Larger GPS, digital terrain elevation data, and ground obstacle databases will be incorporated into future FMS and airport moving map displays. Current systems integrate data from Jeppesen, Lufthansa, and the EAG into a singular database, the ARINC 424. This database provides information on environmental hazards and aviation procedures that may be required over the course of the flight.
The integrity of the computerized navigation and performance systems rests on the quality of the FMC/FMGS databases. 85,000 changes, on average, are made to the database every 28 days, requiring constant updating of systems in order to stay current. As the volume of data coming into the databases intensifies, updates will become more frequent and more extensive (see AoC_078). Furthermore, due to current systems coordinating information from multiple agencies, inconsistencies will occasionally arise, which could lead to serious errors during the course of a flight.
The capacity of in-flight databases is also an issue. Although the amount of data processed by the three major providers is increasing, the size of individual FMC databases is not, and companies will often resort to deleting data from the master ARINC 424 database in order to fit it into their avionic systems. Advances in data compression and miniaturization of technology could correct this issue (see AoC_041).
- Reduced ability to cross-check information
- Failure of process to upload current databases during pre-flight
(Current regulations require a check of the 28-day FMS revision S/W by the database provider as part of the LOA [Letter of Acceptance], with the exception of RNP AR. AMC 20-26 then requires the operator to perform such a check for RNP AR procedures.)
Potential for entering incorrect data through the FMC/FMGS
- Cyber attack