The big engine small plane problem


Well-Known Member
Jul 15, 2010
Fayetteville, AR / USA
Something that seems to be lost on many people.

You can only afford a certain fuel burn in a small airplane, in both dollars and range. Increasing the cruise fuel burn through any means: larger engine, turbo, whatever; impacts the design in a negative way.

You must fix the landing speed at something reasonable. Gust loading limits top speed for a given Q. Therefore additional fuel burn does not help you in any way other than climb rate. This is important for a fighter, not so much for a GA aircraft.

How to best put your additional wing area and fuel burn to use is the issue.

Two solutions emerge:

CS prop, turbo, small engine. (ideal)

Large engine, fixed pitch. (not so ideal...but it works, with a weight penalty)

both cruise at high altitude.

Do the math before you argue....please.