AD/BELL 214/8 Hub Locking Plates

The instrument rests on a few discrete technical and regulatory concepts that determine scope, action and recurrence.

• Applicability by serial number and installed parts. The AD applies only to BHTI model 214B and 214B-1 helicopters with serial numbers 28001 to 28070 that are equipped with the two specific plates: upper locking plate P/N 214‑010‑231‑101 and lower locking plate P/N 214‑010‑232‑101 (Applicability). The AD therefore targets a discrete installed-parts configuration, not the model family as a whole.

• Mandatory replacement with a service-improvement part. Requirement paragraph 1 commands replacement of both the specified lower and upper locking plates with locking plate P/N 214‑010‑569‑101 using Part I of ASB 214-86-36 dated 8 October 1986, “as in force from time to time.” The ASB is therefore incorporated by reference as the technical method for accomplishing the replacement.

• Two inspection regimes. The AD establishes two parallel inspection regimes after the initial replacement:

  • Short-interval visual inspection for hub and lower hub nut slippage as per Part II of the ASB, to begin within 25 hours' time in service after the replacement and to repeat at intervals not to exceed 25 hours (Compliance paragraph 2).
  • Periodic crack inspection of the replacement locking plate P/N 214‑010‑569‑101 as per Part III of the ASB, to begin within 500 hours' time in service after the replacement and to repeat at intervals not to exceed 500 hours (Compliance paragraph 3(a)-(c)).

• Immediate action on detecting cracks. If a crack is found during the crack-inspection, the AD requires replacement of the hub locking plate with a serviceable part before further flight (Requirement paragraph 3(b)). The AD also requires retorqueing of the lower hub nut and installation of the new locking plate as detailed in Requirement paragraph 1 (Requirement paragraph 3(c)).

• Cross-references and source documents. The AD instructs compliance in accordance with ASB 214-86-36 (Part I, II, III as appropriate) and notes that installation instructions for associated hardware (scissors and sleeve) appear in the BHTI 214B Maintenance Manual, Chapter 65-20-00 (Note 1). It explicitly notes that FAA AD 87-11-06 refers (Note 2), indicating an international regulatory cross-reference.

• Temporal starting point. The AD specifies a commencement date (10 July 2018) and gives explicit timing windows for initial and recurring actions (Compliance). The initial replacement window is framed as the earlier of 50 hours' time in service or 30 days after commencement.

These main concepts allocate responsibility for a retrofit and dual inspection regime to operators and maintainers of the affected aircraft, tie technical method to an ASB and the BHTI maintenance manual, and impose specific, short and longer term recurring inspection intervals. The AD is technical and narrowly scoped: it does not purport to address other components or wider maintenance regimes beyond the identified parts and referenced ASB/manual procedures.

The primary affected parties are operators and maintenance organisations responsible for Bell Helicopter Textron model 214B and 214B-1 helicopters within the serial number range 28001-28070 that have the specified locking plates installed. The AD’s Applicability clause makes the scope explicit: it applies to those helicopters “certificated in any category” and “equipped with upper and lower locking plates, part numbers (P/N's) 214‑010‑231‑101 and 214‑010‑232‑101.” That language means the AD targets aircraft by serial number and installed parts configuration, irrespective of their certificate use category (e.g., private, commercial or other) so long as they are certificated.

Who will bear the operational burden and cost: owners and operators of affected airframes will be required to arrange and pay for the replacement parts, labour to carry out the Part I procedures of ASB 214-86-36, and to establish and resource the recurrent inspection tasks (the 25‑hour and 500‑hour inspection cycles). Maintenance organisations and licensed maintenance engineers are responsible for performing the technical work to ASB and maintenance manual standards; Note 1 explicitly points them to the BHTI 214B Maintenance Manual Chapter 65-20-00 for installation instructions for associated hardware (scissors and sleeve), indicating that maintainers must consult that manual to accomplish certain steps correctly.

The AD also affects spare-parts suppliers and inventory managers because the required replacement part is P/N 214‑010‑569‑101 and the AD removes two prior plate part numbers from acceptable installation without replacement. Where operators cannot obtain the new P/N in the required timeframe, operational consequences follow from the AD’s compliance windows; the AD does not provide exemptions or deferrals in the text provided.

Regulatory and oversight personnel within CASA (the AD is signed by a CASA delegate) are implicated as the issuing authority and likely the enforcement agency, although the AD text itself does not set out enforcement procedures or penalties. The AD cross-references FAA AD 87-11-06, so international operators or registrants interacting with FAA oversight may also find that external AD relevant to their compliance approach (Note 2).

Finally, pilots and flight operations managers will be affected operationally because the AD contains a safety‑critical instruction: if the crack inspection finds a cracked locking plate, replacement with a serviceable part is required before further flight (Requirement paragraph 3(b)). That provision directly affects flight release decisions pending maintenance action.

Duties imposed by the AD are expressed in mandatory terms in the Requirement and Compliance sections and are tightly specified. The AD delineates the following duties:

• Replace specified parts: Requirement paragraph 1 obliges replacement of lower locking plate P/N 214‑010‑232‑101 and upper locking plate P/N 214‑010‑231‑101 with locking plate P/N 214‑010‑569‑101, accomplished in accordance with Part I of BHTI ASB 214-86-36 dated 8 October 1986, “as in force from time to time.” The AD thus delegates the technical method to the ASB.

• Inspect for slippage: Requirement paragraph 2 requires a visual inspection of the hub and lower hub nut assembly for slippage in accordance with Part II of the ASB.

• Inspect for cracks and take immediate action: Requirement paragraph 3 requires inspections per Part III of the ASB to inspect the new locking plate for cracks (3(a)), immediate replacement before further flight if a crack is found (3(b)), and retorque the lower hub nut and install the locking plate P/N 214‑010‑569‑101 as detailed in Requirement paragraph 1 (3(c)). The “before further flight” language creates a hard operational constraint: aircraft with a cracked plate may not be flown pending replacement.

• Time-limited compliance windows: Compliance paragraph 1 requires the initial replacement within 50 hours’ time in service or within 30 days after commencement date of the AD (whichever occurs first). Compliance paragraph 2 sets the short-interval inspection cadence to within 25 hours’ time in service after completion of Requirement paragraph 1 and thereafter every 25 hours (or less). Compliance paragraph 3 sets the crack-inspection cadence to within 500 hours’ time in service after completion of Requirement paragraph 1 and thereafter every 500 hours (or less).

Rights or procedural features in the text are limited. The AD does not in its text set out mechanisms for seeking alternate means of compliance, time extensions, or exemptions; it does not set out appeal rights or civil penalties within the text provided. The only procedural nuance is the incorporation of an external technical document (“as in force from time to time”), which provides flexibility in referencing the current ASB revision for technical methods. Note 1 and Note 2 point operators to additional documents (BHTI maintenance manual and FAA AD) but do not create explicit statutory rights.

Operationally, the AD gives aircraft operators clear procedural obligations and a binary operational constraint in the case of cracks,replacement before further flight. The AD links technical compliance to an external ASB and to the manufacturer’s maintenance manual, so operators and maintainers must adopt the technical content of those documents as the method of compliance. The AD’s commencement date and discrete compliance windows convert the duties into firm scheduling obligations for operators and maintenance planners.

The AD text supplied does not specify civil or criminal penalties, nor does it set out an enforcement procedure or administrative sanction regime. The document is an Airworthiness Directive signed by a Civil Aviation Safety Authority delegate (signed 4 July 2018 by Pieter van Dijk) and it states the AD “commences on 10 July 2018.” The nature of an AD, as an instrument of the issuing authority, implies mandatory compliance, but the text itself contains no statutory penalty clauses or references to enforcement mechanisms in other instruments. The AD instead focuses on technical requirements, compliance timing, and referenced documents.

What the AD does explicitly state that has enforcement significance is the mandatory timing and operational restriction: a cracked locking plate identified under Part III inspection must be replaced “before further flight” (Requirement paragraph 3(b)). That constitutes an operational prohibition on flight until the required remedial action is taken.

The AD references and incorporates external technical documents (ASB 214-86-36 and the BHTI Maintenance Manual). In practice, regulators commonly use such technical mandatory documents as the basis for enforcement action where an operator fails to comply, but the AD text itself does not set out the enforcement pathway or penalties. The only named issuing official is a CASA delegate, which demonstrates agency authorship and suggests CASA as the responsible regulator for oversight, but the AD does not purport to describe CASA’s enforcement powers or processes.

Because the AD text does not itself set penalties, any enforcement or penalties would derive from the broader regulatory framework under which CASA issues ADs. That broader framework is not included in the supplied text, and the AD does not reproduce or summarise it. Where parties require clarity on enforcement outcomes (suspension, grounding, fines, certificate action), they must consult the relevant enabling aviation safety legislation and CASA enforcement guidance outside the text provided by this AD.

The AD explicitly crosses to and incorporates external technical documents and points to an FAA AD. Interaction in the text occurs on two levels: technical incorporation and regulatory cross-reference.

• Technical incorporation. The Requirement sections repeatedly require actions to be performed “in accordance with” Parts I, II and III of BHTI ASB 214-86-36 dated 8 October 1986 “as in force from time to time.” That phrase incorporates the ASB’s procedures as the mandated technical method, and also allows for the ASB to be considered in its current or revised form when applied. Note 1 also directs implementers to the BHTI 214B Maintenance Manual Chapter 65-20-00 for installation instructions for scissors and sleeve. Both incorporations mean that this AD interacts operationally with manufacturer-issued maintenance documentation: compliance requires adhering to those documents.

• International/regulatory cross-reference. Note 2 states “FAA AD 87-11-06 refers.” The AD therefore recognises that an FAA airworthiness directive exists on the subject and flags it to operators and maintainers. The AD text does not reproduce the FAA AD nor state how conflicts are to be resolved; it merely indicates the FAA AD’s relevance. Operators subject to multiple jurisdictions may therefore need to reconcile compliance approaches across the relevant regulators.

• Applicability across certificate categories. The Applicability clause states the helicopters are “certificated in any category.” That term means the AD applies regardless of the aircraft’s certificate use category, which avoids interactional ambiguity where an AD might otherwise be limited to, say, commercial operations. The AD therefore interacts with operators’ regulatory obligations irrespective of use-case category.

• Technical manuals vs ADs. By specifying ASB and maintenance manual procedures as the method of compliance, the AD delegates technical detail to manufacturer documents. That creates an operational interaction: maintainers must consult both documents and apply the most current ASB and maintenance manual instructions. Where the ASB is modified “as in force from time to time,” it introduces a dynamic interaction,amendments to the ASB may change the technical steps that satisfy the AD. The AD text itself does not resolve conflicts or state whether later ASB revisions that change fundamental technique remain acceptable, beyond the “as in force from time to time” phrase.

The supplied AD does not reference or modify any other Australian statutes, regulations, or administrative instruments in its text, nor does it state enforcement mechanisms under other laws. To understand full legal interaction,such as enforcement, penalties, certificate consequences, or appeal rights,operators will need to consult the broader regulatory framework under which CASA issues ADs, which is not included in the AD text.

The document provided contains information about its own date and commencement but includes no historical amendments to the AD itself. The AD is dated and signed on 4 July 2018 by a CASA delegate and the text states “This AD commences on 10 July 2018.” There is no textual schedule of prior AD versions, nor are there later amendment entries in the supplied text.

Two external documents referenced have their own dates that are relevant to the AD’s technical provenance. The BHTI Alert Service Bulletin cited as the method for performing the replacement and inspections is ASB 214-86-36 dated 8 October 1986; the AD requires compliance with Parts I-III of that ASB “as in force from time to time.” The ASB date indicates the manufacturer’s original technical instruction date, but the AD’s “as in force from time to time” wording leaves open the possibility that later revisions of the ASB could be relevant. The AD does not record any particular ASB revision beyond the 8 October 1986 date.

Note 2 references FAA AD 87-11-06, indicating an FAA action from 1987 that relates to the same technical issue. The AD does not reproduce that FAA AD date beyond the identifier, and it does not record whether this AD amends, supersedes, or is consistent with FAA treatment.

Because the AD text supplied does not provide a history of prior or subsequent amendments to AD/BELL 214/8, readers who require the amendment chronology (for example to check whether later ADs or revisions modify compliance obligations) must seek the CASA AD registry or other official updates outside the supplied text. The AD as supplied is a single instrument with a commencement date of 10 July 2018 and no alterations or addenda are included in the provided material.

The AD text does not include, refer to, or summarise any litigation history. There are no judicial decisions, enforcement actions, appeals, or administrative hearings mentioned in the supplied document. The only factual incident recorded is an accident investigation from May 1986 that forms the technical basis for the AD: that accident involved a Bell model 214ST helicopter which experienced loss of collective control due to failure of the collective hub bearing retention nut lower locking plate, leading to a ditching at sea (Background). The AD cites that accident as the impetus for the mandated actions to prevent failure and subsequent loss of control (Background), but the AD supplies no litigation narrative stemming from that accident or from the AD’s issuance.

If readers require information on legal challenges to the AD, enforcement proceedings, or court determinations interpreting the AD or surrounding obligations, that material is not present in this document. The AD does not record whether any party sought review or relief against the AD or whether any civil or criminal proceedings arose from compliance failures. To determine whether there is any litigation history, users must consult external legal and regulatory records or the CASA public record beyond the supplied AD text.

Several practical and legal-for-compliance traps emerge directly from the wording of the AD and the documents it references.

• Narrow parts-specific applicability. The AD applies only to helicopters S/N 28001-28070 that are equipped with the two specified plates, P/N 214‑010‑231‑101 (upper) and P/N 214‑010‑232‑101 (lower). If an aircraft has been modified previously or has different plate part numbers installed, the AD’s explicit applicability language matters. Operators must confirm both serial number and current installed parts before assuming the AD applies or does not apply (Applicability).

• “As in force from time to time” incorporates ASB versions dynamically. The AD requires compliance “in accordance with Part I/II/III of BHTI ASB 214‑86‑36 dated 8 October 1986, as in force from time to time.” That phrasing adopts the ASB’s content as the compliance method and allows later ASB revisions to be considered binding for the AD’s purposes. Operators must therefore ensure they are using the current ASB version to comply; using an out-of-date version could lead to non-compliance even if the operator followed a prior ASB version.

• Tight initial timing window. The initial replacement must be done “within the next 50 hours’ time in service or within 30 days after the commencement date of this AD, whichever occurs first.” Operators with limited access to parts or maintenance facilities must schedule quickly. The AD provides no deferral mechanism in the text supplied.

• Two inspection cadences to manage. After the initial replacement, operators must manage a short-interval check (25‑hour cadence for hub and lower hub nut slippage) and a longer-interval crack inspection (500‑hour cadence for the locking plate), which creates a multi-cadence maintenance obligation that must be recorded and tracked. Administrative systems must be able to track both time‑in‑service intervals.

• “Before further flight” on crack detection is non-negotiable. Requirement paragraph 3(b) requires replacement with a serviceable part before further flight if a crack is found. That imposes an immediate operational grounding until the replacement occurs.

• Parts and installation hardware. Note 1 directs readers to the BHTI 214B Maintenance Manual, Chapter 65-20-00, for installation instructions for scissors and sleeve. Failure to follow the maintenance manual instructions for associated hardware could render the replacement incomplete even if the locking plate part has been changed.

• Cross-jurisdictional reference without harmonisation text. Note 2 says FAA AD 87-11-06 refers, but the AD does not explain whether there are differences in timing, technique, or scope between the CASA AD and the FAA AD. Operators under multiple jurisdictions must verify alignment rather than assume equivalence.

• No penalties or enforcement mechanism in the AD text. The AD does not set out penalties, which means operators must look to the wider regulatory framework to assess enforcement risk or consequences for non‑compliance. That may create uncertainty for risk managers who need to know the practical implications of failing to comply within the stipulated windows.

• Single technical remedy mandated. The AD mandates replacement with P/N 214‑010‑569‑101; it does not provide for alternative parts or methods within the text. Operators with aging inventory or supply constraints must source that specific P/N or risk non‑compliance.

• Documentation and record-keeping not specified. The AD prescribes actions and timing but does not specify required records, sign-offs, or logbook entries in its text. Operators should not assume record-keeping is unnecessary; good practice and other regulatory obligations will typically require documentation of the replacement and inspections, but the AD itself does not state the record format or retention.

The AD sets out a stepwise, document-tethered compliance path. Below are concrete steps, drawn precisely from the AD text, that an operator or maintenance organisation should follow to achieve compliance.

1. Confirm applicability.

   • Verify the helicopter model and serial number: confirm the airframe is BHTI model 214B or 214B-1 and S/N is between 28001 and 28070 inclusive (Applicability).
   • Verify the current installed parts: confirm the airframe is equipped with upper locking plate P/N 214‑010‑231‑101 and lower locking plate P/N 214‑010‑232‑101 (Applicability). If either plate is not installed, the AD’s replacement requirement for those plates may not apply.

2. Schedule the initial replacement (Requirement paragraph 1; Compliance paragraph 1).

   • If the replacement has not already been accomplished, carry out replacement of both the lower locking plate P/N 214‑010‑232‑101 and the upper locking plate P/N 214‑010‑231‑101 with locking plate P/N 214‑010‑569‑101.
   • Use Part I of BHTI ASB 214-86-36 dated 8 October 1986 as the method, “as in force from time to time,” so obtain and follow the current ASB Part I procedures.
   • Complete this replacement within 50 hours’ time in service or within 30 days after the AD commencement date (10 July 2018), whichever is earlier (Compliance paragraph 1).

3. Perform hub and lower hub nut slippage inspection (Requirement paragraph 2; Compliance paragraph 2).

   • After completing the replacement under Requirement paragraph 1, conduct a visual inspection of the hub and lower hub nut assembly for slippage in accordance with Part II of the ASB.
   • The first such inspection must occur within 25 hours’ time in service after completing the replacement, and thereafter at intervals not to exceed 25 hours’ time in service since the most recent inspection (Compliance paragraph 2).
   • Ensure inspection findings are recorded per normal maintenance record-keeping practices even though the AD text does not set out a record format.

4. Perform locking plate crack inspections and immediate remedial action (Requirement paragraph 3; Compliance paragraph 3).

   • Inspect the replacement locking plate P/N 214‑010‑569‑101 for cracks as required by Part III of the ASB.
   • The first crack inspection must be performed within 500 hours’ time in service after completing the replacement in Requirement paragraph 1, and thereafter at intervals not to exceed 500 hours’ time in service (Compliance paragraph 3).
   • If a crack is found during any such inspection, replace the hub locking plate with a serviceable part before further flight (Requirement paragraph 3(b)). Do not return the aircraft to service until replacement is complete.

5. Retorque and installation steps (Requirement paragraph 3(c); Note 1).

   • After replacement and as required, retorque the lower hub nut and install locking plate P/N 214‑010‑569‑101 as detailed in Requirement paragraph 1 and the ASB.
   • Consult BHTI 214B Maintenance Manual Chapter 65-20-00 for installation instructions for the scissors and sleeve (Note 1), and ensure those instructions are followed.

6. Use current ASB and maintenance manual editions.

   • Because the AD requires compliance “in accordance with” specified ASB parts “as in force from time to time,” obtain and use the current ASB text and the appropriate maintenance manual chapter for the procedures and torque values.

7. Operational constraints.

   • If during any inspection a crack is detected, aircraft must not fly until the cracked locking plate has been replaced with a serviceable part (Requirement paragraph 3(b)). Plan contingencies for aircraft downtime and parts procurement.

8. Administrative actions and tracking.

   • Although the AD does not specify recordkeeping requirements, maintain contemporaneous records of replacement, inspections, and retorqueing actions (dates, times-in-service, technician signatures, parts installed and serials), because operators typically must demonstrate compliance to the regulator and for continued airworthiness management.
   • Implement tracking for both the 25-hour and 500-hour inspection intervals so that each inspection is performed within the maximum intervals stated (Compliance paragraphs 2 and 3).

9. Cross-reference FAA AD as appropriate.

   • Note 2 indicates FAA AD 87-11-06 refers. If the operator is subject to FAA oversight or has cross-registered maintenance programmes, obtain and review FAA AD 87-11-06 to confirm whether its content imposes additional or differing obligations.

10. Contact points and certification.

• Where questions arise about acceptable means of compliance, ASB revisions, or parts acceptability, operators should consult the issuing authority (the AD is signed by a CASA delegate) and the manufacturer, following normal regulatory channels. The AD text itself does not provide alternate means of compliance or variance procedures.

Following these steps will satisfy the AD’s mandatory elements as stated in the provided text: replace the specified plates with P/N 214‑010‑569‑101 per ASB Part I, perform the hub/ nut slippage checks per ASB Part II on a 25-hour cadence, perform locking-plate crack inspections per ASB Part III on a 500-hour cadence, retorque and install as required, and replace any cracked plate before further flight.