Gossamer Albatross II — same span, two-thirds the areavsPiper PA-28 Cherokee — the Hershey-bar wing
root section l7769 → naca652415 · sweep parameter 7.476 → 0.000 · te thickness 2 mm → 3 mm · dihedral 3.60° → 7.00° · aspect ratio 18.901 → 5.624 · span 29260 mm → 9144 mm
units
These analyses are not directly comparable
- different trim loads (991 N vs 9565 N) — each wing is carrying a different weight
The geometry comparison below is unaffected — it is a comparison of shapes, not of runs.
- Gossamer Albatross II — same span, two-thirds the area
- Piper PA-28 Cherokee — the Hershey-bar wing
What changed
| Property | Gossamer Albatross II | Piper PA-28 Cherokee | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 29260 mm | 9144 mm | -20116 mm | -68.7% |
| Root chord | 1651 mm | 1626 mm | -25 mm | -1.5% |
| Tip chord | 1404 mm | 1626 mm | +222 mm | +15.8% |
| Sweep parameter | 7.476 | 0.000 | -7.476 | -100.0% |
| Dihedral | 3.60° | 7.00° | +3.40° | +94.4% |
| TE thickness | 2 mm | 3 mm | +2 mm | +100.0% |
| Tip cap reach | 0.200 | 0.300 | +0.100 | +50.0% |
| Derived | ||||
| Aspect ratio | 18.901 | 5.624 | -13.277 | -70.2% |
| Area | 45296522 mm² | 14868144 mm² | -30428378 mm² | -67.2% |
| Taper | 0.850 | 1.000 | +0.150 | +17.6% |
| MAC | 1552 mm | 1626 mm | +74 mm | +4.8% |
| Sections | ||||
| Root section | l7769 | naca652415 | 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 — “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×); “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×). 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 | Gossamer Albatross II | Piper PA-28 Cherokee |
|---|---|---|
| 0.012 | 0.374 | 0.334 |
| 0.013 | 0.419 | 0.345 |
| 0.013 | 0.472 | 0.361 |
| 0.014 | 0.498 | 0.371 |
| 0.015 | 0.535 | 0.383 |
| 0.017 | 0.613 | 0.418 |
| 0.018 | 0.655 | 0.443 |
| 0.020 | 0.709 | 0.469 |
| 0.025 | 0.827 | 0.537 |
| 0.025 | 0.829 | 0.538 |
| 0.032 | 0.982 | 0.618 |
| 0.037 | 1.06 | 0.666 |
| 0.043 | 1.18 | 0.715 |
| 0.060 | 1.39 | 0.848 |
| 0.065 | 1.45 | 0.880 |