LeadSled, I have difficulty following your points on required length and differences between AFM and Ops Manual/FOCM/QRH data.
Is required length being intermixed with achievable/actual length?
The requirements for required length are stated in IR OPS.
You imply that AFM actual is the same as Ops Manual actual; I don’t believe this is so.
For all practicable purposes the AFM actual landing values cannot be achieved in operation; factors are applied as per IR OPS for dispatch.
Depending on the interpretation of IR OPS, AFM data could be used for landing with some factoring, not 15%, more likely the full ‘take-off’ factors – equivalent safety. Most operators use Ops Manual data.
Existing, legacy data - the manufacturers’ and Ops Manual “actual” distances, are greater than those in the AFM, primarily because of the increased air distance. However, because reverse may be considered, some distances appear to be less than the AFM. This difference represents the increased risk associated with reverse (failure/selection) which operators should consider.
Although this data is more representative of what might be achieved in operation, for practical purposes the addition of a minimum of 15% is a better estimate of the minimum achievable distance based on operational practice. FAA use this as advisory, IR OPS a requirement.
Many of the problems above were identified by the industry, enhanced by the Midway accident for contaminated operations, which resulted in TALPA. TALPA amended the calculation and reporting of braking action, this was agreed and is probably acceptable for ICAO. Europe plans to implement this as ‘law’ across the various agencies involved; at best the FAA remains advisory - with changes.
Manufactures at TALPA agreed a new basis for preparing landing data which would provide even more representative distances for operations, covering a range of conditions; this uses the runway condition reporting format above.
Europe had already provided a basis for calculating contaminated data, CS 25.1591, which ‘legally’ meets the requirements of IR OPS, but noting that any increased risk in contamination operations has to be mitigated – exposure/frequency and training (IR OPS, but not FAA).
The new calculations provide Operational Landing Data (OLD) or when factored FOLD, this will be greater than previous ‘actual’ data. Europe plans to have, or has this in their requirements, but the FAA action at best will be advisory.
Airbus has published landing data, but it is uncertain which other operators have published.