Balance

[kmccune]

Do they have to balance airliners when they seat people ,I know some rubenesque folks get upset when this comes up , I understand the laws and forces of aerodynamics , was just wondering .

[Joe Guy]

Yes. They put the heaviest people over the wheel area so the plane will have enough traction...

[Gob]

I've never been weighed before flying, so no.

It may be a good idea though

[Scooter]

I have been on planes of up to about 80 seats where passengers have been asked if some of them could move forward/back in order to balance the weight. Typically when the plane is fairly empty but all the passengers are bunched at one end or the other.

[dales]

When I was up in Alaska during the late 1960's, we each had to be weighed (including luggage) before we could board the Grumman Goose.

[MG McAnick]

The airlines use an FAA average passenger weight of 190 lbs (increased from 170 about ten years ago) to configure the passenger load so that the center of gravity (CG) will not be too far forward or too far aft of the proper point on the wing. While the allowable envelope of the CG is MUCH wider on an airliner than it is on a small plane, they still have to pay attention to it. You'll never board an airliner with ALL the passengers in the very front or very back.

For the benefit of those on this forum who don't understand aerodynamics and/or weight and balance, I'll offer a brief explanation. Think of the wing of an airplane, large or small, as the fulcrum of a lever. The fuselage is the lever. If there is too much weight in back of the fulcrum, the airplane may be forced into a high angle of attack, climbing too steeply, to the point that the wing will stall. Yes, when the talking head on the TV news says the plane stalled, like it says on the teleprompter, they are talking about the wing stalling. Whether or not they know it, it's not the engine that stalled.

If the weight is too far forward, the wing will not be allowed to increase the angle of attack to the point where it will be able to gain or sustain flight.

[Bicycle Bill]

I was once on a commuter flight between Madison and Chicago, on a Saab 340-B (little 30-passenger twin-engine turboprop).  As we were flying the pilot came on the intercom and said "If everybody would shift position and look out the right-side windows
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..... the plane will tip up onto one wing!"

-"BB"-

[Guinevere]

It depends on the aircraft. When I took a helicopter tour of the Grand Canyon they weighed the passengers and selected where we sat to balance the load.

[MG McAnick]

Helicopters use the same weight and balance principle, except the center of the rotor is the pivot point. The rotor is simply a set of rotating wings, two, three, four, five, or six. The blades are tilted to increase lift.

(Actually helicopters don't fly. It's all an illusion done with thin wires, mirrors, and pictures of the Grand Canyon, or whatever, on a flat TV screen.)

[kmccune]

Thanks for the serious replies ,I have never flown on an airliner (only on scary little planes at bumpy lower altitudes -my last trip wasnt so bad ,I kept running some of the rules and laws of aerodynamics through my mind {didnt bother me as a kid ,scares the crap out of me now } not something I seek out

[oldr_n_wsr]

We had to switch seats to blance the aircrafton a flight I took from LI to Toronto. Twin engine job (maybe tubine engines).
Never saw/experienced seat change requests on a larger jet.