
FoilSim
Characteristics of Lift and Wing
Area
Answers


 Use FoilSim
to answer the following questions :
 You are flying a 10,000 pound airplane( this
includes personnel and cargo) at an altitude of 2,000 feet. The
wings have an angle of attack of 5 degrees, a camber of 8.75%, a
thickness of 15%, and an area of 100 square feet. What airspeed
should you attain to have to maintain your altitude?
156.4 mph
 Your plane drops 1,500 pounds of supplies to relief
workers. Enter your new weight. What angle of attack will maintain
your altitude of 2,000 feet?
Weight = 8,500 pounds  angle = 2.93 degrees
 You make another drop of supplies, this time 750 pounds of
food. To what value should you change your wing area to
maintain your altitude of 2,000 feet?
Weight is now 7,750 pounds  area = 88.3 sq ft.
 The wings of the airplane you are flying are shaped like the
right triangle below.
 The total area for both of your wings is your
answer in 1c. Knowing the area of a triangle = 1/2 base x
height. What is the length of the base if the height of the
wing is 5 feet?
Area of 2 wings = 88.3 sq ft, area of 1 wing = 44.15 sq ft. A = .5 b h, h = 5, b = 17.66 feet.
 Suppose the total area is 120 square feet, and the base of
1 wing is 20 feet. What is the height?
Area of 2 wings = 120 sq ft, area of 1 wing = 60 sq ft. A = .5 b h, b = 20, h = 6 feet.
 Set these initial conditions:
Airspeed: 100 mph
Altitude: 20,000 feet
Angle: 1.5 degrees
Thickness: 5%
Camber: 3.75%
Select 10 different values of Area between 200
and 700 square feet and record the corresponding values of
Lift.
Answers will vary .. here's a sample
Area (sq. ft.)

Lift (lb.)

200

1750

250

2188

300

2626

350

3063

400

3501

450

3939

500

4376

550

4814

600

5252

650

5690

675

5908

700

6127

 Graph Lift vs. Area with the values you
obtained.
 What did you notice about the line connecting the points
you graphed?
Graph is a straight line.
 From your graph determine the amount of lift you would
generate if you had an area of 550 square feet. Check your
answer by entering 550 square feet for the area and observing
the amount of lift generated.
Area = 550, lift = 4814 pounds
