes the event from there.
Jettisoning fuel
An aircraft that takes off heavy and turns back immediately may be far above any weight at which landing is safe, and the answer is to jettison fuel to reduce the landing mass, the same rationale the air-law course's lesson on emergencies, silence and incidents taught from the controller's side. That lesson also owns the coordination, which this syllabus makes the crew's own learning objective: in controlled airspace the flight crew shall coordinate with ATC the route, which if possible should be clear of cities and towns, preferably over water, and away from reported or expected thunderstorms; the flight level, not less than 1,800 m (6,000 ft); and the duration of the jettisoning.
The system side is certification law. A jettisoning system must be installed unless the aeroplane can already meet the climb requirements at maximum take-off weight less the fuel of a 15-minute flight of take-off, go-around and landing at the departure airport; where required, it must be capable of jettisoning enough fuel within 15 minutes to meet those climb requirements, which is what makes the immediate-return case survivable. The tests behind it demand that the fuel discharges clear of the aeroplane, that no fuel or fumes re-enter, and that controllability is unaffected; and because flaps, slots and slats change the airflow across the wing, a type not shown safe with them deployed carries a placard warning against jettisoning while they are in use, the placard guarding the clearances the tests demonstrated. Two protections finish the design: the system cannot jettison the take-off and landing tanks below the fuel needed to climb from sea level to 10,000 ft and then cruise 45 minutes at maximum-range speed, and the crew can close the jettisoning valve at any point of the operation.