Originally Posted by
Traffic_Is_Er_Was
If the aircraft floats at a weight, the floats are supprting 100% of that weight, irrespective of what it is. The floats will have been designed to provide X kg/pounds max bouyancy each. Exceed that, and the aircraft will sink, irrespective of its BEW or MTOW.
If, however, you had said the floats are designed to support 180% of the aircraft's MTOW......
- Obviously if an a/c floats at a certain weight, then 100% of the weight is being supported.
- Yes floats are designed with a max buoyancy each.
- Yes the plane will sink if that is exceeded.
- Yes, the floats are designed to support 180% of your aircraft types MTOW.
FAR 23.751 requires that the 2 floats of a twin-float floatplane provide 180% fresh water buoyancy. To determine the maximum weight allowed for a seaplane equipped with two floats, divide the total displacement by 1.8.
Specific floats are designed for specific aircraft types. You could in theory put floats of reduced buoyancy capacity on your a/c, and reduce your MTOW accordingly - but that would be rather silly.
What you do, is select a set of floats with enough buoyancy so that the upper limit on your MTOW is not restricted by the buoyancy capacity of your floats.
So I as said, you will install floats that are designed to support 180% of your aircrafts MTOW.
I can’t really help you more on this. It’s really not that complicated, so I’ll leave it at that. Just google FAR 23.751 for more information on float requirements.