Questions tagged [weight]

In science and engineering, the weight of an object is usually taken to be the force on the object due to gravity. Weight is a vector whose magnitude (a scalar quantity), often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus: W = mg. The unit of measurement for weight is that of force, which in the International System of Units (SI) is the newton.

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What are the physical laws for upscaling an RC model to 1:1?

What are the laws of physics for upscaling an RC model from a smaller to larger scale or even to a full sized 1:1 aircraft? I guess the basic thing may be lift/weight ratio which was nicely described ...
Kozuch's user avatar
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9 votes
3 answers
4k views

What is the weight of the fuselage (only) of the Boeing 747?

I'm wondering about the weight of the Boeing 747's fuselage.
user37419's user avatar
29 votes
5 answers
28k views

Why are "counterweights" used in aircraft production?

From this question, manufacturers use "counterweight" or "ballast" when producing aircraft. Why is the use of weight necessary? Supposedly aircraft should be made as light as possible, and ...
kevin's user avatar
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6 votes
1 answer
3k views

What is the average weight difference between composite and metal airliners?

Is there any rule of thumb for weight savings using composite materials. For example, is there an early model large airliner like the B747 or even B737 that later was modified with composite wings or ...
jwzumwalt's user avatar
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4 votes
1 answer
367 views

Why is the thrust/drag increase much lower at a lower FL with weight the only variable?

From and related to: What is the relation between drag and weight? Friction drag is not affected by the angle of attack change. The [induced] drag will increase with the square of the mass ...
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26 votes
4 answers
18k views

What is the reasoning behind using depleted uranium as counterweights in the 747?

I recently found out that some of the earlier models of 747 had between 600 and 1100lbs of depleted uranium as counterweights. These counterweights were found in 747s manufactured between 1968 and ...
Ron Beyer's user avatar
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15 votes
3 answers
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What are the concerns and consequences of an overweight landing?

If a 777 ER has to immediately land after takeoff on a planned 14,594 km trip (in the case of a fire, e.g.), the landing will be executed with a very heavy aircraft. What are the major concerns of ...
Jonas G. Drange's user avatar
30 votes
8 answers
5k views

Can the removal of a duty-free sales trolley result in a measurable reduction in emissions?

Recently, SAS announced that: Withdrawing tax-free sales will reduce the overall weight of the aircraft, which in turn will reduce fuel consumption and emissions. I could buy that this might be a ...
Stelios Adamantidis's user avatar
9 votes
3 answers
6k views

How much water does a passenger airliner carry?

How is the amount of water for (a) toilet and (b) drinking to be carried by a flight calculated in the industry? Is there any formula or thumb rule using which we can roughly estimate the amount of ...
Wright Brother's user avatar
4 votes
2 answers
825 views

On what basis is the weight unit of the FQIS selected by airlines of various countries?

On what basis is the weight unit of the FQIS (Fuel Quantity Indicating System) selected by airlines of various countries? Does it depend on the local country for using imperial or metric units?
Emerson's user avatar
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4 votes
2 answers
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Does Raymer's installed engine equation include the weight of the pylon?

I am currently modelling an aero engine and require the weight breakdown of the individual components, I have the dry weight of the engine and need to verify the pylon and nacelle weight. Raymer has ...
martin 's user avatar
27 votes
3 answers
29k views

Why are airlines so concerned with checked baggage weight?

Why is it that commercial airlines are so concerned with checked baggage weight, such that they charge extra just for the privilege of checking in a suitcase with a limited weight (e.g. 15kg), and ...
komodosp's user avatar
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6 answers
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How does aircraft weight affect landing distance?

I am a private pilot. I posed a question to instructors in the flight school and got differing answers. For a given aircraft, landing at the same speed, with everything the same except for landing ...
Tom Tompkins's user avatar
7 votes
2 answers
2k views

Why has structural efficiency (OEW / MTOW) not improved despite increasing use of carbon fiber?

Where can I find information on the weight breakdown of civil aircraft? I am interested primarily in trying to understand why structural efficiency (OEW/MTOW) has not improved despite increasing use ...
Wasserwaage's user avatar
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6 votes
5 answers
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What happens during a powered descent?

I was having a discussion with my friend about equilibrium condition in flight: Scenario: While going in straight and level flight, say I reduced my airspeed by 30 mph. At the same time keeping the ...
user2927392's user avatar
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5 votes
1 answer
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Why aren't there V-tail airliners?

Since a V-tail is lighter and generates less drag than a conventional empennage, why has this solution been put away from production?
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4 votes
2 answers
1k views

What made Concorde so heavy?

The Concorde burnt five times more fuel per passenger mile than the 747. A huge contributor must have been the immense empty weight per seat, three times that of the B747. B747-300 Concorde Empty ...
Abdullah is not an Amalekite's user avatar
3 votes
1 answer
172 views

How fixed air, gas and fixed weights in rigid airships is computed in this book?

I hope I am posting this in the right forum. My current problem is part aviation, part maths. I have been struggling with the following computation ( Burgess, Charles Paine. Airship Design. Honolulu, ...
Sasquatch's user avatar
3 votes
2 answers
3k views

What is the weight limit for a pilot to eject from an F-100?

What is the maximum weight for a pilot to use the ejection seat in an F-100 fighter?
Pilot's user avatar
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0 votes
1 answer
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Are there any airliners capable of vertical climb with engine thrust only by pointing the nose up?

So, sort of inspired by this question, I was wondering if there were any passenger airliners with enough thrust to fly straight up, supported purely through the thrust of their engines rather than the ...
nick012000's user avatar