Statement of Work
Proposals with a statement of work are normally prepared in cooperation with the prospective client. Your proposal will include cost and calendar schedule and are based on estimated man-hours per task.
DARcorporation's success as a leading provider of contractual technical services usually results in long-term partnerships that go far beyond the initial assignment. A typical design and analysis task will include:
- Sizing of the airplane to a given mission specification.
- Continue work on definition of the following parameters: Take-off Weight, Empty Weight, Mission Fuel Weight, Take-off Power, Wing area and Maximum Lift Coefficients. Class I Drag.
- List comparative airplanes with similar mission performance:
- Overall Configuration Selection
- Fuselage Layout
- Propulsion System Integration
- Wing and Empennage Planform Parameters
- Type and Size of High Lift Devices
- Landing Gear Type
- Class I Weight and Balance
- Preliminary arrangement drawings
- Class I Stability and Control
- Iterations on weights and L/D
- Dimensioned Three-view Drawings
- Major Systems. General system arrangements and location in the airframe.
- Landing gear tires and struts sizing. Verification of landing gear disposition.
- Initial structural arrangement drawings
- V-n diagrams
- Class II weight calculations with center of gravity locations.
- Engine inclination determination
- Calculation of hingemoment derivatives and coefficients for elevator, aileron and rudders. Elevator, rudder and aileron sizing, including horn balance and tabs.
- Lift versus angle of attack curves for power-off, power-on, clean, take-off and landing condition.
- Verify trimmed maximum lift coefficients for the defined flight conditions and flap size verification.
- Calculation of zero angle of attack pitching moment, lift coefficients and stability & control derivatives for the defined flight conditions at forward and aft center of gravity.
- Trim diagrams for the defined flight conditions.
- Stick force, stick-force-gradients and stick-force-per-g gradients for the defined flight conditions at aft and forward center of gravity. DARcorporation will determine whether down-spring and/or bob-weight installation are required. Where necessary, design adjustments will be suggested. Lateral-Directional trim. Control forces will be calculated for different flight conditions for several different bank angles and sideslip angles. Control forces will be compared with applicable FAR regulations.
- Class II (detailed) drag calculations for several flight including power effects:
- Performance calculations for:
- Cruise (maximum speed, range, endurance and payload-range diagram)
- Climb (Rate of climb)
- Take-off
- Landing
- Stall speed
- Maneuver
- Dynamics:
- Calculation of the moments of inertia of the airplane at three different weights.
- Determination of the longitudinal and lateral-directional transfer functions of the airplane.
- Calculation of the damping ratios, frequencies and time constants of the airplane, compare with FAR requirements. This will determine short period, phugoid, spiral, roll and dutch-roll behavior.
- Where necessary, design adjustments will be suggested.
- Preliminary layout drawing for all essential airplane systems.
- Preliminary manufacturing breakdown
- List maintenance and accessibility requirements.
- Preliminary cost analysis
- Detailed loads analysis
- Detailed structural design
- Wind tunnel testing and program management
Please Contact DARcorporation for additional information.