c100,
I have been doing some homework since my last post, just to make certain that I have my facts straight --- something I had drummed into me from an early age by a barrister/politician father.
The results are most interesting.
Re. Australian CAO 20.7.1b ( my post was from the Comlaw web site, the "law", which CASA web site is not) and it looks like the only aircraft able to use the amendment is the A380, probably the QF A-330 in the near future. The latter based on answers to questions to a C&T mate of mine at QF. It is not clear what Virgin are doing.
In both the US and EASA-land, the operational landing field length remains the "certified" or "published" length, being the test flight figures factored by 1.67, or as more correctly expressed in both EASA or FAA regulations, the demonstrated field length is 60% of the published length.
Until there is a suitable rule-making to authorize something like CASA CAO 20.7.1b, landing field lengths LEGALLY remains the certified length.
In the CASA case, it seem there is a disconnect between the Australian Type Acceptance Certificate based Certificate of Airworthiness details, and the adoption of the "advisory" figures as the certified figures. That will now be looked into. Remember, in the Australian legal framework, a CAO does not outrank a regulation.
EASA has indicated (presumably under the terms of the Trans Atlantic Mutual Cooperation Agreement) that they will follow the FAA, which has not got to even an NPRM, as far as I can determine.
It follows that all the "Advisory" information is just that, advisory, and does not supersede the current (traditional) certified landing field lengths.
If you read a bunch of the Airbus publications on the subject, it actually says this, and warns that Advisory is just that, advisory.
Once the law changes, not much will really change, because the length required (was advisory, now "acceptable data" +15%), once you have taken all the factors into account, will be much the same as now, except for wet or contaminated runways, which will be longer than now, as, not only will the equivalent of the present 1.92 factor be mandatory (no Captain's discretion) but the increment for wet or contaminated will actually increase in most circumstances.
Just because words appear in an FCOM or a dispatch manual say it, or an FOI and other specialists have varying interpretations, one thing is certain, it is not the law until it is the law. Then it is what is in the statute books, as it is, not as somebody thought it was going to be.
FAR Part 121 is particularly clear on the subject, the relevant para. is somewhere on this thread.
What will not happen, under any circumstances, and which is where this thread started, will anybody be able to plan, pre-flight or in-flight, to use a runway that is only 60% of the present certified landing distance, or anything like it.
It seems that confusion reigns supreme, a lot of people, and some NAAs have jumped the gun, and misunderstandings abound.
I have seem this often enough in Australia, where FOIs start demanding amendments to FCOMs, "because the law is changing", and then it doesn't happen, or the new "rules" vary very substantially from the CASA
PR and internal training of FOIs. CASR Part 61 is a classic example of an complete shambles, which bears only a fleeting ( and probably accidental) resemblance to the explanatory memoranda and early FOI training.
Tootle pip!!