Accelerating past the critical Mach number may result in which compressibility-related issue?

Accelerating past the critical Mach number may result in which compressibility-related issue?

• A. Control Difficulties
• B. Increased Engine Thrust
• C. Reduced Climb Performance
• D. Improved Stall Characteristics

Answer: (A)

When you accelerate into transonic speeds, parts of the airflow over the wing reach Mach 1 and a shock wave forms. This compressibility effect changes the pressure distribution and greatly increases wave drag. The shock and the associated flow changes can cause boundary-layer separation around the wing and especially on control surfaces, which reduces their effectiveness. With reduced control authority, pilot inputs produce smaller or less predictable responses, so handling becomes more difficult—that’s the compressibility-related issue described. The other choices don’t fit as the primary consequence: thrust isn’t inherently increased by passing the critical Mach number, climb performance isn’t the direct compressibility effect in this context, and stall characteristics aren’t improved by transonic flow.

When you accelerate into transonic speeds, parts of the airflow over the wing reach Mach 1 and a shock wave forms. This compressibility effect changes the pressure distribution and greatly increases wave drag. The shock and the associated flow changes can cause boundary-layer separation around the wing and especially on control surfaces, which reduces their effectiveness. With reduced control authority, pilot inputs produce smaller or less predictable responses, so handling becomes more difficult—that’s the compressibility-related issue described.

The other choices don’t fit as the primary consequence: thrust isn’t inherently increased by passing the critical Mach number, climb performance isn’t the direct compressibility effect in this context, and stall characteristics aren’t improved by transonic flow.