Piper PA-28 Cherokee — the Hershey-bar wingvsGossamer Albatross II — same span, two-thirds the area
root section naca652415 → l7769 · aspect ratio 5.624 → 18.901 · span 9144 mm → 29260 mm · area 14868144 mm² → 45296522 mm² · te thickness 3 mm → 2 mm · dihedral 7.00° → 3.60°
units
These analyses are not directly comparable
- different trim loads (9565 N vs 991 N) — each wing is carrying a different weight
The geometry comparison below is unaffected — it is a comparison of shapes, not of runs.
- Piper PA-28 Cherokee — the Hershey-bar wing
- Gossamer Albatross II — same span, two-thirds the area
What changed
| Property | Piper PA-28 Cherokee | Gossamer Albatross II | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 9144 mm | 29260 mm | +20116 mm | +220.0% |
| Root chord | 1626 mm | 1651 mm | +25 mm | +1.5% |
| Tip chord | 1626 mm | 1404 mm | -222 mm | -13.7% |
| Sweep parameter | 0.000 | 7.476 | +7.476 | — |
| Dihedral | 7.00° | 3.60° | -3.40° | -48.6% |
| TE thickness | 3 mm | 2 mm | -2 mm | -50.0% |
| Tip cap reach | 0.300 | 0.200 | -0.100 | -33.3% |
| Derived | ||||
| Aspect ratio | 5.624 | 18.901 | +13.277 | +236.1% |
| Area | 14868144 mm² | 45296522 mm² | +30428378 mm² | +204.7% |
| Taper | 1.000 | 0.850 | -0.150 | -15.0% |
| MAC | 1626 mm | 1552 mm | -74 mm | -4.5% |
| Sections | ||||
| Root section | naca652415 | l7769 | changed | — |
| Shapedeviation at matched span fractions, 64 samples | ||||
| Chord deviation (max) | 222 mm | |||
| Chord deviation (RMS) | 112 mm | |||
| Twist deviation (max) | 0.00° | |||
| Dihedral deviation (max) | 359 mm | |||
| Tip cap deviation (max) | 10228 mm | |||
Performance
CoefficientsDimensionless — how good the shape is, independent of size and speed.
Spanwise
withheld — “Piper PA-28 Cherokee” integrates to CL 0.007 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.271 (0.03×); “Gossamer Albatross II” integrates to CL 0.118 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.613 (0.19×). A loading that does not integrate back to its own wing’s CL is not a coarse curve, it is a wrong one.
air, ρ = 1.225 kg/m³
data
| CD | Piper PA-28 Cherokee | Gossamer Albatross II |
|---|---|---|
| 0.012 | 0.334 | 0.374 |
| 0.013 | 0.345 | 0.419 |
| 0.013 | 0.361 | 0.472 |
| 0.014 | 0.371 | 0.498 |
| 0.015 | 0.383 | 0.535 |
| 0.017 | 0.418 | 0.613 |
| 0.018 | 0.443 | 0.655 |
| 0.020 | 0.469 | 0.709 |
| 0.025 | 0.537 | 0.827 |
| 0.025 | 0.538 | 0.829 |
| 0.032 | 0.618 | 0.982 |
| 0.037 | 0.666 | 1.06 |
| 0.043 | 0.715 | 1.18 |
| 0.060 | 0.848 | 1.39 |
| 0.065 | 0.880 | 1.45 |