MS21042
BOLT
Specifications
- Part Number
- MS21042
- Manufacturer
- —
- ATA ChapterMaintenance system chapter
- 53 — FuselageField reports: 53 (67%) · 52 (33%) — 3 reports
- CapabilitySystem area (hydraulics, avionics, landing gear…)
- Consumables / Hardware
- Inventory ClassRotable, expendable, or consumable
- Consumable
- Certification
- OEM
- Aircraft Category
- Multi-Category
- Criticality
- Standard
- Life & ShelfTypical service/shelf life — verify against OEM data
- —
Service Reliabilityfrom FAA SDR (Service Difficulty Reports)
* Structural ATA chapter (53). Verb-based propensity is suppressed because "REPAIRED" in the SDR text typically refers to the airframe being repaired around the part, not the part itself. FAA K-code component-change rate is the honest signal.
- SDR reports
- 3
- Replace events
- 1
- Repair events
- 1
- K-code events
- 1
Directional indicator only. Reflects what operators reported to the FAA when a difficulty was logged — not a fleet-normalized failure rate or a cost-based BER. Use alongside operator-specific data.
Airworthiness Directive coverage
FAA / EASA public regulatory data
- FAAAD 2022-20-04effective Dec 23, 2022ProhibitionNamed as replacement part
The FAA is superseding airworthiness directive (AD) 2021-26- 08, which applied to certain Bell Textron Canada Limited Model 206, 206A, 206A-1, 206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4 helicopters. AD 2021-26-08 required removing certain nuts from service; installing newly designed nuts; applying a specific torque, and a torque stripe to each newly installed nut; after the installation of each newly designed nut, inspecting the torque; and depending on the inspection results, either applying a torque stripe, or performing further inspections and removing certain parts from service. AD 2021- 26-08 also prohibited installing any affected nut on any tail rotor drive shaft (TRDS) disc pack (Thomas) coupling. Since the FAA issued AD 2021-26-08, the FAA determined certain torque values and part numbers (P/Ns) need to be revised. This AD was prompted by reports of cracked or missing nuts installed on the TRDS Thomas couplings and the need to revise certain torque values and P/Ns in AD 2021-26-08. This AD requires removing certain nuts from service; installing newly designed nuts; applying torque and a torque stripe; and additional corrective actions if necessary. This AD also prohibits installing any affected nut on any TRDS Thomas coupling, as specified in a Transport Canada AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
- FAAAD 2021-15-14effective Aug 30, 2021Prohibition
The FAA is adopting a new airworthiness directive (AD) for various restricted category helicopters, originally manufactured by Bell Textron Inc. (Bell). This AD was prompted by multiple events involving failure of the tail boom attach structure including the bolts. This AD requires revising the existing Rotorcraft Flight Manual (RFM) for your helicopter to incorporate pre-flight checks; removing paint and sealant, and cleaning; repetitive inspections of structural components that attach the tail boom to the fuselage; and depending on the outcome of the inspections, repairing or replacing components, or re-bonding the structure. The FAA is issuing this AD to address the unsafe condition on these products.
Directives citing this part number in the FAA / EASA regulatory corpus we have processed — not a complete historical AD list. An AD is a compliance requirement that drives scheduled work (inspections, replacements, modifications) on the fleets that carry the part; a directive naming this PN as the replacement part is install demand, not an action against it — and none of this is a prediction that the part will fail.
Airframe Applicability(2)
Data Sources(1)
- 2026-03-07
Quick Facts
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