Gossamer Albatross II — same span, two-thirds the areavsSchempp-Hirth Standard Cirrus — 15 m, two Wortmann sections
root section l7769 → fxs02196 · tip section — → fx6617a2 · tip cap reach 0.200 → 0.450 · area 45296522 mm² → 10001997 mm² · tip chord 1404 mm → 345 mm · sweep parameter 7.476 → 2.946
units
These analyses are not directly comparable
- different trim loads (991 N vs 3237 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
- Schempp-Hirth Standard Cirrus — 15 m, two Wortmann sections
What changed
| Property | Gossamer Albatross II | Schempp-Hirth Standar… | Change | % |
|---|---|---|---|---|
| Geometry | ||||
| Span | 29260 mm | 15000 mm | -14260 mm | -48.7% |
| Root chord | 1651 mm | 855 mm | -796 mm | -48.2% |
| Tip chord | 1404 mm | 345 mm | -1059 mm | -75.4% |
| Sweep parameter | 7.476 | 2.946 | -4.530 | -60.6% |
| Dihedral | 3.60° | 2.00° | -1.60° | -44.4% |
| Tip twist | 0.00° | -2.00° | -2.00° | — |
| TE thickness | 2 mm | 2 mm | +1 mm | +33.3% |
| Tip cap reach | 0.200 | 0.450 | +0.250 | +125.0% |
| Derived | ||||
| Aspect ratio | 18.901 | 22.496 | +3.595 | +19.0% |
| Area | 45296522 mm² | 10001997 mm² | -35294525 mm² | -77.9% |
| Taper | 0.850 | 0.404 | -0.447 | -52.6% |
| MAC | 1552 mm | 705 mm | -847 mm | -54.6% |
| Sections | ||||
| Root section | l7769 | fxs02196 | changed | — |
| Tip section | — | fx6617a2 | changed | — |
| Shapedeviation at matched span fractions, 64 samples | ||||
| Chord deviation (max) | 1059 mm | |||
| Chord deviation (RMS) | 886 mm | |||
| Twist deviation (max) | 2.00° | |||
| Dihedral deviation (max) | 659 mm | |||
| Tip cap deviation (max) | 7622 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×); “Schempp-Hirth Standar…” integrates to CL 0.052 against the polar’s CL at the same α (this analysis predates the loading reporting its own) 0.541 (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.
air, ρ = 1.225 kg/m³
data
| CD | Gossamer Albatross II | Schempp-Hirth Standar… |
|---|---|---|
| 0.012 | 0.374 | 0.514 |
| 0.012 | 0.418 | 0.541 |
| 0.013 | 0.419 | 0.541 |
| 0.013 | 0.472 | 0.574 |
| 0.014 | 0.535 | 0.625 |
| 0.015 | 0.535 | 0.626 |
| 0.017 | 0.613 | 0.703 |
| 0.017 | 0.635 | 0.731 |
| 0.020 | 0.709 | 0.814 |
| 0.022 | 0.748 | 0.867 |
| 0.025 | 0.829 | 0.958 |
| 0.028 | 0.896 | 1.04 |
| 0.032 | 0.982 | 1.13 |
| 0.039 | 1.11 | 1.28 |