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Airline Begins Weighing Passengers For 'Safety'
New submitter Lopsemily writes to note that passengers on Uzbekistan Airways may face a new pre-flight check: In a recent statement, the country's flag carrier announced it will weigh passengers and their carry-on luggage prior to flights to determine how much weight they'll be adding to the plane. 'According to the rules of International Air Transport Association, airlines are obliged to carry out the regular procedures of preflight control passengers weighing with hand baggage to observe requirements for ensuring flight safety,' says the airline's statement.
Worse. https://en.wikipedia.org/wiki/...
Yes, obese passengers have caused air crashes before. The most infamous one I can think of was a Cessna Caravan 208 that crashed in Pelee, Ontario. The findings of the report showed that the average passenger weight was 240lbs in that flight, whereas the airline was using an average weight for men of 188lbs at the time, which contributed to the aircraft being over 500lbs than estimated. This is a bigger issue with small aircraft, where your weight margin is much tighter.
Also note that passenger weight doesn't only include his body weight - it also includes all his carry-on belongings and clothings. Which is another reason a party of hunters with heavy winter clothing and hunting gear can weigh significantly above average as in the above crash
Seriously, has this ever been a problem?
YES!
This is a common issue in commercial AND private aviation. Weight and balance is *critical* to flying safely and as load factors increase and aircraft sizes decrease it becomes very necessary to be more and more accurate. Let me explain why this is.
First is total weight. Aircraft are designed to handle a maximum takeoff and landing weight safely. The calculated performance numbers for the aircraft are based on it's weight. Now for a 777 another 100 lbs might be unnoticeable, but for a C150 I can assure you it is. Being over weight affects take off performance, necessary runway lengths, maximum rate of climb, and stopping distances on aborted takeoffs. It affects landing configurations, cross wind tolerances, and breaking distances. If you are in a position where you are depending on the performance of the aircraft, safety demands that you not be overweight.
Balance is next. Balance has to do with where the center of gravity is on the aircraft. The CG must fall within a very narrow range for both efficiency and safety's sake. If the CG is to far forward, it makes the nose heavier and you must apply downward force on the tail using the elevators to keep the nose up. This extra force creates drag and adds to the amount of lift the wings must create to stay in the air. All this creates drag and lowers efficiency. The problem though is you cannot just move the CG way to the aft or you make the aircraft unstable. If the CG is too far aft and you stall the aircraft cannot be brought out of the stall and will crash so for safety, you need the CG forward. The area between these two points is usually pretty small compared to the length of the aircraft and actually gets smaller as you approach the maximum operating weight.
So why does how much people weigh matter? Quite simply because you cannot exceed the maximum weight of the aircraft, and with today's tendency for people to be a bit porky makes it very easy to get overloaded. Plus, if you have an uneven distribution of porky people between front to back. Moving 100lbs of weight forward might be the difference between living or dying in a stall.
So yes, passenger weight matters, especially at high load factors where we are operating at or near the maximum ratings of the aircraft. And, now that people are weighing more and more, it matters more and more.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
And for what it's worth, underestimating weight can also be hazardous.
They don't. This is what taxes on gasoline are for.
Actually, in the United States the largest share - roughly half - of the cost of roads comes from general revenues, not from user-specific taxes and fees. For example, in 2010, state and local governments spent $153 billion on roads. They collected $41 billion in fuel taxes and $13 billion in tolls and other transportation-related non-fuel taxes and charges related to usage. Another $23 billion was paid in vehicle licensing charges (your flat "access" fee). The remaining $76 billion comes from general revenues. (And then there's an infrastructure deficit - deferred maintenance, repair, and replacements - that isn't being paid for right now but is accumulating nevertheless. Right now we're something like $300 billion in the hole just for bridges which need to be replaced.)
So yeah, non-drivers are very much subsidizing the driving population. One can certainly make an argument that the overall economic benefit of having a functional road system is good for society as a whole, but don't for one minute try to suggest that drivers are actually paying their own way.
~Idarubicin
Many large transport airplanes have an on board aircraft weighing system (OBAWS) that, when the aircraft is on the ground, gives the flightcrew a continuous indication of the aircraft total weight and the location of the CG.
The system consists of strain-sensing transducers in each main wheel and nose wheel axle, a weight and balance computer, and indicators that show the gross weight, the CG location in percent of MAC, and an indicator of the ground attitude of the aircraft.
The strain sensors measure the amount each axle deflects and sends this data into the computer, where signals from all of the transducers and the ground attitude sensor are integrated. The results are displayed on the indicators for the flight crew as a "weight on wheels" value.