Emergency Descent

• Bank angle between 30° and 45° to hold positive load factors through the descent (S4)
• Airspeed +0/−10 knots of the POH-recommended descent speed (S5)
• Level off at the specified altitude ±100 feet (S5)
• Clear the area first, complete the appropriate checklist(s), and use SRM/CRM (S1, S6, S7)

Note the asymmetry in the airspeed tolerance: fast is a bust. The POH speed is bounded above by VNE, VLE, or VFE, so the standard gives you slack only on the slow side (FAA-S-ACS-7B, Task IX.A).

Anything where staying at altitude is itself the threat:

• Uncontrollable in-flight fire — engine, electrical, or cabin
• Sudden loss of cabin pressurization in a pressurized airplane
• Any other condition demanding an immediate and rapid descent

The objective is to get down "as soon and as rapidly as possible while not exceeding any structural limitations of the airplane" (AFH ch. 18). At the commercial level the examiner will usually specify the scenario, and your configuration has to match it.

Per the manufacturer, but the AFH baseline is a maximum-drag descent (AFH ch. 18):

1. Power to idle, except where the manufacturer prohibits it
2. Propeller control to low pitch / high rpm — the prop becomes an aerodynamic brake and resists airspeed buildup
3. Landing gear and flaps extended as the AFM/POH recommends, for maximum drag
4. 30° to 45° of bank, established as the descent begins
5. Descend at the maximum allowable airspeed consistent with that configuration

Drag is what lets you descend steeply without running the airspeed up into a limit.

Whichever ones your configuration invokes — the AFH names three explicitly: VNE, VLE (maximum landing gear extended), and VFE (maximum flap extended). If the descent is flown in turbulence, you are additionally bound by VA, the design maneuvering speed (AFH ch. 18).

Practical consequence: a gear-and-flaps drag descent is a slower descent than a clean one, and that is the point. You trade airspeed for drag and keep the structure intact.

Three reasons, all of which the examiner wants to hear (AFH ch. 18):

• The bank keeps positive load factors (G) on the airframe — a pure pushover unloads the wing and floats loose objects and unbelted occupants
• The turn adds drag and steepens the descent path without adding airspeed
• The turn lets you clear the airspace and terrain below before you descend through it, and lets you look over the possible landing area

Simulated descents "should be made in a turn to check for other air traffic below."

The AFH names the tension without resolving it for you: a high-airspeed descent could blow the fire out, but "the weakening of the airplane structure is a major concern and descent at low airspeed would place less stress on the airplane" (AFH ch. 18).

If fire has been burning long enough to be visible, assume structural damage and treat the airframe as fragile. Follow the AFM/POH — and remember the AFH's framing: the airplane is expendable, the occupants are not.

Recovery is initiated at a high enough altitude to ensure a safe return to level flight or a precautionary landing (AFH ch. 18). On the checkride the examiner specifies a level-off altitude and you owe them ±100 feet, so pick the lead point during the descent rather than improvising it — the descent rate is high by design, and whatever rate your airplane produces in the AFM/POH configuration is the number you lead by.

If the emergency is real and the cause is fire, the descent does not end at level-off. It ends on the ground.

In piston airplanes, "prolonged practice of emergency descents should be avoided to prevent excessive cooling of the engine cylinders" (AFH ch. 18). Once the descent is established and stabilized in training, terminate it. Shock cooling is a maintenance cost you are inflicting on someone's airplane — a professional-pilot consideration the examiner will notice you raising.

• Explosive decompression — a change in cabin pressure faster than the lungs can decompress, with potential lung damage. Normal unrestricted lung release takes about 0.2 seconds; most authorities consider any decompression in less than 0.5 seconds to be explosive.
• Rapid decompression — the lungs decompress faster than the cabin, so no lung over-pressure injury.

Either way, the primary danger is hypoxia. Rapid decompression cuts effective performance time to one-third to one-fourth of normal, because oxygen is driven out of the lungs (PHAK ch. 7).

Time of useful consciousness is the maximum time you have to make and carry out rational, life-saving decisions without supplemental oxygen (PHAK ch. 17, Figure 17-1):

And a rapid decompression cuts those numbers by a factor of three or four. That is why mask first, then descend is the order — not the reverse.

Unpressurized (cabin pressure altitude):

• Above 12,500 ft up to and including 14,000 ft MSL — required minimum flightcrew uses oxygen for that portion exceeding 30 minutes
• Above 14,000 ft MSL — required minimum flightcrew uses oxygen for the entire time at those altitudes
• Above 15,000 ft MSL — each occupant must be provided oxygen (91.211(a))

Pressurized: above FL250, a 10-minute supply for each occupant beyond the (a) requirement; above FL350, one pilot at the controls wears and uses a secured, sealed mask — waived at or below FL410 with two pilots at the controls, each with a quick-donning mask donnable with one hand in 5 seconds (91.211(b)).

On a pressurized airplane the pressurization air system normally scavenges smoke; if the smoke is intense, you either depressurize at altitude (only if oxygen is available for all occupants) or execute an emergency descent (AFH ch. 18).

Unpressurized, you can try the foul-weather windows or cabin air — but if smoke increases when the vents open, close them immediately: airflow is feeding the fire, or the fire is in the heating system or nose baggage area. Note that on some airplanes, lowering the gear or flaps aggravates cabin smoke — an unwelcome interaction with the max-drag descent configuration.

• R1 — altitude, wind, terrain, obstructions, gliding distance, available landing distance. A steep descent eats through a lot of vertical airspace fast; know the MSA and terrain under you before you start.
• R2 — collision hazards. This is why the descent is a turning descent, and why a radio call announcing your intentions "may be appropriate to alert other aircraft in the area" (AFH ch. 18).
• R3 — configuring the airplane. Gear and flaps have speed limits; exceeding VLE or VFE in the middle of an emergency creates a second emergency.
• R4 — distractions, task prioritization, loss of situational awareness. Fly, then configure, then checklist, then talk.

Verbalize the loop rather than silently flying the maneuver:

• Announce the emergency and the plan ("cabin fire, emergency descent, we're going down to 4,000 and landing at the nearest field")
• Delegate — if there is a second pilot or a capable passenger, assign the checklist reading and the radio
• Use ATC as a resource: declare, squawk 7700, and ask for terrain and traffic. Distress communications have absolute priority and MAYDAY commands radio silence on the frequency in use (AIM 6-3-1)
• Automate where it helps — but hand-fly if the automation is fighting you

The examiner is grading whether you managed the emergency, not just whether you flew a 40° bank.

Depends entirely on the cause, and saying so out loud is the mature answer:

• Depressurization — level off at the lowest altitude that is safe for the terrain (MSA or the applicable minimum IFR altitude) and that clears you of the 91.211 oxygen thresholds — crew oxygen is required above 12,500 ft cabin altitude beyond 30 minutes, and continuously above 14,000 ft — then divert. The emergency is over once everyone is breathing without a mask.
• In-flight fire — this is a land-immediately event. Engine compartment fires that appear extinguished "have been known to rekindle with changes in airflow pattern and airspeed," and a brief but intense fire can cause dangerous structural damage (AFH ch. 18). Fly the descent onto a landing site, on or off airport.