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Weight and Strength

How Does an Aircraft Balance Weight and Strength?

Finding a safe compromise between low weight and high strength is critical when creating an aircraft. Aircraft structures must be light yet strong and stiff enough to resist the various forces acting on an airplane during flight. They must also be durable enough to withstand these forces over the airplane’s entire life span.

Wings don’t have to be heavy to be strong. This pilotless aircraft called Theseus was built for high-altitude research flights. The skin consists of a honeycomb material sandwiched between layers of woven carbon fibers embedded in a plastic resin. Similar stiff, lightweight materials are used on other types of aircraft.
Credit: Aurora Flight Sciences, Manassas, Virginia

Any aircraft design is a carefully planned compromise in which many competing factors are traded against one another: payload capacity, cost, range, speed, fuel economy, durability, noise levels, required runway length, and many others. The function of an aircraft—whether an airliner or a fighter, a business jet or a private airplane—is the major influence in balancing these factors. The best design typically provides maximum performance at the lowest weight.

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Ask an Explainer

Q:

Is it really important for an airplane to be lightweight?

A:

The less weight an airplane has the less work the engines have to do, the less fuel it uses, and the farther it can fly. Every bit of weight saved in construction means extra payload (more luggage and/or passengers) can be carried, so the company makes more money.

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Did You Know?

A big focus in the design of airplanes is to make them weigh as little as possible. Materials engineers study materials, both conventional and composite for use in airplane structures. Some areas of concern are the strength and rigidity of the material, its availability, its ease of processing, and its resistance to temperature and fatigue.

Pop Quiz

Excessive weight reduces the efficiency of an airplane.

A) True
B) False

True: Using strong, lightweight materials in airplane design is extremely important for increased efficiency.  Excessive weight can negatively affect an airplane’s speed, take-off and landing distance, rate of climb, ceiling (maximum altitude), maneuverability, and range.  Excessive weight often requires a pilot to reconsider the requirements of the trip.  If maximum range is required, occupants or cargo loads must be decreased.  If a maximum load must be carried, the maximum range of the airplane must be decreased.