Originally Posted by
kcockayne
Yes, but these limits have been reached (at the busiest airports). They have reached, or very nearly reached, the point at which there is no further room for SAFE squeezing - haven’t they ? Surely any procedure which requires an a/c to still be on the R/W when another touches down is inherently dangerous ( you might get away with it for a while, but the time will come when you don’t). This certainly flies in the face of all previously accepted separation standards. I, & other ATCOS, certainly ran things pretty close occasionally, but I would be very dubious about building a continuous system on such procedures. Certainly if it was just because the authorities could not be bothered to supply the appropriate infrastructure. I would go so far as to say that such standards would be criminal, cynical & unacceptable in such circumstances.
Sure, this is a naturally conservative industry. So accordingly, standards such as this are never implemented unless it's been through ICAO SASP (or similar) to validate the math, proximity probabilities etc. and had the ANSP's SMS rigorously applied, then endorsed by the State's regulator. That's why there are conditions to the application of this standard. Having a runway separation standard published, with defined conditions is way better, safer and more professional than running things pretty close occasionally. Either you have a separation standard or you don't. If you don't then you hold your hand up - that's part of the SMS too, and part of a just culture within the ANSP.