<story><title>An American airline wins the right to weigh passengers on its Samoan route</title><url>http://www.economist.com/blogs/gulliver/2016/10/scales-justice</url></story><parent_chain></parent_chain><comment><author>hipaulshi</author><text>Pilot here.&lt;p&gt;Every airplane has a maximum weight it can fly. Different than cars, every airplanes also have an envelope where the center of gravity has to fall enter. If the center of gravity is behind the design envelope, airplane has a tendency to flip backward, stall on take off then crash, it has happened before. It could also means if the airplane enters a spin, the recover may not be possible. If the center of gravity is too forward, it will slow the cruising speed due to increased drag, much easier to stall during cruise and burning more fuel.&lt;p&gt;So for every single flight, pilot or dispatch has to calculate those 2 numbers, for every passenger and baggage, and decide how many fuel to take on each flight.&lt;p&gt;Of course, asking each passengers weight would be awkward at best, so airlines and FAA used an average body weight number to avoid this, it worked until 2003. An accident happened which killed 21 people on board a small transportation aircraft. It is found that the average body weight number FAA and airline used were outdated &lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;www.ntsb.gov&amp;#x2F;Investigations&amp;#x2F;AccidentReports&amp;#x2F;Pages&amp;#x2F;AAR0401.aspx&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.ntsb.gov&amp;#x2F;Investigations&amp;#x2F;AccidentReports&amp;#x2F;Pages&amp;#x2F;AAR...&lt;/a&gt; FAA has since advised airlines that what FAA presumed average weight of its population has increased, and advised airlines to do the same.&lt;p&gt;Of course, this will only work on average cases, and will fail if the sample group is out of average. Resampling has to be done to remain operating in the envelope, and if standard deviation is still out of normal, each individual weight has to be taken.</text></comment>
<story><title>An American airline wins the right to weigh passengers on its Samoan route</title><url>http://www.economist.com/blogs/gulliver/2016/10/scales-justice</url></story><parent_chain></parent_chain><comment><author>_coldfire</author><text>I struggle to see the problem other than human vanity as to why passengers aren&amp;#x27;t weighed with their luggage.&lt;p&gt;If you can accept that your bag costs the airline more in fuel why not accept that your weight contributes also?</text></comment>