Stall begins where the local angle of attack reaches the airfoil’s critical value, and for an untwisted rectangular wing the inner portion encounters that condition first. The flow over the wing changes from attached to separated when the local angle of attack becomes too large. In a simple rectangular wing with no washout, the inner section (near the root) tends to reach that critical state before the outer sections, so the stalled region starts at the root and then expands outward toward the tip as the overall angle of attack is increased. This pattern helps explain why the statement is true: stall initiates at the root and progresses toward the tip. The other conditions—supersonic speeds or turbulence dictating stall location—do not define the basic inboard-to-outboard progression on a rectangular wing.

Turn rate rises when the bank angle is increased and when the airspeed is reduced. In a coordinated turn, the horizontal component of lift provides the centripetal force that makes the aircraft follow a circular path. Increasing bank tilts more lift into the horizontal direction, strengthening that centripetal force and making the aircraft turn more quickly. Slower airspeed means you need less forward speed to complete the same circular path, which reduces the radius of the turn and also makes the turn feel faster. Mathematically, turn rate is proportional to tan(bank) divided by speed, and the turn radius is proportional to speed squared divided by tan(bank). So increasing bank and decreasing airspeed simultaneously increases the rate of turn and decreases the turning radius, which is exactly what's being sought.

In a level turn, lift must balance the weight. When airspeed increases, the lift tends to rise because dynamic pressure is higher for the same angle of attack. To keep the airplane at the same altitude, you need to reduce lift back to the level required for the current bank angle. The straightforward way to do that is to decrease the angle of attack, which lowers the lift coefficient and brings the total lift back to what’s needed to balance weight. If you instead kept the same angle of attack or increased it, lift would stay high or rise further, causing the airplane to climb rather than stay level. Increasing bank angle would change the required lift (and the turn dynamics) but isn’t the direct method to maintain altitude when speed has increased.

Choosing enroute altitudes is about safety and efficiency, driven by terrain clearance, airspace structure, and navigation coverage. You select altitudes that provide enough obstacle clearance along the route and adhere to minimum altitude provisions, so you don’t risk terrain or obstacle incursions. The airspace around the route also constrains your choice, since you must operate within the permitted altitude blocks and maintain required vertical separation from other air traffic and ATC procedures. Navigation coverage matters because you need reliable guidance for fixes and course changes; if you’re in a segment with weak nav signal, you’d need to adjust by staying in good coverage or using RNAV capabilities. The pilot’s personal schedule isn’t a factor in this decision because it doesn’t affect safety, obstacle clearance, or navigation reliability.

Wind shear in areas of convective activity and frontal zones can cause sudden, dangerous changes in airspeed and flight path. The best way to mitigate this is to avoid the affected area if at all possible and follow ATC directions to reroute around active convection. If avoidance isn’t possible, you should enter with an appropriate airspeed and be prepared for rapid changes, staying alert for gust fronts and wind shifts. Relying on a higher airspeed alone doesn’t eliminate shear effects, descending rapidly can put you into more severe conditions, and ignoring ATC advisories is unsafe and increases risk.