Flight management computer (FMC) navigation database capacity

摘要

Navigation database (NDB) capacity (memory size) has always been an issue in aircraft Flight Management Computers (FMC). And, that issue is a concern for Performance-based Navigation (PBN) Implementation as so many new next generation (NextGen) procedures are being developed and many FMCs no longer have the capacity for additions to their NDBs. For the near-term, the problem will just keep getting worse for aircraft with FMCs limited by capacity due to the growth in the number of coded procedures and waypoints to store and limitations in the storage size. Anecdotal evidence finds navigation database suppliers estimating that worldwide procedure production will increase database size approximately 3% to 8% annually for the forseable future.¹ In many cases, the airlines must already strictly tailor the available sets of procedures in their databases according to geographic areas to meet current FMC memory capacity constraints. Fortunately, the trend for the mid-term and far-term is that the projected growth rate will not be such an issue given the actual and “potential” additional memory expansion of new FMCs.