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Federal Aviation Regulations

Appendix C to Part 23 — Basic Landing Conditions

[C23.1 Basic landing conditions ]

ConditionTail wheel typeNose wheel type
Level landingTail-down landingLevel landing with inclined reactionsLevel landing with nose wheel just clear of groundTail-down landing
Reference section23.479(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. g00000.
Shock absorber extension (hydraulic shock absorber)Note (2)Note (2)Note (2)Note (2)Note (2).
Shock absorber deflection (rubber or spring shock absorber), percent100100100100100.
Tire deflectionStaticStaticStaticStaticStatic.
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′00.
Tail (nose) wheel loads ( Df )00 KnW b′/d′00.
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 §23.735(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).

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

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