Failure - Interactions
An excerpt from the Boeing Report, pgs 3 & 4, Summary section: the internal draft copy by Boeing's R.A. Davis is dated Aug 21 '79; formally sent to NTSB dated 24Sep79. NTSB's IIC Kampschror had requested Boeing's conclusions during a June 6th meeting with R.A. Davis. Later, since this early "analysis" from Boeing violated the NTSB's explicit prohibition against any premature speculation about "cause", Boeing later requested that the first four pages of that Boeing Report (24Sep79) be removed from the public record. The NTSB's IIC didn't invite the other parties to submit any analysis-conclusions until AFTER the field phase of the investigation, after the Tech' Review: Only then, in a letter dated Nov'21st 1979, the NTSB's IIC invited the pilots' association to submit ALPA's "recommendations on the conclusions to be drawn from the evidence" [letter from NTSB's Kampschror to ALPA's McIntyre, dated 21Nov79].
The Boeing Report presented the FDR-data, and the Parts Trajectory.
The Boeing Report hinted at the next step, but didn't explicitly offer this overlay of the two profile views.
NTSB's AAR-81-8 simply omitted
this step from their analysis of
The Trajectory Analysis works-backward from this Trail of Debris, offering the possible airborne profiles of separated components.
The mishap aircraft suffered the subtle INITIAL slice-to-vertical Yaw x Roll upset
-- then a second protracted phase of uncontrolled yawing-rolling high-speed DIVE from 39,000 Ft down to the final recovery;
-- AFTER pilots repositioned the Landing Gear Lever to the DOWN position, then followed the controlled high-G RECOVERY phase.
Lessons from the Boeing-driven
Night FL390 CRZ Yaw x Roll = DIVE
Hitchcock termed this writers' tool
"but there are no lions
in the Scottish Highlands."
. . . the most important thing to remember
about the MacGuffin is that
it contains the word “guff,”
which means a load of nonsense.
. . . writes Spoto, “but watch out for
It will lead you nowhere.”