Even before the
UA585 accident at COS,
had provided investigators
with Yorke's Paradigm:
“My head whirls … Your words have dazed me.”
“The principal difficulty in your case,” remarked Holmes, in his didactic fashion,
“lay in the fact of there being too much evidence.
What was vital was overlaid and hidden by what was irrelevant.
Of all the facts which were presented to us
we had to pick just those which we deemed to be essential,
and then piece them together in their order,
so as to reconstruct this very remarkable chain of events.”
“The Naval Treaty”: first published in
The Strand Magazine, October and November 1893;
Harper’s Weekly, October 14 and October 21, 1893.
Memoirs of Sherlock Holmes, pg 236, By Sir Arthur Conan Doyle
| prēˈrekwəzət |,
noun : a thing that is required as a prior condition for something else to happen or exist.
adjective : required as a prior condition : the student must have the prerequisite skills.
. . . (2) • historical: a thing that has served its primary use
and is then given to a subordinate or employee as a customary right.
. . . 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's "Structure", Ch1, pg5-6.]
Training and various line upsets, and
Yaw x Roll = Dive,
a subtle 1-G "slicing-to-vertical"
Flight test, upset-breakup, 18Mar1939.
... Normal accident investigation, the activity in which most investigators inevitably spend almost all their time, is predicated on the assumption that the investigation-community (eg, NTSB and the parties) has mastered the various interactions & err-lessons available from accident-investigation. Much of the success of any investigation derives from the community's willingness to defend that assumption.
Accident investigators often suppress fundamental novelties (rumors, gossip, conspiracy theories, crazy scenarios) because such "novelties" are subversive of the investigators' basic commitments. Nevertheless, so long as the investigators' commitments retain an element of the arbitrary the very nature of normal accident investigation usually ensures that any legitimate or possible "novelty" shall not be suppressed for very long. . . .
[OR perhaps translated better as ... the very nature of normal accident investigation sometimes conceals even a legitimate or possible "novelty", a scenario that might be suppressed for the duration of the official investigation.]
[ an interpretation or translation -- from Kuhn's language of "science" as it applies to the community of accident-investigation.]
. . . . . Contrast two investigations described here.
First is the model, or main PARADIGM:
. . . . . . . . . the C.A.B.'s George Van Epps' case of AA-Flight-One.
. . . . . . . . . . . .. . . . .. .
Then contrast that INVESTIGATION against the later investigation by
working the mysterious inflight upset of a B-727 / 4Apr79, N840TW.
Both Van Epps (C.A.B. during his 1962-3 case), and
Kampschror (NTSB during his 1979-81 investigation)
were experienced Investigators. Both men had served recently on other investigations, and both men could be deemed "over-worked". Both served as the lead investigator, now called Investigator-in-Charge, or shortened to "Eye-Eye-See", usually written as "IIC".
Here's the I-I-C's job description:
The designated investigator-in-charge (IIC) organizes, conducts, controls, and manages the field phase of the investigation, regardless of whether a Board Member is also on-scene at the accident or incident site. (The role of the Board member at the scene of an accident investigation is as the official spokesperson for the Safety Board.) The IIC has the responsibility and authority to supervise and coordinate all resources and activities of all personnel, both Board and non-Board, involved in the on-site investigation. The IIC continues to have considerable organizational and management responsibilities throughout later phases of the investigation, up to and including Board consideration and adoption of a report or brief of probable cause(s).
Failure - Interactions
By the early 1960's, our craft “accident investigation”, had progressed to the stage where it was essential for the investigator to learn from earlier techniques, to thus provide him the required new paradigms, to fill-the-gap in the investigator's capabilities; helping him identify the new failure-interactions that eventually presented as a new "mysterious", unexplained, airliner upset, LoC-I , Loss-of-Control.
There proved a limit to the heap of information which an untrained "investigator" (one lacking Kuhn's "anticipation") could assimilate. The hard-learnt mishap-paradigms, learnt from incidents and accidents of the late '50's and early '60's, provided the investigator the template to integrate information gleaned from the "bloomin' buzzin' confusion":
. . . . the post-accident onslaught of "evidence",
. . . . . . . . analysis, "simulation", "flight test" data --
. . . . . . . . . . . . . from every direction (by various "parties").
In the case of George Van Epps' investigation,
of AA-Flight-One / 1Mar62,
investigators were forcefully confronted with masses of data,
simulation and flight test data from
-- the airline,
-- the certification agency, and
-- the manufacturer,
"data" from test-conditions (hidden-assumptions) which Van Epps' could not accept as representative of interactions overtaxing those mishap-pilots.
Note the detailed teardown examinations conducted by
the Systems Group -- for the CAB's AA Flight One case:
"All of the sudden, there it was."
"The key is to erect a genuine account of
If anomalies are approached with white gloves, it is little wonder that they seem to tell us only that there is an error somewhere and . . . are silent about its source. We have to become shrewd inquisitors of errors, interact with them . . . amplify them:
we have to learn to make them talk.
A genuine account of learning from error . . .
explaining the growth of scientific knowledge."
Error and the Growth of Experimental Knowledge
NTSB: We must rely on ...
The investigator's View Through A Paradigm:
"...something like a paradigm is prerequisite to perception itself. What a man sees depends both upon what he looks at and also upon what his previous visual-conceptual experience has taught him to see. In the absence of such training there can only be, in William James's phrase,
"a bloomin' buzzin' confusion".
[Kuhn's Structure, pg 116.]
Without the "anticipation" provided by this paradigm, derived from events with "discrepant Rudder", those key observations -- discoveries -- during the 1990's B-737 investigations, would never have been recognized:
1990's Rudder Pedal events of
-- Captain Mack Moore's observation at ORD on 16July92 (AAR-01/01 pg69), and
-- Boeing test pilot Jim McRoberts' discovery of Tuesday 29Oct96 at BFI.
The earlier crisis generated by the USA's NTSB AAR-81-8, in 1981,
. . . led to the long PROCESS of
. . , , , , , , , , , , , .conjecture & refutation
. . . . . . . . . . . . . . . (Popper and later Kuhn).
Inside the more "scientific" community of aerospace engineers (among experts known as S&C specialists), during the 1980's, such a PROCESS of revolution began with the powerful insight (Kuhn's "paradigm") offered by the more experienced community that had been excluded from
. . . the NTSB's system of investigation:
. . . . . . . . their closed "one-party system" observed
. . . . . . . .. . . . . . . . during the TWA841- investigation.
Their "Paradigm" had been learnt after the
......upset-breakup of Boeing 307 on March 18, 1939, and relearnt after
.......... the upset-impact of B-707 AA-Flight-One on March 1, 1962.
These are part of the paradigms passed down to today's "investigators": specifically handed down by Duane Yorke (former Grumman Director of Supersonic Aircraft Development), and from Bill Cook (Boeing) who recited the lessons from Eddie Allen and George Schairer. These paradigms, or "models", are both perquisite and prerequisite for an accident-investigator working a "mysterious" inflight upset: