nightsta1ker Posted May 17, 2012 Report Share Posted May 17, 2012 To get back to the OP, useful load is the difference between the Max Gross weight (which is a hard number unless otherwise published), and the basic empty weight, which will vary per airframe (no two are the same). Performance considerations that may whittle the operational weight down further have nothing to do with it and you use your performance charts to figure out what weight you can operate at at a given density altitude. The useful load as calculated using the published numbers for your aircraft is not really intended for performance purposes at all. It's more of a stress limit on the airframe, hence different max gross weights for internal amd external loads. Quote Link to comment Share on other sites More sharing options...
jjsemperfi Posted May 17, 2012 Author Report Share Posted May 17, 2012 You know with all of this said, I really like the definitions in the text "Principles of Helicopter Flight" by Wagtendonk. His definitions make sense. He doesn't use useful load at all. He uses Basic Operating Weight: includes the empty aircraft weight, pilot and crew, crew's baggage, food, water etc..., total load except payload and fuel. Zero Fuel Weight: Basic operating weight plus payload. It just makes so much sense. The FAA definitions are too bland for me. Quote Link to comment Share on other sites More sharing options...
nightsta1ker Posted May 17, 2012 Report Share Posted May 17, 2012 Better get used to it... Quote Link to comment Share on other sites More sharing options...
jjsemperfi Posted May 17, 2012 Author Report Share Posted May 17, 2012 That's what I'm realizing with this CFI checkride coming up. Who cares what you think. Just memorize and answer his questions. Quote Link to comment Share on other sites More sharing options...
Pohi Posted May 17, 2012 Report Share Posted May 17, 2012 That's what I'm realizing with this CFI checkride coming up. Who cares what you think. Just memorize and answer his questions. The DPE might be looking for more than rote memory :-). I'm sure you know that though. Quote Link to comment Share on other sites More sharing options...
jjsemperfi Posted May 17, 2012 Author Report Share Posted May 17, 2012 Oh for sure! Our DPE is a 28 year old CareFlight pilot. Needless to say, he knows his stuff. And the length of his orals shows it. He has conducted a 17 hour oral at our school before. Not looking forward to it. Quote Link to comment Share on other sites More sharing options...
nightsta1ker Posted May 18, 2012 Report Share Posted May 18, 2012 Well, know it, learn to love it, and you're gonna have to teach it too, even if you disagree with certain aspects of it. The system is set up the way it is, and if you go teaching your students stuff that doesn't jive with whats in the system, you are setting them up to fail too. Â As far as this thread goes, I think you were simply taking a difference in wording "Max takeoff weight" and "Max gross weight" to have two different meanings. I think they represent the same thing. So the meaning of "useful load" stays the same. Â Some of the discussion that has come out of this thread has been a bit muddied as Mike pointed out earlier. This is pretty cut and dry stuff. Don't make it more complicated than it needs to be Quote Link to comment Share on other sites More sharing options...
jjsemperfi Posted May 18, 2012 Author Report Share Posted May 18, 2012 I don't disagree with any of it. I am just trying to learn the right stuff like you said. If I am teaching the wrong material then my students are screwed right from the start. I can spit out the definition of useful load to a DPE no problem. That's not the issue. But someday, I'm sure a student will ask, well why does my book have one definition and the other book has another. That's why I'm asking these questions. 1 Quote Link to comment Share on other sites More sharing options...
nightsta1ker Posted May 18, 2012 Report Share Posted May 18, 2012 I am not criticizing you at all for asking the question. You asked it, and you got a lot of conflicting feedback. The question was relatively straight forward, and it had a relatively straight forward answer IMO. The discussion that ensued seemed to be chasing after aircraft performance rather than the definition of the terms. Max Gross Weight and (I suspect) Max Takeoff Weight both refer to the maximum amount of weight that the airframe is able to safely operate at without being subjected to forces that would stress it excessively. It has nothing to do with calculating performance. It's a structural limit. Quote Link to comment Share on other sites More sharing options...
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