What is the motivation behind the flight range limits?
Rules on flight range limits (particularly the One sea Zone Rule) are designed to impose a measure of historical realism. Axis & Allies (like all wargames) is an abstraction of reality, of course, but even granting that, the 2nd Edition rules on aircraft flight ranges are too unrealistic. For example, 2nd Edition rules allow German fighters that begin their turn in Western Europe to fly three spaces and attack Moscow (that is, provided they have a place to land). It is more realistic to require these fighters to redeploy to new bases before launching an attack. [In later rules sections, aircraft combat range is restricted even more].