How would you weigh a plane without scales?

( this a question that is listed as one that could be asked at a job interview, and I am trying to prepare)

Tracy L2012-09-12T14:43:16Z

Favorite Answer

Just a question on creativity! There are several ways, one park the plane on a platform attached to a steal lever with a weight platform on the other end, add weights until the bar is level. You now know the weight of the plane. (Like using a "see-saw" when you were a kid.). Another way would be to attach a rope to a hook at the balance point of the plane. Route the rope to a pulley route the other end to a platform to which you add weight. When the plane lifts, you have the weight. I also know you could place the plane on a barge, measure how much water is displaced by the addition of the plane. Calculate the weight.
Now for the one I really like and actually should work.

Use a tire pressure gauge and a ruler.

Find the tire pressure of each tire using a gauge.
Measure the area of the tire rubber that touches the ground, using the ruler.
Plug in the values of all tires, one by one, by using the Physics formula, pressure equals force divided by surface area (P = F/A). In this instance, the force is equal to the weight an object asserts on the tires.
Solve the equation by rearranging the values to read that force equals the surface area times tire pressure (F = P x A). When you multiply square inches (surface area) by pounds per square inch (tire pressure), the square inches cancel out and you are left with pounds, which is the weight each tire is carrying.

Add together the values of all the tires to get the combined weight of the airplane.
Done!
OK, I stole that one from e-how
http://www.ehow.com/how_7248259_weigh-plane-scale.html
The point is, they just want to check your logic, not your aircraft knowledge.... Good Luck!

PS - you could just check the weight and balance sheet! But then nobody reads these days! :-)
Or be really smart . Since they didn't say airplane, a plane is simply defined by three points in space, thus it does not have weight!

Ben2012-09-13T05:19:37Z

Due to regulations when aircraft are weighed as part of their schedule it must be indoors(eg a hangar) otherwise wind flow around the aircraft could give false readings.As for the procedure they put pressure pads under the wheels ,a computer then interprets the pressure exerted into a weight(technically speaking it's actually a mass) just like your bathroom scales but on a much bigger scale.

It's about as simple as that really.

cy2015-01-28T18:52:33Z

There are two easy says. Look for a plate that gives gross weight or, contact the manufacturer with the plane's serial number and have them give you the gross weight. It could also be a trick question. Possible answer is that a plane does not have scales because it's not a reptile, fish, etc.

Chris2013-11-13T10:24:38Z

I would weigh it the same way as I would a plane with scales. Even though I have never seen a plane with scales, it would make sense in a way for better wind resistance moving forward and it would certainly decrease fuel consumption with a good tail wind. =)

Kaz2014-01-26T12:48:37Z

I'm not sure how the interviewer would respond, but I'd probably say something like this:

If I were to encounter a plane with scales, I'd probably ask the owner if he meant to build a submarine;-)

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