HISTORY WITHOUT IMPORTING AN OLD OPERATING LIMIT
A historical source is strongest when it answers a historical question. A contemporary report can establish when a milestone was reported; a retrospective can explain its later significance. Neither automatically establishes the limits of an aircraft flown decades later. Photographs also need checking: a modern example may illustrate an early milestone without actually depicting that event. The aircraft shown and the wording of its caption are separate evidence.
The 1998 manufacturer briefing is explicit: it is for information, will not be updated and must not be used as an official operational reference. We use it to document architecture and historical differences. Current Fenix implementation, software issues and operating data for the loaded aircraft are established through their own sources. [4, PDF p. 1]
Identify the model, the standard and the purpose of a source before using its data. When sources appear to disagree, first check whether they describe the same event or aircraft. The same habit prevents an old performance table, a new livery configuration and an unrelated MCDU example from being combined into one convincing but incorrect flight plan. [23, Operational preparation and aircraft-specific data discipline]