Please understand that statutory landing filed lengths are the minimum, advisory information, including performance estimates in non-normal configurations, is very helpful, but except in an extreme emergency, you must meet the statutory requirement as a minimum
.
Once inflight the statutory landing distance requirement does not apply.
From the CASA documents (I am not an expert in the CASA regulatory structure so may have quoted the incorrect document).
CAAP 235-5(0) New performance provisions for CAO 20.7.1B and CAO 20.7.4
5.3 Actual landing distance
5.3.1 In response to recommendations of the FAA’s Take-off and landing performance assessment aviation rule making committee (TALPA ARC), the manufacturers of some jet-engine aeroplanes now supply actual landing distance information to help pilots make more accurate in- flight assessments of the landing distance required in unusual situations. Actual landing distance information takes into account: reported meteorological and runway surface conditions, runway slope, aircraft configuration, planned approach speed, thrust reversers and any other deceleration devices planned to be used for the landing. The FAA’s Safety Alert For Operators (SAFO 06012) contains useful information about the recommendations of the TALPA ARC.
5.3.2 Actual landing distance information is intended to show landing performance that can realistically be achieved by flight crews in commercial operations. This is distinct from landing performance demonstrated by test pilots during flight tests for aircraft type certification. The safety factor applicable to
in-flight actual landing distance information is 1.15. The safety factor applied to aircraft type certification for
pre-flight planning landing distance is 1.67. Pilots of jet-engine aeroplanes that do not have actual landing distance information should continue to make in-flight assessment of landing distance required using the manufacturers landing distance information with an applicable safety factor.
5.3.3 Two major manufacturers, Boeing and Airbus, have introduced a new reference for
in-flight landing distance performance, catering for both normal and abnormal system operations. The new distances are referred to by Airbus as Operational Landing Distances (OLD) and In-flight Landing Distance (IFLD) whereas Boeing incorporates the actual landing distance in the Performance In- flight section of the Quick Reference Handbook. Both manufacturers have included this data in their respective performance applications.
The actual landing distances are a realistic representation of operationally achievable landing performance. The representation of this information is generally “unfactored” unless otherwise stated.
The CAO 20.7.1B amendment facilitates the adoption of manufacturers’ performance applications along with the application of the 1.15 safety factor.
May 2014
CAAP 235-5(0) New performance provisions for CAO 20.7.1B and CAO 20.7.4 5
FAA and EASA have adopted the in-flight landing distance factoring as policy, and along with ICAO are in the process of rulemaking.