Originally Posted by
peekay4
So unless the pilots pulled CBs within 10 minutes of the gate arrival (while passengers were still disembarking), the CVR might have been completely overwritten in any case.
And I'm not even sure it's standard procedure for AC pilots to pull CBs on their own after every possible reportable incident. Probably the pilots were told to "call the tower" at this point and were still wondering / discussing what had just happened amongst themselves.
At many U.S. carriers the CVR circuit breaker is on the shutdown checklist and should be pulled in the event of an NTSB Part 830 reportable incident or an accident. That procedure has been in place in the U.S. for several years, I'm sure someday it will be SOP in Canada as well if it is not already.
But, as you can see from my earlier comments, I'm not too surprised that the CVR recording was somehow unavailable for the NTSB investigation of an incident that occurred around midnight on a Friday evening.