The Fallacy of Full Fuel & Full Seats
Most GA airplanes were never designed to be able to fill the tanks and the seats with adults. Heck, even the widebody airplane I fly for a major carrier can’t do this. Yet, the misunderstanding of this subject persists to the point where buyers still reject viable market offerings for this very reason.
Let’s take a deeper dive into the subject.
First, one has to realize that both variables (the number of seats and the capacity of the fuel tanks) is often decided upon purely for marketing purposes so that a manufacturer can say, often in the same ad, that their plane will go XYZ miles and that it has a 4, 6, 8, or whatever seating capacity. What they don’t tell you, unless it’s in the little bitty print at the bottom of the page, is that the airplane can’t do these things simultaneously.
Take the A36 Bonanza, for example. Let’s pretend we’re looking at a model with a 1300 lb useful load. The airplane has 6 seats and two tanks that add up to 74 gallons of fuel, which equals 481 lbs of gas. Subtract this from the useful load and you’re left with 819 lbs for passengers and bags, which equates to just 4, 180 lb people plus a little extra. No, you cannot fill both fuel and seats, but with 4 people you can fly for 3.5 hours with reserve.
The pragmatic question then becomes, when you have a group of 4 people together, how many of them will likely be able to sit for that long without having to use the restroom?
For another example, let’s look at a Saratoga with 1150 lbs of useful load. This airplane came out of the factory with a whopping 107 gallon fuel capacity (102 usable). That’s over 5 hours aloft, plus reserves, on one tank of gas! With those full tanks there will be just 487 lbs for people and bags. But, again, if you were able to fill all 6 seats do you think all of those folks will make it for 5+ hours without needing to empty a bladder? The answer is an emphatic “NO!” But, if you have just one or two people who really want to stretch the legs of the airplane — and don’t mind relieving themselves in front of one another — then you can go a long, long way.
Besides, how often are you going to fill every seat? In the 5 years we’ve owned our current airplane, we’ve never filled all 6 seats. 5, yes. 6, no.
The clear solution is to buy a plane that will fit 75-80% of your mission. If you need to fly 6 people non-stop halfway across the country, just take the airlines or drive. Trust me, that strategy will not only make you a happier aircraft owner, it will keep your bank account happier too.
In any case, get past the notion that you can buy a single-engine GA airplane and fill the seats and the tanks. Because, unless you have a family of very tiny people, it’s just not going to happen.