Questions tagged [flaps]

Surfaces that extend from the wings to increase lift, allowing flight at slower speeds (such as for takeoff and landing).

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Thoughts on Idea - AP Disengage, Land Flap Selection

When AP disengages the aircraft goes into a slight roll or the possibility exists for the aircraft to go into a degree of roll. Do you think it would be prudent for airlines to include as an SOP for ...
oshsec's user avatar
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Visually see flap settings from passenger window behind wing

I've flown on a lot of Airbus and seen a lot of trip reports on YT and wonder if you can visually see the different flap settings (if you are seated at a window behind the wing), for example Up, Flap ...
DilKent's user avatar
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Why such a small Krueger flap on 777-300?

Why is there such a small Krueger flap just inboard of the engine pylon on the Boeing 777-300, when the rest of the wing (including the further-inboard section of the wing) has leading edge slats? I ...
pr1268's user avatar
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what is the cross section of an elevator and trailing edge flap?

Is the cross section of both a Trailing edge flap and elevator an aerofoil please or, like i've shwon in in image below? I tried to find a side view of an elevator and TE deflected to see this for ...
SirTimothy's user avatar
1 vote
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Is there a known problem with the Airbus A340, fuel, flaps/slats and temperature?

From the press I read that the German minister of foreign affairs stranded with an Airbus A340 in Abu Dhabi, because the flaps or slats would not correctly retract. To return to the airport they had ...
U. Windl's user avatar
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What would the effect be of flap deployment on a UAV such as the Reaper or Predator?

I've read answers that said that the climb performance is usually worse with flaps extended, and the pilots would, if they could, just retract them and get into a clean config as soon as possible. ...
Sharva Potdar's user avatar
3 votes
3 answers
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How come deflected flaps cause a nose-up pitching moment in high-wing aircrafts and a nose-down pitching moment in low-wing aircraft?

I imagine that the increased downwash due to the new camber of a high-wing aircraft causes a down-force on the horizontal stabilizer which in turn causes a nose-up pitching moment. However, I read ...
mino's user avatar
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Role of Spoilers in Conjunction with Flaps A350

Upon observing the Airbus A350, I have noticed that both the outboard and a few of the inboard spoilers are deployed maybe three quarters of an inch when the flaps are fully extended. I assume this is ...
Eddie's user avatar
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How does a trailing edge flap move on an Airbus A320?

Airbus flaps move in flight direction [link] I don't exactly understand how that works, do they move just 180 degrees (opposite direction) of the flight path or is it something else? And doesn't ...
Aviation Enthusiast's user avatar
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Disadvantages of the Fowler trailing edge flap?

I get that the trailing edge plain flap has disadvantages (like tendency to separate flow as I read on a question on here) But what’s so bad with the fowler flap? Aren’t they like really efficient and ...
FlightWatcher's user avatar
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Which one of these flaps is used on take off and land?

I’m really confused about which one of these flaps is used on take off and land? I didn’t even know there were different types, I thought that the top configuration was the only used one today? Also, ...
FlightWatcher's user avatar
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3 answers
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Why are trailing edge flaps used for landing? [duplicate]

Why are flaps used when landing? Doesn’t a flap increase lift? Edited: why are there so many different flaps on the back of a wing? Isn’t one just used when taking off and landing? Are the others ...
FlightWatcher's user avatar
1 vote
3 answers
478 views

Why is a level off required for flap retraction after a single engine failure?

In the Airbus A320, why do we need to level-off for flap-retraction after a single engine failure? Even if we maintain a climb, the airspeed will still accelerate and be enough to retract the flaps ...
Sachin Chaudhary's user avatar
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Trailing edge flap disadvantages

What does ‘high local surface curvature’ mean with respect to trailing edge flaps? I’ve been reading up on them, and that came up as one of their disadvantages?
MikeKnows's user avatar
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Is there any significance to the flap design on some Cessna citations?

In some business jets, I've noticed that the flaps seem to be split into sections. Here is one example on Cessna citation As you can see, the flaps are split into three sections. The Embraer Phenom ...
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What is the additional planform area added to an A380 on take-off flaps setting (Flaps 1+F)

I would like to know how I can approximate the additional area added to wing on flaps 1+F: Can someone use other dimensions they know of the A380 wing and approximate what this area would be, we can ...
vLxgic's user avatar
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How does varying camber affects control over an aeroplane? [duplicate]

How does a trailing edge flap actually help an aeroplane? It just changes camber but what does that exactly do that’s beneficial?
Ranulph's user avatar
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What flaps are used for, if the aircraft has already landed? [duplicate]

When watching the below clip in the final approach sequence we can clearly hear setting flabs to 1, 2 and then to maximum. At 12:05 into the clip, when fully landed ...
trejder's user avatar
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Flaps type for Beech Bonanza V-35B

I'm writing a thesis on airplanes' flaps and I was analizing the flaps on the Beech Bonanza V-35B: on the book "The wind and beyond - Volume II" published by NASA on page 375 states that ...
Lollo's user avatar
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What happens to aerofoil downwash with Flaps extended vs retracted and how does it affect the Tail down force?

In my logic: Flaps extended will cause a greater Angle of Attack, to maintain Straight and Level Flight, AoA will be reduced, due to the increased "Surface", this allows to fly at lower ...
Ted Staggs's user avatar
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How long does it take to complete a partial and full flap overspeed inspection?

I am trying to determine the cost of a flap overspeed inspection. Ignoring the cost of any parts. On average, how long does a flap overspeed inspection take? Or how long would a partial/full flap ...
Pilot Collins's user avatar
1 vote
3 answers
210 views

Can the flap on one wing be used to reduce a left turning tendency?

I fly a single engine Jabiru UL45 and it has a tendency to turn left during straight and level flight. Is it possible, in order to reduce a "Heavy Wing" to slightly increase the degree of ...
Kev's user avatar
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Is a plane stalled during landing rollout?

IMAGE SOURCE: https://pilotinstitute.com/wp-content/uploads/2022/01/Parts-of-a-Wing.jpg As the lift dumpers are extended on landing they cause the air to move away from the wing. Also as the flaps are ...
Aviation Enthusiast's user avatar
5 votes
4 answers
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Why is flap retraction done in stages?

After takeoff and upon achieving positive climb, why is flap retraction done in stages? For example, in the Airbus there are characteristic speeds after which flaps can be retracted (S and F speeds) ...
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10 votes
1 answer
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Can flaps on Airbus/Boeing airliners be deployed at high speeds during cruise, still?

Brief Background of the Incident Mayday Season 22 Features an Episode "Terror over Michigan" (Episode 6) based on the events of TWA Flight 841. The Episode revolves around a Boeing 727 ...
Atheesh Thirumalairajan's user avatar
1 vote
1 answer
192 views

How do GA aircraft flaps stay in place?

On most small GA aircraft such as the well-known Cessna 172P "Skyhawk", the flaps are electrically actuated. Now - how do they stay at the setting selected by the pilot after extension ? Is ...
TheEagle's user avatar
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1 vote
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Is it possible to reduce the angle of fully extended flaps of an aircraft without affecting lift generated?

I think flaps are inspired from eagle feathers which increase the overall wing surface area and help provide the necessary lift at lower speeds. However, fully extended flaps hang lower and cause more ...
lousycoder's user avatar
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2 answers
135 views

Reasoning for an inboard flap- take off [duplicate]

so Ive been looking into airplane flaps, like the longer one for take off- Is it correct to say that the only reason to have one is for take off, to make it take off easier? And so when they take off, ...
Jonathan Ching's user avatar
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Elevator or Aileron?

I was just looking at an airplane take off, and when it was taking off, some flaps were facing down at the back of the main wings- Are these Ailerons or elevators please? I did some research but the ...
Jonathan Ching's user avatar
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1 answer
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How can I calculate 'Max aircraft Load Factor' and 'Max aircraft Speed' when flaps are fully extended on a civil aircraft? [closed]

I am trying to calculate the critical loading conditions for Flaps (in order use them inside my Finite Element Analysis to, determine if the Flaps will be able to bear these critical loads) during the ...
Rameez Ul Haq's user avatar
3 votes
1 answer
234 views

Does use of flaps or ailerons affect the aerodynamic forces distribution on the wing area before them?

Assume I want to use the flaps or ailerons at a specific altitude for some maneuevers on an aircraft. We know that the overall aerodynamic forces like lift and drag on an aircraft wing will change ...
Rameez Ul Haq's user avatar
15 votes
6 answers
7k views

Why aren't takeoff flaps used all the way up to cruise altitude?

In general aviation aircraft such as Diamond star DA-40, flaps to take-off are used until 500ft AGL and speed before retracting flaps is Vy (best ROC speed)-67kts and after retracting flaps is 80kts. ...
Krishna Kanth's user avatar
4 votes
1 answer
615 views

Is all the extra lift from flaps added upstream where the spars sit?

Flaps can significantly increase the lift for a wing, is all that extra lift added upstream where the spars sit? I ask this question because the flaps in airliners seem to be only connected by a few ...
Mridul's user avatar
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2 votes
1 answer
502 views

Does the A220-300 have krueger flaps or are all of its leading-edge highlift devices slats?

They look like slats to me, but I could be wrong. I'm asking because I know the 737, a very similar airplane, has inboard krueger flaps. Also, what number of slats/krueger flaps does it have?
stevederekson555's user avatar
2 votes
1 answer
2k views

What trailing edge flap design does the A350 use? Is it similar to the A380?

Both Airbuses have similar flap deployment based on some YouTube videos I have watched, just wondering if they both have the same flap design being "Single-Slotted Fowler Flaps".
Isaac's user avatar
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3 votes
1 answer
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How many Krueger flaps does the 737-700 have?

How many Krueger flaps does the 737-700 have? It has inboard krueger flaps, but I'm trying to make out if it has one or two.
stevederekson555's user avatar
7 votes
2 answers
3k views

What flap design does the A380 use? Is it Fowler flaps, slotted flaps or a combination?

I have looked at maintenance manuals, the Airbus website, and Wikipedia but still could not find a definite answer as to what trailing edge flaps the Airbus A380 uses.
Isaac's user avatar
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What are the approach speeds for each flap setting in a Cessna 152?

I am still trying to understand how the approach speeds for different flap speeds work. I cant find it in the handbook but I want to know the different approach speeds for the following flap settings: ...
C.D.Smith's user avatar
2 votes
0 answers
500 views

How can I design a slotted flap?

I have not been able to find satisfactory methods on design of slotted flaps, or flaps in general. Most of the answers are about eyeballing or experience. Can you guide me on what could be good ...
Mridul's user avatar
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2 votes
1 answer
333 views

Why does the Information Manual say "C172S - Flaps 10 (Preferred) for Normal Takeoff", when the models before S-model do not have this note?

Do Flaps 10 really do anything performance-wise other than reducing ground roll and distance over a 50-foot obstacle? If not worried about clearing an obstacle, does a Flaps UP-normal takeoff make ...
Jacob Doore's user avatar
2 votes
1 answer
218 views

Who manufactured the 737 MAX flap track fairings?

I can't seem to find the information online, would anyone of you know where / by who the flap track fairing for the B737 MAX is produced?
Max's user avatar
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Is pitch-flap coupling an aerodynamic effect or an intrinsic property of a delta 3 offset?

I am modelling a propeller, in particularly the equations of motion of the various pitch/lag/flap angles as the propeller is turning around. The blade includes a $\delta_3$ angle, which provides pitch-...
Thomas Wagenaar's user avatar
9 votes
6 answers
2k views

Can flaps be used to perform rotation and flare?

TL; DR using flaps to directly control sink/climb rate near ground = simpler and faster response = easy to fly airplane? Rotating is the pitch up during takeoff that causes the aircraft to leave the ...
Abdullah is not an Amalekite's user avatar
2 votes
2 answers
644 views

Is there a cockpit indication if the B737 flap load relief is not working properly?

On a 737, does the pilot get any cockpit indication that his Flap Load Relief is not working properly? Say for instance due to a Flap Lever Position Switch failure?
Aaron Thompson's user avatar
0 votes
1 answer
3k views

Why does it feel like a plane stops in mid-air during approach?

At some stage while on approach to an airport in a commercial jet, it feels like the plane is almost coming to a complete stop in mid-air. Is this maybe as a result of the flaps engaging or the ...
shaz737's user avatar
7 votes
1 answer
1k views

Is it safe to fly if the flaps won't retract on ground?

The Piper Archer (PA-28) i had this morning had issues returning flaps to normal after being fully extended ON THE GROUND. It required a non trivial amount of push on the air-frame itself to restore ...
Jake's user avatar
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1 answer
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Is flap-asymmetry protection on airliners still active even on the ground?

On aircraft with flaps, a general certification requirement is that it must not be possible for the aircraft to suffer a loss of lateral control secondary to an asymmetric-flap condition. This ...
Vikki's user avatar
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3 votes
1 answer
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Are overwing exits still useable if the flaps can’t be lowered?

Essentially all narrowbody airliners (except for the very smallest propliners), and many widebodies as well,1 are equipped with one or more overwing exits for use in an emergency evacuation; these ...
Vikki's user avatar
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18 votes
1 answer
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Why is the DC-9-80 ("MD-80") prohibited from taking off with a flap setting between 13 and 15 degrees?

A bit of digging into the 7Z9363 accident investigation has brought up some interesting information regarding the DC-9-80 ("MD-80")'s flap system: Flaps may be positioned in any of the six ...
Vikki's user avatar
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6 votes
1 answer
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Why is there an altitude limitation on operating the slats/flaps on the A320?

As per the FCOM limitations chapter there is an altitude limitation of 20000 feet for operating the flaps/slats on the A320? Why this specific altitude?
Jai's user avatar
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