For the wing and its attachment to the hull or main float—

(a) The aerodynamic wing lift is assumed to be zero; and

(b) A downward inertia load, corresponding to a load factor computed from the following formula, must be applied:

$$ where— n = inertia load factor; CTO = empirical seaplane operations factor equal to 0.004; VS1 = seaplane stalling speed (knots) at the design takeoff weight with the flaps extended in the appropriate takeoff position; β = angle of dead rise at the main step (degrees); and W = design water takeoff weight in pounds. [Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-23, 35 FR 5673, Apr. 8, 1970]