Image map page header with links also located at bottom of page Link to Icing Research Tunnel Virtual Tour Link to Educator Resources Link to Glenn Learning Technologies Homepage Link to Aeronautic Educational Resources Link to Internet Access Research
Left side image map with list of links located at bottom of page Link to Engine Sim Problem Sets Link to Aerodynamics Problem Sets Link to Foil Sim Problem Sets Link to Propulsion General Information and Free Java Software Link to Aeronauts 2000 Link to Foil Sim General Information and Free Java Software Link to Propulsion General Information and Free Java Software Link to Free Software Link to Beginner's Guide to Aeronautics Link to Videoconferences with the U.K. Link to ModelRocketSim Link to Aeronautics Lessons and Activities Link to Engine Sim General Information and Free Java Software Link to Wind Tunnel Web Pages Link to Aerodynamics General Information and Free Java Software Trimmed Aircraft Problems
If so instructed by your teacher, print out a worksheet page for these problems.
Open the slide called Trimmed Aircraft (with text) and read the explanation on how to calculate wing and tail lift and wing and tail distance in trimmed flight.

 

Click on image for detailed description

Total Lift = W + T

 

  1. An airplane in trimmed flight has a wing lift (W) of 30,000 Newtons. It has a wing distance (dw) of 2 meters and a tail distance (dt) of 10 meters, both located aft (behind) cg . (Assume direction aft of cg is positive.)
    1. What is the magnitude of the the tail lift (T)?

      ___________________________

    2. Is the tail lift positive or negative?

      ___________________________

    3. What is the total lift of this trimmed aircraft?

      ___________________________

     

  2. You must design an airplane with a wing that has a lift (W) of 40,000 Newtons, a tail lift (T) of - 8,000 Newtons, and a wing distance (dw) of 3 meters aft of cg.
    1. What is the total lift?

      ___________________________

    2. Aft of cg, what must the distance of the tail (dt ) be?

      ___________________________

    3. Your customer now wants a wing distance (dw ) of 2 meters aft of cg. Aft of cg , what must the tail distance (dt ) be?

      ___________________________

       

  3. Your customer wants the tail in this design placed forward of the center of gravity (a canard configuration).
    1. Is the canard lift in this design positive or negative?

      ___________________________

    2. Forward of cg , what must the distance of the tail (dt ) be?

      ___________________________

    3. Is the canard distance (dt) from the cg positive or negative?

      ___________________________

    4. What is the total lift for this canard configuration?

      ___________________________

    5. How does the total lift differ from the conventional design?

      ___________________________

    6. What type of tail design did the Wright Brothers' Airplane have?

      ___________________________

       

  4. A cargo plane trimmed for normal flight has a total lift of 120,000 Newtons. This aircraft's Wing lift (W) is 150,000 Newtons, and it has a wing distance (dw) of 5 meters behind cg. What is the tail distance (dt) behind cg?

     

     

  5. The airplane in the previous problem had some of it's cargo shift aft. This caused it's cg to shift 2 meters aft.
    1. What is dw now?

      ___________________________

    2. What is dt now?

      ___________________________

    3. With no adjustment by the pilot, what will the airplane do?

      ___________________________

    4. If wing lift (W) remains constant, to what must the pilot adjust tail lift (T) to maintain trimmed flight?

      ___________________________

 

Please send any comments to:
Curator: Tom.Benson@grc.nasa.gov
Responsible Official: Kathy.Zona@grc.nasa.gov