Safetypee, I had a feeling that keeping my post so short would come back to bite me. BTW I too am referring to 75/76 autobrakes.
Yes, I have been considering all the variables you mentioned during the many years I have been flying aircraft with autobrakes.
With regard to the comments made by AB and agreed with by me, what I was thinking about were the airports that we constantly use and are totally familiar with, when you have to sit and watch even the correct setting being overridden so that manual braking can be “practiced”.
I believe we were both talking about familiar airports in favorable conditions.
We also fly to airports with longer runways (Pisa for example) where I encourage the FO to leave the autobrakes off and just brake manually to get the feel of them there.
On longer runways where we want “to make” an earlier turn off I sometimes suggest using a lower setting initially and then increasing the auto setting if necessary when we have lost some speed in order to reduce the heat build up.
Equally if the runway is not particularly long or as familiar and the conditions or aircraft weight are less favorable I prefer to err on the high brake setting side!
When landing a 767 at Sanford, I know that early cancellation of autobrake followed by manual braking, always results in much higher brake temp readings than when letting the autobrakes continue the braking down to taxi speed.
At the company I work for, our sop is to use idle reverse only, where possible, so there are very few times when the reverse negates the brakes entirely and another thing that happens too often is idle reverse being cancelled at 60 kts instead of leaving it in until down to taxying speed. It is surprising how much braking is available from idle reverse even when below that speed.
Your statement “but the economics should not be a consideration on a limiting or slippery runway” really is rather stating the obvious. Also when you say “in most accidents involving autobrake the setting was too low,” I would wager that the the brake setting was a secondary factor in the accident and not the main cause.
“A professional pilot must develop, and continue to improve the skills of aircraft handling.” – no argument there.
“There is no excuse for not using manual braking.” What do you mean by that? That statement taken in isolation sounds strange. If you added something like “when the conditions are suitable and an individual needs the practice” then fair enough. Maybe we ought to take the autopilot out as well in order to make sure we all get enough handling practice.
As we all know, there are a multitude of variables, and dozens of ways to skin a cat.