Surf / pump foil — 900 mm reference front wingvsCessna 172 Skyhawk — the most-built wing in aviation
root section a18 → naca2412 · area 111865 mm² → 16463140 mm² · tip chord 76 mm → 1310 mm · span 900 mm → 11000 mm · te thickness 0 mm → 3 mm · mac 128 mm → 1504 mm
units
These analyses are not directly comparable
- different fluids (water-salt vs air) — density and viscosity both differ, so the drag numbers are not on the same footing
- different trim loads (932 N vs 10791 N) — each wing is carrying a different weight
The geometry comparison below is unaffected — it is a comparison of shapes, not of runs.
- Surf / pump foil — 900 mm reference front wing
- Cessna 172 Skyhawk — the most-built wing in aviation
What changed
| Property | Surf / pump foil | Cessna 172 Skyhawk | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 900 mm | 11000 mm | +10100 mm | +1122.2% |
| Root chord | 150 mm | 1630 mm | +1480 mm | +986.7% |
| Tip chord | 76 mm | 1310 mm | +1234 mm | +1623.7% |
| Sweep parameter | 8.553 | 1.666 | -6.887 | -80.5% |
| Dihedral | -1.50° | 1.73° | +3.23° | -215.3% |
| Tip twist | -2.00° | -3.00° | -1.00° | +50.0% |
| TE thickness | 0 mm | 3 mm | +3 mm | +1100.0% |
| Sections | 30 | 40 | +10 | +33.3% |
| Tip cap peak (chord fraction) | 0.450 | 0.500 | +0.050 | +11.1% |
| Tip cap reach | 0.350 | 0.200 | -0.150 | -42.9% |
| Derived | ||||
| Aspect ratio | 7.241 | 7.350 | +0.109 | +1.5% |
| Area | 111865 mm² | 16463140 mm² | +16351276 mm² | +14617.0% |
| Taper | 0.507 | 0.804 | +0.297 | +58.6% |
| MAC | 128 mm | 1504 mm | +1375 mm | +1071.4% |
| Sections | ||||
| Root section | a18 | naca2412 | changed | — |
| Shapedeviation at matched span fractions, 64 samples | ||||
| Chord deviation (max) | 1480 mm | |||
| Chord deviation (RMS) | 1375 mm | |||
| Twist deviation (max) | 1.00° | |||
| Dihedral deviation (max) | 178 mm | |||
| Tip cap deviation (max) | 5251 mm | |||
Performance
CoefficientsDimensionless — how good the shape is, independent of size and speed.
Spanwise
withheld — “Surf / pump foil” integrates to CL 0.022 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.363 (0.06×); “Cessna 172 Skyhawk” integrates to CL 0.034 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.344 (0.10×). A loading that does not integrate back to its own wing’s CL is not a coarse curve, it is a wrong one.
mixed fluids (water (sea), air)
data
| CD | Surf / pump foil | Cessna 172 Skyhawk |
|---|---|---|
| 0.011 | 0.254 | 0.308 |
| 0.011 | 0.284 | 0.334 |
| 0.012 | 0.294 | 0.344 |
| 0.013 | 0.320 | 0.363 |
| 0.014 | 0.363 | 0.400 |
| 0.015 | 0.387 | 0.422 |
| 0.016 | 0.416 | 0.443 |
| 0.019 | 0.481 | 0.497 |
| 0.021 | 0.513 | 0.529 |
| 0.023 | 0.563 | 0.567 |
| 0.030 | 0.667 | 0.667 |
| 0.032 | 0.681 | 0.685 |
| 0.042 | 0.803 | 0.794 |
| 0.054 | 0.901 | 0.920 |