Beware of the Weight Shift

As you burn fuel in flight, the CG may move beyond the limit.

Tip Beech Bonanza
Tip Beech Bonanza

You already know that it is important to do a weight and balance calculation prior to any flight to make sure you don't put too much weight in the airplane and that the center of gravity is within the published limits. But you may not realize that you should do at least two weight and balance calculations.

As you burn off fuel during your flight the weight clearly is reduced. A reduction in weight is only going to bring you further under the max gross weight and is not going to affect the safety of your flight.

However, in some airplanes the center of gravity may move outside the envelope as you burn off fuel. Some Bonanzas, for example, are tail heavy, which means you want to shift as much of the weight forward as possible when you load the airplane to stay within the forward and aft limits. But as you burn off fuel in flight, in the case of the Bonanza, the weight shifts aft. If the CG shifts beyond the aft limit, you could potentially get into trouble as pitch control becomes compromised.

So before you take off in your airplane with a load that you haven't previously calculated, do a weight and balance calculation for the weight at the time of the departure and a second calculation for the landing weight based on the estimated fuel burned during the flight. If you are below max gross weight for takeoff and within the CG range for both the takeoff and landing scenarios, you are guaranteed to be within the limits for the rest of the flight too.

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