Do not use HDG SEL or ROLL CWS north of ______ N. or south of ______ S.

• A. 89°30'
• B. 90°00'
• C. 88°15'
• D. 89°00'

Answer: (A)

The key idea is that polar regions can disrupt heading and roll control references. HDG SEL and ROLL CWS depend on stable reference data, but near the poles the meridians converge and magnetic/gyro references become unreliable. To avoid unsafe control behavior, certain autopilot modes are restricted beyond a latitude boundary.

For the P-8A limit, that boundary is 89°30' in both the northern and southern hemispheres. So you’re not to use HDG SEL or ROLL CWS north of 89°30' N or south of 89°30' S.

That’s why 89°30' is the correct fill for both blanks. The other values place you either at or beyond the pole or inside a region where the limit isn’t defined for these modes, which is not correct per the operating limitations.