Does anybody know much about the M-series airfoils? Specifically the M-6, which is used on the earlier ("flatwing") Pitts Specials, and also on the Starduster and Acrosport (possibly because "if it was good enough for Curtis..."). My interest was piqued because the builder of my Rose Parrakeet also used the M-6 instead of Rose's original choice of the 2412.
I also don't know why the builder of my Parrakeet chose it, but it may be because of the Pitts use, and also the same reason he changed from struts to wires and from two to four ailerons, "because I wanted to."
I know a bit about the NACA 4, 5, and 6 digit airfoils and their development, but the M-series are earlier (?), designed by Max Munk while he was at Langley. I haven't yet dug out my copy of TOWS to see if there's anything there.
It's interesting that Curtis chose the relatively obscure M-6... the performance doesn't look all that different from more common sections, except for reduced pitching moment due to the reflex... but if one really wants low Cm, the 23xxx airfoils shine there.
Of course, the above polars were generated by xfoil, which may not capture real world differences.
I also don't know why the builder of my Parrakeet chose it, but it may be because of the Pitts use, and also the same reason he changed from struts to wires and from two to four ailerons, "because I wanted to."
I know a bit about the NACA 4, 5, and 6 digit airfoils and their development, but the M-series are earlier (?), designed by Max Munk while he was at Langley. I haven't yet dug out my copy of TOWS to see if there's anything there.
It's interesting that Curtis chose the relatively obscure M-6... the performance doesn't look all that different from more common sections, except for reduced pitching moment due to the reflex... but if one really wants low Cm, the 23xxx airfoils shine there.
Of course, the above polars were generated by xfoil, which may not capture real world differences.
