Glide Flight Performance Characteristics

This code is a GUI type that calculates the Glide flight performance for both Minimum Sink Rate and Minimum Glide Angle (Flattest Glide). The code outputs are:

For Minimum Glide Angle:

• Minimum Glide Angle.
• Flight Speed (For Minimum Glide Angle).
• Lift Coefficient (For Minimum Glide Angle).
• Drag Coefficient (For Minimum Glide Angle).
• Flight Efficiency (For Minimum Glide Angle).
• Flight Range (For Minimum Glide Angle).
• Flight Time ‘Endurance’ (For Minimum Glide Angle).
• Sink Rate (For Minimum Glide Angle).

For Minimum Sink Rate:

• Glide Angle (For Minimum Sink Rate).
• Flight Speed (For Minimum Sink Rate).
• Lift Coefficient (For Minimum Sink Rate).
• Drag Coefficient (For Minimum Sink Rate).
• Flight Efficiency (For Minimum Sink Rate).
• Flight Range (For Minimum Sink Rate).
• Flight Time ‘Endurance’ (For Minimum Sink Rate).
• Minimum Sink Rate.

Required Inputs are:

To run the program you need to insert the following six values:

• Initial Glide Height.
• Final Glide Height.
• Reference Area
• Airplane Weight
• Zero-Lift Drag Coefficient CDo
• K: constant of CL^2 in the drag polar equation (CD = CDO + K*CL^2)

The code based on Pamadi[1] and Saarlas[2] equations of performance of jet engine aircraft in cruise flight.

Example you can try with this program:

A glider having weight W = 2000 N, reference area S = 8.0 m2, and drag polar given by CD = 0.009 + 0.06CL^2, is launched from a height of 300 m. Determine the maximum range, corresponding glide angle, forward velocity, and lift coefficient.

Used Terms:

• L: Lift
• D: Drag
• CD0: Zero-Lift Drag Coefficient
• K: Weight of CL^2 in Drag Polar (CD = CD0 + K*CL^2)
• CL: Lift Coefficient

Program Interface:

The Program has one interface where you need to inter 6 requirements from the studied airplane and you will get 8 results for each case, there are a chart you can present it by clicking on the button ‘Show Chart’ this chart explains some of the parameters you are going to find.

Notes:

1. The negative sign for Glide Angle means the the flight in tending downward.
2. The final height of the airplane is zero ‘0’ or any flight less than the initial one.

References:

[1] Bandu N. Pamadi, Performance, Stability, Dynamics, and Control of Airplanes, Second Edition,  at NASA Langley Research Center, Hampton, Virginia.

[2] Maido Saarlas, Aircraft Performance, Department of Aeronautics Engineering at U.S. Naval Academy.