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Plain flap

Name: Plain flap dimension sheet
Creator: Xem Studio
License: https://creativecommons.org/licenses/by/4.0/

What is a plain flap and how much lift does it add? · Standard part · basis: Design rules and figures from the cited sources; example geometry by Xem Studio

Also called: simple flap, hinged flap, plain flap rc, plain flap lift increase, flap types, trailing edge flap, camber flap, plain flap vs split flap

Exact dimensions. True size, with no printing tolerance added.

sizes: 6 in table

Notes

A plain flap is a hinged section of the trailing edge that increases camber and lift coefficient at a given angle of attack; it greatly increases drag and moves the centre of pressure aft, pitching the nose down (FAA PHAK ch.6).
Its section CLmax increment is about 0.9 (Arnedo, data from Franchini et al.); on a NACA 0012, a 20% chord flap at 40 deg raises CLmax from just under 1.6 to 2.4 (Virginia Tech Appendix A, NACA data).
Wing-level gain for plain flaps scales with flapped area ratio and cos^3 of quarter-chord sweep (Arnedo).
The file is a reference example built by Xem Studio from the numbers above. Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

Plain flap size chart

parameter	value or range	source
Section delta-CLmax	0.9	Arnedo (Franchini)
NACA 0012 + 20% chord flap at 40 deg	CLmax ~1.6 -> 2.4 (Re 6e6)	Virginia Tech Appendix A
NACA 0012 zero-lift angle with that flap	about -12 deg	Virginia Tech Appendix A
Wing delta-CLmax	0.92 x dCl x (Sflapped/S) x cos^3(sweep)	Arnedo
Typical CLmax/cos(sweep), plain flap	1.4-1.6 takeoff (20 deg) / 1.7-2.0 landing (60 deg)	Arnedo (Franchini)
Reference build	chord 100, 25% flap, 300 span, 20 deg	Sadraey/Arnedo-range example

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

FAA	Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25), Ch. 6 Flight Controls	web	Publisher's page; dimensions are facts
LibreTexts (Arnedo, Fundamentals of Aerospace Engineering; data from Franchini et al.)	3.4.3 Increase in CLmax (high-lift devices)	web	Publisher's page; dimensions are facts
Virginia Tech Pressbooks (data from Abbott & von Doenhoff, NACA)	Appendix A: Airfoil Data	web	Publisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

plain-flap-wing-segment

plain flap: wing segment 100 mm chord × 300 mm, 25 % chord surface deflected 20°

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Plain text: sheet.txt · JSON: /api/geometry?object=plain-flap