NACA 23018 Airfoil
The NACA 23018 is the thick, 18% member of the 230-series. Its depth makes it a natural wing-root section — often paired with a thinner 230-series tip on a tapered wing — keeping the family's forward camber and low pitching moment while giving plenty of room for spars and structure.
What the numbers mean
NACA 23018 is a 5-digit section. The first digit 2 times 0.15 is the design lift coefficient (0.3); the next two digits 30 are twice the position of maximum camber, placing it at 15% of the chord; the middle 0 marks the standard, non-reflexed camber line; and the last two digits 18 are the maximum thickness as 18% of the chord.
Aerodynamic characteristics
The 230-series forward camber keeps the pitching moment small; at 18% thickness the maximum lift is a little lower than the thinner members because the thick section separates slightly earlier, but the stall stays gentle and the structural depth is large.
| Property | Typical value |
|---|---|
| Zero-lift angle α₀ | ≈ -1.1° |
| Lift coefficient at 0° | ≈ 0.11 |
| Lift-curve slope | ≈ 0.11 /deg |
| Max lift coefficient Cl,max | ≈ 1.5–1.6 |
| Stall angle | ≈ 16–18° |
| Pitching moment Cm,c/4 | ≈ -0.013 |
Conditions: Reynolds number Re = 1×10⁶, low speed (Mach ≤ 0.15), smooth surface. Values are representative figures from thin-airfoil theory and published XFoil / wind-tunnel data, rounded for reference.
Where it's used
- Tapered wing roots — blended into a thinner 230-series tip section.
- Structural wing sections — large internal volume for spars and fuel.
- Transports and larger light aircraft — following DC-3-era practice.
- Low-moment thick wings — depth without large trim loads.
Coordinates
Surface coordinates as fractions of the chord (x/c, y/c), generated from the standard NACA 4-digit equations with a closed trailing edge. For the full high-resolution coordinate file, use the DAT export inside the explorer.
| x/c (upper) | y/c (upper) | x/c (lower) | y/c (lower) |
|---|---|---|---|
| 0.000 | +0.0000 | 0.000 | +0.0000 |
| 0.016 | +0.0444 | 0.033 | -0.0313 |
| 0.091 | +0.0856 | 0.100 | -0.0522 |
| 0.226 | +0.1050 | 0.223 | -0.0707 |
| 0.391 | +0.1011 | 0.387 | -0.0741 |
| 0.546 | +0.0847 | 0.543 | -0.0646 |
| 0.718 | +0.0582 | 0.716 | -0.0457 |
| 0.846 | +0.0340 | 0.845 | -0.0272 |
| 0.930 | +0.0163 | 0.929 | -0.0132 |
| 0.982 | +0.0043 | 0.982 | -0.0035 |
| 1.000 | -0.0000 | 1.000 | +0.0000 |
Explore 4-digit airfoils in the interactive tool →
The live 3D explorer currently covers the NACA 4-digit family. Use it to orbit a 3D wing and watch live Cl / Cd polar charts as you change camber, thickness, angle of attack and Reynolds number.
Open the explorer →Frequently asked questions
NACA 23018 is a thick NACA 5-digit airfoil with a 0.3 design lift coefficient, maximum camber at 15% chord and 18% thickness — the deep root member of the 230-series.
The first digit (2) times 0.15 gives the 0.3 design lift coefficient, the 30 is twice the 15%-chord camber position, and the 18 is the 18% thickness; the 0 marks the standard camber line.
Its depth gives structural volume and stiffness for a wing root, while the 230-series forward camber keeps the pitching moment small.
Slightly — the thicker shape separates a little earlier, so its peak lift is a touch below the 23012 or 23015, though the stall remains gentle.