Choose the correct landing flap setting using aircraft procedures, runway performance, wind, weight, icing limits and approach speed.
Choose the landing flap setting specified by the aircraft’s POH/AFM or operator procedure, then confirm it meets runway, wind, weight and system constraints. Use the normal landing setting unless performance data or an approved procedure calls for another; recalculate approach speed and landing distance whenever the configuration changes.
In Aviation & Real-World Flying, the controlling sources are the Aircraft Flight Manual, Pilot’s Operating Handbook, approved performance data and, where applicable, the operator’s procedures. Flap angles and lever labels are not transferable between aircraft. Our guide to basic flap aerodynamics and operating trade-offs explains why each configuration changes lift, drag, stall speed and handling differently.
How should you choose a landing flap setting?
Start with the aircraft’s normal landing configuration and depart from it only for a documented operational or performance reason.
- Identify the approved configurations. Check limitations, normal procedures and landing-performance tables. An airline procedure may permit several landing settings while a light-aircraft handbook may specify one normal setting plus exceptions.
- Use the normal setting as the baseline. This gives the expected handling, sight picture, approach speed and go-around procedure. “Full flap” is not automatically the normal setting on every aircraft.
- Check landing distance available. Use the declared landing distance rather than total pavement length. Account for aircraft weight, wind, runway slope and surface condition, pressure altitude and temperature wherever the approved data require them.
- Apply condition-specific guidance. Crosswind, turbulence, icing, contamination or a system fault may call for another configuration, but only when the handbook, checklist or operator procedure supports it.
- Match the speed to the configuration. Calculate or select the correct VREF or final-approach speed for the actual weight and flap position, including only the prescribed wind correction.
- Brief and stabilise. Select the planned flap setting below its applicable extension-speed limit and early enough to establish a stable approach. If the configuration changes, rerun the speed and distance checks.
| Configuration | Typical use | Main trade-off |
|---|---|---|
| Normal landing flap | Routine landing within published limits | Predictable handling and standard speeds |
| Maximum approved flap | Often used when low touchdown speed or short-field performance is needed | More drag and a more demanding configuration change during a go-around |
| Reduced flap | Only when permitted for wind, performance or operational reasons | Higher approach speed and usually more landing distance |
| Limited-flap or no-flap | Abnormal procedure after a fault or restriction | Substantially higher speed, distance and workload |
Is full flap always best for landing?
No. Maximum approved flap commonly produces the lowest approach and touchdown speed, greater drag and less float, so it often gives the best short-field result. It can also create larger pitch and trim changes, make a go-around more demanding and be unsuitable under a particular limitation or abnormal procedure.
Aircraft-specific data settle the question. The Cessna 152 short-field example shows why runway performance can favour full flap, while the Boeing 737 Flaps 30/40 performance choice illustrates how transport-aircraft crews balance VREF, runway distance, drag and operating procedure.
Do not assume that more flap always means a shorter ground roll. The published landing figure includes the complete configuration, speed and test assumptions. Braking action, touchdown accuracy, spoilers, reverse thrust where applicable and excess approach speed can matter more than one extra flap increment.
What flap setting should you use in a crosswind?
Use the normal landing flap unless the aircraft handbook or operator procedure recommends or permits a reduced setting for the crosswind conditions.
Less flap may give a firmer control response or reduce some aircraft-specific handling concerns, but it also raises approach and touchdown speed. That increases kinetic energy and normally requires more runway. A gust correction changes the target speed according to the approved method; gusts alone do not automatically require less flap.
Maximum demonstrated crosswind is not necessarily a legal limitation unless the aircraft documentation identifies it as one. It is also not a flap-selection table. If the wind exceeds the crew’s capability, company limit or available performance margin, changing flap cannot make the landing acceptable.
How do flap setting and approach speed work together?
Every approved landing configuration must be paired with its corresponding approach speed at the aircraft’s actual weight.
There is no safe generic rule such as adding a fixed number of knots for every flap notch. Use the POH table, performance tool, flight-management calculation or operator data appropriate to that aircraft. The Cessna 172 speed guidance by landing configuration provides a practical light-aircraft example.
A common failure in both real-world training and simulation is selecting reduced flap but retaining the full-flap speed. The aircraft then approaches too close to the stall for its actual configuration. The opposite mismatch produces excess speed, float and a longer landing.
When should landing flaps be extended?
Extend each flap stage below the published speed limit for that position and early enough to be fully configured by the applicable stable-approach gate.
Some aircraft have different limits for initial and later flap positions, so a single VFE figure may not cover every selection. Avoid a large, late flap change close to the ground: it alters drag, lift, pitch and trim just when the approach should be settled. If the result is unstable, go around rather than trying to repair it during the flare.
What if the flaps do not deploy normally?
A flap disagreement, asymmetry or jam turns flap selection into an abnormal procedure, not a choice between ordinary landing settings.
Stop making uncommanded or repeated selections, maintain control and follow the aircraft’s checklist. The required landing speed and distance may rise sharply, and a longer runway or diversion may be necessary. During a go-around, retract flap only in the published sequence; dumping all flap at once can cause a serious loss of lift.
Which flap-selection mistakes cause the most trouble?
Most flap-related landing problems come from using the right-looking setting without checking whether it suits the aircraft, speed and conditions.
- Copying a flap angle or lever position from another aircraft type.
- Assuming full flap is mandatory simply because the runway appears short.
- Choosing reduced flap for a crosswind without checking the extra landing distance.
- Exceeding the extension-speed limit, especially where later flap stages have lower limits.
- Trusting the lever position without confirming the actual flap indication.
- Changing configuration late but retaining the original VREF or target speed.
- Adding an arbitrary speed margin, which increases float and runway use.
In a flight simulator, use the model’s checklist and performance documentation because add-ons vary in how accurately they reproduce flap drag, failures and landing-distance calculations. The same decision rule still applies: approved normal setting first, aircraft-specific exception second, then a matching speed and performance check.