Altitude question
Trying to fill lockdown I am using x-plane 11 FliSIm and trying to fly a 737-800 and very interesting it is too. I am a retired helicopter pilot so altitude/economy was not the problem it is for jet aircraft. (Although it was to some extent on the Commercial Chinook.)
Jet aircraft fly as high as possible for the best fuel economy. As trip distances decrease there must come a point when the shorter distance makes it uneconomical to climb to cruise at FL350 plus. Is there a formula/accepted practice that determines the best altitude to fly over any distance less than the minimum required to make flight at FL350 economical? I'd appreciate any details.