AD/ROBIN/27 Amdt 2 - Rudder Pedal Bars

The Directive organises its obligations around a small number of technical and administrative concepts which drive what must be done, when, and by whom. The principal concepts in the source text are:

• Applicability by model, serial number, and part-fitment. The AD lists affected types (Model R 2100, R 2100 A, R 2112, R 2120 U, R 2160 variants, HR 200 variants and Model R 2000 series), restricts applicability to serial numbers 1-378, and excludes aircraft already fitted with reinforced rudder bars P/N 27.40.31.010 and P/N 27.40.31.020 (Applicability). A specific exemption is recorded for R 2000 series aircraft manufactured by Alpha Aviation, on the ground that those aircraft are fitted with reinforced rudder bars at manufacture (Applicability Note 2).
• Replacement as terminating action. The AD states that installing the reinforced rudder bars P/N 27.40.31.010 (left) and P/N 27.40.31.020 (right) “is terminating action to the requirements of this Directive” (Requirement Note 2). That means once replacement is completed in accordance with the specified service bulletin, the inspection regime in the AD no longer applies.
• Measurable geometric criteria and thresholded responses. For HR 200 and R 2120 U aircraft the Directive prescribes specific measurements with instruments while maintaining the pedals in neutral, identifying distortion as the difference between measured pairs (G1 vs G2, D1 vs D2). It sets three outcome bands and required follow-up: (i) no significant distortion if differences are within +/- 5 mm, re-inspect at up to 500 hours TIS; (ii) 5-10 mm distortion, re-inspect at up to 100 hours TIS until replacement; (iii) ≥10 mm distortion, replace both rudder bars immediately in accordance with AA-SB27-003 (Requirement 1 a-c and Figure 1).
• Use of a manufacturer/service-provider document for technical work. Replacement and the details of the reinforced parts are to be carried out “in accordance with Alpha Aviation Service Bulletin AA-SB27-003” (Requirement 1). The AD thus delegates the work specification to that service bulletin and refers to it as the authoritative procedural document.
• Compliance timing and staged interim obligations. The Directive sets two specific windows for compliance: an initial (50-hour/17 January to 17 April 2008) window for certain actions, and a 100-hour window and periodic re-inspection cadence under Requirement 2 until replacement is effected (Compliance). The Amendment is recorded as effective from 17 January 2008.
• Cross-reference to another regulator. The AD cites the related New Zealand CAA AD DCA/R2000/23B (Requirement Note 3 and Background), and records that Amendment 2 was issued in response to a revision of that NZ CAA AD, which expanded applicability and reduced inspection intervals (Background).

These elements create a compliance architecture that is technical (measurements and parts), prescriptive (specified part numbers and service bulletin), and time-bound (the compliance windows and re-inspection intervals). The text ties the technical remedy to a terminating action (fitment of specified parts) and refers to an external service bulletin and an overseas regulator’s AD as the sources of technical detail and policy drivers.

The Directive affects a defined set of parties directly and has implications for a broader set of aviation stakeholders. The source text identifies the following affected actors and roles:

• Owners and operators of the listed aircraft models whose airframes have serial numbers 1 through 378 and which are not already fitted with reinforced rudder bars P/N 27.40.31.010 and P/N 27.40.31.020. The models named in the Applicability table include Model R 2100, R 2100 A, R 2112, R 2120 U, R 2160, R 2160 D, R 2160 I, the HR 200 family (HR 200/100, HR 200/100S, HR 200/120, HR 200/120B, HR 200/160), and Model R 2000 series aircraft, subject to the Note excluding Alpha Aviation-manufactured R 2000 series aircraft fitted at manufacture (Applicability and Note 2).
• Maintenance organisations, licensed aircraft engineers, and technicians who will carry out the inspections, measurements and replacements. The AD’s technical tasks include geometrical measurement of dimensions G1, G2, D1, D2 and the physical replacement of left and right rudder bars in accordance with the Alpha Aviation service bulletin AA-SB27-003; those tasks fall to maintenance providers with the necessary capability and approval (Requirement).
• Aircraft registrars and continuing airworthiness managers. While the AD does not spell out record-keeping requirements, the compliance windows and periodic inspection intervals implied by the AD mean that registrars and continuing airworthiness managers will need to schedule inspections and replacements to remain compliant with the AD’s time limits (Compliance).
• The Type Certificate holder and service bulletin author (Alpha Aviation). The AD directs replacement work to Alpha Aviation Service Bulletin AA-SB27-003, and the Background notes the action was prompted by a report and by the new Type Certificate holder Alpha Aviation; this places Alpha Aviation at the centre of the technical remedy and means that maintenance organisations must rely on materials Alpha Aviation publishes (Requirement; Background).
• The regulator issuing the Directive. The Civil Aviation Safety Authority (CASA) , signalled by the “Delegate of the Civil Aviation Safety Authority” signature block , is the issuing authority and thus the decision-maker that determines applicability, compliance timing and the legal force of the Directive (header and signature).

Collateral stakeholders include pilots (who will operate aircraft subject to short-term inspection or potential loss of availability while replacements occur), insurers (whose risk exposure may change if aircraft are grounded or subject to special inspections), and overseas regulators and standards bodies referenced in the AD (the NZ CAA AD is specifically cited). The AD does not mention penalties or enforcement mechanisms in its text, nor does it specify who bears the monetary cost of inspections or replacements; however, the technical work and parts replacement implied will be borne by the aircraft owners/operators and their maintenance providers, who must arrange for parts identified by P/N and follow AA-SB27-003.

The AD spells out concrete duties for operators and maintenance providers and identifies the remedial action that discharges ongoing obligations under the Directive. The key duties and the corresponding operational rights (as derived from the text) are:

Duties

• Determine applicability. Parties must determine whether the aircraft serial number falls within the specified range (1-378) and whether reinforced rudder bars P/N 27.40.31.010/P/N 27.40.31.020 are already fitted. If the aircraft already has those parts installed in accordance with a previous issue of the Directive, the AD is not applicable (Applicability and Note 1).
• For Model R 2000 series aircraft: replace specific rudder bars. The AD requires replacement of left rudder bar P/N 27.23.05.010 and right rudder bar P/N 27.23.05.020 with reinforced rudder bars P/N 27.40.31.010 and P/N 27.40.31.020 respectively, and mandates that replacement must occur “in accordance with Alpha Aviation Service Bulletin AA-SB27-003” (Requirement 1).
• For Model HR 200 and R 2120 U aircraft: perform the geometrical check. Operators must place rudder bars in neutral, measure G1, G2 and D1, D2 and determine distortion as the difference between the pairs. The AD prescribes actions based on measured distortion: no significant distortion (differences within +/- 5 mm) - re-inspect at intervals not to exceed 500 hours TIS; distortion 5-10 mm - re-inspect at intervals not to exceed 100 hours TIS until replacement; distortion ≥10 mm - replace both rudder bars per AA-SB27-003 (Requirement 1 a-c and Figure 1).
• Comply with the timing windows. The AD requires compliance within 50 hours TIS after 17 January 2008 or before 17 April 2008, whichever occurs first, unless already accomplished. There is a further requirement to comply within 100 hours TIS after 17 January 2008 and thereafter at the specified intervals until parts are replaced (Compliance).
• Use the specified service bulletin. Replacement procedure and the identification of the reinforced parts are tied to Alpha Aviation Service Bulletin AA-SB27-003 (Requirement 1).

Rights / terminating actions

• Termination by installation. The AD grants a clear terminating action: once both reinforced rudder bars P/N 27.40.31.010 and P/N 27.40.31.020 are installed in accordance with AA-SB27-003, the requirements of this Directive are terminated (Requirement Note 2). That provides owners/operators with a compliance path to permanent removal of the AD’s inspection cadence.
• Exclusions. The AD records that aircraft already fitted with reinforced rudder bars in accordance with a previous issue of the Directive are not subject to the current Directive (Applicability Note 1). It also records that R 2000 series aircraft manufactured by Alpha Aviation are not applicable because they are fitted at manufacture with reinforced bars (Applicability Note 2).

The Directive does not lay down explicit rights to delay or to alternative compliance routes, nor does it prescribe record-keeping procedures, authorise delegation beyond the specified service bulletin, or specify any formal exemption mechanism in the text provided. It also does not state penalties or enforcement measures; the only enforcement-related language in the source is the use of the words “Requirement” and “Compliance” and the signature of the CASA delegate, which imply compulsory regulatory force. The direct effect is that owners/operators must either meet the inspection schedule in the AD or install the reinforced parts in accordance with AA-SB27-003 to remove the AD’s ongoing requirements.

The source text sets mandatory actions and compliance windows but does not contain explicit penalty provisions or describe enforcement processes. The AD is issued by the Civil Aviation Safety Authority through its delegate (David Villiers), which establishes the directive’s regulatory character and effective date (the Amendment becomes effective on 17 January 2008). From the source text itself the following enforcement-related observations can be stated exactly as provided:

• Command language and effective date. The document uses the terms “Requirement” and “Compliance” and includes definitive compliance timeframes (for example, “Within 50 hours time in service after 17 January 2008 or before 17 April 2008, whichever occurs first, unless already accomplished,” and “Within 100 hours time in service after 17 January 2008, and thereafter at the intervals specified in Requirement 2, until both rudder bars are replaced...”) (Compliance). This language indicates mandatory obligations imposed by the issuing authority.
• No penalties or sanction clauses are recorded in the AD text provided. The document does not state fines, certificate suspension, grounding conditions, or other administrative penalties within the text supplied. The AD likewise does not describe the enforcement procedure CAS A would follow in case of non-compliance.
• Issuing authority and signature. The AD is signed by “David Villiers, Delegate of the Civil Aviation Safety Authority” and dated 29 November 2007, and shows the Amendment’s effective date as 17 January 2008. The presence of the CASA delegate’s signature locates the origin of the Directive and the statutory or regulatory authority under which it was issued, as presented in the document (signature block and effective date).
• Cross-reference to other regulator documentation. The AD references NZ CAA AD DCA/R2000/23B and cites that Amendment 2 responds to a revision of that NZ CAA AD; this cross-reference is an administrative link to another regulator’s mandatory directive, but the AD text does not specify how domestic enforcement will interact with NZ CAA actions (Requirement Note 3 and Background).

Because the AD itself does not define penalties or enforcement steps in the supplied text, readers should not infer penalty regimes or enforcement practices beyond what is stated. The only enforceable elements in the document are the mandatory requirements and compliance timelines; any actual sanctions, inspections, or enforcement mechanisms would be established by CASA’s wider regulatory framework and enforcement policies, which are not reproduced in this document. The AD makes clear what must be done and by when, but it leaves unspecified the concrete enforcement consequences of non‑compliance in the text provided.

The AD explicitly references other technical regulatory material and a foreign regulator’s directive, creating cross-jurisdictional and inter-document interactions. All interaction claims below are grounded in the AD text:

• Reference to a New Zealand regulator directive. The AD states “NZ CAA AD DCA/R2000/23B refers” (Requirement Note 3) and records in the Background that Amendment 2 was issued “in response to a revision of the related NZ CAA AD, which expands aircraft applicability and reduces the inspection interval for unmodified HR 200 and R 2120 U aircraft.” This demonstrates a direct policy linkage between CASA’s AD and the New Zealand CAA’s AD; the Australian AD has been adjusted to reflect changes made by the NZ counterpart. The interaction is therefore one of regulatory alignment on an airworthiness matter across national regulators as represented in the document.
• Reliance on a manufacturer/service bulletin for technical compliance. The AD requires replacement “in accordance with Alpha Aviation Service Bulletin AA-SB27-003.” That means compliance with the AD depends on adhering to the procedures and instructions contained in that service bulletin. The AD therefore interacts with private technical documents issued by the Type Certificate holder; the service bulletin becomes the operational implementation specification for a statutory requirement.
• Interaction with aircraft continuing airworthiness obligations. While the AD does not quote or reproduce broader statutory continuing airworthiness duties, the mandatory inspections and replacement requirements are themselves a form of continuing airworthiness directive; owners/operators will need to incorporate the AD’s inspection intervals and replacement work into their maintenance programs to satisfy the Directive’s compliance timeframes. The AD’s compliance cadences (50-hour and 100-hour windows and subsequent intervals) therefore interact with maintenance scheduling and certification of airworthiness determinations, though the AD itself does not recite those statutory maintenance rules.
• Applicability exclusions that affect factory-fitted components and earlier directives. The AD excludes aircraft already fitted with the reinforced rudder bars in accordance with a previous issue of this Directive (Applicability Note 1) and excludes R 2000 series aircraft manufactured by Alpha Aviation on the basis that those aircraft were fitted with reinforced bars at manufacture (Applicability Note 2). This shows interaction with prior versions of this AD and with the manufacturing records and Type Certificate holder’s production standards. The AD therefore relies on aircraft build records and previous directives or factory fitment as determiners of applicability.
• Cross-references for terminating action. The AD identifies the installation of specified part numbers as terminating action to the requirements of the Directive (Requirement Note 2). That creates an interaction between the AD and spare parts/part-number control regimes: once the specified parts are installed in conformity with the service bulletin, the operator’s obligation under this AD ceases.

The AD text does not reference civil aviation statutes, administrative penalties, import/export rules for parts, or other primary legislation; it is a directive focused on corrective/mitigative airworthiness action and its interactions are with service bulletins, aircraft production/fitment status, and a named foreign AD. Any further interactions with statutes, enforcement processes or contractual obligations are not contained in the AD text and therefore are outside the document’s explicit scope.

The document itself is styled as AD/ROBIN/27 Amdt 2 and contains an internal narrative of why the Amendment was issued. The source provides the following amendment history and reasons for changes:

• Original and Amendment numbers. The AD is presented with the heading AD/ROBIN/27 Amdt 2, indicating this is the second amendment to AD/ROBIN/27. The text reproduces the AD identification multiple times and records “1/2008” as the date stamp for the Amendment.
• Background to Amendment 1. The Background reports that the manufacturer (unnamed in the snippet except that Alpha Aviation is later referenced) received a report of rudder bar distortion during intensive aerobatic operation. It further states that “Amendment 1 was issued in response to a NZ CAA AD, which was prompted by the new Type Certificate holder for the HR 200 and R 2000 series aircraft, Alpha Aviation; correcting the applicable aircraft serial number range and including a means of identifying reinforced rudder bars.” Thus Amendment 1 (prior to the present Amendment 2) adjusted serial number applicability and included identification means for the reinforced bars.
• Rationale for Amendment 2. The Background continues: “Amendment 2 is issued in response to a revision of the related NZ CAA AD, which expands aircraft applicability and reduces the inspection interval for unmodified HR 200 and R 2120 U aircraft.” Therefore Amendment 2 reflects a responsive change to harmonise with or incorporate the NZ CAA AD’s broader scope and tighter inspection intervals for certain unmodified types.
• Effective date. The Amendment states “This Amendment becomes effective on 17 January 2008,” while the document itself is dated 29 November 2007 under the signature of the CASA delegate. The compliance windows in the AD use the 17 January 2008 effective date as their reference point (Compliance).
• Notes on termination and prior compliance. The AD notes that the Directive “is not applicable if reinforced rudder bars are already installed in accordance with a previous issue of this Directive” (Applicability Note 1), indicating that earlier directives and prior compliance are acknowledged and provide an exclusion from later obligations.

The amendment history in the source text is narrowly focused on the operational technical drivers (a distortion report, new Type Certificate holder and alignment with NZ CAA AD changes). The AD does not include versioned text of Amendment 1 itself or a redline; it summarises the purpose of Amendment 1 and states that Amendment 2 responds to NZ CAA changes. The AD explicitly identifies that the technical terminating action (fitment of specific P/N parts) and the inspection intervals have been the levers adjusted across amendments. No other historical administrative or legal citations are included in the supplied text.

The AD contains no references to litigation, judicial review, court decisions, enforcement proceedings, appeals or any legal challenges. The document confines itself to technical requirements, applicability, compliance timeframes and the administrative reasons for the amendments (Background). Specifically:

• No case names or litigation citations appear in the text. The AD exclusively references service bulletins, part numbers, and a New Zealand CAA AD (NZ CAA AD DCA/R2000/23B) but does not mention any litigation arising out of the matter.
• No procedural or appeal mechanisms are set out in the AD. The document does not provide a remedies or dispute-resolution clause, nor does it reference avenues for review or dissatisfaction with CASA’s action within the text provided.
• The Background and Amendment notes explain the administrative and technical history (manufacturer report, Type Certificate holder Alpha Aviation, and NZ CAA AD revisions) without indicating any litigation or controversy beyond regulatory adjustments.

Therefore, based solely on the AD text supplied, there is no litigation history to report. Any judicial or administrative challenges to the AD, or disputes arising from enforcement, are not contained in this document and cannot be stated from this source.

The AD contains a number of technical and administrative details that may cause confusion or be overlooked in practice. These points are grounded in the document text and should be checked carefully by owners, maintainers and airworthiness managers:

• Serial number and model language can be confusing. The Applicability language lists multiple model designations (Model R 2100, R 2100 A, R 2112, R 2120 U, R 2160 variants, HR 200 family, and Model R 2000 series) and ties applicability to serial numbers 1-378. Users must check the aircraft’s serial number and model designation against this exact list rather than relying only on broad family names. The AD also contains wording that could be misread , for example Requirement 1 begins “For Model R 2000 series aircraft, replace...” while Applicability Note 2 says the Directive “is not applicable to the R 2000 series aircraft manufactured by Alpha Aviation. These aircraft are fitted with reinforced rudder bars at manufacture.” That means an owner must determine whether their R 2000 is an Alpha-manufactured airframe (excluded) or another R 2000 within the serial range (liable to the requirements).
• Dependence on part-number identification. Applicability is partly defined by whether the aircraft is “not fitted with reinforced rudder bars part number (P/N) 27.40.31.010 and P/N 27.40.31.020.” Operators must verify current part numbers fitted to the airframe. The AD notes that reinforced rudder bars have a “flat welded reinforcing gusset on the right side and a bent welded reinforcing gusset on the left side” (Requirement Note 1) and refers to AA-SB27-003 for details. Maintenance personnel must use part numbers and the service bulletin to correctly identify acceptably reinforced bars.
• Measurement method and interpretation. The AD prescribes measurement of G1, G2, D1, D2 “maintain the rudder bars in the neutral position” and defines distortion as the difference between the pairs; however, Figure 1 is referenced for the geometrical shape and measurement points and the text includes an image tag (image.002.png) but does not reproduce full measurement drawings in the AD excerpt. Practitioners must therefore secure and follow Figure 1 and AA-SB27-003 to ensure consistent measurement technique; failure to follow the precise measuring method may yield different outcomes regarding required action (Requirement and Figure 1 reference).
• Effective dates and multiple compliance windows. The AD has overlapping compliance instructions: an initial 50-hour window “after 17 January 2008 or before 17 April 2008, whichever occurs first” and a 100-hour window “after 17 January 2008” for initial inspections and continued intervals until replacement. Owners must interpret the timing carefully relative to an aircraft’s time in service at the effective date; the AD does not include an allowance for aircraft that were not in use at the effective date, so record evidence confirming TIS at the relevant dates should be retained (Compliance).
• Interim inspection intervals vs replacement. For HR 200 and R 2120 U aircraft a distortion between 5 mm and 10 mm triggers a re-inspection interval not to exceed 100 hours TIS “until replaced with reinforced rudder bars P/N 27.40.31.010 and P/N 27.40.31.020 in accordance with AA-SB27-003.” Practically, operators must plan for recurring inspections in the short term and eventual replacement as the terminating action, which has scheduling and parts‑availability implications (Requirement 1 b).
• Service bulletin dependency and termination. The AD delegates the replacement procedure to Alpha Aviation Service Bulletin AA-SB27-003. Operators must obtain and follow that bulletin for the technical steps that accomplish the replacement and the terminating action; failure to follow the prescribed service bulletin might raise compliance questions even where the correct part numbers are fitted (Requirement 1).
• Interaction with factory fitment and prior ADs. Aircraft that are “already installed in accordance with a previous issue of this Directive” are excluded (Applicability Note 1). Maintenance records and provenance of earlier compliance must therefore be clear; vague maintenance entries or undocumented part changes may not be sufficient to satisfy the AD’s exclusion (Applicability Note 1).
• The AD does not set out penalties or enforcement procedures. The absence of explicit penalties in the text means practitioners should not rely on the AD for guidance about sanctions; instead owners should consult CASA’s broader regulatory material for enforcement and compliance consequences. The AD’s silence on this point can create ambiguity for operators considering prioritisation and resource allocation.

Those points are drawn exactly from the AD’s text and structure. Addressing them requires careful record review, strict adherence to the specified service bulletin and measuring methods, and attention to which serial-numbered airframes are caught by the Directive.

The AD sets measurable tasks, timing deadlines and an identified terminating action. Practical compliance steps, derived from the AD text, are as follows. Each step should be executed with documentary evidence because applicability hinges on serial numbers and part fitment.

1. Confirm applicability and exclusions

   • Check the aircraft model designation and serial number against the Applicability list (models including Model R 2100 variants, R 2112, R 2120 U, R 2160 variants, HR 200 variants, Model R 2000 series , serial numbers 1-378). Determine whether the aircraft is one of the R 2000 series produced by Alpha Aviation; if so, the AD states it is not applicable because those were fitted at manufacture with reinforced rudder bars (Applicability and Note 2).
   • Physically verify whether the rudder bars are already the reinforced parts P/N 27.40.31.010 (left) and P/N 27.40.31.020 (right). If they are installed in accordance with a previous issue of this Directive, the AD is not applicable (Applicability Note 1).

2. Obtain technical documents

   • Acquire Alpha Aviation Service Bulletin AA-SB27-003. The AD makes this bulletin the mandated procedure for part replacement and the source of reinforced-bar identification (Requirement 1).
   • Obtain the referenced Figure 1 and any drawings showing the measurement points for G1, G2, D1, D2, since the AD directs geometrical checks “in accordance with Figure 1” (Requirement 1 and Figure 1 reference).

3. Schedule and perform inspections within the prescribed compliance windows

   • For actions required by the initial compliance window: ensure that the first required actions are completed “within 50 hours time in service after 17 January 2008 or before 17 April 2008, whichever occurs first, unless already accomplished,” if the aircraft is within applicability (Compliance).
   • For interim inspections: ensure at least one required action within “100 hours time in service after 17 January 2008” and thereafter at the intervals specified by the AD (Compliance).
   • For HR 200 and R 2120 U aircraft, conduct the geometrical inspection while maintaining the rudder bars in the neutral position and measure G1, G2 and D1, D2 to compute distortion as the difference between the pairs (Requirement 1).

4. Interpret measurement results and act per thresholds

   • If D1=D2 and G1=G2 within +/- 5 mm, no immediate action other than re-inspection at intervals not to exceed 500 hours time in service is required (Requirement 1 a).
   • If distortion is between 5 mm and 10 mm, re-inspect at intervals not to exceed 100 hours time in service until replacement with reinforced rudder bars P/N 27.40.31.010 and P/N 27.40.31.020 is carried out in accordance with AA-SB27-003 (Requirement 1 b).
   • If distortion is equal to or greater than 10 mm, replace both rudder bars in accordance with AA-SB27-003 (Requirement 1 c).

5. Replace parts per service bulletin as terminating action

   • For Model R 2000 series aircraft: replace left P/N 27.23.05.010 and right P/N 27.23.05.020 with reinforced P/N 27.40.31.010 and P/N 27.40.31.020 respectively, in accordance with Alpha Aviation Service Bulletin AA-SB27-003 (Requirement 1).
   • Where replacement is required by measurement thresholds, perform replacement following AA-SB27-003; installation of these parts in accordance with the service bulletin is specified as terminating action to the AD’s requirements (Requirement Note 2).

6. Documentation and recordkeeping

   • Although the AD does not detail documentation requirements, retain clear records showing serial number verification, part numbers fitted before and after any work, dates and time-in-service at inspection and replacement, measurement results (G1/G2/D1/D2), and references to the service bulletin used. Because Applicability and terminating action depend on part numbers and prior compliance, well-maintained records will demonstrate compliance with the AD’s stated conditions (Applicability, Requirement Note 2).

7. Communicate with maintenance providers and supply chain

   • Source the correct reinforced parts by P/N (27.40.31.010 and 27.40.31.020) and confirm the parts have the reinforcing gussets described (flat welded reinforcing gusset on the right side and a bent welded reinforcing gusset on the left side) as referenced in the AD (Requirement Note 1).
   • Coordinate scheduling with approved maintenance organisations able to carry out replacement in accordance with AA-SB27-003, and account for lead times and aircraft downtime.

8. Monitor related regulator communications

   • The AD references NZ CAA AD DCA/R2000/23B and notes that Amendment 2 responds to a revision of that NZ CAA AD. Operators should consider whether additional related communications or follow-up service bulletins are issued by Alpha Aviation or CASA that refine measuring techniques or replacement procedures (Requirement Note 3; Background).

Following these steps, grounded in the AD text, will achieve compliance with the Directive’s technical and timing requirements. The AD identifies the replacement parts and the service bulletin that provides the detailed work instructions; obtaining and following AA-SB27-003 and recording measurements and part replacements are the practical essentials that discharge the AD’s obligations.