David Paule
Well Known Member
Step 1 - Identify all the possible faults.
Step 2 - Assess the hazard if that fault occurs.
Step 3 - Attempt to devise ways to make that fault non-critical, if it should be a critical one.
Note that there are several levels of hazard, generally ranging from something to fix on the ground to loss of vehicle and crew.
Similarly, there are different ways to mitigate the risk, ranging from a design solution that eliminates it completely (the best choice) to a crew procedure (the worst choice). This latter approach is why I cringe when someone says to just pay attention to the checklist. People seem to be human and we all know that us humans aren't 100% reliable.
You might think that between steps 2 and 3 there ought to be this one:
Step - Determine the relative risk of it happening.
Murphy, of course, says that it will happen. That being the case, we don't need to assess its likelihood. Given a long enough time in service, the relative risk is near 100%. That said, we do accept that some things have a very unlikely chance of happening if certain other engineering criteria are met.
Dave
Step 2 - Assess the hazard if that fault occurs.
Step 3 - Attempt to devise ways to make that fault non-critical, if it should be a critical one.
Note that there are several levels of hazard, generally ranging from something to fix on the ground to loss of vehicle and crew.
Similarly, there are different ways to mitigate the risk, ranging from a design solution that eliminates it completely (the best choice) to a crew procedure (the worst choice). This latter approach is why I cringe when someone says to just pay attention to the checklist. People seem to be human and we all know that us humans aren't 100% reliable.
You might think that between steps 2 and 3 there ought to be this one:
Step - Determine the relative risk of it happening.
Murphy, of course, says that it will happen. That being the case, we don't need to assess its likelihood. Given a long enough time in service, the relative risk is near 100%. That said, we do accept that some things have a very unlikely chance of happening if certain other engineering criteria are met.
Dave
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