Flaps are a high-lift device consisting of a hinged panel or panels mounted on the trailing edge of the wing, usually near the root. Their function is to increase lift and drag, reduce stalling speed at a given weight, and thereby let the aircraft take off and land more slowly while being controlled from the cockpit.
Expert behind this article
Jim Goodrich
Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.
What are flaps in aviation?
Flaps are hinged surfaces on the trailing edge of an aircraft's wings used to increase lift and drag. They are a high lift device consisting of a hinged panel or panels mounted on the trailing edge of the wing. Flaps increase the wing's curvature (camber) and increase the wing area, while induced drag is caused by distorted spanwise lift distribution on the wing with flaps extended.
Flaps are hinged surfaces mounted on the trailing edge of each wing. They are high-lift devices that increase camber and, when extended, enlarge wing area. Plain flaps hinge downward, slotted flaps add a slot that delays boundary-layer separation, split flaps drop only the rear lower panel, and Fowler flaps first slide aft to increase chord before hinging downward, so they increase both area and camber.
Flaps are hinged surfaces on the trailing margin of the airfoils. Their basic function is to extend the wing's surface area and alter the airplane's physical structure. This modification produces additional lift at lower airspeeds, so without flaps the approach velocity would be big and the necessary landing strip distance would be larger. By permitting the aircraft to keep a sharp descent viewpoint without gaining excessive speed, the control surface also raises drag, offering a steady way and a larger leeway for error during touchdown.
What do flaps do on a plane?
Flaps allow aircraft to fly at lower speed, increase lift, and increase drag. By altering the shape of the wing, flaps increase lift by increasing camber and, on some types like the Fowler flap, increase wing area. The added lift lowers the required angle-of-attack to balance the four forces of flight, which in turn lowers stall speed and lets the pilot fly slower without losing control. Flying slower reduces landing roll distance and landing distance overall.
The extra drag flaps create also acts as an air brake, helping the aircraft slow down and providing the ability to make a steeper descent. This flexibility lets pilots avoid obstacles during approach. Split flaps, which increase lift but produce even more drag, are best for steep descents. Thus flaps give flexibility: they increase lift to permit safe flight at lower speed while the increased drag coefficient lets the aircraft descend steeply and stop quickly.
Flaps are subsystems that change the shape of the wing. This modification creates extra lift at low speed. By extending the flaps, pilots raise the airfoil's surface region, producing the lift needed for safe takeoffs and landings. The same extension intensifies retarding force, letting the jet advance along the airstrip while staying airborne at reduced velocity.
Where are flaps located on a plane?
Flaps are mounted on wing trailing edges, normally occupying the inboard sections that lie between the fuselage and the ailerons. Main flap panels cluster closer to the wing root, with slotted versions extending outward along the same rearward edge. Some aircraft supplement this arrangement by positioning Krueger flaps on the leading edge.
How do airplane wing flaps work?
Wing flaps work by altering the shape of the airplane wing. They extend rearward and downward, increasing camber and wing area. Fowler flaps slide aft, zap flaps slide rather than roll, and slotted flaps create a narrow slot. High-pressure air from below the wing flows through the slot into the upper surface, energizing the airflow and delaying boundary-layer separation. The energized airflow increases lift and, simultaneously, adds drag.
When do you use flaps on a plane? Wing flaps are a vital part of the takeoff and landing process. During takeoff, partial extension of the flaps produces more lift at lower speed and during landing fuller extension enables a steeper descent angle and reduces stall speed.
With flaps up the wing keeps its clean, low-drag shape suited to cruise. With flaps down the increased camber and extended area give high lift at low speed, but the same extension creates marked drag, allowing slow flight and controlled steep approaches.
I acknowledge the usefulness of flaps aviation. Expanding the flaps raises contour and enlarges the wing's surface region, giving high-lift design. This allows the aircraft to descend at a steady pace.
Jim GoodrichPilot, Airplane Broker and Founder of Tsunami Air
Do airplane flaps go up?
Yes, airplane flaps can go up. After use for take-off or landing, pilots command the flaps to retract upward until they lie flush with the wing. Fowler flaps extend outward and downward for low-speed flight, then pull back inside the structure and rise to the stowed position once cruise begins.
Flaps are kept up in normal cruise because the wing already produces adequate lift at high speed and the pilot wants the least drag. Fowler flaps extend outward, increasing chord length and camber only when extra lift or drag is needed. Once that phase ends, returning them to the up position restores the clean aerodynamic shape and cuts fuel burn.
Flaps do go up, but their main function is to modify the wing's physical structure for landing, not for ascent. When the aircraft is ready for departure, the surfaces are already in the up position. After touchdown, the pilot pulls them back up, returning the wing to a neutral aerodynamic situation.
Where should plane flaps be during take off?
The setting depends on runway length, surface, and ambient conditions. Most light aircraft, including the Cessna 172S, lift off with 0° when the runway is long and firm. The same principle recommends 10° when the strip is short, soft, or hot and high. Partial extension - commonly 10°, occasionally up to 15° - lowers liftoff speed and reduces ground roll while keeping climb performance efficient.
Intermediate positions near 25° appear in aircraft like Cherokees and the Pilatus PC-12 for short or soft-field work, but only when the POH explicitly authorises the setting. Full flaps are not customary for takeoff in everyday operations, yet any flap angle is permissible whenever the handbook calls for it. After takeoff, flaps are retracted gradually as the aircraft gains altitude and airspeed, leaving the wing in a clean, low-drag configuration for the remainder of the climb.
During take-off, flaps are set to a lower surface place that adds lift yet limits retarding force, letting the aircraft go airborne. This choice is determined by circumstances of the airstrip: a flap expansion is needed for a brief airstrip or a high-altitude airfield where the atmosphere is sparse, whereas a lower wing flap setting may be optimal on a lengthy flight strip. The aviator's operating manual gives exact conditions for several scenes.
How do pilots configure flaps when landing a plane?
Pilots configure aircraft with flaps and gear for landing. The pilot ensures that the flaps and landing gear are in the proper configuration, extending flaps in stages on approach: the first notch is added when entering the traffic pattern, then more flaps on base and finally as speed decreases.
For a normal landing, flaps can be set to full whereas in a gusty crosswind, aircraft use partial flaps. Flaps must remain extended until the aircraft is safely on the ground and decelerating. By extending, the surface enlarges and tilts, so drag helps slow the aircraft while the increase in lift coefficient allows the same lift at lower speed, lowering the stalling speed.
I expand flaps incrementally, following the general flap rules advised by the aircraft's operating handbook. Distributing flaps to highest positioning generates greatest drag and shortest stall rate, letting me keep steep inclination at less velocity.
Jim GoodrichPilot, Airplane Broker and Founder of Tsunami Air
How to control flaps on a plane?
Controlling flaps begins with the flap selector. In the cockpit, the flap selector is a handle that looks like a flap. It is usually mounted on the instrument panel and has detents so the pilot can click to specific plane flap settings. Behind the panel, the movement starts with a simple switch: the pilot activates an electric motor, and the motor drives an actuator whose linkage is situated within each wing. A hinged flap and a control rod are attached to that actuator, so when the rod extends the flap pivots downward and increases camber. Modern flight-control computers let the plane fly with flaps controlled automatically. Flaps can then be controlled in autonomous modes based on an airspeed schedule, removing the pilot's hand from the switch during climb or approach. Whether the motion is manual or automatic, the pilot retains separate controls for ailerons and flaps, and must adjust trim to maintain the desired approach speed. Because some pilots prefer less than full flaps for better control authority, they can specify two speeds and two flap settings. Once the runway is assured, the handle is returned to the retracted detent, the actuator rewinds the rod, and the flaps streamline against the wing.
I expand the flaps in phases, step by step adding lift and drag, as stipulated in the aircraft's operating handbook. One must keep in mind parameters like velocity, the wanted pace of fall, and frame load. A gradual rate permits for a stabilized descent route and a good touchdown. The procedure includes a continual evaluation of the state, assuring an even, intentional stimulus that avoids sudden alterations in lift and drag.
Jim GoodrichPilot, Airplane Broker and Founder of Tsunami Air
