Remember this airline route needs to make the longitude and latitude smaller

I believe, if memory serves right, it is the great circle route. The great circle route is Northeast to Michigan, to Newfoundland (sometimes a stopover at Gander) to Ireland, and then onto heathrow in London.

The great circle route is the arc across the earth's surface that is defined by a plane containing (a) the starting point, (b) the ending point, and (c) the center of the earth. Here's a neat on-line tool that can plot the great circle route for any two points:

Great Circle Mapper