Bad fuel gauges?

In article ,
wrote:

But aviation safety is not about being prepared for every single problem
no matter how unlikely. *Aviation safety is about reducing the residual
risk to an acceptable level. *

Agreed. Or more precisely, it's about reducing the risk-to-cost ratio
to an acceptable level.

No. Cost is not part of the equation wrt reducing risk, at least as far
as the FAA is concerned. If you were an applicant and tried to get
an aircraft certified that didn't meet the standards in AC 23.1309 or
AC 25.1309 because it would cost too much, the FAA would deny
the application.



Some particular small risk might be deemed
acceptable if it would cost $100,000 to avoid, but unacceptable if it
would cost $100 to avoid.

More important is the hazard, not the risk.




These levels are defined in AC 23.1309 and AC 25.1309.

The levels are implicitly defined throughout the FARs. For instance,
whenever some item of equipment is deemed necessary for airworthiness,
the FAA is thereby stipulating that the risk of not having that
equipment (in operable condition) is unacceptable, compared to the
cost of having and maintaining that equipment.

Have you read AC 23.1309 or AC 25.1309?

--
Bob Noel
(goodness, please trim replies!!!)