Give reason for the following-
(i) Aeroplanes cannot always follow Great Circle routes.
Answers
Answer:
Explanation:
The shortest and most direct distance between any two points on a map (or a globe) is known as the 'great circle' path. While it might appear intuitive for aircrafts to fly the great circle from it's origin to the destination - it cannot do so, for operational protocols and conventions (which are designed to ensure efficiency and safety of flights).
Most high altitude flights follow a virtual 'highway' in the sky, known as 'victor airways' (or just 'airways'). These airways usually have a name, consisting of numbers and letters (V1, UL32, etc.). A specific airway is a straight line following a great circle path, with named check points to keep track (also known as 'waypoints', with unique lettered names). Some of these checkpoints are virtual 'milestones' in the air, while others could be a reference to an airport or navigation device on the ground. When an airway intersects another airway, it is known as an 'intersection' and is the highway equivalent of a traffic junction.
Without going into any further complexity, what you see as the route of an aircraft in a map is usually the flight path of the aircraft, as it traverses through the airways between its origin and destination. While some short flights have a direct single airway between the origin and destination - most IFR flights traverse several airways, 'changing lanes' at intersections, which make the flight path anything but a direct and straight line.
In modern aircrafts, a flight computer such as the FMS manages the schematics of the flight, including the flight path that the aircraft will traverse. In smaller or older aircrafts, a simpler GPS/GLONASS device would be used, along with redundancies in the form of VOR and NDB radio navigation systems.
Answer
While it might appear intuitive for aircrafts to fly the great circle from it's origin to the destination - it cannot do so, for operational protocols and conventions (which are designed to ensure efficiency and safety of flights).