Centaurus,
A great insight into the design of the QRH, thank you for posting.
You're core point is that the during an onboard smoke/fire event, the biggest risk is time to land, even and off airport landing/ditching may be required whilst control is still possible.
In the QRH, Checklist Instructions section, it lists the minimum items for which landing at the nearest suitable airport must be performed. There is a reference to "fire or smoke continues", but important item is "any other situation determined by the flight crew to have a significant adverse effect on safety if the flight is continued"
Later it says that if the smoke, fire or fumes becomes uncontrollable then even an off-airport landing or ditching maybe required.
The way I see it, all the airmanship advice contained in the text in the QRH and FCTM are elements that should be considered before during and after actioning specific non-normal checklists. The non-normal checklist should not be robotically called without considering the possible ramifications if other measure are not considered first.
Therefore I think Boeing intend us to depart from the script as and when we deem it necessary, it says so right there, in dark grey and light grey (as distinct from black and white). Last time I did this procedure in the sim as PF, we immediately diverted without waiting for the checklist. Naturally, the checklist must be started when the safest course of action has been determined. Boeing give us the tools to think like this and that is what I hope we would do for real.
It is my personal opinion that any fire, smoke or fumes situation is probably unquantifiable to any reasonable degree of certainty and you won't know till it is too late anyway, so I classify the situation as uncontrollable until we know better. Like I said, that is my opinion and it can only be my opinion because if you prioritise initially in favour of attempting to complete the checklist, you'd probably be justifiable in most cases.
Perhaps seems to me that Boeing have performed a neat ACM (Ar5e Covering Manoeuvre) in providing a comprehensive checklist with additional advise to for more extreme situations. Perhaps it very much depends on the quality and nature of the training as to how individuals handle such a situation, what kind of weight they give the advice in the FCTM and QRH relative to specific non-normal checklists and ultimately whether they repeat past mistakes or land safely and at worst unnecessarily.
In interesting link:
Skybrary: In-flight fire guidance to to flight crew
An interesting table from Skybrary on in-flight fires:
