Sec. 25.529 - Hull and main float landing
conditions.
(a) Symmetrical step, bow, and stern
landing. For symmetrical step, bow, and stern landings, the limit
water reaction load factors are those computed under §25.527. In addition
--
(1) For symmetrical step landings, the
resultant water load must be applied at the keel, through the center of
gravity, and must be directed perpendicularly to the keel line;
(2) For symmetrical bow landings, the
resultant water load must be applied at the keel, one-fifth of the
longitudinal distance from the bow to the step, and must be directed
perpendicularly to the keel line; and
(3) For symmetrical stern landings, the
resultant water load must be applied at the keel, at a point 85 percent of
the longitudinal distance from the step to the stern post, and must be
directed perpendicularly to the keel line.
(b) Unsymmetrical landing for hull
and single float seaplanes. Unsymmetrical step, bow, and stern landing
conditions must be investigated. In addition --
(1) The loading for each condition
consists of an upward component and a side component equal, respectively,
to 0.75 and 0.25 tan β times the resultant load in the corresponding
symmetrical landing condition; and
(2) The point of application and
direction of the upward component of the load is the same as that in the
symmetrical condition, and the point of application of the side component
is at the same longitudinal station as the upward component but is
directed inward perpendicularly to the plane of symmetry at a point midway
between the keel and chine lines.
(c) Unsymmetrical landing; twin float
seaplanes. The unsymmetrical loading consists of an upward load at the
step of each float of 0.75 and a side load of 0.25 tan β at one float
times the step landing load reached under §25.527. The side load is
directed inboard, perpendicularly to the plane of symmetry midway between
the keel and chine lines of the float, at the same longitudinal station as
the upward load.