Posted on 02/11/2024 10:01:52 AM PST by ProtectOurFreedom
Juan does an excellent job reviewing the NTSB preliminary report. Note that he just got back from a Sydney route and immediately did this review and report. He is really dedicated!
The Captain & First Officer did an outstanding job responding to the plug blow-out. They executed the Rapid Depressurization Checklist promptly and precisely. The Captain had 12,700 hours of flight experience including 6,500 in the accident airplane make and model (B-737). The FO had 8,300 hours total flight experience and 1,500 in the accident airplane make and model. The FO was female. The pilot was flying and the FO monitoring.
The captain said there was a loud bang and his head was pushed forward into the Heads Up Display. This indicates sudden deceleration of the aircraft which, I guess, was caused by the rapid change in the aerodynamic profile of the fueselage. The flight deck was very noisy after the cockpit door blew open and it was hard to communicate.
The bang occurred at 14,850 ft and the plane continued to climb to 16,320. At 17:12:34 the Master Caution was activated and it was deactivated by the pilots at 17:12:52.
At 17:13:56 ATC had authorized descent to 10,000 and the crew changed the Selected Altitude from 23,000 to 10,000. Juan says these indicate that the flight crew had their act together and was responding to the emergency very well.
Details on the aircrew action here.
(Excerpt) Read more at youtube.com ...
Here’s the NTSB preliminary report:
https://www.ntsb.gov/investigations/Documents/DCA24MA063%20Preliminary%20report.pdf
Also see Juan Brown on the Brancolirio channel YT.
“Juan Brown on the Brancolirio channel YT.”
That’s what I posted - his “Brancolirio” YT channel.
Yes, I see you did. My apologies.
In my opionion, missing arrestor bolts caused this calamity. Unmarred paint around the bracket holes looks like arrestor bolts and nuts were never installed at the factory. Here’s a quote from the preliminary finding in the report:
“Overall, the observed damage patterns and absence of contact damage or deformation around holes associated with the vertical movement arrestor bolts and upper guide track bolts in the upper guide fittings, hinge fittings, and recovered aft lower hinge guide fitting indicate that the
[Page 14 of 19 DCA24MA063 This information is preliminary and subject to change.]
four bolts that prevent upward movement of the MED plug were missing before the MED plug moved upward off the stop pads.”
Yes, the inside of the holes still had the factory paint, unscratched.
Chinese or muslim DEI mechanic?
Watch the video. The bolts were installed at Spirit Areosystems in Kansas. The breakdown happened in Seattle when warranty repair work had to be accomplished on the fuselage near the door plug...
“:The bolts were installed at Spirit Areosystems in Kansas. The breakdown happened in Seattle when warranty repair work had to be accomplished on the fuselage near the door plug...”
I guess if you are working on an airplane and have parts left over when you finish you should pay attention, it’s not like this is a lawnmower.
My guess is a breakdown during shift changes and contractor handoffs.
It says: Billy Bob & Ray done forgot they did not put the bolts back in and it was lunch time too. They later used the 4 bolts they found in their lunch bucket for the engine mount for one of their trucks.
Just imagine the joys of flying when 50% of United pilots are DEI hires.
Watch the video. The bolts were installed at Spirit Areosystems in Kansas. The breakdown happened in Seattle when warranty repair work had to be accomplished on the fuselage near the door plug...
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Then I don’t understand. Was the plane at Spirit Areosystems for the door installation? The bolts go through parts of the fuselage frame. The bolts keep the door from sliding up and off their perch on both sides. In looking at the preliminary investigation, I don’t see any sign that bolts had been installed in the holes in the airframe. Maybe I’m not looking at the right frame mounting bracket. I can’t get the YouTube channel to open on my computer.
Try a different web browser...
NTSB Preliminary Report:
https://www.ntsb.gov/investigations/Pages/DCA24MA063.aspx
https://www.ntsb.gov/investigations/Documents/DCA24MA063%20Preliminary%20report.pdf
NTSB Preliminary Report:
https://www.ntsb.gov/investigations/Pages/DCA24MA063.aspx
https://www.ntsb.gov/investigations/Documents/DCA24MA063%20Preliminary%20report.pdf
_______________________________________
I’m still leaning toward the position that the two bolts on the top slide locking collars were not there. The bolts are critical because they go through the top door collars that are designed to act as sliding-down locking door hangers. The collars are obviously integral to the frame of the aircraft and the securing bolts prevent the door from sliding up and off the collars. If the door does come off those collars, the top of the door will swing out, and abrupt depressurization will then tear the door off. That’s why the design provides for cotter-keyed castle nuts on each of the two collar bolts as an extra safety feature to prevent the nuts from ever coming loose and falling off. If the bolts were actually installed (which I seriously doubt) with the keyed castle nuts, there is no way the bolts could have come loose and thus the door could not have slide up and off the two collar perches. The perches have to be part of the airframe so as the NTSB briefer stated they will look for “witness” marks (paint marring, metal wear, etc.) on those collars where the bolts were supposed to have been fastened. Another thing to note is that it appears the lower door mounting brackets have heavy springs on the pins to help the workers lift the door up and off the upper perches for servicing. This would make it even more critical that the bolts were properly installed through the collar perches, preventing this movememt. Without the bolts, vibration might be enough, with help of the lower bracket springs, to raise the door up and off the their respective perches.
Left side of aircraft. Lower left (toward rear of the plane) Plug Door Hinge Guide bracket showing its Vertical Arrestor Bolt correctly installed (with cotter key installed). This photo was taken by a United Airlines tech., within a few days of January 5, 2024:
From the recent NTSB Preliminary Report:
When the door is installed for the purpose of being used in an emergency; interior view:
YES. At the two upper guide locations of the plug door, of the Boeing 737 -9 Max aircraft in question, the Arresting Bolts were missing - not installed.
In addition, at the lower two positions (re the top photo above), both of the Arresting Bolts were missing.
In addition, from what seemed to be said/written in all the reports that I have seen, a few other bolts of the entire assembly, were also missing.
At the bottom of the diagram illustration are two "Bonding Jumpers" according to Boeing. We used to call those Flexible Grounding Straps; and one is seen in the top photo above.
Such slip-shod work of not installing the retaining bolts is criminal negligence and demands prosecution of those assigned the work detail. Another possibility is that it’s sabotage, but if the bolts were installed properly and later removed by a saboteur, the paint would be defaced (witness marks) around the bolt-hole shoulder where the washer tightens against the collar. If that flat washer also happens to be a split lock washer (unlikely) there clearly will be witness marks. It will be interesting to see what the final inspection concludes.
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