Retrofit Certification
- by Bill Evjen
Impact of Regulations on Cabin Systems Installation John Courtright, Structural Integrity Engineering There are “heightened” FAA attention to technical issues related to IFE and Wi-Fi Systems Installations The Aging Aircraft Safety Rule – EWIS & Damage Tolerance Analysis The Challenge: Maximize Flight Safety While Minimizing Costs Issue Papers & Testing, Testing, Testing The role of Airworthiness Directives (ADs) on the design of many IFE systems and all antenna systems. Goal is safety AND cost-effective maintenance intervals and inspection techniques The STC Process Briefly Stated Type Certifications (TC) Supplemental Type Certifications (STC) The STC Process Project Specific Certification Plan (PSCP) Managed by FAA Aircraft Certification Office (ACO) Type of Project (Electrical/Mechanical Systems or Structural) Specific Type of Aircraft Being Modified Schedule Design & Installation Location What does the STC Plan (PSCP) Cover? System Description – What does the system do? System qualification – Are the components qualified? Certification requirements – What FARs are applicable? Installation detail – what is being modified? Prototype installation – What is new? Functional hazard Assessment (FHA) – is it safe? EZAP-EWIS Requirements – Any aging aircraft issues? Certification Data – How is compliance achieved? Delegation and FAA involvement – Who is doing the work? Proposed certification schedule – When is the installation? Certification documentation – What the FAA Expects to see Cabin Systems Certification Concerns In addition to meeting the requirements for DO-160, Cabin System Certification needs to address issues related to: Power management: Generally, IFE and Wi-Fi Systems are classified as “Non-Essential Equipment” from a certification viewpoint. Connected to “non-essential” power buses Must be able to shed IFE & Wi-Fi Systems in a smoke/fire event or Other electrical emergency (FAA Policy 00-111-160) FAA is more relaxed with testing wi-fi. It used to be that you had to have 150 seats with laptops running wi-fi, but now it is down to around 50. Aging aircraft concerns – electrical and structural Issue papers addressing technical concerns involving: “Structural Certification Criteria for Large Antenna Installations” Antenna “Vibration/Buffeting Compliance Criteria” DO-160 : Environmental Test Procedures DO 160 – “Environmental Conditions and Test Procedures for Airborne Equipment”, Issued by RTCA Provides guidance to equipment manufacturers as to testing requirements Temperature: –40C to +55C Vibration and Shock Contaminant susceptibility – fluids and dust Electro-magnetic Interference Cabin systems are generally classified as “non-essential” Swissair 111 crashed (in part) due to non-standard wiring practices. EWIS Design Implications Installation design must take EWIS Requirements into account. This generally means: Aircraft surveys are needed to identify proper wire routing Ensure existing wiring diagrams are correct Identify primary/Secondary/Tertiary bus locations Verify proper separation of wire bundles exist Required separation from fuel quantity indicator system (FQIS) to prevent fuel tang ignition Enhanced Zonal Analysis Procedure (EZAP) Performed EZAP was developed by the Aging Transport Systems Rulemaking Advisory Committee (ATSRAC) EZAP is the method for analyzing airplane zones with an emphasis on evaluating wiring systems and the existence of combustibles in the cabin. Certification Considerations for Wi-Fi Systems Electrical – All existing DO 160 testing required Issue papers required Onboard EMI testing – any interference with aircraft systems when multiple wi-fi users are logged on? Vibration/Buffeting compliance criteria – what is the effect of the antenna on aircraft flight characteristics? Structural certification criteria – what are the stress loads on the aircraft at the antenna location and what is the impact on maintenance inspection criteria for the airline? Damage tolerance analysis required Goal – minimize maintenance inspection intervals
