The power of recorded flight data analysis to support ILS sustainment studies

The instrument landing system (ILS) remains a key component of today's air traffic management (ATM) system. Continued ILS service is critical to all of the world's large airports, where economic developments put increasing pressure on signal quality. EUROCONTROL has been working in the ICAO Navigation Systems Panel to standardize advanced reduced localizer coverage ground systems to address these challenges. In order to determine the operational acceptability of these measures, an airline advanced flight operational quality assurance (FOQA) data recording and analysis tool was used. The tool, coupled with expert knowledge of both piloting and technical standards, proved very effective in resolving complex questions about the ILS intercept maneuver and the timing of ILS approach operations in general. A key aspect of the work focuses on the ILS IDENT, which still serves important safety functions. Using the FOQA tool, timing and taskload of the aircrew were studied for demanding approach geometries. The study will serve to support the technical validation of the proposed sustainment measures. In addition to giving an overview of a contemporary ILS issue, the paper illustrates the benefit of advanced FOQA tools, which will become increasingly important for developing the ATM system to meet the challenges of the future, such as increased air -ground interoperability.