Old 23rd May 2020, 01:43
  #22 (permalink)  
djpil
 
Join Date: May 2002
Location: Melbourne, Australia
Posts: 1,111
Originally Posted by AC103 View Post
I agree, "And further provided" has an "AND" operator. It looks like the FAA changed their mind or realized that they hadn't been clear and didn't want to invite a whole load of paper MAUW increases.
Yes, it seems to me that something has changed and I missed it. Perhaps they have been seeing faster airplanes wrt to their wing loading than earlier designs? I see this from the Light Aircraft Association http://www.lightaircraftassociation....0envelopes.pdf. I like what was quoted from VLA: "It is recommended that Vc should not be less than 0.9 Vh" Perhaps Francis Donaldson could fill in the history and perhaps explain why the AC mangles the text of the rule instead of changing the rule. Of course, we have a fancy new FAR 23 now and I eagerly await a new AC 21-19.

Originally Posted by AC103 View Post
Please do share any designs you know of that have Vcmin below 38 √ W/S. That would be a very interesting list. I have not managed to find any yet besides the later Cherokees.
The Aviat Husky series is one that I am very familiar with. The current model A-1C has W/S of 12 so 33 √ W/S = 114 kts but Vc used in design and Vno is 103 kts.

Originally Posted by AC103 View Post
Don't get me started on design vs operational Va... now that is a proper mess.
Sorry but I take more interest in this now, having retired from engineering and instruct aerobatics these days. I like the bit in AC 21-19A about "For airplanes where VA>VS√n, the pilot would have to check the maneuver; otherwise the airplane would exceed the limit load factor." Sometimes my discussions with instructor trainees venture into that area. Perhaps the subject of another thread.
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