multi-engine formula??
 

Some time ago on one of the forums, someone asked if two .25 engines were equal to one .50, far as thrust, etc. Someone replied with some formula, rule of thumb, or something similar. Is there an approximate rule of thumb for calculating this?
Randy

RE: multi-engine formula??
 

Randy:

I don't find it now, but my preference is 60%, in other words a 0.60 single would have 0.36 (or a little larger) engines on it.

Others double the original. A single 0.60 would be replaced with two 0.60 engines.

The 60% rule generally gives about the same performance as the original plane with its single engine.

Anywhere between works.

Bill.