Emergency operations — engine failure, system malfunctions, equipment
**Engine failure in flight:** the first action is to establish **best glide** speed (published in the POH — ~68 KIAS for a C172). Then:
1. **Aviate** — pitch for best glide, trim. 2. **Navigate** — pick a landing site within glide range. Into the wind when possible; prioritize flat, long, open terrain. 3. **Troubleshoot** (if time permits): fuel selector to BOTH, mixture rich, throttle, carb heat ON, mags BOTH/LEFT/RIGHT, primer locked, master switch check. 4. **Communicate** — 121.5 MHz, squawk 7700, declare MAYDAY, brief passengers. 5. **Secure** — fuel OFF, mixture ICO, mags OFF, master OFF (just before touchdown).
**Emergency descent** (cabin fire, rapid structural concern): maximum allowable airspeed (Vno in smooth air, Va in turbulence), throttle idle, carb heat as appropriate, descent with a bank to maintain positive G and clearing turns.
**14 CFR 91.3(b):** in an in-flight emergency requiring immediate action, the PIC may deviate from any rule to the extent required to meet that emergency. A written report may be required if ATC requests it.
**NTSB 830.5 reporting:** operators must immediately notify NTSB of aircraft accidents and certain serious incidents (flight control system malfunction, in-flight fire, propeller-blade failure, overdue aircraft believed to be in an accident).