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leading edge, so the stowed panels are nominally flat, albeit twisted a small amount along the leading edge of the wing. Using two sets of identical linkages per flap, the fiberglass panel is deployed and bent to an optimal aerodynamic shape for low speed flight, while a separate aluminum folding nose that is stowed inside the wing is deployed tangent to the fiberglass panel.
102:. Conversely, slats extend forwards from the upper surface of the leading edge. Also, when deployed, Krueger flaps result in a much more pronounced blunt leading edge on the wing, helping to achieve better low-speed handling. This allows smaller-radius wing leading edges, better optimized for cruise. Leading edge Krueger flaps enhance wing's low speed
204:
133:
Invented by James B. Cole and
Richard H. Weiland of Boeing in the mid-1960s, the "VCK" (Variable Camber Krueger) flaps deployed from the lower leading edge of the wing similar to rigid panel Krueger flaps. The high speed lower wing in that region of the wing is a straight line normal to the wing
225:
vertical tail. The left wing was modified to include a 6.7 m-span glove section supporting a variable-camber
Krueger flap to be deployed during landing, protruding just ahead of the leading edge. Although Krueger flaps had been tried before as insect-mitigation screens, previous designs caused
192:
230:(NLF) on an aircraft wing can reduce fuel burn by as much as 15%, but even small contaminants from insect remains could trip the flow from laminar to turbulent, destroying the performance benefit. The test flights were supported by the European airline group
90:(in those cases where there is a gap or slot between the flap trailing edge and wing leading edge), they are deployed differently. Krueger flaps, hinged at their foremost position, hinge forwards from the under surface of the wing, increasing the
184:
using a fixed flap and a skid on the after-body. After the Boeing test flight on the B-707 prototype on 15 July 1954, Krueger flaps were first used in production for the Boeing 727 which made its maiden flight on 9 February 1963.
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58:, the main wing upper surface and its nose is not changed. Instead, a portion of the lower wing is rotated out in front of the main wing leading edge. The
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used
Krueger flaps on the wing leading edge. Several modern aircraft use Krueger flaps between the fuselage and closest engine, but use
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additional drag. The newer design is variable-camber and retracts as seamlessly as possible into the lower wing surface. Increasing
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in 1943 and evaluated in the wind tunnels in Göttingen, Germany. One of the earliest civil applications was the
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with an extreme attitude take-off with the tail dragging on the runway, a scenario that had caused two
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also used a mix of inboard
Krueger flaps and outboard slats, although it had no engine between them.
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wing was redesigned with optimized VCK flap panels that were similar to the original 747.
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material and were designed to be intentionally distorted into a much more efficient
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407:"The Road to the 707" Cook, William H., TYC Publishing Company, Bellevue, 1991,
308:
Aircraft Flight
Instruments and Guidance Systems: Principles, Operations and ...
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as part of the agency’s
Environmentally Responsible Aviation (ERA) program.
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While the aerodynamic effect of
Krueger flaps may be similar to that of
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X-Planes of Europe II, Tony
Buttler Hikoki Puplication 2015. Page 193.
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J. B. Cole (Dec 17, 1966), Design of the
Variable Camber Flap
217:
conducted a series of test flights in 2015 with a modified
180:
accidents. A preliminary flight test had been made on the
172:
fighter which flew in 1955. The flap was added to prevent
42:, are lift enhancement devices that may be fitted to the
221:, incorporating new wing-leading-edge sections and an
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460:"757 EcoDemo Focuses On Laminar And Active Flow"
515:
144:Another airplane that used VCK flaps was the
8:
522:
508:
500:
168:claimed the first use of the flap in its
18:
264:
187:
488:, London: Universal Books Ltd., 1990.
7:
1488:German inventions of the Nazi period
425:Hitchens, Frank (25 November 2015).
365:Niels KluĂźmann; Arnim Malik (2012).
118:The Krueger flaps developed for the
70:outboard of the closest engine. The
14:
275:Ace the Technical Pilot Interview
428:The Encyclopedia of Aerodynamics
202:
190:
23:Krueger flaps deployed from the
305:Wyatt, David (21 August 2014).
1432:In-flight entertainment system
1129:Horizontal situation indicator
462:. Aviation Week. 23 March 2015
156:KrĂĽger flaps were invented by
31:(top left and right in photo).
1:
1412:Environmental control system
278:. McGraw-Hill Professional.
164:, whereas the Swiss company
114:Variable Camber Krueger Flap
371:. Springer. pp. 193–.
234:and conducted jointly with
182:Boeing 367-80 (the Dash 80)
1514:
1089:Course deviation indicator
780:Electro-hydraulic actuator
1320:Conventional landing gear
106:production especially on
1483:Aircraft wing components
1104:Flight management system
272:Gary V. Bristow (2002).
98:. It produces a nose-up
1407:Emergency oxygen system
1169:Turn and slip indicator
964:Leading-edge droop flap
934:Drag-reducing aerospike
909:Adaptive compliant wing
904:Active Aeroelastic Wing
130:section on deployment.
1447:Passenger service unit
1248:Self-sealing fuel tank
1144:Multi-function display
197:Krueger flap operation
122:were constructed from
32:
1427:Ice protection system
1345:Tricycle landing gear
1335:Landing gear extender
552:Aft pressure bulkhead
368:Lexikon Der Luftfahrt
346:U.S. Patent 3,504,870
22:
1473:Aircraft wing design
1392:Auxiliary power unit
800:Flight control modes
337:Taylor 1990, p. 114.
228:natural laminar flow
1371:Escape crew capsule
1278:War emergency power
1149:Pitot–static system
994:Variable-sweep wing
702:Vertical stabilizer
96:coefficient of lift
1079:Attitude indicator
1059:Airspeed indicator
1054:Aircraft periscope
486:The Lore of Flight
484:Taylor, John W.R.
248:Flap (aeronautics)
178:de Havilland Comet
33:
16:Aerodynamic device
1478:Aircraft controls
1460:
1459:
1387:Aircraft lavatory
1124:Heading indicator
1069:Annunciator panel
1049:Air data computer
959:Leading-edge cuff
397:978-1-9021-0948-0
378:978-3-642-22500-0
1505:
1442:Navigation light
1422:Hydraulic system
1397:Bleed air system
1325:Drogue parachute
999:Vortex generator
617:Interplane strut
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253:High-lift device
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1498:1943 in Germany
1493:1943 in science
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1452:Ram air turbine
1417:Flight recorder
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1268:Thrust reversal
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1154:Radar altimeter
1119:Head-up display
1029:
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914:Anti-shock body
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745:Artificial feel
727:Flight controls
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587:Fabric covering
537:
533:components and
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100:pitching moment
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46:of an aircraft
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1359:Escape systems
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1380:Other systems
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1366:Ejection seat
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682:Trailing edge
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662:Stressed skin
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494:0-9509620-1-5
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438:9781785383250
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413:0-9629605-0-0
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317:9781317938316
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285:0-07-139609-8
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158:Werner KrĂĽger
151:
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61:
57:
53:
49:
45:
41:
37:
36:Krueger flaps
30:
26:
21:
1402:Deicing boot
1330:Landing gear
1273:Townend ring
1263:Thrust lever
1238:NACA cowling
1203:Autothrottle
1195:fuel systems
1193:devices and
984:Stall strips
954:Krueger flap
953:
924:Channel wing
870:Wing warping
860:Stick shaker
855:Stick pusher
775:Dual control
760:Centre stick
627:Leading edge
597:Flying wires
557:Cabane strut
485:
464:. Retrieved
454:
442:. Retrieved
427:
420:
403:
387:
367:
360:
351:
342:
333:
321:. Retrieved
307:
300:
289:. Retrieved
274:
267:
213:
155:
146:Boeing YC-14
143:
139:Boeing 747-8
136:
132:
117:
110:aircraft.
94:and maximum
81:
44:leading edge
40:KrĂĽger flaps
39:
35:
34:
25:leading edge
1350:Tundra tire
1233:Intake ramp
1164:Transponder
949:Gurney flap
890:Aerodynamic
805:Fly-by-wire
687:Triple tail
92:wing camber
56:droop flaps
1467:Categories
1340:Oleo strut
1228:Inlet cone
1223:Gascolator
1189:Propulsion
1179:Yaw string
1174:Variometer
1030:instrument
1009:Wing fence
944:Gouge flap
919:Blown flap
875:Yaw damper
850:Stabilator
835:Side-stick
770:Dive brake
657:Stabilizer
632:Lift strut
622:Jury strut
291:2009-02-16
259:References
219:Boeing 757
174:wing stall
162:Boeing 707
124:fiberglass
120:Boeing 747
108:swept wing
72:Boeing 727
64:Boeing 747
60:Boeing 707
29:Boeing 747
1315:Autobrake
1243:NACA duct
1218:Fuel tank
1208:Drop tank
1191:controls,
1074:Astrodome
1064:Altimeter
929:Dog-tooth
894:high-lift
845:Spoileron
830:Servo tab
810:Gust lock
765:Deceleron
750:Autopilot
707:Wing root
692:Twin tail
677:Tailplane
612:Hardpoint
582:Empennage
545:structure
78:Operation
50:. Unlike
1283:Wet wing
1258:Throttle
1004:Vortilon
865:Trim tab
795:Flaperon
785:Elevator
740:Airbrake
712:Wing tip
637:Longeron
607:Fuselage
543:Airframe
531:Aircraft
466:23 March
242:See also
170:FFA P-16
128:aerofoil
1293:Landing
1084:Compass
1032:systems
1024:Avionic
1014:Winglet
897:devices
840:Spoiler
735:Aileron
717:Wingbox
642:Nacelle
592:Fairing
535:systems
479:Sources
444:16 July
415:, p.249
323:16 July
152:History
1028:flight
989:Strake
820:Rudder
790:Elevon
755:Canard
697:V-tail
672:T-tail
602:Former
562:Canopy
492:
435:
411:
395:
375:
314:
282:
232:TUI AG
215:Boeing
1213:FADEC
1099:EICAS
974:Slats
815:HOTAS
667:Strut
88:slots
84:slats
68:slats
52:slats
38:, or
27:of a
1295:and
1159:TCAS
1139:ISIS
1094:EFIS
1039:ACAS
1026:and
979:Slot
939:Flap
892:and
880:Yoke
652:Spar
577:Dope
490:ISBN
468:2015
446:2020
433:ISBN
409:ISBN
393:ISBN
373:ISBN
325:2020
312:ISBN
280:ISBN
236:NASA
137:The
104:lift
62:and
48:wing
1134:INS
1114:GPS
969:LEX
647:Rib
166:FFA
86:or
54:or
1469::
431:.
148:.
523:e
516:t
509:v
496:.
470:.
448:.
381:.
327:.
294:.
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