In order to estimate the total weights of aircraft I know that the dispatchers use average weights for adults / children etc.

But since this is an average I suppose there's a standard deviation and sufficient allowances must be kept for safety etc. i.e. Factors of safety since the estimation itself is imprecise.

Question: I am wondering how much would be the efficiency advantage (if any) if a commercial airline decided to have weighing scales at check in for exact weight determination of every PAX? By efficiency I mean if you knew the exact passenger weight, you wouldn't have to use as large a factor of safety (conceivably) and hence could accurately pack in more cargo in the holds.

Are any airlines actually doing this? Or is the benefit insignificant to justify the modification? I mean airlines do go pretty far to ensure they can carry max payload right?

Note that I'm not asking about charging PAX by weight. Just about exploiting your load capacity to the fullest by reducing estimation errors.

If not during check in, is there a safety advantage to incorporating a scale in the jetbridge to track total weight going in? Just to guard against dispatcher errors?

Alternatively, what about load cells in the wheel suspension itself. That would not only give the pilot the accurate weights but the relative loads would also indirectly indicate the position of the CG? Is that impractical or too expensive?

There's already a weight on wheels sensor, correct? How difficult would it be to convert it to a quantitative sensor calibrated for newtons?

This question was partially motivated by this related SE Aviation question :

How does a commercial airliner measure its weight/mass?

  • $\begingroup$ MEL item : one scale may be inoperative provided another one is operational and within 12 months from last calibration. $\endgroup$ – vasin1987 Jul 9 '17 at 16:09
  • $\begingroup$ I would think the time spent weighing passengers during boarding would far outweigh any savings from efficiency. Not to mention that the first airlines to try this will have to deal with the inevitable objections and loss of business from the invasion of privacy. $\endgroup$ – jamesqf Jul 9 '17 at 18:36
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    $\begingroup$ The "weight scale on the wheels" idea was tried, somewhere in the 60s~80s IIRC. The engineers found that the scales need calibration quite frequently to provide a useful accuracy, and the idea was soon abandoned. $\endgroup$ – kevin Jul 9 '17 at 19:00