Design and development approach for the localised fire detection and suppression function of Columbus APM

The Localised Fire Detection and Suppression (FDS) Function has been re-introduced in the Columbus Attached Pressurised Module (APM) baseline during the Phase C/D Contract negotiations. This Function requires to insure local fire detection in two Deck Racks and in four Starboard Cone Panels which are hosting system avionic hardware. Also the Upper Stand-Off's, although containing only electro-mechanical items and harness, are requested to provide such function. The key requirements are relevant to the maximum fire detection time and to the percentage of oxygen concentration that shall be reached within 1 minute from the activation of the Portable Fire Extinguisher. The paper analyses these key requirements and their consequences in terms of design implementation, both at the level of functional concept and of hardware definition. In specific, the results of the preliminary analyses are discussed in view of identifying the derived needs in terms of flow deviators. To support the design of the Localised FDS Function, a development test campaign has been started in June '96. The campaign encompassed qualitative air ventilation tests (with visualisations of the air flow pattern using a smoke tracker and laser generated light-planes), quantitative air ventilation tests (in which the air velocity has been measured using hot-wire anemometers) and CO2 distribution tests (where the fire suppression transient in the set-up was simulated and the variation of CO2 concentration was measured). The paper presents the results of the tests, provides an overview of their analytical assessment and draws the relevant conclusions. Lessons learned and critical areas are also discussed, in particular for what concerns proper tests preparation/execution and analysis correlation difficulties.