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Old 13th Mar 2019, 05:03
  #918 (permalink)  
ozaub
 
Join Date: Jan 2008
Location: australia
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In long ago days of “excessive government red-tape” new airliners were assessed and certificated by aviation authorities in each country where they flew. For Boeing aircraft we all now rely on certification by the US Federal Aviation Administration and in turn FAA delegates most analysis and testing to Boeing.

Until recently senior company engineers called ''Designated Engineering Representatives'' assessed compliance on behalf of FAA. Delegation went further on the Boeing 787. It was first airliner approved under a new ''Organisation Designation Authorisation'' (ODA) arrangement, specifically intended to reduce FAA involvement.

Somehow hazardous lithium ion batteries slipped undetected through the new procedures. Several batteries caught fire and the 787 was grounded. Independent National Transportation Safety Board investigators found:
  • “Boeing’s electrical power system safety assessment did not consider the most severe effects of a cell internal short circuit and include requirements to mitigate related risks, and the review of the assessment by Boeing authorized representatives and Federal Aviation Administration certification engineers did not reveal this deficiency."
  • ”Boeing failed to incorporate design requirements in the 787 main and auxiliary power unit battery specification control drawing to mitigate the most severe effects of a cell internal short circuit, and the Federal Aviation Administration failed to uncover this design vulnerability as part of its review and approval of Boeing’s electrical power system certification plan and proposed methods of compliance."
  • "Unclear traceability among the individual special conditions, safety assessment assumptions and rationale, requirements, and proposed methods of compliance for the 787 main and auxiliary power unit battery likely contributed to the Federal Aviation Administration’s failure to identify the need for a thermal runaway certification test.”

737 Max is second aircraft to be certificated under ODA. After two fatal accidents FAA and Boeing claim the aircraft is safe but admit that mandatory design changes are needed to a Maneuvering Characteristics Augmentation System (MCAS) which is unique to the MAX.

In a “Continued Airworthiness Notice to the International Community” FAA says its “oversight activities” include:
  • Boeing’s completion of the flight control system enhancements, which provide reduced reliance on procedures associated with required pilot memory items. The FAA anticipates mandating these design changes by AD no later than April 2019.
  • Design changes include:
  1. · MCAS Activation Enhancements
  2. · MCAS AOA Signal Enhancements
  3. · MCAS Maximum Command Limit

Which confirms Boeing is running the show and almost invites foreign authorities to play safe and ground the Max.

Who’s ever heard of a “CANIC”? Surely a Notice of Proposed Rule Making is required?

Boeing and FAA swept Lionair accident under the carpet but cannot do same with Ethiopian because it’s more reputable and real people (US and UN) were killed; not just Indonesians on an LCC.
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