PoF Chapter 13 High Speed Flight

As the speed of the aircraft decreases:

• Shockwaves start to form first at the lower surface of the wing above Mach 1

• Shockwaves start to form above the upper surface of the wing below Mach 1

• The distance between the aircraft and pressure waves decreases

• The distance between the aircraft and pressure waves increases

Mach number will...

• increase if altitude is decreased at a constant CAS

• decrease if altitude is decreased at a constant IAS

• decrease if altitude is increased at a constant IAS

• decrease if altitude is increased at a constant TAS

Which of the following statements is correct regarding change of TAS with constant Mach number?

• As altitude increases, the temperature will drop, local speed of sound will decrease and TAS will increase

• As altitude decrease, the temperature will rise, local speed of sound will decrease and TAS will increase

• As altitude decreases, the temperature will rise, local speed of sound will increase and TAS will increase

• As altitude increase, the temperature will increase, local speed of sound will decrease and TAS will decrease

Which of the following statements is correct?

• The thinner the wing, the higher the M_CRIT

• The thicker the wing, the higher the M_CRIT

• The higher the angle of attack, the higher the M_CRIT

• The higher the air density, the higher the M_CRIT

Which of the following statements is correct?

• The airflow velocity increases when flowing through a normal shockwave

• The airflow direction does not change when flowing through an expansion wave

• The airflow direction does not change when flowing through a normal shockwave

• The airflow direction does not change when flowing through an oblique shockwave

When airflow passes through a normal shockwave:

• density increases

• velocity increases

• temperature decreases

• static pressure reduces

As speed increases above M_CRIT, shockwaves starts to form and:

• lift increases

• drag increases

• weight increases

• thrust decreases

Which of the following statements is correct?

• The wing root usually has a thicker section than the wing tip so will have a lower M_CRIT

• Shock-induced separation will occur at the wing tip first

• For a swept back wing, the CP will move towards the tip, causing the aircraft to pitch nose down

• For a swept back wing, the CP will move towards the root, causing the aircraft to pitch nose down

A heavier aircraft will encounter:

• coffin corner at a lower altitude

• coffin corner at a higher altitude

• higher stalling angle

• slower stall speed

Which of the following statements is correct?

• vortex generators result in a lower M_CRIT

• thinner wings have a lower M_CRIT

• sweepback wings have a higher M_CRIT

• thicker wings have a higher M_CRIT