PBL;
I'd like to hear some thoughts on the written guidance on landing distances, and how it could accommodate slip-ups, but it doesn't appear to be the theme du jour.
The QRH data which is always employed for ECAM abnormals requiring corrections to landing distances and which, in one case, I used to calculate landing data (discussed in #113 and #120), requires a very aggressive touchdown and stopping regime. The AOM states that the distance is calculated from 50ft, that there is "little flare", followed by immediate, maximum braking until stopped. The distance does not take into account the effects of reverse thrust. Spoilers are assumed to be operating normally.
A wise crew (faced with an abnormality - not commenting on this crew), will also consult the other QRH tables which are labelled, Autoland Distance with Autobrake, (Config 3 or Full) to assess the difficulty of the landing. There are columns for Low and Med braking as well as for varying runway conditions and the inclusion of reverse, (not a high percentage, btw). I was impressed with the recently posted numbers for CGH with "no spoilers" - very interesting work.
The circumstances faced by this crew coupled with the time they had to assess deceleration rates and create alternative solutions was for all practical purposes, nil - not the actions, (which would have been immediate brake application), but the assessment and decision(s). I think the runway condition and precip certainly played a role in the accident if only in severity as did the timing of manual brake application. Like everyone else, I'm still examining the FDR traces as well. Can anyone get them to print? My pdf file won't permit it.
As to transducers, resolvers and whatnot, I have no idea, even though I have a full set of 320 AMMs on CD - the failure of such, while never impossible, is improbable, especially given industry experience.
The question of going-around has arisen from time to time through the posts with varying opinions on the potential for success. Many here are familiar with the Cranbrook 737 accident so it and the warning to never go-around after reverse has been selected need not be belaboured. Given this and the calculations made on the deceleration rates by PBL, it is likely stating the obvious (given the almost-2000 posts on the topic), but by the time the crew was aware of the seriousness of their situation (manual braking time, I suspect), the remaining time and operational circumstances they faced likely precluded a successful decision to either stop
or go-around.
As to human factors and various aircraft types, I think the largest issues are training issues and not the so-called "helmet fire" syndrome. Humans make mistakes certainly but as a recent poster offered, the ejection drill was so second-nature that nothing entered the active consciousness and it was done accurately with success. The Airbus takes longer to get accustomed to (about one year) but thousands of crews have made the transition with success and without incident. The propensity of design (ergonomics) and humans to fail to interact with robust comprehension and easy success is the subject of many, many books and papers. When I first stepped into the cockpit of a 320 (after flying the B727, L1011 & B767), I frankly felt as though there was a "veil" between me and the airplane but after the transition training, and a year's time on the airplane, "what's it doing now?" was largely a humourous statement and not a real question.
The industry, not a specific aircraft design, has suffered the kind of occurence as happened at CGH and must in some way come to terms with its possibility albeit extremely rare. That said, the numbers as provided earlier regarding something like 50 million landings etc, certainly impress in terms of risk. In doing daily data analysis for a major 320 fleet, I can attest that there are far more serious issues outstanding.