25:
274:
324:
213:
wings. In most cases they did not include any means for a pilot to control the aircraft roll—they could control only the elevator and rudder. The unpredicted effect of this was that it was very hard to turn the aircraft without rolling. They were also strongly affected by side gusts and side winds
173:
Early attempts at heavier-than-air flight were marked by a differing concept of stability from that used today. Most aeronautical investigators regarded flight as if it were not so different from surface locomotion, except the surface was elevated. They thought of changing direction in terms of a
342:
A less stable aircraft requires smaller control deflections to initiate maneuvering; consequently, drag and control surface imposed stresses will be reduced and aircraft responsiveness will be enhanced. Since these characteristics will typically make control by the pilot difficult or impossible,
233:" or "lean" into the turn just like a bird or just like a person riding a bicycle. Equally important, this method would enable recovery when the wind tilted the machine to one side. Although used in 1903, it would not become widely known in Europe until August 1908, when
164:
is an example of a stable aircraft. Similarly, an aircraft with neutral stability will not return to its original attitude without control input, but will continue to roll or pitch at a steady (neither increasing nor decreasing) rate.
315:) was introduced to compensate for the MD-11's rather short horizontal stabilizer and ensure that the aircraft would remain stable. However, there have been incidents in which the MD-11's relaxed stability caused an "inflight upset".
178:, so the flying machine would remain essentially level in the air, as did an automobile or a ship at the surface. The idea of deliberately leaning, or rolling, to one side either seemed undesirable or did not enter their thinking.
151:
This can be contrasted with the behaviour of an aircraft with positive stability, which can be trimmed to fly at a certain attitude, which it will continue to maintain in the absence of control input, and, if perturbed, will
339:. Greater stability leads to lesser control surface authority; therefore, a less stable design will have a faster response to control inputs. This is highly sought after in fighter aircraft design.
229:(drooping) wings, which are inherently unstable. They showed that a pilot can maintain control of lateral roll and it was a good way for a flying machine to turn—to "
300:
and enable it to penetrate air defenses with relative impunity. However, the flat facets of the design reduce its stability to the point where a computerized
197:, sought the ideal of "inherent stability" in a very strong sense, believing a flying machine should be built to automatically roll to a horizontal (
387:"Simulator study of stall/post-stall characteristics of a fighter airplane with relaxed longitudinal static stability. NASA Technical Paper 1538"
160:
on a decreasing scale around, and eventually return to, the trimmed attitude. A positively stable aircraft will also resist any bank movement. A
148:, and will, when disturbed in pitch or roll, continue to pitch or roll in the direction of the disturbance at an ever-increasing rate.
89:
311:
has a neutral stability design which was implemented to save fuel. To ensure stability for safe flight, an LSAS (Longitudinal
61:
663:
644:
561:
522:
486:
145:
253:
An aircraft with a "high" wing position (i.e., set on top of the fuselage) has a higher roll stability. For example, the
68:
42:
578:"The Effect of High Altitude and Center of Gravity on The Handling Characteristics of Swept-wing Commercial Airplanes"
198:
108:
75:
577:
46:
57:
312:
385:
Nguyen, L. T.; Ogburn, M. E.; Gilbert, W. P.; Kibler, K. S.; Brown, P. W.; Deal, P. L. (1 December 1979).
296:
Nighthawk, for instance, employs a highly non-traditional fuselage and wing shape in order to reduce its
356:
278:
343:
artificial stability will typically be imposed using computers, servos, and sensors as parts of a
226:
361:
308:
182:
137:
35:
202:
157:
82:
682:
476:
336:
328:
260:
An aircraft with a "low" wing (i.e., underneath the fuselage) has less roll stability. The
8:
553:
Airplane stability and control: a history of the technologies that made aviation possible
514:
414:"Landing approach handling qualities of transport aircraft with relaxed static stability"
297:
210:
634:
261:
238:
130:
659:
640:
557:
518:
482:
433:
222:
608:
425:
335:
Many modern fighter aircraft often employ design elements that reduce stability to
286:
551:
507:
290:
218:
194:
141:
249:
The vertical positioning of the wing changes the roll stability of an aircraft.
413:
186:
386:
676:
437:
234:
190:
344:
301:
230:
509:
Eccentric France: the Bradt guide to mad, magical and marvellous France
254:
161:
136:
An aircraft with negative stability will have a tendency to change its
289:") designs, often exhibit instability as a result of their shape. The
201:) position after any disturbance. They achieved this with the help of
656:
To
Conquer The Air: The Wright Brothers and the Great Race for Flight
366:
153:
429:
140:
angles spontaneously. An aircraft with negative stability cannot be
24:
556:(2 ed.). Cambridge : Cambridge Univ. Press. pp. 335–337.
273:
206:
122:
323:
241:
of elevator, rudder and roll control for making effective turns.
307:
Relaxed stability designs are not limited to military jets. The
175:
513:. Chalfont St. Peter, England: Bradt Travel Guides. pp.
293:
384:
451:
285:
Modern military aircraft, particularly low observable ("
237:
demonstrated to
European aviators the importance of the
209:
structure, including the vertical panels) and strongly
636:
The Bishop's Boys: A Life of Wilbur and
Orville Wright
481:. Mineola, NY: Dover Publications. pp. 39–53.
49:. Unsourced material may be challenged and removed.
531:
506:
412:Wilhelm, Knut; Schafranek, Dieter (October 1986).
411:
674:
626:
549:
181:Some of these early investigators, including
550:Abzug, Malcolm; Larrabee, E. Eugene (2002).
318:
478:Contact!: the story of the early aviators
244:
109:Learn how and when to remove this message
322:
272:
606:
504:
474:
16:Aircraft with low or negative stability
675:
632:
457:
405:
653:
570:
537:
378:
331:is an intentionally unstable design.
268:
47:adding citations to reliable sources
18:
500:
498:
470:
468:
466:
281:is not an inherently stable design.
13:
658:. New York: Simon & Schuster.
543:
376:
304:system is required for it to fly.
14:
694:
168:
639:. New York: WW Norton & Co.
607:Pasztor, Andy (March 24, 2009).
495:
463:
23:
475:Villard, Henry Serrano (2002).
34:needs additional citations for
609:"FedEx Jet Has Control Issues"
600:
125:, an aircraft is said to have
1:
313:Stability Augmentation System
627:General and cited references
372:
7:
391:NASA Technical Publications
350:
10:
699:
357:Index of aviation articles
129:if it has low or negative
337:increase maneuverability
279:Lockheed F-117 Nighthawk
223:1903 first powered Flyer
505:Letcher, Piers (2003).
362:Dual control (aviation)
319:Intentional instability
309:McDonnell Douglas MD-11
203:Hargrave cellular wings
633:Crouch, Tom D (2003).
393:(19800005879). NASA: 1
332:
282:
245:Vertical wing position
158:simple harmonic motion
144:to maintain a certain
654:Tobin, James (2004).
326:
276:
329:F-16 Fighting Falcon
43:improve this article
460:, pp. 167–168.
418:Journal of Aircraft
298:radar cross section
58:"Relaxed stability"
333:
283:
264:uses a "low" wing.
665:978-0-7432-5536-3
646:978-0-393-30695-8
563:978-0-521-80992-4
524:978-1-84162-068-8
488:978-0-486-42327-2
269:Unstable aircraft
127:relaxed stability
119:
118:
111:
93:
690:
669:
650:
621:
620:
618:
616:
604:
598:
597:
595:
593:
574:
568:
567:
547:
541:
535:
529:
528:
512:
502:
493:
492:
472:
461:
455:
449:
448:
446:
444:
409:
403:
402:
400:
398:
382:
347:control system.
114:
107:
103:
100:
94:
92:
51:
27:
19:
698:
697:
693:
692:
691:
689:
688:
687:
673:
672:
666:
647:
629:
624:
614:
612:
605:
601:
591:
589:
576:
575:
571:
564:
548:
544:
536:
532:
525:
503:
496:
489:
473:
464:
456:
452:
442:
440:
430:10.2514/3.45377
424:(10): 756–762.
410:
406:
396:
394:
383:
379:
375:
353:
321:
271:
247:
239:coordinated use
221:designed their
219:Wright brothers
195:Voisin brothers
171:
115:
104:
98:
95:
52:
50:
40:
28:
17:
12:
11:
5:
696:
686:
685:
671:
670:
664:
651:
645:
628:
625:
623:
622:
599:
569:
562:
542:
530:
523:
494:
487:
462:
450:
404:
374:
371:
370:
369:
364:
359:
352:
349:
320:
317:
270:
267:
266:
265:
258:
246:
243:
214:upon landing.
205:(wings with a
170:
169:Early aircraft
167:
138:pitch and bank
117:
116:
31:
29:
22:
15:
9:
6:
4:
3:
2:
695:
684:
681:
680:
678:
667:
661:
657:
652:
648:
642:
638:
637:
631:
630:
610:
603:
587:
583:
582:Aero Magazine
579:
573:
565:
559:
555:
554:
546:
540:, p. 70.
539:
534:
526:
520:
516:
511:
510:
501:
499:
490:
484:
480:
479:
471:
469:
467:
459:
454:
439:
435:
431:
427:
423:
419:
415:
408:
392:
388:
381:
377:
368:
365:
363:
360:
358:
355:
354:
348:
346:
340:
338:
330:
325:
316:
314:
310:
305:
303:
299:
295:
292:
288:
280:
275:
263:
259:
256:
252:
251:
250:
242:
240:
236:
235:Wilbur Wright
232:
228:
224:
220:
215:
212:
208:
204:
200:
196:
192:
191:Santos-Dumont
188:
184:
179:
177:
166:
163:
159:
155:
149:
147:
143:
139:
134:
132:
128:
124:
113:
110:
102:
91:
88:
84:
81:
77:
74:
70:
67:
63:
60: –
59:
55:
54:Find sources:
48:
44:
38:
37:
32:This article
30:
26:
21:
20:
683:Aerodynamics
655:
635:
613:. Retrieved
602:
590:. Retrieved
585:
581:
572:
552:
545:
533:
508:
477:
453:
441:. Retrieved
421:
417:
407:
395:. Retrieved
390:
380:
341:
334:
306:
284:
262:Piper Pawnee
248:
216:
189:, and later
180:
172:
150:
135:
126:
120:
105:
96:
86:
79:
72:
65:
53:
41:Please help
36:verification
33:
588:(2). Boeing
458:Crouch 2003
345:fly-by-wire
302:fly-by-wire
538:Tobin 2004
255:Cessna 152
162:Cessna 152
69:newspapers
615:1 October
438:0021-8669
373:Citations
367:Trim drag
154:oscillate
131:stability
99:June 2009
677:Category
351:See also
291:Lockheed
227:anhedral
211:dihedral
207:box kite
193:and the
146:attitude
123:aviation
592:29 June
287:stealth
199:lateral
187:Chanute
183:Langley
174:ship's
142:trimmed
83:scholar
662:
643:
560:
521:
485:
443:6 July
436:
397:6 July
176:rudder
85:
78:
71:
64:
56:
611:. WSJ
517:–39.
294:F-117
225:with
90:JSTOR
76:books
660:ISBN
641:ISBN
617:2015
594:2022
558:ISBN
519:ISBN
483:ISBN
445:2022
434:ISSN
399:2022
327:The
277:The
231:bank
217:The
62:news
426:doi
156:in
121:In
45:by
679::
584:.
580:.
515:38
497:^
465:^
432:.
422:23
420:.
416:.
389:.
185:,
133:.
668:.
649:.
619:.
596:.
586:1
566:.
527:.
491:.
447:.
428::
401:.
257:.
112:)
106:(
101:)
97:(
87:·
80:·
73:·
66:·
39:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
