Balloons that used hot air to rise were developed in the _____.
Correct Answer: 1700s
By the 1700s, man had developed balloons that used hot air to rise, and by 1783, a balloon that could lift passengers was developed.
In 1914, traveling was made better through commercial flying when the first airline flight took off from and landed in:
Correct Answer: St. Petersburg, FL to Tampa Bay, FL
In 1914, Tony Jannus flew passengers from St. Petersburg, Florida to Tampa Bay, Florida.
In 1918, air mail service began between what cities?
Correct Answer: New York, NY and Washington, DC
In 1918 the U.S. Post Office began air mail service. Initially being offered between New York, NY and Washington DC, the service eventually branched out allowing for quicker exchange of mail over long distances.
While very devastating, WWII produced major positive advancements for aviation. Of the following, which is not an official development that occurred during WWII
Correct Answer: Breaking of the sound barrier
Development of jet aircraft, rockets/missiles, fighters and bombers, and women as wartime pilots, all occured during WWII.
The first person to fly faster than the speed of sound was _____.
Correct Answer: Chuck Yeager, a U.S. Air Force pilot
In October of 1947, a skilled US Air Force pilot by the name of Chuck Yeager flew the Bell X-1 at a speed of 807.2 mph with an altitude of 45,000 ft. This became the first recorded manned supersonic flight.
The four forces that enable flight are:
Correct Answer: Drag, Lift, Thrust, and Weight
Yaw occurs about which aircraft axis?
Correct Answer: Vertical
The vertical axis runs from the ‘ground to the sky’ through the center of the aircraft. The aircraft will yaw, or rotate side to side about this axis
The glider’s weight is affected by _____.
Correct Answer: all of the above
Weight is the combined mass of all of the components that make up the glider itself, multiplied by the gravitational pull from earth. Gravitational force is a field force, meaning the earth does not need to be in physical contact with the glider to generate the gravitational force.
What is true about the mass and weight of your glider?
Correct Answer: On the moon, the mass would be the same, but the weight would be less than on Earth.
Weight is dependent upon gravity. Since the gravitational pull on the moon is less than that of Earth, the weight of the glider on the moon would be less. Mass is the amount of matter in an object, so it doesn’t change if the pull of gravity changes.
You can alter the mass and thus the weight of your glider by changing either the _____.
Correct Answer: density or volume
Since mass = density × volume, changing either will change the mass. Mass and weight are directly related, so changing the mass will also change the weight.
Which variables that affect weight are ones you can control?
Correct Answer: Volume and density
What is the mass of basswood wing with these dimensions: 26.9 cm x 5.5 cm x 0.15 cm?
Correct Answer: 9.10 g The volume of this wing is 26.9 x 5.5 x 0.15 = 22.19 cm3. From the table, density is 0.41 g/cm3, so mass = 22.19 cm3 x 0.41 g/ cm3 = 9.10 grams
What is the weight of a glider with a mass of 4.9 grams? (Hint: watch your units!)
Correct Answer: 0.048 N
We need to convert grams to kg (4.9 g x .001 kg/g = 0.0049 kg), then multiply the converted mass by the constant for gravity. Thus, weight = 0.0049 x 9.8 = 0.048 N.
Calculate the planar area of a rectangular wing with a span of 0.205 m and a chord of 0.052 m. (Note: the wing span is the width of the wing and is measured from wing tip to wing tip, or perpendicular to the fuselage. The wing chord is the length of the wing measured parallel or along the length of the fuselage.)
Correct Answer: 0.01066 m2
Calculate LER for the rectangular wing from the previous question if the weight of the glider is 0.0500 newtons.
Correct Answer: 0.2132
LER = Wing Planar Area (WA)/Glider Weight (GW) = 0.01066/0.05 = 0.2132. Please go to the next scenario.
Calculate LER for the same wing if we increase the span to 0.245 m. By increasing the span, we also increase the glider weight to 0.0598.
Correct Answer: 0.2130
WA = 0.245 x 0.052 = 0.01274 m2. Then, LER = 0.01274/0.0598 = 0.2130/. Please go to the conclusion.
Which of the two previously described wing designs should result in a longer flying time?
Correct Answer: Scenario 1
Scenario 1 should be the better design. The Lift Efficiency Ratio helps evaluate the trade-off between a larger wing and added weight. The LER in scenario 1 is slightly greater than in scenario 2, which should result in a longer flying time.
Adding a paper clip to the vertical stabilizer of your glider will have what effect on its Center of Gravity (CG)?
Correct Answer: The CG would move toward the rear.
By adding mass to the vertical stabilizer (which is at the rear of the plane), you will cause the center of gravity to move back toward the rear.
In what ways can you modify the location of the neutral point?
Correct Answer: All of the above.
The position of the neutral point depends on the size of the wing relative to the horizontal stabilizer and the distance between them.
A good rule of thumb is to design the horizontal stabilizer so that its area is about 1/6 to 1/8 of the area of the wing. If the area of the wing is 101.25 cm2, which of the following would be a good horizontal stabilizer design?
Correct Answer: Stabilizer with area = 14 cm2.
A horizontal stabilizer with a 14 cm2 area would be 14/101.25 = 0.138. This is within range (1/6 = 0.167, 1/8 = 0.125).
A positive static margin _____.
Correct Answer: all of the above
The static margin is a positive number if the neutral point is behind the center of gravity and is important for longitudinal stability. A good rule of thumb is to design your aircraft such that the neutral point is less than 1 inch, or 25.4 mm behind the center of gravity.
Which of the following represents the most stable design?
Correct Answer: Static Margin = 24.5 mm
A good rule of thumb is to design an aircraft with a positive static margin that is less than or equal to 1 inch, or 25.4 mm.
Nose-First Dive / Fuselage DesignWhat should you do if your glider dives nose-first, and why?
Design fuselage to absorb impact: strong nose, flexible tail. Tapering the tail increases flexibility, reduces damage.
Principle: Newton’s 3rd Law — the ground “hits back,” so a flexible tail reduces stress on the glider.
Lift and FlapsHow can flaps improve your glider’s flight?
Adjust lift for takeoff, reduce drag in flight.
Principle: Lift depends on wing area, velocity, and angle of attack. Flaps change effective airfoil shape.
