THEORY OF FLIGHT M11.1 Flashcards
Which form of drag is reduced by boundary layer control?
Wave drag
Which of the following statements is true?
Spoilers and speed brakes always reduce lift and increase drag
Spoilers only increase drag and speed brakes reduce lift
Speed brakes only increase drag
Spoilers and speed brakes always reduce lift and increase drag
How are the leading edge devices (slats) deployed?
By the same lever as for flap deployment
Regarding aerodynamic heating, which material loses 80% of its strength at 250°C?
Aluminium alloy
What can be said about changes in velocity, pressure, and density in a shockwave?
Changes occur suddenly and sharply
What happens to the airflow as an aircraft approaches the speed of sound Mach 1?
Areas of supersonic airflow increase and shockwaves move closer to the trailing edge
What is the increase in lift provided by a slat?
Up to 35% lift
When does the boundary layer lose contact with the surface?
When the kinetic energy inside the boundary layer is too low
What is the critical Mach number?
The point at which the local airflow reaches Mach 1
When is a control surface correctly balanced?
When the centre of gravity of the surface is located on the hinge line
What is done to prevent extreme pressures and temperatures at the engine compressor during high speed flight?
1 normal shockwave and up to 3 oblique shockwaves are formed to slow the airflow
What is the disadvantage of an anti-balance tab?
The pilot requires more effort to deflect the control surface
How is profile thickness expressed in aerodynamics?
As the relationship between actual thickness divided by chord length
