Aerospace Knowledge Quiz

What mainly determines the speed of sound in the atmosphere?

• Air density

• Air temperature

• Altitude

• Humidity

At a constant IAS, Mach number will:

• Increase with altitude

• Decrease with altitude

• Stay the same at all altitudes

• Depend only on humidity

Stall speed increases when:

• Air density increases at low altitude

• Altitude increases due to lower density

• Temperature increases significantly

• Thrust-to-weight ratio is higher

The speed ranges are usually divided into:

• Transonic → Hypersonic → Subsonic

• Supersonic → Transonic → Subsonic

• Subsonic → Transonic → Supersonic

• Subsonic → Supersonic → Hypersonic

When an aircraft reaches its Critical Mach number:

• Shock waves begin to form on the wing

• Stall occurs immediately

• The center of gravity shifts aft suddenly

• Lift increases abruptly

Mach tuck can be described as:

• Nose-up pitching moment at low AoA

• Nose-down pitching moment due to aft CP shift

• Rolling moment caused by asymmetric stall

• Yaw instability at high Mach

Conventional empennage configuration refers to:

• Elevator mounted on fin

• Horizontal tailplane behind main wing

• Tailplane in front of main wing

• V-tail arrangement

T-tail configuration has the elevator:

• Mounted at the bottom of fin

• Attached at mid-fuselage

• Located on top of vertical fin

• Placed in front of the wing

V-tail combines the function of:

• Elevator and ailerons

• Elevator and rudder

• Rudder and spoilers

• Stabilizer and canard

Coffin corner is the flight condition where:

• High-speed buffet occurs only

• Aircraft faces both shock stall and low-speed stall limits

• Climb rate is maximum

• Lift-to-drag ratio is highest