Abnormal and Emergency Procedures
Memory items versus checklists
Emergencies split into memory items (time-critical: engine fire, loss of cabin pressure, rejected takeoff) and reference items (everything else). The error questions target is doing a reference checklist from memory while the aircraft descends into terrain, or delaying a memory item while hunting for the QRH. Fly the airplane first: aviate, navigate, communicate.
Decompression and emergency descent
For a rapid decompression: don oxygen masks, establish communications, descend to the lowest safe altitude or 10,000 ft (whichever is higher, terrain permitting), and level off. Passenger oxygen is time-limited - know the duration for your altitude. Structural damage, fire, or a jammed control changes the plan; declare an emergency and get vectors.
Engine failure and driftdown
After an engine failure in cruise, driftdown to the single-engine service ceiling is a planned maneuver, not an emergency improvisation. Secure the engine per the checklist, set maximum continuous thrust, and accept the driftdown altitude that clears terrain. Do not restart a failed engine without confirming the cause if fire or damage is suspected.
Worked example: Cabin altitude climbing through 14,000 ft with masks on and an emergency descent initiated at Mmo/Vmo - the priority is a controlled descent, not a rapid one that overspeeds or overstresses the airframe.
Rule of thumb: for smoke or fire, land as soon as possible; for most other failures, land as soon as practicable.