Appendix C to Part 23 - Basic Landing Conditions

Appendix C to Part 23 - Basic Landing Conditions

[C23.1 Basic landing conditions]

Condition	Tail wheel type		Nose wheel type
	Level landing	Tail-down landing	Level landing with inclined reactions	Level landing with nose wheel just clear of ground	Tail-down landing
Reference section	23.479(a)(1)	23.481(a)(1)	23.479(a)(2)(i)	23.479(a)(2)(ii)	23.481(a)(2) and (b).
Vertical component at c. g	nW	nW	nW	nW	nW.
Fore and aft component at c. g	KnW	0	KnW	KnW	0.
Lateral component in either direction at c. g	0	0	0	0	0.
Shock absorber extension (hydraulic shock absorber)	Note (2)	Note (2)	Note (2)	Note (2)	Note (2).
Shock absorber deflection (rubber or spring shock absorber), percent	100	100	100	100	100.
Tire deflection	Static	Static	Static	Static	Static.
Main wheel loads (both wheels) (Vr)	(n-L)W	(n-L)W b/d	(n-L)W a′/d′	(n-L)W	(n-L)W.
Main wheel loads (both wheels) (Dr)	KnW	0	KnW a′/d′	KnW	0.
Tail (nose) wheel loads (Vf)	0	(n-L)W a/d	(n-L)W b′/d′	0	0.
Tail (nose) wheel loads (Df)	0	0	KnW b′/d′	0	0.
Notes	(1), (3), and (4)	(4)	(1)	(1), (3), and (4)	(3) and (4).

Note (1). K may be determined as follows: K = 0.25 for W = 3,000 pounds or less; K = 0.33 for W = 6,000 pounds or greater, with linear variation of K between these weights.

Note (2). For the purpose of design, the maximum load factor is assumed to occur throughout the shock absorber stroke from 25 percent deflection to 100 percent deflection unless otherwise shown and the load factor must be used with whatever shock absorber extension is most critical for each element of the landing gear.

Note (3). Unbalanced moments must be balanced by a rational or conservative method.

Note (4). L is defined in § 23.725(b).

Note (5). n is the limit inertia load factor, at the c.g. of the airplane, selected under § 23.473 (d), (f), and (g).

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as amended by Amdt. 23-7, 34 FR 13099, Aug. 13, 1969]