1. Weighbridges
2. Automatically weighing passengers at the boarding gate
3. Asking passengers to write their weight at check-in
4. Scales built in to wheel struts
Whilst this might not often be a safety issue of the kind exhibited in the article, knowing the actual weight might be cost effective because it would enable airlines to more accurately tune fuel and freight components, which are significant cost and revenue centres respectively.
This feels like a requirements problem, more than an inadvertent bug. It makes me wonder why someone would decide to guess age (and thus weight) based on the name string alone. Don't the airlines usually have the birthdates of passengers anyway?
> The operator subsequently introduced manual checks to ensure adult females were referred to as Ms on relevant documentation.
Allowing the use of approximate models leads to airlines trying to push the boundaries to earn more profits (when paid per kilo for cargo, an overloaded plane is more profitable than a correctly loaded one).
“ Despite the issue, the thrust used for the departure from Birmingham on 21 July 2020 was only “marginally less” than it should have been, and the “safe operation of the aircraft was not compromised”, the AAIB said.”
The PDF isn't long and is worth a read if you're interested in learning from other peoples mistakes. Of note is that the issue was known and there was a manual workaround that was not used for that flight because the team doing it didn't work on a weekend.
Reading the document it looks like the manual workaround was then implemented into software. This hack just masks the underlying problem rather than providing a robust solution.