NACA 0009 airfoil — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/naca-0009-airfoil/ (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/) Basis: Computed from the NACA equations (Report 460 / Report 610, restated in NASA TM-4741) Catalog version: 2026-10-20 Overall (mm): length 100.0, width 20.0, height 9.0 - NACA 0009 is a symmetric 4-digit section 9% chord thick (designation per NASA TM-4741). Being symmetric it makes no lift at zero angle and has zero moment about its aerodynamic centre, so it behaves the same upright and inverted (Virginia Tech Appendix A, on symmetric sections). - Thin symmetric sections are the natural choice for tails and fins, which must lift either way; Drela's Bubble Dancer uses its own thin ht21 for both tail surfaces (CRRC). - NACA 4-digit sections have good stall behaviour, small centre-of-pressure movement and low roughness sensitivity, but a low CLmax, relatively high drag and high pitching moment (Aerospaceweb summary). - NACA 0009: symmetric, 9 % thick. - NACA 4-digit: first digit = maximum camber in % of chord, second = its position in tenths of chord, last two = maximum thickness in % of chord (NACA Report 460). - Ordinates are in % of chord from the leading edge, computed from the published equations with the closed-trailing-edge thickness coefficient (−0.1036, as in NASA TM-4741). The original reports use an open trailing edge (−0.1015); the difference is under 0.03 % of chord near the trailing edge. - The file is a 100 mm chord section, 20 mm deep: scale it uniformly to your chord, or import the STEP and sweep or loft it into a wing. Thickness scales with chord; the shape is the same at any size. - Max thickness: 9% chord (from designation) (NASA TM-4741) - Camber: 0 (symmetric) (NASA TM-4741) - Zero-lift angle: 0 deg (symmetric section) (Virginia Tech Appendix A) - Moment about a.c.: zero (symmetric; c.p. = a.c.) (Virginia Tech Appendix A) - 4-digit code: 1st digit max camber %c; 2nd digit camber position in tenths c; last two thickness %c (NASA TM-4741; Aerospaceweb) - Thickness equation (t/c = 0.20 basis): y/c = 0.2969 sqrt(x) - 0.1260 x - 0.3516 x^2 + 0.2843 x^3 - 0.1015 x^4, scaled by (t/c)/0.20 (NASA TM-4741) x (% chord) upper x upper y lower x lower y 0 0.000 0.000 0.000 0.000 1.25 1.250 1.420 1.250 -1.420 2.5 2.500 1.961 2.500 -1.961 5 5.000 2.666 5.000 -2.666 7.5 7.500 3.150 7.500 -3.150 10 10.000 3.512 10.000 -3.512 15 15.000 4.009 15.000 -4.009 20 20.000 4.303 20.000 -4.303 25 25.000 4.456 25.000 -4.456 30 30.000 4.501 30.000 -4.501 40 40.000 4.350 40.000 -4.350 50 50.000 3.965 50.000 -3.965 60 60.000 3.410 60.000 -3.410 70 70.000 2.725 70.000 -2.725 80 80.000 1.929 80.000 -1.929 90 90.000 1.024 90.000 -1.024 95 95.000 0.528 95.000 -0.528 100 100.000 -0.000 100.000 0.000 Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - NACA (NASA Technical Reports Server): Report 460: The characteristics of 78 related airfoil sections from tests in the variable-density wind tunnel (Jacobs, Ward, Pinkerton, 1933) — web — Publisher's page; dimensions are facts — https://ntrs.nasa.gov/citations/19930091108 - NASA: TM-4741: Computer program to obtain ordinates for NACA airfoils (Ladson, Brooks, Hill, Sproles, 1996) — web — Publisher's page; dimensions are facts — https://www.pdas.com/refs/tm4741.pdf - NASA Langley (Ladson et al.), NASA TM-4741: Computer Program to Obtain Ordinates for NACA Airfoils — web — Publisher's page; dimensions are facts — https://www.pdas.com/refs/tm4741.pdf - Virginia Tech Pressbooks (data from Abbott & von Doenhoff, NACA): Appendix A: Airfoil Data — web — Publisher's page; dimensions are facts — https://pressbooks.lib.vt.edu/aerodynamics/?p=52 - Aerospaceweb.org: NACA Airfoil Series — web — Publisher's page; dimensions are facts — https://aerospaceweb.org/question/airfoils/q0041.shtml - Charles River Radio Controllers (M. Drela designs): Bubble Dancer 3m RES sailplane — web — Publisher's page; dimensions are facts — https://charlesriverrc.org/articles/on-line-plans/mark-drela-designs/bubble-dancer/ Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/naca-0009-airfoil/index.json API: https://xemstudio.com/api/geometry?object=naca-0009-airfoil