AD/BELL 407/9 Amdt 3 - Tailboom Skin

The AD is built around a small set of precise regulatory mechanisms; understanding these is necessary to implement the directive and to assess its operational impact.

Applicability and identification

• Applicability is narrow and part-number specific: only Model 407 helicopters with tailboom part numbers 407-030-801-107 and 407-530-014-101/-103 are captured (Applicability). The AD therefore depends first on accurate parts identification in the helicopter technical records.

Incorporation by reference and procedural dependency

• The AD does not set out detailed inspection procedures within its text; it mandates compliance with the procedures in BHTC Alert Service Bulletin (ASB) 407-07-80 (original issue) or any later Transport Canada approved revision (Parts II-IV). That makes implementation operationally dependent on the ASB’s content and any future TC-approved revisions.

Tiered inspection regime

• The inspection regime is tiered: an initial surface preparation and inspection (Part II), a daily visual check (Part III), and a 100-hour detailed inspection (Part IV). The AD prescribes tools or magnification for at least some checks (e.g., a 10x magnifying glass for the Part II inspection of the “Daily check area” indicated in Figure 2 of the ASB).

Mandatory corrective action before flight

• If any inspection detects a crack, the AD requires replacement of the tailboom with a serviceable part before further flight (Parts II, III, IV). That is an operationally binding requirement: detection triggers removal of the aircraft from flight until a compliant replacement is installed.

Record-keeping obligation

• Part I requires entry of the appropriate tailboom part number in the helicopter technical records and annotation if the tailboom is not affected. The AD therefore creates a documentary trigger for applicability and future compliance checks.

Terminating action and part substitution

• Replacement with specified newer tailboom part numbers (407-030-801-201/-203/-205) or later part numbers is declared a terminating action to the Directive (Part V). The AD also notes that BHTC introduced a new chemically milled skin tailboom not subject to the inspections required by the Directive, and earlier amendments limited applicability where those parts were fitted (Background, Amendment history).

Inter-jurisdictional reference

• The AD explicitly references Transport Canada AD CF-2008-04 and accepts later Transport Canada approved revisions of the ASB, creating cross-reference to Transport Canada’s regulatory actions (Note).

Temporal force

• Compliance dates are fixed and immediate relative to the effective date 15 February 2008 (Compliance). The AD became effective on that date and Amendment 3 was issued in response to a Transport Canada AD mandating new inspection requirements introduced by ASB 407-07-80 (Background).

These concepts show that the AD functions by combining a part-number gate, mandated record updates, incorporation by reference to a manufacturer ASB, prescribed inspection cadence and methods, and an explicit pre-flight prohibition on flying with a cracked tailboom, plus an express terminating action via specified replacement part numbers.

The AD affects a narrow set of industry actors directly and several others indirectly through operational dependencies. The source text enables precise identification:

Primary affected parties

• Registered owners/operators of Bell Model 407 helicopters that have tailboom part numbers 407-030-801-107 or 407-530-014-101/-103 installed (Applicability). Those owners must verify whether those part numbers are installed (Part I(a)) and must annotate the technical records with the correct part number (Part I(b)-(c)). The obligation to mark records falls on the operator or their delegated maintenance organisation as part of the aircraft’s technical records regime.

Maintenance personnel and approved maintenance organisations

• Maintenance staff performing inspections are affected because the AD mandates specific inspection procedures and tolerances (for example use of a 10x magnifying glass to inspect areas indicated as “Daily check area” on Figure 2 of ASB 407-07-80) and references specific parts of the ASB for surface preparation and protective finishing (Part II). The AD requires that these inspections be conducted in accordance with the ASB original issue or later Transport Canada approved revision, so maintenance organisations must ensure they hold and apply the correct revision.

Pilots and flight departments

• Flight crews and flight operations are affected because the AD requires a Daily Visual Inspection before the first flight of the day and states that if a crack is detected the tailboom must be replaced before further flight (Part III). That creates pre-flight duties and potential operational interruptions.

Supply chain and manufacturers

• BHTC (Bell Helicopter Textron Canada) is implicated as the provider of the ASB and replacement tailbooms. The AD notes that BHTC introduced a new tailboom with a chemically milled skin that is not subject to the inspections required by this Directive (Background). The AD also specifies terminating tailboom part numbers (407-030-801-201/-203/-205), creating demand for those parts.

Regulators and cross-jurisdictional actors

• The Civil Aviation Safety Authority (CASA) is the issuing authority, represented by the delegate who signed the AD (David Villiers), and Transport Canada is referenced as the approving authority for later ASB revisions and as the source of a related AD, CF-2008-04 (Background, Note). This affects how the AD is interpreted for ASB revisions and part approvals.

Maintenance records auditors and inspectors

• Because the AD requires a part-number entry and annotations indicating whether a tailboom is affected, auditors and airworthiness inspectors will use record evidence to verify compliance (Part I).

Insurance and lessee/owner contractual relationships

• While the AD does not mention insurance or lease obligations, the duties it imposes (inspection cadence, record-keeping, mandatory replacement before further flight when a crack is found) will affect risk exposure, potential downtime and the allocation of maintenance costs,,factors of relevance to insurers, lessors and lessees.

Secondary and indirect effects

• Scheduling and flight availability will be affected for any operator whose helicopter is captured. If a crack is found “before further flight” replacement requirement will cause immediate removal from service. The timeline in the Compliance section (Part II within 25 flight hours or 30 days; Part IV within 100 flight hours and thereafter at intervals not to exceed 100 flight hours) creates recurring maintenance obligations that affect operating costs and aircraft availability.

In short, the AD binds owners/operators and maintenance organisations of the specifically identified Model 407 helicopters to immediate and recurring inspection and record-keeping obligations; it also shapes the supply and maintenance decisions of manufacturers and parts suppliers, and it indirectly affects flight operations, scheduling and contracting stakeholders.

The AD creates a compact set of mandatory duties, plus a single clearly defined regulatory “right” for operators in the form of a terminating action. All duties and the practical effect of that right are stated in the AD itself.

Primary duties imposed by the AD

• Verify part number and record it: Part I(a)-(b) requires verification of whether the affected tailboom PNs are installed and entry of the appropriate tailboom part number into the helicopter technical records. Part I(c) requires annotation that the tailboom is not affected where applicable. This creates a documentary duty that serves as the basis for determining applicability and future compliance.
• Follow ASB procedures: Parts II, III and IV require inspections and preparatory work in accordance with BHTC ASB 407-07-80 original issue or any later Transport Canada approved revision. The AD therefore imposes a duty to obtain, understand and follow the ASB content or later Transport Canada approved revisions.
• Conduct the initial surface preparation and inspection: Part II requires preparing the tailboom surface for the “Daily Visual Check” per the ASB Part II paragraphs (1)(a) to (e), inspecting both areas indicated as “Daily check area” using a 10x magnifying glass, and applying a thin coat of clear coating if no cracks are found (Part II).
• Perform daily pre-flight visual checks: Part III requires a visual check in accordance with the ASB Part III paragraphs (1) and (2) before the first flight of the day (Part III).
• Perform 100-hour inspections: Part IV requires a 100-hour inspection per the ASB Part IV, to be done within 100 flight hours after 15 February 2008 and thereafter at intervals not exceeding 100 flight hours (Part IV, Compliance).
• Replace cracked tailbooms before further flight: If any inspection (Part II initial inspection, Part III daily check, Part IV 100-hour inspection) detects a crack, the AD requires replacement of the tailboom with a serviceable part before further flight (Part II, Part III, Part IV). That duty effectively prevents continued operation of an affected helicopter with a detected crack.

Record and annotation duties

• Part I explicitly requires entering the tailboom part number into the helicopter technical records and annotating when the tailboom is not affected. Those records will be the primary compliance evidence for regulators.

Terminating action (operational right)

• Part V identifies replacement of the affected tailboom with part number 407-030-801-201/-203/-205, or later part numbers, as terminating action to the Directive. That is the principal “right” offered by the AD: operators may remove recurring inspection obligations under this AD by installing the specified newer tailboom parts. The AD also notes that BHTC has introduced a chemically milled skin tailboom that is not subject to the inspections required by the Directive (Background). Where the replacement tailboom itself is identified in the AD’s applicability section, the AD specifically requires continuation of the inspections (Parts III and IV contain that proviso), so the terminating right applies only when replacement tailboom part numbers are those identified in Part V.

Interpretive duties

• The AD requires operators to rely on ASB 407-07-80 original issue or later Transport Canada approved revisions; that creates a duty to track Transport Canada approvals for ASB revisions and to apply those approved revisions. The AD’s integration with Transport Canada AD CF-2008-04 (Note) implies cross-reference duties: operators must be alert to related ADs and cross-jurisdictional approvals.

Limitations and scope of duties

• The AD’s duties are limited to the applicability set out in the AD. Part I(c) requires annotating the helicopter technical records where the tailboom is not affected, thus removing uncertainty for unaffected helicopters.

Summary

• Duties: verify and record tailboom PN; prepare surfaces and perform initial inspections; conduct a specified daily pre-flight check; carry out 100-hour inspections at prescribed intervals; replace any tailboom on which a crack is found before further flight; follow the ASB procedures (original or later TC-approved revisions).
• Right: install specified terminating replacement tailboom part numbers (407-030-801-201/-203/-205 or later part numbers) to terminate the Directive’s inspection obligations.

All these duties and the terminating action are explicit in the AD text (Parts I-V, Compliance, Background).

The AD text itself sets out mandatory duties and effective dates but does not enumerate civil or criminal penalties, fines, or enforcement procedures within the instrument’s text. The AD does, however, create operational and regulatory consequences by mandating actions and by using phrases that have immediate operational effect. From the AD text the following enforcement-relevant mechanisms and de facto constraints can be identified.

Mandatory compliance and effective date

• The AD has an effective date (15 February 2008) and specific compliance deadlines for each Part (Compliance). That temporal specification makes the AD operationally binding from that date.

Operational effect of "before further flight"

• The AD requires that if a crack is detected “before further flight, replace the tailboom with a serviceable part” (Parts II, III, IV). That phrasing imposes an immediate operational constraint: an aircraft found with a crack may not be flown until the replacement is effected. In regulatory practice, such a requirement functions as a grounding instruction until corrective action is completed. The AD itself uses this language to compel immediate remedial action.

Record evidence for compliance

• The AD requires entries in the helicopter technical records (Part I). Those records will be the primary evidence used by airworthiness inspectors or auditors to verify compliance. Failure to maintain the required records will impede proof of compliance.

Implicit enforcement channels (from the AD text)

• Although the instrument does not list penalties, the AD is issued by the Civil Aviation Safety Authority delegate (signed by David Villiers). In the regulatory context the issuance of an AD is a regulatory instrument directing airworthiness actions; non-compliance with an AD typically exposes the operator to the applicable regulatory enforcement mechanisms administered by the issuing authority. The AD text does not itself specify what those mechanisms are.

Inter-jurisdictional references that affect enforcement

• The AD references Transport Canada AD CF-2008-04 and requires the ASB original issue or later Transport Canada approved revisions for inspection procedures (Part II, Note). That cross-reference ties compliance to the content and approvals of another national regulator, which can affect enforcement where jurisdictions recognize each other’s ADs or where approval of ASB revisions is a precondition for procedural change.

Practical enforcement consequences identifiable from the text

• Immediate grounding until replacement where a crack is detected (due to “before further flight” requirement).
• Requirement to demonstrate correct part-number entries in technical records.
• Requirement to follow the ASB procedures as adopted or subsequently approved by Transport Canada, which means enforcement could involve verification that the current TC-approved ASB revision was used.

What the AD does not state

• There is no explicit statement in the AD text of monetary fines, licence sanctions or criminal penalties for non-compliance. The AD also does not set out inspection frequencies as a basis for periodic enforcement audits beyond the specified inspection deadlines and intervals.

In summary, enforcement mechanisms that follow from the AD are implicit and operational (grounding until replacement; record-based compliance checks) rather than specified as explicit fines or penalties in the AD text. The AD’s cross-reference to Transport Canada action and its issuance by CASA imply conventional regulatory enforcement channels would be available, but those channels are not detailed within the AD itself.

The AD explicitly references and incorporates external documents and a related foreign regulator’s AD. These references determine part of its operational and legal interaction with other regulatory instruments and obligations.

Incorporation of manufacturer service bulletin as regulatory standard

• The AD requires compliance with BHTC Alert Service Bulletin (ASB) 407-07-80 original issue, or later Transport Canada approved revision, for Parts II-IV (Part II, Part III, Part IV). This creates a direct interaction between the AD and the ASB: the ASB content, and any Transport Canada approved revisions of it, become mandatory for the purposes of this AD. Thus, changes to the ASB that have not been Transport Canada approved are not automatically incorporated by the AD.

Cross-reference to Transport Canada AD

• The AD explicitly refers to Transport Canada AD CF-2008-04 (Note). The AD states that Amendment 3 is issued in response to a new Transport Canada AD, which mandates new inspection requirements introduced by ASB 407-07-80 (Background). This establishes a cross-jurisdictional relationship where CASA’s AD aligns its requirements with those mandated by Transport Canada. For holders operating across jurisdictions, that creates a synchronised expectation: the ASB revisions approved by Transport Canada are the reference standard for the CASA AD.

Effect on parts substitution and regulatory status of replacement parts

• The AD identifies certain tailboom part numbers as terminating action (407-030-801-201/-203/-205) and notes that BHTC introduced a chemically milled tailboom skin that is not subject to the inspections required by the Directive (Part V, Background). The regulatory status of a tailboom changes with part number: installing a specified terminating tailboom or a later part number changes the operator’s obligations under this AD. The ASB and any associated certification documentation will be relevant to demonstrate that a substituted part indeed meets the terminating action requirements.

Relationship to aircraft technical records regime

• The AD requires entry of tailboom part numbers in the helicopter technical records (Part I). That interacts with the broader legal framework governing aircraft maintenance records and continuing airworthiness, because those regimes typically determine retention, auditability and transfer of records between operators, lessors and regulators.

Potential interaction with air operations (pre-flight) requirements

• The AD mandates a Daily Visual Inspection to be performed before the first flight of the day as part of pre-flight checks (Part III). Where national or operator flight operations rules prescribe pre-flight checks, this AD’s daily inspection will be performed within that wider pre-flight regime and thus will interact operationally with flight crew responsibilities.

Interplay with other CASA or jurisdictional ADs and approvals

• Although the AD does not list other CASA ADs, its method of incorporating a manufacturer ASB only when Transport Canada approves revisions means that procedural changes may require approvals from another jurisdiction (Transport Canada) before being mandatory under this CASA AD. That unusual chain means the AD interacts across jurisdictions through the channel of ASB approval.

What the AD does not specify about legal interaction

• The AD does not state how conflicts between different ADs would be resolved, nor does it lay out how Transport Canada approvals are to be obtained or recognised in Australia beyond the instruction to rely on Transport Canada approved ASB revisions. The AD also does not state explicit provisions for exemptions or alternative methods of compliance; any such mechanisms are not set out in the AD text.

In sum, the AD interacts with other laws and instruments primarily by incorporating by reference the manufacturer’s ASB subject to Transport Canada approval and by aligning itself with a Transport Canada AD. It thereby creates a cross-reference channel whereby Transport Canada’s approvals of ASB revisions determine which procedural versions are mandatory under this CASA AD. It also affects the aircraft continuing airworthiness and technical records regimes by requiring specific record entries as a determinative step for applicability and compliance.

The AD text itself contains an internal amendment history summarised in the Background section and evident in the title of the instrument (AD/BELL 407/9 Amdt 3). The AD records the sequence of previous amendments and the operational reasons for them.

Amendment chronology and practical effects

• Original Directive: The AD’s initial issue is not reproduced in full in the supplied text, but the Background refers to earlier actions: “There have been several reports of cracks to the tailboom skin on the left side in the area of the horizontal stabiliser. The cracks were found by normal visual inspection.” That statement explains why inspections were first mandated (Background).
• Amendment 1: According to the Background, Amendment 1 limited the applicability of the AD to helicopters equipped with certain part number tailbooms. It also notes that BHTC introduced a new tailboom with a chemically milled skin not subject to the inspections required by the Directive. The practical effect of Amendment 1 was to narrow the universe of aircraft subject to the inspections by excluding the newer chemically milled tailboom designs (Background).
• Amendment 2: The Background states that Amendment 2 introduced modifications to some existing tailbooms, imposed a life limitation of 5,000 hours on certain tailbooms, and introduced a new inspection interval of 150 hours. These changes adjusted both life-limits and inspection cadence that operators had to follow under the AD’s obligations (Background).
• Amendment 3 (current): The instrument before us is Amendment 3. The Background explains Amendment 3 was issued in response to a new Transport Canada AD which mandates new inspection requirements introduced by ASB 407-07-80. The current AD therefore implements those new inspection requirements by referring to the ASB and setting the current inspection scope, magnification requirement and timelines for Parts I-IV, and defining the terminating action in Part V (Background, Parts I-V, Compliance).

Effective dates and amendment timing

• The current Amendment becomes effective on 15 February 2008 (Compliance). The AD itself was signed on 13 February 2008 by David Villiers as delegate of CASA (signature block). The compliance timings for Parts I-IV are all anchored to the effective date (Compliance).

Relation to Transport Canada action

• Amendment 3 is explicitly described as being issued in response to a Transport Canada AD (Background). The AD also contains a note that Transport Canada AD CF-2008-04 is referred. Thus the amendment history records an iterative alignment with Transport Canada regulatory action and corresponding manufacturer ASB content.

Documented changes in technical measures

• From Amendment 1 through Amendment 3, the recorded technical measures have evolved from generic visual detection of cracks to part-number specific applicability, life limits on certain tailbooms, revised inspection intervals (150 hours moved earlier under Amendment 2, then current 100-hour formalisation under Compliance), and finally the integration of ASB-prescribed inspection methods (such as 10x magnification in Part II) required by Transport Canada (Background, Parts II-IV, Compliance).

What the AD’s amendment history signals operationally

• The sequence shows a regulatory response evolving with information: initial crack reports, limitation of applicability when newer tailboom designs were introduced, imposition of life limits and revised inspection intervals, and then harmonisation with transport-authority-mandated ASB inspection requirements. For operators, that history means the AD has changed scope and technical requirements over time and that subsequent revisions may continue to adjust obligations in response to manufacturer or foreign-regulator inputs.

The AD text contains the summary of these amendments but does not reproduce the full text of Amendments 1 and 2; it records their substantive outcomes (limited applicability, new tailboom design, life limitation, inspection interval changes) and states the cause for Amendment 3 (Transport Canada AD).

The AD text contains no reference to any litigation, legal challenges, court decisions, or appellate review relating to this Directive or its previous amendments. The supplied document does not name any cases, judicial reviews, or contested enforcement actions.

What the source states

• The AD is an administrative instrument issued by the Civil Aviation Safety Authority delegate (David Villiers) and dated 13 February 2008. The document’s Background and Compliance sections record regulatory facts and amendment history but do not refer to litigation or dispute resolution relating to this AD (Background, Compliance).

Implication for readers

• Because the AD includes no litigation history, any analysis of legal challenges, precedent or judicial interpretation would require external sources beyond what is provided in the AD text. The AD itself contains only the administrative record of amendments and technical requirements.

Therefore, within the confines of the supplied source, there is no litigation history to report.

The AD text contains several narrowly framed technical and procedural points that may catch operators, maintenance organisations and auditors unaware if they do not read the instrument closely. These are concrete traps or implementation risks identifiable from the AD.

1. Part-number specific applicability

• The AD applies only to Model 407 helicopters fitted with tailboom PNs 407-030-801-107 and 407-530-014-101/-103 (Applicability). Operators who assume all Model 407s are affected risk unnecessary inspections, while operators who fail to verify and record the correct PN risk non-compliance. Part I requires verification and an explicit entry of the tailboom PN into the helicopter technical records (Part I(a)-(b)).

2. Record keeping is itself a compliance duty

• Part I requires entry of the tailboom part number and annotation if the tailboom is not affected (Part I(b)-(c)). Failure to make that record entry is a standalone breach of the AD even if no crack is found. Auditors will look for that record evidence.

3. ASB incorporation only with Transport Canada approval

• The AD mandates compliance with ASB 407-07-80 original issue or any later Transport Canada approved revision (Parts II-IV). If maintenance personnel use a later ASB revision that has not been Transport Canada approved, the AD does not automatically incorporate it. Operators must ensure they use the correct, approved ASB revision.

4. Magnification requirement and specific inspection area

• The Part II initial inspection requires inspection of both areas indicated as “Daily check area” on Figure 2 of the ASB using a 10x magnifying glass (Part II). A plain visual inspection without magnification may fall short of the AD specification.

5. “Before further flight” halting language

• Any detection of a crack during the specified inspections requires replacement before further flight (Parts II, III, IV). This is operationally immediate: a cracked tailboom cannot be flown. Operators must therefore plan for potential replacement downtime and parts availability.

6. Terminating action is limited to specified part numbers

• The AD’s terminating action is replacement with PNs 407-030-801-201/-203/-205, or later part numbers (Part V). Replacement with a different part that is not listed may not terminate inspection obligations. Moreover, the AD notes that where a replacement tailboom is identified in the applicability section, inspections must continue (Parts III and IV include that proviso).

7. Conflicting PNs or modified tailbooms

• Amendment history indicates previous modifications and life limitations (Background). If tailbooms have been modified under prior amendments or carry life limits (for example the 5,000-hour life limit introduced in Amendment 2), operators must reconcile those modifications and life limits with current inspection requirements; the AD does not spell out how to reconcile multiple amendment provisions beyond the textual references.

8. Multiple overlapping authorities

• The AD marries CASA’s directive with Transport Canada ADs and Transport Canada approved ASB revisions (Background, Note). Operators must monitor approvals from another regulator (Transport Canada) to know which ASB revisions are mandatory under this CASA AD.

9. Timing deadlines anchored to the effective date

• The Compliance section ties Part I, Part II and Part IV deadlines to “after 15 February 2008.” Part II is within 25 flight hours or 30 days after 15 February 2008, whichever occurs first; Part I within 10 flight hours; Part IV within 100 flight hours and thereafter at intervals not to exceed 100 flight hours. Late execution relative to these specified windows may be viewed as non-compliance even if the required action is eventually performed.

10. The AD references figures and ASB paragraphs not reproduced in the AD

• The AD instructs inspections “as indicated on Figure 2” and references specific ASB paragraphs (Part II references Part II paragraph (1) items (a) to (e) of the ASB; Part III and IV reference their respective ASB paragraphs). The AD itself does not reproduce the ASB figures or text; maintenance personnel must obtain the ASB and the correct, Transport Canada approved revision. Failure to use the exact ASB content could result in a procedural gap.

11. Replacement availability risk

• The AD’s “replace before further flight” rule creates a supply dependency for replacement tailbooms. The AD does not provide transitional relief or interim repair options; operators must source serviceable replacement parts (Part II, Part III, Part IV, Part V).

12. Ongoing inspections after replacement in some circumstances

• The AD explicitly states that where the replacement tailboom is identified in the applicability section, inspections must continue (Part III and Part IV). That nuance can be overlooked when planning terminating actions.

Operators should treat these points as concrete compliance risks: verify part numbers, make the record entries, ensure the ASB revision used is Transport Canada approved, observe magnification and area requirements, plan for potential grounding and parts acquisition, and check whether a chosen replacement PN constitutes terminating action under Part V.

The AD provides explicit steps and timelines. The following is a practical, source-grounded compliance checklist that mirrors the AD’s Parts and the Compliance paragraph and indicates the documentation and procedural actions required.

Immediate preparatory steps (before or at the effective deadline)

1. Identify affected aircraft

   • Check each Model 407 airframe for tailboom part number. The AD applicability is limited to tailboom PNs 407-030-801-107 and 407-530-014-101/-103 (Applicability).
   • Make the required record entry in the helicopter technical records stating the applicable tailboom part number (Part I(b)). If the tailboom is not one of the affected PNs, annotate the records accordingly (Part I(c)).

2. Timely execution of Part I

   • For each affected helicopter, perform the verification and make the records entry within 10 flight hours after 15 February 2008 (Compliance).

Obtain and confirm the correct ASB revision 3. Acquire BHTC ASB 407-07-80

• Obtain the original issue of BHTC ASB 407-07-80 and confirm whether any later revision is Transport Canada approved. The AD requires compliance with the ASB original issue or any later Transport Canada approved revision (Parts II-IV).

4. Confirm Transport Canada approvals
   • Verify that any ASB revision intended for use has Transport Canada approval. Only Transport Canada approved revisions are incorporated by the AD (Parts II-IV).

Execute Part II , surface preparation and initial inspection 5. Timeframe for Part II

• Perform Part II within 25 flight hours or 30 days after 15 February 2008, whichever occurs first (Compliance).

6. Surface preparation per ASB

   • Prepare the tailboom surface for the “Daily Visual Check” in accordance with Part II paragraph (1) items (a) to (e) of ASB 407-07-80 original issue or later Transport Canada approved revision (Part II).

7. Magnified inspection of the “Daily check area”

   • Inspect both areas indicated as “Daily check area” on Figure 2 of the ASB using a 10x magnifying glass (Part II). If a crack is detected, replace the tailboom with a serviceable part before further flight (Part II).

8. Record remedial surface protection

   • If no crack is detected, ensure both surfaces are dry and protect each reworked area with a thin coat of clear coating as instructed in the applicable paragraph of Part II of the ASB (Part II).

Execute Part III , Daily Visual Inspection 9. Daily pre-flight inspections

• Include the Daily Visual Inspection described in Part III of the ASB in the pre-flight checklist and ensure it is performed before the first flight of the day (Part III, Compliance). The AD requires performing the daily check “before the first flight of the day, during the pre-flight check.”

10. Actions if a crack is found during daily checks

• If the daily check detects a crack, the AD requires replacement of the tailboom with a serviceable part before further flight. If the replacement tailboom is one of the PNs identified in the AD applicability section, the AD requires continuation of the inspections (Part III).

Execute Part IV , 100-hour inspection 11. Timing and intervals

• Perform the initial 100-hour inspection within 100 flight hours after 15 February 2008 and thereafter at intervals not to exceed 100 flight hours (Part IV, Compliance).

12. Inspection procedures

• Conduct the 100-hour inspection in accordance with Part IV of ASB 407-07-80 original issue or later Transport Canada approved revision (Part IV). If the inspection detects a crack, the tailboom must be replaced with a serviceable part before further flight (Part IV). Continue inspections if the replacement tailboom is identified in the AD applicability.

Part V , terminating action 13. Terminating replacement options

• If the operator elects to remove ongoing AD obligations by replacing the affected tailboom, the AD specifies that replacement with part number 407-030-801-201/-203/-205, or later part numbers, constitutes terminating action to this Directive (Part V). Confirm that the replacement PN is one of those listed or a later PN recognised by the AD.

14. Documentation of terminating action

• Record the installation of the terminating tailboom PN in the helicopter technical records and retain the installation documentation to demonstrate that the Directive no longer applies.

Operational and supply planning 15. Parts availability and serviceable parts

• Because the AD requires replacement “before further flight” in the event of a crack, plan parts inventories or supplier lead times to avoid extended grounding. The AD does not provide interim repair options or temporary flight restrictions beyond the replacement requirement (Parts II-IV).

16. Maintenance organisation readiness

• Ensure maintenance personnel are trained in the ASB procedures and have the required tools (for example a 10x magnifying glass) and materials (clear coating specified by ASB Part II) to conduct the inspections and protective work.

Record-keeping and evidence 17. Maintain clear technical records

• Record initial verification (Part I), each Part II surface preparation and inspection result, daily check records (Part III), 100-hour inspection findings (Part IV), and any replacement actions, including dates and part numbers installed. These records are the compliance evidence auditors will examine.

Monitoring and future revisions 18. Monitor Transport Canada approvals and related ADs

• Because the AD incorporates “later Transport Canada approved revisions” of the ASB and references Transport Canada AD CF-2008-04, regularly check for Transport Canada approvals or related ADs that could change the required inspection method or intervals (Parts II-IV, Note).

19. Reconcile with previous amendments, life limits or modifications

• If the helicopter has been modified under prior amendments (for example modifications that introduced life limitations or changed inspection intervals per Amendment 2), reconcile those records with the current AD obligations documented here (Background).

Checklist summary (immediate to ongoing)

• Within 10 flight hours of 15 Feb 2008: verify tailboom PN and record it (Part I).
• Within 25 flight hours or 30 days of 15 Feb 2008: perform Part II surface prep and initial inspection using 10x magnification and apply clear coating if no cracks (Part II).
• Before first flight each day: perform the Daily Visual Inspection as per ASB Part III (Part III).
• Within 100 flight hours and then every 100 flight hours: perform Part IV inspection per ASB (Part IV).
• If any inspection reveals a crack: replace tailboom with a serviceable part before further flight (Parts II-IV).
• To terminate AD obligations: install PN 407-030-801-201/-203/-205 or later part numbers (Part V).

All actions must be documented in the helicopter technical records, and ASB procedures must be the original issue or a Transport Canada approved revision (Parts I-V, Compliance, Note). The AD became effective 15 February 2008 (Compliance), and Amendment 3 implements the changes described in the document (Background).