Expert: Capt Paul - 4/7/2007

Question
Sir,

Please confirm whether aerial distance between two airports and road distance between the same two aiprort can be the same..?

In reference to the query.. Hyderabad Aerodrome in India and a town named "Warangal" aerodrome calculated aerial distance is 144kms. Where as the road distance between the two cities is also around 145-150 Kms.
I have calculated the aerial distance by selecting the aerodrome reference points ( latitude and longitude) of these two airports.
Can you please advise whether aerial and road distances can be same which is not logical..?
if not, how do i calculate the aerial distance between two aerodromes?
Looking forward to hearing from you.
Thanks.

Answer
Yes, they can be the same.  Imagine for a moment, that an airplane traveled to a place by following a given road.  The aerial distance and the road distance would be the same.

Now, imagine that a perfectly straight road existed between two airports.  In effect, the aerial distance and the road distance would be the same.

For longer distances, the road would have to follow a "Great Circle" path over the ground, and then, the distances would again be the same.

Cheers