Today I moved this project from a Facebook “Note” page, to a proper blog.
The PBY “Catalina” actually came in a number of different versions, as WW2 progressed:
XP3Y-1 : original prototype
X-PBY-1 : modified prototype
PBY-1 : first production (60 made)
PBY-2 : minor modifications (50 made)
PBY-3 : better engines (66 made)
PBY-4 : better engines, new propeller spinner (32 made)
PBY-5 : better engines, new spinner, waist gun blisters (684 made)
PBY-5A : retractable landing gear (802 made)
PBY-6A : new tail design, radome over cockpit (175 made)
GST (“Gydro Samoliot Transportnyj”, aka PBN-1, aka “Nomad”) : Russian variant
PB2B: Boeing built
OA-10/OA-10A : US Army Air Forces (USAAF) version
(the above is a rough reference, I’ll try to update it in more precise details)
For the past couple of weeks, I’ve been looking at the airfoil (cross section of the wing) for this plane, and I found that while every reference I came across lists it as a standard NACA 0021, Stanford university thinks it’s a Davis airfoil (for version 5 and later).
As it turns out, while all the historic references and engioneering papers I’ve come across say otherwise, Stanford University might be right: the Davis airfoil was used on the model 31 (experimental/prototype XP4Y “Corregidor”) as well as the model 32 (B-24 “Liberator”).
http://en.wikipedia.org/wiki/XP4Y_Corregidor
http://en.wikipedia.org/wiki/Davis_wing
That being said… I came across a picture, going through the National Archives website (www.nara.gov) that shows a bunch of workers for the Consolidated Aircraft Corporation, having lunch, and sitting against a bunch of prefabricated PBY wings. The problem is, some of those wings have a symmetrical airfoil and some don’t. NACA0021 is symmetrical, and Davis’ airfoil isn’t.
To top it off, I also came across information that the Davis airfoil is actually a lot more efficient than the NACA 21 airfoil, for the real plane, as well as a model. Since the design of the wing is going to be critical to my model, I may have to use a Davis airfoil anyways.
PBY Catalina RC model 