[staplegun]

Originally Posted by tgrayson

Seems like a valid objection. Still, the standard analysis doesn't take this into account, such as here:

http://selair.selkirk.bc.ca/aerodyna...nce/Page5.html

I'll have to check my other references when I get home.

From the same web-site, page 9:

Jet Aircraft

The TSFC of the jet engine improves up to the altitude for the coldest air temperature. In the ISA this is the tropopause. (TSFC holds constant in the stratosphere.)

1. Endurance will increase with altitude as long as temperature decreases with altitude. Maximum endurance will therefore occur at the tropopause.




Kevin