The 2016 Edition of NFPA 409 Standard on Aircraft Hangars was issued by the Standards Council at their April 2015 meeting. This new edition incorporates several significant changes that impact the design of fire protection systems in new Group I and Group II aircraft hangars. #1 - Foam System Zoning. Low-level foam systems in Group I hangars can now be divided into zones that are independently activated, based on activation of an associated sprinkler zone or automatic detection zone. Manual activation is still required to cause all zones to discharge simultaneously and to provide coverage over the entire storage and...