OPNLguy From , joined Dec 1969, posts, RR:
Reply 2, posted (10 years 4 months 3 days 15 hours ago) and read 32767 times:
Quoting FredT (Reply 1): The terminology is somewhat confused. My definition is that slats (and slots) are leading edge devices while flaps are trailing edge devices.
It gets more confusing because Boeing uses leading edge Krueger flaps. MEL deferrals on L/E indication systems can get challenging sometimes because of the phonetic similarity between flaps (not deferrable) and slats (deferrable, with exceptions), and one has to annunciate very clearly.
Starlionblue From Greenland, joined Feb 2004, 17351 posts, RR: 67
Reply 3, posted (10 years 4 months 3 days 15 hours ago) and read 32767 times:
Slats are usually mounted on the leading edge. Slats extend the edge and sit like a glove on the edge.
Flaps are usually mounted on the trailing edge but can be mounted on the leading edge. They extend the edge but are not mounted like a glove. They either pivot only (simple and split flaps), extend and come down (complex and slotted flaps) or extend and camber (Krueger flaps). There are other types as well.
"There are no stupid questions, but there are a lot of inquisitive idiots."
Avioniker From United States of America, joined Dec 2001, 1109 posts, RR: 11
Reply 9, posted (7 years 2 weeks 1 day 20 hours ago) and read 32767 times:
Very simply put (and there are exceptions) Flaps are an extension of the wing and may or may not affect the aerodynamic chord length and angle.
Slats are more akin to an additional wing, forward of the wing, and act more to add lift than drag. Of course many aircraft have slats with more than one selectable position that may or may not be sealed to the wing in partial extension. So they act as flaps or slats depending on position.
Both flaps and slats act to lower the stall speed of the aircraft and provide enhanced low speed maneuverability.
I personally like the "slotted flap" explanation/definition. It makes sense and is easy to visualize.
One may educate the ignorance from the unknowing but stupid is forever. Boswell; ca: 1533
WPIAeroGuy From United States of America, joined Aug 2007, 269 posts, RR: 0
Reply 11, posted (7 years 2 weeks 1 day 15 hours ago) and read 32767 times:
Flaps, slats, kreuger flaps, etc. all work by increasing the camber of the wing, which allows for a higher AoA and increased drag. Some flaps also increase the chord.
Slats have a gap between the slat and the LE, airflow through the slot is redirected over the top surface of the wing, increasing airflow over the wing which increases lift. Slotted flaps work on the same princicple, the slots in the flaps allows for the airflow to remain stay attached through higher angles of attack, ergo creating more lift.
I know the Bf-109 and F-86 had leading edge devices that responded automatically to prevent loss of lift in high AoA situations. I believe the F-22 has similar devices though I may be very wrong.
Wingscrubber From UK - England, joined Sep 2001, 858 posts, RR: 0
Reply 12, posted (7 years 2 weeks 1 day 14 hours ago) and read 32767 times:
JAM747, Flaps are trailing edge lift aids/drag inducers, slats are leading edge lift aids/drag inducers. Flaps are on most anything that flies with some exceptions, but slats are generally only prevalent on bigger aircraft, but there's exceptions to that too.
This is my favourite wing design ever - achieves fantastic STOL. Big fat camber with fixed slat and flaperon. Brilliant.
Pihero From France, joined Jan 2005, 4943 posts, RR: 78
Reply 17, posted (7 years 1 week 5 days 7 hours ago) and read 32767 times:
Quoting Wingscrubber (Reply 12): This is my favourite wing design ever - achieves fantastic STOL. Big fat camber with fixed slat and flaperon. Brilliant.
....and really nothing new since the Fieseler Storch .
From Wiki : " Penned by chief designer Reinhold Mews and technical director Erich Bachen, Fieseler's entry was the most advanced in terms of STOL performance, by far. A fixed slat ran along the entire leading edge of the long wings, while the trailing edge, inspired by earlier 1930s Junkers aircraft wing control surface designs, including the ailerons, was a hinged and slotted flap. The wings could be folded back along the fuselage, allowing it to be carried on a trailer or even towed slowly behind a vehicle. "... "The first Fi 156 V1 prototype flew in the spring of 1936. It was powered by a 180 kW (240 hp) inverted-vee Argus As 10C V8 engine, which gave the plane a top speed of only 175 km/h (109 mph), enabling the Storch to fly as slow as 50 km/h (32 mph), take off into a light wind in less than 45 m (150 ft), and land in 18 m (60 ft). "
My recollection is that the droop leading edge on the Trident 1 increased the lift by 40pc. When the pilot retracted the droops the plane stopped flying.
The original Trident design had two levers, a droop lever and a flap lever. After this accident they were interconnected with a baulk system, and from that day (1968) all aircraft had a single lever.
Later Tridents had slats instead.