Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

NTSB Findings & Bearing Failure

• Commenters praise the NTSB report for its technical clarity and forensic depth.
• Discussion centers on the aft engine-mount spherical bearing: race cracking, bearing seizure, excess play, and how that can transfer unexpected loads into surrounding structure and bolts.
• Some initially think a split race alone might not be “safety of flight” critical; others explain how a seized or failed bearing can quickly become catastrophic given the loads on an engine mount.
• There’s speculation that Boeing’s original analysis might have only modeled a cracked race, not the full lug fracture scenario later found by NTSB.

Inspections, Maintenance & Aging Aircraft

• Concern that a 60‑month visual inspection interval is too long for a 30+ year-old aircraft doing heavy cycles, especially for a largely inaccessible part buried in the wing.
• Explanation of A/B/C/D checks and D-check teardown scale (tens of thousands of man-hours) surprises some readers.
• Several people argue visual checks of this specific bearing are unrealistic without significant disassembly or special preparation to reveal hairline cracks.
• Strong defense of maintenance crews as highly trained professionals who also face emergencies, not just routine servicing.

Boeing’s Knowledge, Communication & Culture

• Key fact: Boeing issued a 2011 notice about this bearing issue but stated it would not create a “safety of flight” condition.
• Some view this as an understandable (if now proven wrong) engineering judgment; others see it as emblematic of a company that repeatedly downplays safety issues.
• Debate over whether this is a coverup vs. “sometimes engineers are wrong”; critics point to a pattern of cost-cutting and McDonnell Douglas–style financial culture.
• The bearing redesign without mandating retrofit is seen as another example of “good enough” risk posture until something fails.

MCAS, Optional Safety Features & Blame

• Parallels are drawn to MCAS: early attempts to blame non‑US pilots; later evidence that US crews also faced MCAS issues and survived partly by luck and specific choices.
• Discussion of optional AoA disagreement alerts: critical safety indications treated as paid software options, likened to “BMW heated seats, but for life-critical alerts.”
• Many argue focusing on manufacturer fixes is more scalable than demanding extraordinary pilot skill worldwide.

Risk Management, Regulation & Responsibility

• Several comments restate that zero-risk designs are impossible; decisions always weigh cost vs. expected fatalities.
• Pushback emphasizes a difference between unknown emergent risks and knowingly accepting preventable, specific hazards in critical systems.
• Concerns about regulatory capture and corruption reduce trust that FAA/NTSB and Boeing interactions are fully independent.
• Debate over how much airlines (and their insurers) should independently challenge manufacturer guidance, especially post‑MCAS.