AD/AS 355/88 Amdt 1 - Cabin Vibration Damper Assembly

Applicability. The AD applies only to Eurocopter AS 355 E, F, F1, F2 and N helicopters that are fitted with (a) a cabin vibration damper assembly installed on the RH side and (b) an automatic flight control system. The applicability clause therefore limits the population to aircraft that have both the physical component and the avionics fitment (the AD lists the exact models and the two fitment conditions in the Applicability paragraph).

Inspection requirement. The AD mandates a visual inspection focused on the visible areas of the blade of the RH vibration damper assembly. The inspection is to be conducted in strict accordance with paragraph 2.B.1 of Eurocopter AS 355 Alert Service Bulletin (ASB) No. 05.00.46, or any later EASA‑approved revisions. The AD makes the ASB text the technical standard for how the inspection is to be performed, thereby delegating the detailed inspection method to the manufacturer’s service bulletin as approved by EASA (Requirement 1).

Corrective action. If a crack is found in the blade during inspection, the operator must remove the RH vibration damper assembly, replace the cracked blade, re‑install the assembly fitted with a new blade, and adjust the vibration damper in accordance with the same ASB paragraph (Requirement 2). The AD therefore ties corrective steps and post‑replacement adjustment to the ASB’s instructions.

Modifications and terminating action. For helicopters previously modified by MODs 072262, 071543 and OP1055, the AD requires installation of a vibration damper/casing assembly on the RH side in accordance with paragraph 2 of Eurocopter ASB No. 53.00.22 (or later EASA‑approved revisions). The AD declares that compliance with Requirement 2 (the replacement and adjustment) provides terminating action to the repetitive inspections detailed in Requirement 1, signalling that the AD contemplates a path to remove the ongoing inspection burden by effecting the specified modification or replacement (the AD states: "Terminating Action. Compliance with Requirements 2 provides terminating action to the repetitive inspections detailed in Requirement 1 of this AD").

Temporal structure. The Compliance clauses set the timing: the inspections are to be performed "repetitively before the first flight of the day after the effective date of this AD" (daily preflight inspections), corrective removal/replacement must be done "before further flight" when a crack is discovered, and installation of the damper/casing assembly for the MOD‑affected helicopters must be completed "no later than 30 June 2007" (Compliance 1-3). The AD thus combines immediate daily actions with an absolute calendar deadline for modification.

References to external documents. The AD anchors technical compliance to manufacturer ASBs and to EASA AD 2006‑0273. The ASBs are specified at particular paragraphs for inspection and modification tasks, and the AD permits reliance on any later EASA‑approved revisions of those ASBs. The AD therefore embeds a mechanism for later technical updates to become conforming means of compliance, subject to EASA approval.

Issuing authority and administrative facts. The document is an amendment issued by a CASA delegate and explicitly records its effective date and the background safety rationale: a failed RH damper blade can interfere with the trim actuator rod and potentially jam the flight controls (Background; signature and dates). The amendment supersedes or updates the original AD (original effective 20 June 2005) and becomes effective 23 November 2006.

Operators and aircraft owners. The primary economic actors affected are owners and operators of the specified Eurocopter AS 355 E, F, F1, F2 and N helicopters that have both the RH cabin vibration damper assembly and an automatic flight control system. Those operators must perform daily preflight visual inspections of the visible areas of the RH damper blade, carry out immediate removal/replacement if a crack is found, and, for helicopters with the listed prior MODs, install the damper/casing modification by 30 June 2007. The AD text (Applicability, Requirements, Compliance) assigns the tasks to the operator/maintenance organisation as the responsible party for airworthiness compliance.

Maintenance organisations and engineers. Licensed maintenance personnel or approved maintenance organisations will perform the visual inspections, removals, replacements, adjustments and the installation of the damper/casing assembly. The AD specifies that these actions must follow Eurocopter ASB No. 05.00.46 paragraph 2.B.1 and ASB No. 53.00.22 paragraph 2, or their later EASA‑approved revisions; so maintenance providers must have access to and follow those ASBs to meet the AD's technical standards.

Pilots and flight crews. Because inspections are required "before the first flight of the day", pilots or other preflight inspection delegates are affected operationally: the AD establishes a daily task that must be completed prior to dispatch. If an inspection reveals a crack, the aircraft cannot be flown "before further flight" until replacement and adjustment are completed. In practice this affects day‑to‑day dispatch decisions, scheduling, and may lead to aircraft unavailability if parts or maintenance resources are not immediately available.

Supply chain and parts suppliers. The AD creates demand for replacement blades and for the damper/casing assembly specified in ASB No. 53.00.22. Suppliers and spares inventory managers will be affected by the need to have replacement parts available to avoid grounding when a crack is discovered. For the MOD‑affected helicopters, the requirement to install a specific assembly by a hard date concentrates demand for the assembly within a defined period (by 30 June 2007 for this AD).

Regulatory bodies and delegates. CASA, through its delegate who signed the amendment, is the issuing authority and therefore responsible for promulgation and effective dates. The AD also cross‑references EASA ADs and EASA‑approved revisions of Eurocopter ASBs; this creates a legal/technical link between national regulator action and EASA technical approvals. The AD therefore affects CASA’s oversight obligations insofar as operators must demonstrate compliance.

Less affected parties. Helicopter owners/operators outside the specified AS 355 models, or those without an RH cabin vibration damper assembly or without an automatic flight control system, fall outside the AD’s applicability and are not obligated by this instrument. Similarly, helicopters already having the required damper/casing assembly installed in accordance with the ASB as of the effective date may avoid some of the inspection burden if that condition meets the AD’s terminating action,operators must check the ASB references and the AD’s text to confirm whether their aircraft are already compliant.

Duties imposed by the AD. The AD sets clear mandatory duties for applicable aircraft:

• Daily inspection duty: Repetitively inspect the visible areas of the RH vibration damper blade "before the first flight of the day after the effective date of this AD" in accordance with paragraph 2.B.1 of Eurocopter ASB No. 05.00.46, or any later EASA‑approved revisions (Requirement 1; Compliance 1). That creates a recurrent, preflight maintenance/inspection obligation.

• Corrective action duty: If a crack is found, the operator must remove the RH vibration damper assembly, replace the cracked blade, re‑install the assembly with a new blade and adjust the damper in accordance with paragraph 2.B.1 of ASB No. 05.00.46 (Requirement 2). The AD uses the ASB as the prescriptive method for removal, replacement and adjustment.

• Modification duty for MOD‑affected helicopters: For aircraft modified by MODs 072262, 071543 and OP1055, the AD requires installation of a vibration damper/casing assembly on the RH side in accordance with paragraph 2 of Eurocopter ASB No. 53.00.22 (or later EASA‑approved revisions) no later than 30 June 2007 (Requirement 3; Compliance 3).

Rights and available compliance path. The AD explicitly provides a terminating action: compliance with Requirement 2 "provides terminating action to the repetitive inspections detailed in Requirement 1 of this AD". Thus the AD creates a compliance pathway that allows operators to trade a recurring inspection obligation for a one‑off corrective modification or replacement that satisfies the AD’s safety objective. The AD also permits reliance on "any later EASA approved revisions" of the referenced ASBs, giving operators and maintenance organisations the right to use updated, EASA‑approved ASB revisions as the technical standard. That linkage to later approved revisions gives flexibility where Eurocopter issues improved procedures and EASA approves them.

Delegation of technical detail. The AD delegates detailed technical methods to the manufacturer’s ASBs as approved by EASA by citing specific ASB paragraphs for inspection and installation. Operators therefore have the duty to follow the ASB paragraphs specified, but the AD does not itself set out the step‑by‑step technique; instead it mandates compliance with the ASB paragraphs. This creates a duty to obtain and follow the current EASA‑approved version of the ASB.

Timing and immediacy duties. The wording "before further flight" for corrective replacement is immediate in nature: if a crack is found, the aircraft must not proceed to fly until the replacement and adjustment are completed in accordance with the ASB. The "before the first flight of the day after the effective date" language makes the inspection obligation effective from the day after the AD takes effect, thereby imposing rapid operational change.

Documentation and proof. While the AD text itself does not spell out recordkeeping or logbook entries, operators will be required in practice to demonstrate compliance to CASA or their continuing airworthiness authority; the AD’s reference to ASBs suggests that operators must retain evidence that inspections and any replacements/modifications occurred per the ASB. However, the AD text supplied does not set out documentary requirements, so the explicit right or duty to retain records is not stated in the instrument itself.

Scope limits and exclusions. The duties apply only to helicopters meeting the two applicability conditions. Helicopters without the RH cabin vibration damper assembly or without an automatic flight control system are not within scope according to the Applicability language.

What the AD states. The AD text supplied records that it is issued by the Delegate of the Civil Aviation Safety Authority and gives an effective date (23 November 2006). It sets out requirements and compliance timings but does not include express penalty provisions, infringement schemes, or enforcement mechanisms within the text provided. The AD references EASA AD 2006‑0273 and Eurocopter ASBs as the technical standards to be followed.

Inferred enforcement context, limited to source. The instrument itself is an airworthiness directive issued by CASA via its delegate. Within the provided text the authority of the delegate is evident, but the AD does not itself detail the sanctions, inspection, or enforcement procedures that CASA may apply for non‑compliance. The AD therefore imposes mandatory duties without specifying the enforcement sanctions or procedures in the AD text provided.

Practical enforcement implications operators should note. Although the AD does not lay out penalties, airworthiness directives are typically issued by civil aviation authorities to mandate corrective actions for unsafe conditions. The practical consequence for operators is that the AD requires the actions specified (daily inspections, replacement when cracks are found, and installation of a specified assembly by a calendar date for certain MOD‑affected helicopters). Failure to comply will leave an aircraft non‑compliant with the AD; in operational terms that usually affects the aircraft’s legal airworthiness and may be subject to an authority’s enforcement action. However, since the AD text supplied does not itself set out those enforcement processes, one must not assert any particular sanction contained in this document.

Evidence and oversight. The AD references Eurocopter ASBs and EASA approvals as the technical standards; operators will therefore need to show that inspections and corrective actions were performed in accordance with those ASBs (or their later EASA‑approved revisions). The AD’s effectiveness is tied to CASA’s authority to issue airworthiness directives, and operators should expect that CASA, as the issuing body, will be the entity to review compliance though the AD does not set out monitoring or audit procedures.

Need to consult the regulator for enforcement detail. Because the AD text does not include penalty clauses or enforcement mechanisms, parties seeking clarity about sanctions, acceptable forms of evidence of compliance, or enforcement procedures should consult CASA’s wider regulatory framework, the issuing delegate’s guidance, or legal counsel. The AD itself provides the mandatory technical duties and timing but not the enforcement apparatus in the supplied text.

Direct references in the AD. The AD explicitly references Eurocopter Alert Service Bulletins (ASB) No. 05.00.46 and No. 53.00.22 as the normative technical standards, and it permits compliance using "any later EASA approved revisions" of those ASBs. It also references EASA AD 2006‑0273 dated 4 September 2006. Thus the AD creates a direct interaction with manufacturer service documents and with EASA’s airworthiness directives. The AD does not, in the text supplied, reference domestic legislation, specific CASA regulations, or other statutory provisions.

Normative technical chain. The AD embeds a compliance chain: CASA issues the AD, it references manufacturer ASBs, and it allows later EASA‑approved revisions of those ASBs to be used. That means the AD relies on the international technical approvals process (EASA approval) to validate later ASB revisions as acceptable means of compliance. The AD therefore creates an operational link between domestic regulatory direction and EASA's technical approvals.

Implications for maintenance standards and approvals. Because the AD requires maintenance and modification actions to be performed "in accordance with" specific ASB paragraphs or later EASA‑approved revisions, the technical content of those ASBs effectively becomes part of the compliance standard for the work. If other domestic regulatory instruments or currency provisions require maintenance work to be performed by particular licence‑holders or approved organisations, those regulatory obligations remain in force alongside the AD; the AD does not supplant such requirements but sets the substance of the required work. The AD text supplied does not expressly reconcile or replicate such licensing requirements; operators must ensure that any work done pursuant to the AD is also carried out in conformity with the relevant maintenance licensing and approval rules applicable in their jurisdiction.

Harmonisation with international directives. By referencing EASA AD 2006‑0273 and permitting later EASA‑approved ASB revisions, the AD suggests harmonisation with EASA’s determinations about the unsafe condition and the correct technical remedy. For operators with international operations or supply chains tied to EASA processes, this provides a consistent technical baseline. The AD does not, however, state whether compliance with the EASA AD alone suffices for CASA compliance; it expressly mandates actions in accordance with the cited ASBs and EASA approvals.

No express interaction with other domestic statutes in text. The supplied AD does not include cross‑references to domestic aviation safety regulations, recordkeeping statutes, penalties provisions, or other administrative law instruments. Therefore, within the source text itself there is no explicit mapping of how this AD alters obligations under other named Australian laws. Practically, operators must assume the AD sits within the broader civil aviation regulatory system and may interact with maintenance, operations, and safety management obligations established elsewhere, but the AD text does not formally set out those interactions.

Mod status and prior amendments. The AD records that it is an amendment (Amdt 1) and replaces or updates an earlier AD that became effective on 20 June 2005. The AD’s amendment history and its reference to EASA ADs create temporal interactions: later EASA approvals of ASBs can alter technical compliance means, and the AD’s amendment supersedes prior domestic AD content for the same unsafe condition.

Documented timeline in the AD. The AD supplied is titled "AD/AS 355/88 Amdt 1" and records several key dates. The original issue of the AD became effective on 20 June 2005 (Background). This amendment (Amdt 1) becomes effective on 23 November 2006 (Compliance table and signature block). The AD also notes that EASA AD 2006‑0273 was dated 4 September 2006, and that the amendment introduces a mandatory modification which terminates the repetitive inspection called up in the AD (Background and Requirement notes).

What changed in this amendment. The amending text introduces a mandatory modification requirement for the vibration damper assembly to terminate repetitive inspections and clarifies the inspection and corrective action requirements by referencing specific paragraphs in Eurocopter ASBs and allowing later EASA‑approved revisions. The amendment language explicitly states that it "introduces a mandatory modification to the vibration damper assembly which terminate[s] the repetitive inspection called up in this AD." The initial AD (effective 20 June 2005) is therefore updated by this Amdt 1 to add the modification path and the terminating action.

Relationship to EASA ADs and ASBs. The AD cites EASA AD 2006‑0273 (4 September 2006) as a reference, indicating that the EASA action predated this amendment and informed it. The AD’s technical instructions require actions "in accordance with paragraph 2.B.1 of Eurocopter AS 355 Alert Service Bulletin (ASB) No. 05.00.46 or any later EASA approved revisions" for the inspection and replacement, and paragraph 2 of Eurocopter ASB No. 53.00.22 or subsequent EASA‑approved revisions for the modified installation. The amendment therefore imports EASA’s technical determinations into the domestic AD via these references.

Effective dates and deadlines. The amendment sets an immediate operational timing for inspections ("repetitively before the first flight of the day after the effective date of this AD") and for corrective action ("before further flight"). It also imposes a calendar deadline for installation of the damper/casing assembly for MOD‑affected helicopters ("No later than 30 June 2007"). The amendment’s effective date is 23 November 2006; the installation deadline is 30 June 2007, giving a finite compliance window for the mandatory modification.

Authorship and signatory. The AD is signed and dated (13 October 2006) by James Coyne, Delegate of the Civil Aviation Safety Authority, and states that the amendment becomes effective on 23 November 2006. The signature and dates document the administrative provenance of the amendment.

No further amendments recorded in the supplied text. The document provides this singular amendment history (original AD effective 20 June 2005, Amdt 1 effective 23 November 2006, with reference to EASA AD 2006‑0273 dated 4 September 2006). The supplied text does not record subsequent amendments, withdrawals, or further updates beyond Amdt 1.

No litigation recorded in the source. The supplied AD text contains no references to judicial proceedings, challenges, appeals, or case law. There are no citations to administrative review decisions or to courtroom rulings in the document. The AD does cite EASA AD 2006‑0273 and Eurocopter ASBs, but the text does not mention any disputes relating to the AD, its technical content, or its enforcement.

Implication for researchers. Because the AD itself does not include litigation history in the supplied text, anyone seeking to know whether the AD was contested or whether compliance obligations were the subject of litigation will need to search external records: regulator enforcement archives, administrative review tribunals, court databases, or industry legal reporting. The AD as given does not provide such materials.

Typical review avenues not described in the AD. The document does not describe any appeal mechanisms, review rights, or administrative processes to challenge the AD’s content or to seek an alternative means of compliance. If operators require relief or clarification (for example, alternative procedures or extended compliance timelines), they must approach CASA or rely on applicable administrative processes outside the AD text. The supplied AD does not set out those procedures.

No named cases. The AD does not cite any judicial decisions or precedent cases. The only documents cited are EASA AD 2006‑0273 and Eurocopter ASBs (No. 05.00.46 and No. 53.00.22). Therefore, within the source material there is no litigation history to summarise.

Scope specificity. The AD applies only to AS 355 E, F, F1, F2 and N helicopters that have both an RH cabin vibration damper assembly and an automatic flight control system. Helicopters missing either element fall outside the AD. Operators must verify both fitments precisely; assuming applicability based solely on model is insufficient because the RH damper and AFCS fitment are both required by the AD’s Applicability paragraph.

"Visible areas" limitation. The inspection requirement is limited to the "visible areas of the blade of the vibration damper assembly" and must be done "in accordance with paragraph 2.B.1 of Eurocopter AS 355 ASB No. 05.00.46." Operators should not assume a generic blade inspection suffices; the AD ties the inspection to the ASB paragraph for definitions and methods. Failure to consult the ASB and paragraph 2.B.1 may lead to incomplete inspections that do not conform to the AD’s technical standard.

Timing nuance for inspections. The AD requires inspections "repetitively before the first flight of the day after the effective date of this AD." That phrasing means the inspection obligation begins on the day after the AD becomes effective and must be performed before the aircraft’s first flight each day. Operators that perform multiple flights in one day cannot avoid the inspection requirement simply because a prior day's inspection was clean; the AD requires a pre‑first‑flight‑of‑day inspection. Additionally, the AD specifies that Requirement 2 is "before further flight" if a crack is found, which imposes immediate grounding until the corrective work is done to ASB standards.

Terminating action tied to a specific corrective step. The AD’s terminating action statement associates termination of the repetitive inspections with "Compliance with Requirements 2". That is, replacement and adjustment as specified in Requirement 2 provides the path to end daily inspections. However, the AD does not say that any other remedy or alternative procedure will terminate the inspection requirement. Operators must ensure that the precise steps in Requirement 2 and the ASB are followed to secure the terminating effect.

Mod list and installation requirement. The AD requires installation of a damper/casing assembly for helicopters modified per MODs 072262, 071543 and OP1055, in accordance with ASB No. 53.00.22 paragraph 2, by 30 June 2007. Operators need to check whether their aircraft have been modified under those MOD numbers; misidentification can result in either unnecessary work or failure to meet the AD’s obligations. The deadline is a hard calendar date in the AD; missing it would leave the aircraft out of compliance with the AD’s stated requirements.

Dependence on ASBs and EASA approvals. The AD makes compliance conditional on following specified paragraphs of Eurocopter ASBs or "any later EASA approved revisions." That creates two potential procedural traps: first, operators must obtain and follow the exact ASB paragraph referenced; second, if relying on a "later EASA approved revision," they must confirm that the revision is EASA‑approved and that it indeed replaces the earlier paragraph in the manner intended. Ambiguity about which ASB revision counts as "EASA approved" could delay compliance decisions.

No explicit penalties in the AD. The supplied AD text does not specify penalties or enforcement mechanisms. That absence can mislead operators into thinking enforcement is permissive; the AD nonetheless imposes mandatory technical duties. Operators should not mistake silence on sanctions for lack of regulatory consequence; the AD remains an authoritative safety directive issued by CASA.

Parts availability and maintenance capacity. The AD requires removal and replacement of cracked blades "before further flight" and installation of a damper/casing assembly by 30 June 2007 for certain helicopters. If replacement blades or the assembly are in short supply, operators risk grounded aircraft until parts and qualified maintenance are available. The AD does not provide interim relief options or alternative measures in the supplied text.

Interpretation of "repetitively". The AD uses "repetitively before the first flight of the day" which implies a daily repetitive schedule, but the text does not define the required frequency beyond that phrasing. Operators conducting multiple flights in a day should interpret this as at least once per day prior to the first flight; however, the AD ties the inspection method to the ASB, which may provide further clarity on frequency. Not consulting the ASB risks misinterpretation.

Stepwise compliance path from the AD text. The AD sets out a clear sequence of actions; operators should adopt the following concrete steps, carried out in strict accordance with the cited ASB paragraphs and within the specified timing.

1. Confirm applicability. Review the aircraft configuration to verify that the helicopter model is one of AS 355 E/F/F1/F2/N and that it is fitted with both (a) a cabin vibration damper assembly on the RH side and (b) an automatic flight control system. Record the aircraft’s modification status to determine if MODs 072262, 071543 or OP1055 have been applied (Applicability).

2. Obtain the referenced ASBs and EASA approvals. Acquire Eurocopter ASB No. 05.00.46 and ASB No. 53.00.22, and confirm their current EASA‑approved revision status. The AD requires performing inspections and installations "in accordance with" particular ASB paragraphs,specifically paragraph 2.B.1 of ASB No. 05.00.46 for inspection and replacement/adjustment, and paragraph 2 of ASB No. 53.00.22 for installation of the damper/casing assembly (Requirements 1-3). If relying on a later ASB revision, ensure it is EASA‑approved and document that approval.

3. Implement daily inspection routine. Starting on the day after the AD’s effective date, incorporate a visual inspection of the visible areas of the RH vibration damper blade into the preflight checklist "before the first flight of the day" and perform it "repetitively" thereafter as required (Compliance 1; Requirement 1). Ensure that personnel performing the inspection are trained in the ASB’s prescribed inspection technique and that the inspection is recorded per the operator’s maintenance documentation practices.

4. Prepare corrective action procedures. Establish standing procedures that, if a crack is found during inspection, the helicopter will be removed from service and the RH vibration damper assembly will be removed, the cracked blade replaced, the new blade installed and the damper adjusted in accordance with paragraph 2.B.1 of ASB No. 05.00.46 and "before further flight" (Requirement 2; Compliance 2). Ensure replacement blades and adjustment tools/specifications are available or readily obtainable. Define roles and responsibilities for maintenance staff to effect the replacement promptly.

5. For MOD‑affected helicopters, schedule modification. If the helicopter was modified under MODs 072262, 071543 or OP1055, schedule and carry out installation of the RH vibration damper/casing assembly in accordance with paragraph 2 of ASB No. 53.00.22 no later than 30 June 2007 (Requirement 3; Compliance 3). Confirm that the installation follows the ASB’s steps and that any parts used meet the ASB’s part numbers and specifications.

6. Recordkeeping and proof of compliance. Although the AD text provided does not set out explicit recordkeeping requirements, maintain contemporaneous records showing that daily inspections were performed, the ASB revision relied upon, and any corrective replacements or installations were executed in accordance with the ASB paragraphs. Retain work orders, parts log entries, and maintenance release documents to enable demonstration of compliance to CASA if requested.

7. Confirm terminating action status. If Requirement 2’s replacement and adjustment have been carried out in full and per the ASB paragraph specified, note that the AD itself declares that this provides terminating action to the repetitive inspections required by Requirement 1. Document the replacement and adjustment as evidence that the terminating action condition has been met, following the ASB instructions that the AD references.

8. Address parts and supply chain risks. Given the "before further flight" obligation when a crack is found, ensure spare blades and the damper/casing assembly parts are stocked or have identified suppliers with delivery lead times compatible with operational needs. If parts are not available, plan for alternative operational measures (e.g., aircraft substitution) and liaise with CASA for guidance if needed.

9. Liaise with CASA or maintenance authority for clarifications. If there is ambiguity about whether a later ASB revision is EASA‑approved, or if alternative methods of compliance are being considered, contact CASA (or the delegate as appropriate) in advance to obtain formal acceptance or instruction. The AD permits reliance on later EASA‑approved ASB revisions, but operators must ensure and document that the revision is indeed EASA‑approved.

10. Integrate into safety management processes. Because the AD arises from a safety risk (possible jamming of flight controls due to a broken RH damper blade interfering with the trim actuator rod), integrate the AD’s inspection and modification requirements into the operator’s safety management system, hazard registers and continuing airworthiness plan to ensure sustained compliance and to capture lessons for maintenance scheduling and inventory control.

Operational notes. The AD does not detail licences or approvals required to perform the work; ensure that maintenance work is carried out by appropriately licensed personnel or approved organisations in accordance with applicable domestic maintenance regulations. Also, verify that any replacement parts, modifications and adjustments match the ASB part numbers and procedures and that post‑maintenance functional checks are carried out per the ASB instructions.

By following the AD’s explicit requirements and the ASB paragraphs it references, documenting each step, and planning for parts and manpower, operators can meet the inspection, corrective, and modification obligations set out in AD/AS 355/88 Amdt 1.