Impact of Regulations on Cabin Systems Installations John - - PowerPoint PPT Presentation

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Impact ¡of ¡Regulations ¡on ¡Cabin ¡Systems ¡Installations ¡ John ¡Courtright, ¡Structural ¡Integrity ¡Engineering ¡

1 APEX TC Meeting•22-23 February 2011•Huntington Beach, CA USA

APEX TC Meeting•22-23 February 2011•Huntington Beach, CA USA 2

Agenda ¡Points ¡



The STC process "briefly" stated - application to installation



"Heightened" FAA attention to technical issues related to IFE & 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.

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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)  Aging Aircraft Concerns – Electrical & 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 - -40ºC to +55º C  Vibration & Shock  Contaminant Susceptibility – Fluids, Dust  Electro-Magnetic Interference (EMI)

 Radio Emissions – Testing Across Multiple Frequencies  Radio Susceptibility  Power Input, Surges & Power Interruptions (200msec)  Bus Noise

 Lightning  HIRF

Installation Design Considerations: Wiring Practices

 Cabin Systems Are Generally Classified as “Non-Essential”  “Non-Essential” Systems Are Connected to “Non-Essential” Power Buses

 Must Be Able to Shed Cabin System in a Smoke/Fire Event.

Wiring Practices & Safety

 The U.S. Transportation Safety Board (TSB) Determined, in Part, That the

Swissair 111 Tragedy Was Caused By Non-Standard Wiring Practices.

 TSB Report Causal Factors (Partial List)

 TSB Factor #6: “A segment of the [system] power supply unit cable a region

• f resolidified copper on one wire that was caused by an arcing event. This

resolidified copper was determined to be located…..in the area where the fire most likely originated.”

 TSB Finding re Risk #8: “Examination revealed various wiring discrepancies

that have the potential to result in wire arcing.”  Changes Recommended Resulted in New Regulations

 FAR 25 and CS 25- Subpart H  Develop Electrical Wiring Interconnection System Definition (EWIS)  Develop New Instructions for Continued Airworthiness (ICA) for Wiring

BAD WIRING – AN EXAMPLE

 Susceptible to Chafing & Arcing

EWIS-WHAT IS IT?

 Electrical Wiring Interconnect System  “Any wire, wiring device, or combination of these,…installed in any

area of the aeroplane for the purpose of transmitting electrical energy, including data and signals between two or more intended termination points.” CS-25 Subpart H

 “Electrical wires and cables must be designed and installed so they

are compatible with the circuit protection devices required by 25.1357, so that a fire or smoke hazard cannot be created under temporary or continuous fault conditions.” FAR 25.1717

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 Tank 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.

 Maintenance & Inspection Criteria Are Developed Based on EZAP

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

Modified Structure & Antenna Systems

Structural Considerations: Damage Tolerance Analysis

 All Wi-Fi (and All Satcom) Involve Penetration of the Fuselage (Pressure

Vessel) to One Degree or Another.

 When a Hole Is Drilled In an Aircraft, A Damage Tolerance Analysis (DTA) Is

Required To Determine How To Minimize Damage To the Aircraft

 Solutions Include Adding Doublers/Triplers to the Affected Area  Determination of the potential crack growth & the maintenance and

inspection procedures needed to prevent catastrophic damage.

 Maintenance Procedures Considered Include:

 Type of Inspections – Visual, NDT (HFEC/LFEC), etc.  Inspection Intervals – Cycles, Flight Hours or Time.

 DTA is Vital Input Into the Operators Instructions for Continued Airworthiness

and the Aircraft Maintenance Manual (Supplements).

Start Evaluation STC/Non-STC Modification

Does installation affect an existing SSI listed in the SSID? Has installation substantially altered the affected structure

• r increased/

redistributed the loads acting on it? Damage Tolerance Assessment required to comply with the AD. Note: The Repair Assessment Guidelines (RAG) CANNOT be used as AMOC. Damage Tolerance Assessment and supplemental inspections not required.

Repair

Has installation physically altered the pressure boundary (fuselage and cargo door skins)? Does installation affect an existing SSI listed in the SSID? Does installation affect an existing SSI listed in the SSID? Damage Tolerance Assessment required to comply with AD 98-11-03/04 R1. Damage Tolerance Assessment and supplemental inspections not required. Damage Tolerance Assessment required to comply with AD 12-34-56-78 R1. The Repair Assessment Guidelines can be used as AMOC, as applicable. Refer to Repair Assessment Guidelines for supplemental inspection requirements, no AMOC approval required. NO NO NO NO YES YES YES YES YES NO

Sample DTA Flow Chart

Aging Aircraft Safety Rule (AASR)

 As of December 20, 2010, airlines that operate airplanes under Title

14 of the Code of Federal Regulations (CFR) 121 or 129 must revise their U.S. Federal Aviation Administration (FAA)-approved structural maintenance program to comply with the FAA’s Aging Airplane Safety Rule (AASR).

 This revised maintenance program must include damage-tolerance-

based inspections; a means to address the effects that repairs, alterations, and modifications may have on fatigue-critical structure and these inspections; and a means by which all changes to the maintenance program receives FAA approval. Airbus & Boeing has developed materials to help operators comply with this new rule

Why Damage Tolerance Analysis Is Important

 Aloha Airline Flight 243 - 1988

OTHER CONSIDERATIONS: AIRWORTHINESS DIRECTIVES (ADs)

 An AD is a Compulsory Modification or Maintenance Ordered by the FAA or

EASA Usually In Reaction To a Problem With ANY Element of the Aircraft.

 Operator Must Comply By a Given Date  May Involve Multiple Aircraft Types or a Subset of Aircraft Types  ADs Are An Important Regulatory Tool to Ensure Air Safety

 In An STC Program Situation – The Operator and the Engineering Firm

MUST Take Into Account All ADs That Apply to That Aircraft.

 If there Is a Pending AD on the Aircraft, the Installation Design Must Not

Adversely Affect the AD

 This Requires Research & Investigation of the Affected Areas of the Install

and Any Pre-Existing ADs.

THANK YOU

John Courtright Structural Integrity Engineering jcourtright@SIEinc.com (425) 493-2828 (206) 618-3128