The usage of tons vs. pounds is usually for effect. There are 2000 lbs in a ton, so 123,000 lbs would be 61.5 tons. But most people, unless they work in an industry that deals with very large weights of things, don't have any concept of a ton, and plus, adding "millions" or "thousands" to the end of a number makes it sound big and exciting.

The following is not directed at fantomas, but at the other metric-heads in this thread...

It's also interesting that you would bring up the metric ton (or tonne). This unit is descended from the centuries-old unit of tun, relating to the weight of a cask of wine. It was standardized as 1000 kg, because it's much less silly to say "ton" than to say "megagram", the official metric equivalent.

I always found it amusing that Europeans who think metric is The One True Way seem to prefer using another totally made up unit (metric ton) instead of following the metric system (megagram) because it's easier, and that's the way they've always done it.

All units are inherently arbitrary anyway, and there is no way you can ever get around conversion factors (1 ml of water weighs 1 g, but only at 25 C; at other temperatures, or with other substances, there is some conversion factor). The best units for any given situation are the ones that are the easiest to think in for that application, the ones that are easiest to estimate in. I maintain that Fahrenheit is best for weather because a cold day is 0 and a hot day is 100, whereas Celsius is best for lab work because 0 is freezing and 100 is boiling (for water), and Kelvin is best for physics because the 0 point is based on molecular motion. The meter is based on what, the speed of light? How often do we encounter such a thing in everyday life? That fact makes it just as arbitrary as the foot, or the yard. Besides, multiples of twelve are much easier to divide into meaningful, whole number fractions than multiples of ten, which is why the Arabians chose 12 and 60 as the basis for measuring time. I notice the metric-heads have no trouble calculating or estimating time in day-to-day life, even though it is not based on the One True Decimal System.

Just because it's easy to multiply by 10 does not make the unit any more useful or meaningful for a given application. It's all still based on completely arbitrary standards we, as human measurers of our decidedly disorderly world, have put in place to make sense of things.

You have no idea what you are talking about. Ten seconds on Google would get you to Title 14, Part 36 of the Code of Federal Regulations, "Noise Standards: Aircraft Type and Certification". All airplanes built in the United States are certified to this standard. Europe (EASA) has very similar regulations, and most of the other national regulatory bodies in the world pattern their regulations off of the FAA/EASA regulations.

Wait, what? Are you seriously implying that 9/11 was the FAA's fault? Citation please.

Please point me in the direction of some of these "well documented ... effects."

Light rail is awesome, and has nothing to do with the FAA.

Ok, but your ticket prices will go up.

Also, you asked for quieter and more efficient aircraft, so here you go.

The FAA's job is not to make the airlines profitable. It's to make them safe.

Translation: 250G ought to be enough for anybody.