29.753—Main float design.
        
        (1) 
         The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is requested; and
    
    
        
        (2) 
         The vertical loads prescribed in  § 29.521(a), distributed along the length of the bag over three-quarters of its projected area.
    
    
        
        (b) Rigid floats.
         Each rigid float must be able to withstand the vertical, horizontal, and side loads prescribed in  § 29.521. An appropriate load distribution under critical conditions must be used.