Medium Altitude Endurance study conducted by Center for Naval Analysis
The main criteria CNA posited for a MAE UAV appropriate for shipboard ops :
• 24 hours on station at 500 mmi
• Takeoff weight under 3000 pounds
• Extremely short takeoff and landing (ESTOL) for minimal impact to flight deck operations
• 300 pound payload capability
• Mechanical simplicity
The CNA study
In 1999 CNA performed a comparative analysis of four shipboard ops concept UAVs: (i) fixed-wing UAV, (ii) STOVL tilt-rotor, (iii) low disc-loading helicopter UAV, and (iv) freewing tilt-body UAV. Preliminary conclusions about their relative merits are listed in this table, and led to a more rigorous study, portions of which we excerpt, below:
| Fixed-Wing | Tilt-Rotor | Low Disc-Loading Helo | Freewing Tilt-Body |
| A 2-stroke diesel, fixed-wing UAV would have the range and endurance required, but would not be easily integrated into carrier operations. | A V/STOL UAV, such as the tilt-rotor, could be better integrated into flight deck operations but severely compromises range and endurance. | Sensitive to turbulence, especially wake turbulence downwind of superstructure during landing ops. | The only air vehicle concept that seems to be able to (in theory) satisfy these objectives is the Freewing, tilt-body concept. |
