Ask Captain Lim

Hello Capt Lim,

I've been looking for an answer for my doubt in all internet, ant the most closer I´ve found was in your WEB site.

My question is, Why the transcontinental flights are curved?

You wrote that a 747 makes a straight line between TYO and LAX, but it appears to be curved. I understand in very well.

I flew from Frankfurt to Mexico City. On the monitors I saw that the aircraft went to the North, it flew over United Kingdom, Greenland, Canada, U.S. and Mexico, but it cross U.S. by the middle of it, (over Kansas). It may be same that TYO - LAX, but I still feel it went too far.

My sister traveled from LAX to Melbourne (or Sydney, I don't remember exactly), and she said that the monitors shown a route in "s" (to the North and then to the South)

Is it all the same? for describing a smallest distance between to points in a sphere?

Greetings,

Rolando Venegas

Hi Rolando,

]If you have read my explanations in my earlier FAQs, Airlines will endeavor to fly the nearest air route to save cost, a straight line like how a crow will fly, so to speak. Transcontinental flights are never curved but appears to be so on maps found on the Cabin TV screens or magazines because all the maps you see are not the real representation of the Globe. A real and correct representation between two points is the air routes found on a Globe map. The next time you see a curve route, tell yourself that it is actually a distorted representation only - it is in fact the shortest possible air route flown! Of course, some routes are slightly curved due to the nature of the routes, mainly because it was designed to avoid or take advantage of strong jet streams, especially those air routes across the Atlantic Ocean.

Your description of the journey from Frankfurt to Mexico appears to be normal because, the Airline was attempting to fly a Great Circle route, which is the nearest route between two destinations on the earth. It would be uneconomical to deliberately fly a longer route.

Your sister's description of a 'S' air route between Los Angeles and Melbourne is rather abnormal. If it were so, the airplane was merely doing a minor air diversion due to weather, but definitely not a short air route at all!