Hi everyone
In brushing up on general knowledge of the C172, I've seen written many times that the ailerons, whilst described by the AFM as conventional are in fact of both differential and Frise type.
Having found a maintenance manual I had a look for information with respect to how they're rigged, but couldn't find anything pertaining to whether or not they're differential. Does anyone know of any approved documentation in which this is mentioned (I may well have just overlooked it in the AMM, I only gave it a quick scan)?
As for whether or not they're of Frise type, I'm not sure. At least by my understanding of what constitutes a Frise aileron, they're not though. The axis of the hinge is forward of the upper leading edge, however the lower leading edge does protrude slightly forward of this. It would seem to me, having had a look at an aircraft today, that the extent to which the leading edge travels down when the trailing edge moves up is so small as to almost be negligible.
Having had a look for a clear definition of a Frise aileron, the best I could find was a section from a textbook (Airplane Stability and Control, Second edition), which starts as follows [
https://books.google.co.nz/books?id=...ge&q&f=false]:
"The hinge line of the Frise aileron, invented by Leslie George Frise, is always at or below the wing’s lower surface. If one sees aileron hinge brackets below the wing, chances are that one is looking at a Frise aileron."
My own principles of flight textbook, PadPilot, says:
"Frise ailerons. The leading edge of the aileron is asymmetrically shaped and set in front of the hinge. The edge is so designed that when the aileron is deflected upwards its leading edge protrudes into the airstream to increase form drag..."
By my interpretation of the former, the Skyhawk does not have Frise ailerons, but the latter would seem to suggest it does. Is there perhaps an 'official' definition of a Frise aileron published by NACA or even Leslie Frise himself? Perhaps most likely of all, am I missing something fundamental here and is my interpretation is just plain wrong?