Geeks With Blogs


Bill Evjen's Blog Code, Life and Community

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
Posted on Tuesday, February 22, 2011 8:17 AM | Back to top

Comments on this post: Retrofit Certification

No comments posted yet.
Your comment:
 (will show your gravatar)

Copyright © Bill Evjen | Powered by: