CPC Aircraft Performance & Systems Knowledge for Controllers

Question 1

What is wake turbulence, and from which part of the aircraft does it originate?

Accepted Answer

Wingtip vortices generated by lift production that trail behind and below an aircraft

Answer

Wake turbulence consists of counter-rotating wingtip vortices that form whenever an aircraft generates lift; they sink and trail behind and below the generating aircraft.

Question 2

According to FAA wake turbulence categories, which aircraft type generates the most severe wake?

Accepted Answer

Super category aircraft like the A380 and AN-124

Answer

The 'Super' category (A380, AN-124) generates the most severe wake turbulence, requiring the greatest separation from following aircraft.

Question 3

What is the standard IFR departure separation behind a Heavy jet for a Small aircraft departing the same runway?

Accepted Answer

2 minutes or 3 nautical miles radar

Answer

A small aircraft departing behind a Heavy must wait 2 minutes (or maintain 3 NM if radar is used) to avoid wake turbulence encounter.

Question 4

What does 'MACH tuck' or 'Mach tuck' refer to, and why is it relevant to high-altitude ATC?

Accepted Answer

A pitch-down tendency as an aircraft approaches critical Mach number due to shifting center of lift

Answer

Mach tuck occurs when an aircraft nears its critical Mach number and the center of pressure shifts aft, creating a nose-down pitching tendency that can be difficult to recover from.

Question 5

What is 'coffin corner' and which aircraft type is most susceptible?

Accepted Answer

A narrow speed range at high altitude between stall speed and MMO where there is little margin; affects high-altitude jets

Answer

Coffin corner is the narrow altitude band where an aircraft's stall speed and MMO (maximum operating Mach) converge, leaving almost no safe airspeed range; it primarily affects high-flying jets.

(CPC) Certified Professional Controller Practice Test

(CPC) Certified Professional Controller Practice Test

CPC Aircraft Performance & Systems Knowledge for Controllers