I agree with DC10, but i would suggest you do so many times over.
One person described a hazard and weakness in current/poposed system, and ensures this is recorded. Maybe Mgt disregard, but if anything happens they can be found negligent
20 people report the same hazard (in their own words). Mgt have to address it. You may still not like their answer but they have to address it.
If you still aren't satisfied then alert the union, who are empowereed to act on safety issues. they could also coordinate with the CAA.
IF you believe there really is a safety issue, then you are morally obliged to do this. And you are negligent if you don't IMO