★ PTS mapping: This lesson aligns to FAA-S-8081-20A (Nov 2023), Area of Operation VIII — Emergency Procedures (per Lesson→Area map). It is a PTS, so items are Tasks/elements (no ACS K/R/S codes); read the exact Task lettering and tolerances from the current published PTS.
Trade altitude and airspeed for rotor energy, glide to a chosen spot, and cushion the touchdown.
When the engine can no longer drive the rotor, the freewheeling unit disengages the engine and upward airflow through the descending rotor disc keeps the blades turning. The disc divides into a driven (propeller) region near the tips that absorbs energy, a driving (autorotative) region in the mid-blade that sustains RPM, and a stall region near the root. The pilot's job is to keep the system in equilibrium so that rotor RPM (Nr) stays in the green — the stored rotational energy in the blades is what cushions the final touchdown. Lose Nr and you lose your one chance at a soft landing.
On a (simulated or actual) power loss the immediate actions are to lower the collective to preserve/recover Nr, apply pedal to keep the aircraft in trim (yaw changes as torque disappears), and set the autorotation glide attitude and airspeed. Confirm Nr is within limits — too low risks blade stall, too high risks overspeed. Speed of the collective-down input matters: delay lets Nr decay quickly, especially at low inertia. This is why the engine-failure / autorotation entry is a memory item.
| Phase | Pilot actions (confirm exact values/technique with POH & CFI) |
|---|---|
| Entry | Lower collective promptly, pedal to trim, establish glide attitude and recommended autorotation airspeed, verify Nr in limits |
| Glide / steady state | Hold airspeed and Nr, pick and adjust toward a touchdown area, account for wind, cross-check rate of descent |
| Flare | At the recommended height, apply aft cyclic to slow descent and forward speed and to build rotor RPM |
| Touchdown / cushion | Level the aircraft, raise collective progressively to cushion using stored rotor energy, touch down with minimal forward speed (or run-on as conditions require) |
Each helicopter has a recommended autorotation airspeed that gives a sensible glide ratio and a manageable flare, and a recommended/minimum-rate-of-descent airspeed if range or sink rate must be managed. Higher airspeed generally flattens the glide for distance; minimum-rate speed reduces sink for time/altitude. Throughout, keep Nr inside the green arc by metering collective. The exact R44 autorotation airspeed and the Nr limits/normal operating band are aircraft-specific — see the fill-in box. Wind matters: turn into wind for the touchdown when you can, and remember a tailwind lengthens ground distance.
The flare near the surface does three jobs at once: it slows the rate of descent, reduces forward groundspeed, and momentarily increases rotor RPM as the flow through the disc changes. Then you level the aircraft and progressively raise the collective — the cushion — converting stored rotor energy into lift to soften the touchdown. Timing and height judgment are everything: flare too high and you sink hard with depleted RPM; flare too low and you cannot arrest the descent. Touchdown is made with minimal forward speed or as a controlled run-on depending on surface and aircraft.
The HV diagram shows combinations of height and airspeed from which a safe autorotative landing may not be achievable after a power loss — the low-airspeed/low-altitude region and the high-speed/low-altitude region. ATP-level airmanship means operating to minimize time in the avoid areas on takeoff and approach so that if the engine quits you have either airspeed or altitude (energy) to trade. Treat the HV chart as an energy-management map, not just a takeoff curve.
Curated reference clip — “Autorotation - Landing a Helicopter without Engine Power” · Douglas Sims (YouTube), verified via oEmbed. Embedded with the creator's player; we don't host or alter it.
✈️ Your test aircraft: the R-44 fill-in values cover its single-engine, piston, VFR figures. ATP-H practical tests are normally flown in a turbine and/or multi-engine helicopter, where autorotation entry behavior (low-inertia vs. high-inertia rotor, turbine spool/needle-split) differs — use your actual test aircraft's data (§3-§4 procedures, autorotation airspeed and Nr figures) from its RFM/POH for items marked aircraft-specific.