Hi all,
My name's Matt, and I'm planning on making 3d models of the short-wing B-26 Marauder variants (B-26, B-26A, B-26B, B-26B-2 to B-26B-4). I've been doing research on the aircraft (along with a few other planes) for around 4 years on and off, and have recently been more dedicated to finding information on it. I originally started posting about my effort to find information on these planes on ww2aircraft.net, and a member there recommended I try posting here as well.
I've been putting all technical information I find on an excel spreadsheet, and I update it quite often. This includes the list of all fuselage and wing stations, along with short descriptions of what can be found there, the limits of movement for control surfaces and other similar information, and the angles and dimensions of most components (still WIP).
I'm making this thread both to share my findings and because there's a lot of things I still don't know, and was hoping to talk to someone with access to either diagrams and documents or a B-26 currently in restoration. The most important information I'm lacking are actual dimensions of parts, especially fuselage and nacelle frames, windows, landing gear components and flap components.
A few findings I wanted to highlight:-The B-26's fuselage and nacelle are based on NACA airfoils, specifically the 00xx-64 series, with a few modifications.
-The change in the aircraft's attitude while parked between early and intermediate variants (short wing models vs all models prior to the B-26F) is due to the nose landing gear strut being moved lower on the fuselage (not lengthened). This is also why the small bulge on the bottom of the forward fuselage plane appeared in later variants.
-The vertical and horizontal stabilizers and their control surfaces were not redesigned for the long wing variants, the old versions were simply fitted with extensions at their original attachment points.
-Both early and intermediate aircraft's wings have the same angle for the leading edge and the same chord at Station 46 (the point where the outer wing panels attach to the center wing). The long wing models changed the angle of the trailing edge to increase the chord at the tips and allow for the wing to be extended. The new wingtip still attaches at the same location on the wing (Station 364), but is significantly longer.
-Very little of the fuselage was modified between these variants and most frames seem to stay the same up until nearing the end of the tail section, the biggest changes being due to the addition of the tail turret.
List of documents I currently have access to:-B-26/B-26A Flight Manual
-B-26/B-26A Service Manual
-RB-26/RB-26A/RB-26B Erection & Maintenance Manual/Service Manual (Both are exactly the same, just have different covers)
-B-26B-1/C Parts Catalog (Weirdly no dimensions and no 3-views/orthographic projections)
-B-26B-1/C Erection & Maintenance Manual? (Cover and some pages are missing, I don't know. Also no dimensions and no 3-views)
-B-26F/G Flight Manual
-B-26/B-26A/B-26B Wing Station Diagram
-B-26B-1/C Wing Station Diagram
-B-26B Fuselage Station Diagram
-B-26B-1/C Fuselage Station Diagram
-B-26B-1/C Horizontal Stabilizer Station Diagram
-B-26B-1/C Vertical Stabilizer Station Diagram
-A low resolution/hard to read copy of the B-26/B-26A general arrangement drawing (Martin Drawing No. 5K-17988, extremely useful)
-Pictures of one out of four sheets of the B-26/B-26A inboard profile (Martin Drawing No. AP-B-26-075, or maybe -025, sadly most of the information I need is in the other three sheets)
-Pictures of B-26B-1 general arrangement drawing (extremely useful)
Approach to the Excel spreadsheet:Information on the B-26 isn't extremely hard to find, but it tends to be very contradictory.
-"Fuselage Stations" and "Wing Stations" are a result of comparing the fuselage and wing station diagrams between variants, along with information from the manuals and observing photographs of aircraft in restoration with frames exposed.
-"Other Dimensions" is the section containing dimensions, angles and locations of parts, and I'd argue is the most important one. This section was made by comparing information listed on the two Martin-produced general arrangement drawings, using a lot of trigonometry (and making the parts in blender) since the dimensions and angles listed are in 3 different planes of reference: The thrust line, the fuselage zero lift line and the wing chord plane. This mix of trigonometry and building the parts in blender is how I arrived at some of my larger conclusions regarding part compatibility between versions of the aircraft.
I hope this thread is interesting, and look forward to sharing more of my findings about this wonderful aircraft with you all. If anyone wants to add more information, ask questions, or has any suggestions, please let me know.
Edit: Rephrased some confusingly worded sentences, moving the link to the spreadsheet to here, since it was previously hard to find in the middle of the text:
Excel Spreadsheet