BOAC;
Re, "
There could well be occasions when 8000ft is not enough! "
Very true...those of us who operate (or did operate!) in Canadian winter conditions know this well. That said, in my experience 6000' is viewed as "short".
Runway distance remaining is always a concern in such operations, especially when contaminated. The
CRFI (Canadian Runway Friction Index) is a very helpful tool in the decision-making process.
FOQA Programs can also help. FOQA can go well beyond just recording aircraft parameters and event thresholds.
Using the longitudinal accelerometer parameter, the available runway length data and some mathematics to calculate the runway remaining from the t/d point, a "potential overrun" FOQA event can be created by making an assumption of deceleration rates. While a bit subjective, "heavy braking" is generally around 0.4g to 0.5g longitudinal acceleration. "Normal" braking is around 0.2 to 0.3g.
If normal braking rates are assumed for the purposes of the event, then the runway remaining
at that deceleration rate can be calculated. It is an easy matter to then see how that distance compares to the distance remaining from the touchdown point. If the distance is less, theoretically, there is "runway remaining". If the distance is greater, then a possible overrun event is created. That data, always de-identified, is trend-monitored and fed-back to Ops and Training as well as the pilots.
In terms of the calculation, runway surface condition don't matter - what matters is the achieved deceleration rate.
The focus is clearly on shorter runways and airports where runway contamination occurs. But landing long or hot just because the runway distance can handle it can form habits that don't serve one well when one has to "get it right" on a short runway.
NOTE:
For those who may not know about or understand FOQA/FDM programs,
a caveat and warning; This will not prevent any individual overrun accident by providing real-time data to the pilot. FOQA is a data-analysis program which provides feedback on daily operations through data analysis. This kind of event is just one in a huge toolbox of events which, when fed back to operations and pilots, help determine and validate training priorities, SOPs, operational techniques and associated risk factors.
That said, the results of this particular event are
very interesting and can help pilots understand the risks of non-stabilized approaches, long landings and the risks of overrun, especially now in winter ops.
PJ2