Emergency Descent Calculator
How fast can you get down: emergency-descent profiles compared — the time and distance from altitude to breathable air or VMC, configuration by configuration.
Per the POH, an emergency descent is typically: power idle, prop full forward, gear out (if extendable at speed), bank 30–45° and hold the gear/flap limit speed — the bank adds load, which adds drag, which steepens without overspeeding. Smoke/fire may dictate even more aggressive profiles.
Formula
⚠️ For flight planning and education only — verify with current charts, AFM and ATC clearances. Not for primary navigation.
How fast can you get down: emergency-descent profiles compared — the time and distance from altitude to breathable air or VMC, configuration by configuration.
About Emergency Descent Calculator
Hypoxia, fire, a medical event below — some situations price every minute of altitude in consequences. This calculator quantifies emergency-descent options: from altitude to target at the rate your configuration achieves, returning time, ground covered and path angle. The differences are stark and worth knowing cold — 15,000 to 8,000 ft is seven minutes at a polite cruise descent, but barely two in a gear-out spiraling emergency profile.
How to use Emergency Descent Calculator
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula time = Δalt ÷ rate; the rate itself comes from the POH emergency-descent procedure substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Emergency Descent Calculator?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula time = Δalt ÷ rate; the rate itself comes from the POH emergency-descent procedure with sources cited on the page
- ✓Per the POH, an emergency descent is typically: power idle, prop full forward, gear out (if extendable at speed), bank 30–45° and hold the gear/flap limit speed — the bank adds load, which adds drag, which steepens without overspeeding. Smoke/fire may dictate even more aggressive profiles.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
What's the fastest safe way down in a light single?+
The POH's emergency descent procedure, typically: throttle idle, propeller full forward (adds braking), landing gear extended if the speed permits, then a steep bank (30–45°) holding the relevant structural speed. The bank is the clever part — load factor raises induced drag and lets a steep descent stay below limit speeds. Practiced clean variants reach 2,000–3,000 fpm; gear-out spirals more.
Why does hypoxia make the first minute matter so much?+
Time of useful consciousness collapses with altitude: roughly 30 minutes at 18,000 ft but 3–5 at 25,000. The descent's early seconds happen at the worst altitude — which is why the drill is memorized (oxygen ON, then descend, then troubleshoot) and why pulse oximeters and a practiced emergency descent belong together for anyone cruising in the teens.
Does a spiraling descent beat a straight one?+
For staying over one spot (a landing site below, or avoiding weather ahead), yes — and the bank's load factor steepens the achievable path as above. For covering distance toward an airport while descending, straight ahead at the same rate obviously wins ground. The calculator's distance output frames the choice: 7,000 ft at 2,500 fpm covers 7 nm at 150 kt — spiral if that 7 nm doesn't help you.
What about shock cooling the engine?+
The emergency outranks the engine — every POH emergency descent accepts thermal stress that babying-the-engine dogma would avoid, and the evidence for catastrophic shock cooling is thin anyway. For PRACTICE descents, split the difference: partial power, mixture leaned appropriately, cowl flaps closed, and the airframe limits respected. Train the profile so the real one is muscle memory, not improvisation.
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