John Courtright, Structural Integrity Engineering

Transcription

1 Impact of Regulations on Cabin Systems Installations John Courtright, Structural Integrity Engineering APEX TC Meeting February 2011 Huntington Beach, CA USA 1

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. APEX TC Meeting February 2011 Huntington Beach, CA USA 2

3 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

4 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

5 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 ) Aging Aircraft Concerns Electrical & Structural Issue Papers Addressing Technical Concerns Involving: Structural Certification Criteria for Large Antenna Installations Antenna Vibration/Buffeting Compliance Criteria

6 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

7 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.

8 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 of 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

9 BAD WIRING AN EXAMPLE Susceptible to Chafing & Arcing

10 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 , so that a fire or smoke hazard cannot be created under temporary or continuous fault conditions. FAR

11 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

12 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

13 Modified Structure & Antenna Systems

14 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).

15 Sample DTA Flow Chart Start Evaluation STC/Non-STC Modification Repair YES Does installation affect an existing SSI listed in the SSID? YES NO Has installation substantially altered the affected structure or increased/ redistributed the loads acting on it? NO YES YES Does installation affect an existing SSI listed in the SSID? NO Has installation physically altered the pressure boundary (fuselage and cargo door skins)? YES NO Does installation affect an existing SSI listed in the SSID? NO 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. Damage Tolerance Assessment required to comply with AD 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. Damage Tolerance Assessment required to comply with AD /04 R1. Damage Tolerance Assessment and supplemental inspections not required.

16 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-tolerancebased 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

17 Why Damage Tolerance Analysis Is Important Aloha Airline Flight

18 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.

19 THANK YOU John Courtright Structural Integrity Engineering (425) (206)