Several readers have asked for the weights of the Green Flight Challenge competitors. Here they are, pound for pound, among the most efficient flying machines on the planet.
Those who wish can calculate different takes on that efficiency, including overall glide ratios for the course, ton-miles per gallon energy equivalent, or more exotic parameters.
|
Empty Weight |
Takeoff Weight in Competition |
|
|
Pounds |
Pounds |
|
| e-Genius |
1670.2 |
2070.2 |
| Pipistrel G4 |
2491.0 |
3294.1 |
| Embry-Riddle |
1970.0 |
2370.0 |
| Phoenix |
754.0 |
1199.7 |
Comments 2
For the Pipestral G4 assuming a 0.85 efficiency in converting battery energy (65.4kWh) into thrust, I calculate that it achieved an effective L/D of 23.1:1. If that efficiency was 0.8 then glide angle was 24.5:1.
Rutan Model 76 Voyager had estimated 27:1 on its round the world flight (186km/hr).
Virgin Atlantic Global Flyer had estimated L/D of 37:1 on its round the world (590km/hr).
Comparison is not fair – given the fact that energy was measured for a full flight, including take-off, climb, etc, and not only during cruise. So also your L/D assumptions may be called “average flight L/D”, nothing more, nothing less. The L/D of the Taurus G4 at 115 mph is upwards of 28:1.