The Cessna 172 best-glide speed is usually 65–68 KIAS. Learn the 172S figure, model differences, weight effects and correct simulator technique.
The Cessna 172’s best-glide speed is typically 65–68 KIAS with the engine inoperative and flaps up. A 172S uses 68 KIAS, while many earlier variants use about 65 KIAS. Use the exact POH or checklist for the model, weight and configuration being flown rather than treating one figure as universal.
Which best-glide speed applies to each Cessna 172 model?
The correct figure comes from the Pilot’s Operating Handbook (POH) or approved checklist for that particular aircraft.
| 172 variant | Typical clean best glide | What to check |
|---|---|---|
| Cessna 172S | 68 KIAS | POH engine-failure procedure and any aircraft-specific supplements |
| Cessna 172R | 65 KIAS | Exact handbook and operating weight |
| Earlier 172 variants | Often around 65 KIAS | Some older handbooks and instruments use miles per hour rather than knots |
KIAS means knots indicated airspeed. Do not substitute true airspeed, GPS groundspeed or a value copied from a different Skyhawk variant. The POH figure also normally assumes a clean aeroplane with the flaps up and may specify a windmilling propeller and reference weight.
Why does Cessna 172 best-glide speed change?
Best-glide speed changes mainly with weight, configuration and wind, although the published indicated airspeed remains the safest standard target during an actual emergency.
- Weight: A lighter aircraft reaches its best lift-to-drag ratio at a lower indicated speed. The theoretical correction is
Vbg,current = Vbg,reference × sqrt(Wcurrent / Wreference). Use this only where the POH or training procedure supports it; an engine failure close to the ground is not the time for mental arithmetic. - Configuration: Flaps, an open door, airframe icing and a damaged or stationary propeller can all change drag. Published maximum-glide data often assumes flaps up and a windmilling propeller.
- Wind: The POH value is an aerodynamic airspeed, not a groundspeed. A strong headwind favours a somewhat higher airspeed for maximum distance over the ground, while a tailwind favours a lower one, subject to a safe stall margin.
- Altitude: Fly the published KIAS. True airspeed rises with altitude, but that does not mean the indicated target should be increased solely because the aircraft is higher.
Best glide maximises distance through still air per unit of height lost. It is not necessarily the minimum-sink speed, which aims to maximise time airborne rather than distance.
How do you establish best glide after an engine failure?
Set the best-glide attitude immediately, confirm the correct indicated speed and trim the aircraft so it is not continually accelerating or slowing.
- Set the attitude: Move the nose promptly towards the attitude that produces 68 KIAS in a 172S or the value specified for the model.
- Reduce unnecessary drag: Keep the flaps up while range is needed and fly coordinated. Avoid steep or repeated turns, which consume height quickly.
- Trim for the target: Make small pitch corrections and allow the airspeed to settle before retrimming. Our guide to using the Cessna 172’s controls and airspeed indications explains the pitch-and-trim relationship.
- Select a landing area: Choose a field that is comfortably within reach rather than one at the theoretical edge of the glide footprint. Allow for wind, obstacles and manoeuvring.
- Run the approved checklist: Attempt a restart and configure for landing only when height and circumstances permit. Aircraft control and reaching the landing area come first.
A mistake we see constantly in simulators is chasing the vertical-speed indicator. Best glide is flown by attitude and indicated airspeed; sink rate is the result, not the primary target.
Is best glide the same as landing speed?
No. Best glide is the clean maximum-range speed, whereas the final approach may use flaps and a different target based on model, weight and conditions.
Once the landing area is assured, the pilot transitions from conserving range to configuring and controlling the approach. Our breakdown of Cessna 172 approach and touchdown speeds explains why 68 KIAS should not simply be carried to touchdown.
How should best glide be practised in a flight simulator?
Practise at a safe altitude, in calm weather and at a known weight so that changes in technique are easy to recognise.
- Start consistently: Use the same altitude, weight and cruise condition for each attempt.
- Simulate the failure: Use the simulator or aircraft add-on’s engine-failure function where available. Throttle idle may leave residual thrust or produce different propeller drag.
- Pitch and trim: Establish the model’s published KIAS without staring at the vertical-speed indicator.
- Compare range: Repeat slightly above and below the target in no wind. Large control inputs and uncoordinated turns will usually cost more distance than a one-knot speed error.
Flight-model quality and failure modelling vary between add-ons, so the simulated optimum may not match the POH perfectly. Treat the handbook value as authoritative for real-world flying and use the exercise to sharpen attitude, trim and speed control. Our Cessna 172 simulator training advice covers the related setup and handling fundamentals.
In a real aircraft, engine-failure practice should follow an instructor-approved procedure; do not shut down the engine merely to test glide performance.