Airworthiness Standards for Seaplanes

The airworthiness standards for seaplanes have been updated.  Instead of multiple regulations for specific float characteristics, the regulations have been refined to have fewer specific requirements and are now more general in nature.  Although there remains a requirement for having at least eighty percent excess float displacement, the other requirements have been simplified.  An example of a change is that the previous regulations required the floats to have a minimum of four compartments and be able to stay afloat with two floats fully flooded.  Although this specific requirement has been removed, the regulations still require the floats should have sufficient margin, so the seaplane will stay afloat at rest in calm water without capsizing in case of float or hull flooding.  Some of these regulatory changes are given that there are new designs and methods to meet the safety requirements.  In addition, these changes place the burden on the manufacturer to ensure safe characteristics rather just meeting specific requirements.  The new regulations that relate only to seaplanes are detailed below.  In addition to these regulations, the seaplane must also meet the other applicable parts of 14 CFR 23 that relate to airplanes in the normal category.

14 CFR 23.2155 Ground and water handling characteristics

For airplanes intended for operation on land or water, the airplane must have controllable longitudinal and directional handling characteristics during taxi, takeoff, and landing operations.

14 CFR 23.2220 Ground and water load conditions

The applicant must determine the structural design loads resulting from taxi, takeoff, landing, and handling conditions on the applicable surface in normal and adverse attitudes and configurations.

14 CFR 23.2310 Buoyancy for seaplanes and amphibians

Airplanes intended for operations on water, must:

(a) Provide buoyancy of 80 percent in excess of the buoyancy required to support the maximum weight of the airplane in fresh water; and

(b) Have sufficient margin so the airplane will stay afloat at rest in calm water without capsizing in case of a likely float or hull flooding.

Airworthiness Standards for Seaplanes Change Mapping

The table below lists the new airworthiness standards for seaplane design along with the regulations that it replaced.