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45 votes
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Why didn't the Concorde have flaps or slats?

Why no flaps? Flaps change the pitching moment of a wing. After all, they add lift over the full chord, so the sum of the increased lift attacks at about mid-chord, which is a quarter chord aft of the ...
Peter Kämpf's user avatar
19 votes
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When does a 'flaps/slats misconfiguration' warning sound during takeoff roll?

For the Boeing 727-100 and 747-100/200 the answers are: when does the system know when to sound the alarm? When the thrust levers are advanced to begin the takeoff, if flaps and slats and a few ...
Terry's user avatar
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13 votes
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How do slats reduce stall speed?

It's because leading edge devices allow a higher Angle of Attack. The four types of leading edge devices work by pointing the nose of the wing downwards so that at higher AoA there is no flow ...
Koyovis's user avatar
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13 votes
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What is this tiny slat for?

The item 1 is a Krüger flap, a leading edge device which allows the wing to operate to a higher angle of attack. The wing-root fairing makes a small triangular segment necessary; outboard of it slats ...
Peter Kämpf's user avatar
12 votes
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Why are Krueger flaps called flaps and not slats?

A flap increases airfoil camber, and can be on the leading edge or trailing edge. The Krueger Flap is a Leading Edge Flap, the actual generic term. The Krueger dude developed the LE flap used on ...
John K's user avatar
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10 votes
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Why are the outboard Krueger Flaps retracted before the others on the B747?

This is from memory and applies to 747-100/200 aircraft, which I last flew in 1999. The video shows, I think, a -400. However, to the best of my knowledge, it has the same flap settings. The flap ...
Terry's user avatar
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8 votes

When does a 'flaps/slats misconfiguration' warning sound during takeoff roll?

On most aircraft I have flown, the Takeoff Config warning sounds when the thrust levers are advanced for takeoff power.
Mike Sowsun's user avatar
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8 votes
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Does the Piper Aztec have flaps and slats and if so what kind?

The Piper Aztec has standard (plain) flaps: Source: Sky4Buy.com Another View: Source: Same as above The Aztec does not have slats as can be seen in the image from the front of the wing: Source: ...
Ron Beyer's user avatar
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7 votes

Why such a small Krueger flap on 777-300?

Due to wing sweep the engine nacelle blocks airflow that would feed a slot in that location, so the Kreuger flap is used instead. Outboard the pylon there is no such problem. ref
Pilothead's user avatar
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6 votes
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What exactly are the "sealed" leading-edge slats in B737 short field performance aircraft?

A "sealed" slat has no slot between it and the main wing. According to b737.org.uk, sealing flaps allows for more lift at a lower AOA (Angle of Attack). Reference from Flightglobal.com "Short Field ...
Robert DiGiovanni's user avatar
6 votes
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Materials for temporary dent repair?

What usually happens is the crew doing the walkaround spots something that looks like damage, calls airline maintenance, and techs come look at it. For a ding, they will consult the Structural Repair ...
John K's user avatar
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6 votes

Why are Krueger flaps called flaps and not slats?

For a leading edge high-lift device to be called a slat, it has to have a slot behind it. Otherwise, it is a leading edge flap (or, if it's of a specific design, a Krueger flap). Because: By ...
Jpe61's user avatar
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6 votes

How do slats reduce stall speed?

The two main leading edge devices are leading edge slots and leading edge flaps: Slots energize the boundary layer to delay stall by allowing higher pressure air from below to "leak" in a controlled ...
John K's user avatar
  • 132k
5 votes

What effect do slats have on descent rate?

If the slats would increase L/D, they would not be retracted in cruise. TomMcW is right, any high lift device increases drag when compared to a polar point that is within the regular operating ...
Peter Kämpf's user avatar
5 votes

How do slats reduce stall speed?

Slats increase the camber of the wing, which increases the coefficient of lift. When you deploy slats, the AOA is actually lowered for that part of the wing. This is the same washout principle Dunne ...
Robert DiGiovanni's user avatar
4 votes

Meaning of XX below Slat FLap Trim on A350 with flap setting 1

The number below the flap indication is not the position of the flaps/slats, but the position of the flap lever. When the lever is moved, the number becomes cyan indicating that the flaps/slats are in ...
busdriver's user avatar
  • 3,340
4 votes

Why didn't the Concorde have flaps or slats?

Because with a delta wing the trailing edge has the elevators and it's too far aft to have a flap. They depend on wing area and the ability to operate at much higher AOAs than straight wings to get ...
John K's user avatar
  • 132k
4 votes

What suits best for lateral controllability at high Angle of Attacks- a vortex generator or wing slots?

Vortex generators can be used at the leading edge to energize flow and delay separation. They are widely used as an add-on device to improve low speed behaviour of a range of light aircraft, and in ...
John K's user avatar
  • 132k
4 votes
Accepted

How do slats actually work?

A slat is a retractable version of a device known as “leading edge slot”. It is basically a slot just behind the leading edge. When an airplane is flying slow, it will probably either be somewhat ...
Abdullah is not an Amalekite's user avatar
3 votes
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Does the A220-300 have krueger flaps or are all of its leading-edge highlift devices slats?

All are slats. Here is one taking off. and a better view of one in the air. It looks like there are as many as four sections but they all extend and retract together.
Pilothead's user avatar
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3 votes
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Would adding a slat and a slotted flap increase the max CL of a multi element airfoil to 6.5?

The theoretical maximum lift of a cylinder is 4π. At that point the forward and rear stagnation points coalesce on the bottom of the cylinder. Practical solutions use rotating cylinders (Flettner ...
Peter Kämpf's user avatar
3 votes

What is this tiny slat for?

1) Appears to be where the inboard leading edge slats retract into. 2) Ram air inlet for the air conditioning/equipment cooling.
Konrad Smit's user avatar
3 votes
Accepted

What would be the effect of skinning over the gap in fixed leading-edge slats?

To answer your question, I suggest to look at the effect of slats. NACA technical report 407 studied a fixed slat similar to what is used on the Zenith CH-750, and the result of the optimum geometry ...
Peter Kämpf's user avatar
2 votes

Difference between multi slats and three slats on B737 ? (leading edge devices)

Prior to the NG, the total number of slats is 6, that is 3 slats per wing Thus there are 6 slats numbered from 1 to 6, that is slats 1 and 6 are the outer slat The NG's have an extra outboard slat ...
user40476's user avatar
  • 1,797
2 votes

Why are the outboard Krueger Flaps retracted before the others on the B747?

Flaps, Krueger flaps, and slats are all ways of modifying the wing's airfoil to effectively increase its camber. Stalling happens when the air-flow separates. That is, rather than continuing to flow ...
Jerry Coffin's user avatar
  • 3,177
2 votes

How to calculate the lift coefficient of a multi element airfoil?

It depends. Are the c$_l$ values referenced to the local chord? Then you need to convert them to the chord of the full airfoil so they can be added. I wonder, however, how you can have individual ...
Peter Kämpf's user avatar
2 votes

What high-lift devices are used on the Bombardier Dash 8 Q400?

The Dash8 - Q400 - Aeroplane General PDF (courtesy of smartcockpit.com) indicates on page 27 that there are inboard and outboard flaps. Reading through the Dash8 - Q400 Flight Controls PDF (also from ...
FreeMan's user avatar
  • 16.4k
2 votes

Why is there an altitude limitation on operating the slats/flaps on the A320?

Why would you want to deploy high lift devices at any juncture except for departure and arrival? Holding is the predominant scenario. Above 20,000ft ICAO holding speeds are higher thus allowing clean ...
skipper44's user avatar
  • 1,615
2 votes

Why do fixed slats have a cusp?

Fixed slats are called slots. They are not in the position shown in your picture, as this produces high drag at low angles of attack. Slots are normally aligned with the wing so that drag is lower in ...
Pilothead's user avatar
  • 20.7k

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