EAA Sport Aviation - February 2011

establishes how heavy it can be and still perform according to a set of criteria, for example, the ability to climb at a certain minimum number of feet per minute. There is a direct, inverse relationship between aircraft weight and performance, obviously. More of the first leads to less of the second.

Weight is especially significant for those of us who fly lightweights. Not to dismiss the importance of weight for a Cessna 172 or a Piper Cherokee, but a few extra pounds can mean a lot more to us. For ultralights and light-sport aircraft (LSA), which start out life not much less than MTOW and with engines operating at some large percentage of full power just to keep the airplanes aloft, there isn’t much margin left after pilot and fuel are aboard.

A friend of mine (we’ll call him Darius) was determined to get his 1946 Ercoupe 415-C down to its official empty weight of

While having a specific number for maximum takeoff weight is good, we are probably better off regarding higher weights as a range, rather than fixating on one number.

820 pounds. Inspired by the thought of an improved climb rate and being able to travel greater distances on his frequent cross-countries, he removed everything not officially listed as part of the airplane’s type certificate in 1946.

When Darius attended Ercoupe fly-ins,
he looked at the other Ercoupes not only
with the usual desire to see how sleek their
owners had made them, but also to guess
how much weight they had gained in the
process. A few had the factory-standard
wooden prop, which weighed 12 pounds
less than a metal one, and all had a standard
upgrade for the baggage compartment,
adding 65 pounds. Metal wings were
common and weighed 13 pounds apiece
more than fabric. Almost all had complete
paint jobs, typically adding 14 pounds. Most
had 30-plus-pound custom interiors. Most
had elaborate (and heavy) instrument
panels. Almost all had starters, generators,
and batteries.