Lesson for NTSB- Systems Group  Leader

Don't expect  Boeing  engineers  to   explicitly  disclose  the combinations of latent-faults   that  result in  

complex failure interactions  --

the  systems Group    should  include

                   a  strong   "systems" engineer.


  Another form of the  manufacturer's    "stacking-the-deck":

     omission of background information about systems

           that might disclose   failure-interactions.


B-727   Operations Manual Bulletin  75-7 

      (revised),   dated  March 1976.

This  revised- Bulletin from the manufacturer  in 1976   subtly

     revealed  the   combination

            of  latent-failures   and conditions 

 (Slat Retract Lock-fault,     loss of System-A Hydraulic pressure,

                                                                 Mach > 0.8M,    and    SpdBrks EXTENDED)

that would  permit    aerodynamic loads   

     along the wing's leading-edge

         to   PULL  the Slat  from its RETRACTED position.  

  

  Yet  in 1979  the manufacturer  advised   otherwise,

      misleading   the NTSB's  investigators:  

  "Boeing tells us it's impossible for the slats

            to pop out   because of aerodynamic loads." 

                     [see IIC's inverview above in Sep'79].   

Breach of  Investigator's  Professional standards

Alpa had notified the Chairman of the NTSB

citing specific investigator-Misconduct


". . . the integrity and credibility of this investigation . . . seriously compromised . . . "

--------------------------------------------------------------------------------------------------------
 Letter, dated 6Feb1980: ALPA's President wrote to NTSB's Chairman:
"Due to unfounded allegations concerning the crew attributed to Mr. Kampschror in the media (Aviation Consumer  for example, attached), his conduct at the probable cause hearing on January 17, 1980,  and his extraordinary and unreasonable emotional outburst at the Kansas City deposition, it appears to us that Mr. Kampschror is no longer a neutral and impartial investigator in regard to this accident.... For this reason, we request that Mr. Kampschror be immediately replaced as Investigator-in-Charge."
------------------------------------------------------------------------------------------------------
21Mar1980 -- Reply-letter from NTSB Chairman J. King
denying request to remove Kampschror as their Investigator-In-Charge.

.

Lessons from the Boeing-led  

NTSB  INVESTIGATION

Night FL390  CRZ   Yaw x Roll = DIVE

B727 N840TW,  TWA 841 /  4Apr'79

Failure - Interactions

Update  --   August  2016  publication:

Scapegoat ...  from heroes to villains 

See Chapters 14 and 15,  pages  148 - 172:


The best   publicly   available                                                                    

transcription   of the NTSB's    Board Meeting

 "Sunshine meeting"   of   January 1980.


Amazon-link

A common solution used by  UK, NZ, and Canada:

A  Final   Failure  in  USA's

    investigative  Process


Weaknesses,   bureaucratic privileges,

 built-into  the  USA's    "independent"  Safety Board:

Glines' story -- Continued --  from pg 6,  of  the Nov' 1981  issue



The   INVESTIGATIVE   Crisis

   in  January 1980


  The   First   NTSB-   "Sunshine Meeting"   on   Jan' 17th,

 

      then    NTSB's    deposition    of the crew on  Jan' 29,  1980


  At the first Sunshine Meeting

               (Jan'17th 1980) 

   Board Member  McAdams

             expressed  his outrage 


"the crew should   be given  the opportunity to comment  upon  all  of  the  evidence  on which the Board will  ultimately base its final determination of cause." 

More lessons for  better  technical  investigations

Cause ?   or   Effect ?


Mistaking  one  mere   after-effect  

(a sudden Slat- extension  that happened  much later in the dive)

as instead  the  "cause"  for the INITIAL  upset.


As you read through  writer Glines'  account of  the  "analysis" phase of this investigation,   consider that  these  analysts   were boxed-in,  

    fixated  on a false paradigm:

            an  INITIAL  upset    induced by    an Extended Slat -- at  CRZ FL390.


The NTSB's  investigators   seemed blocked,  or constrained,  or unable   to  even consider  more traditional  interactions,   more expected  "causes",  that  had led to earlier  airliner   Yaw x Roll upsets.


Lesson for NTSB staff engineers: 

Don't expect  Boeing engineers to educate you about   earlier  faults and failures,

                     nor about  the company's lessons-learned,

                           nor about the company's history of earlier airliner inflight upsets.


   NTSB's  Jan'1980   Investigative  "Crisis"

     pointed   toward  a    Kuhn-style   "revolt"

               against   this   boeing-method   of   accident investigation.


     ". . .  Sometimes a normal problem,   one that ought to be solvable by known

   rules and procedures,   resists the reiterated onslaught of the ablest members of

   the group within whose competence it falls. . . .    revealing an anomaly

   that cannot,   despite repeated effort,    be aligned with professional expectation. . . .

   normal science repeatedly goes astray. . . .    the profession can no longer evade

   anomalies  that subvert the existing tradition of scientific practice --

     then begin the  extraordinary investigations  that lead the profession at last

      to a new set of commitments,    a new basis for the practice of science. . . . 

         scientific revolutions. . . .    the tradition-shattering   complements

             to  the tradition-bound  activity  of  normal science. . . ."


Kuhn, Thomas S.        The Structure of Scientific Revolutions: 50th Anniversary Edition.     Revised, University of Chicago Press, 2012. Ch1, pp 5-6.

    This  investigative "Revolution",  

         was the solution offered by a   Grumman Engineer,

                    who finally   refuted   the Boeing Scenario.

​    

Washington Post:

 . . . Knowledgable federal officials

. . .  some action in the cockpit  . . .    

Washington Post,    Jan'30th, 1979,    Pg A6.

The IIC    &      the Chairman

  "Scoop"   &  "Maggie"  

 NTSB Chairman King:

-- Refused  the request to Replace the IIC,

-- refused  any   "Public Hearing",


 --  Refused  Board Member's request  to hear testimony from the crew, 

 to test   it   against the gossip,  

and thus  judge   The Boeing Scenario. 


6

 or   here for  pdf  New York Times, 

next-day story  about the first NTSB  Sunshine Meeting on Jan'17, 1980