AD/CONVAIR/8 - NLG Drag Strut Upper Left Hand Segments

The Directive operates by a narrow mechanical mandate: identify fatigue cracking in a discrete, defined component (the NLG drag strut upper left hand segments) on a defined fleet, and either remove cracked parts or replace parts in ways that change ongoing inspection obligations. Core concepts and mechanisms in the text are:

• Applicability: The rule applies only to Convair Model 340 and 440 aircraft and any of those models converted to turbopropeller power. The scope is fleet-limited and component-specific (Applicability clause).
• Part specificity: The Directive identifies three specific part numbers for inspection , P/N 340-5210103, P/N 5215103, and P/N 340-7310231 , and prescribes replacement parts by P/N (340-7310231-1 as the new part that terminates inspections) or by reference to serviceable parts listed in Convair Service Engineering Report No. 340-44A/440-44A (Requirement 2).
• Inspection locus and methods: The area to be inspected is depicted in Figure 1, view A-A of General Dynamics SB 640 (340D) No. 32-7 (dated 20 June 1973). The allowable NDI methods are dye penetrant, eddy current, or ultrasonic, and disassembly of the strut is explicitly not required (Requirement 1).
• Conditional termination of ongoing obligations: Installing a new P/N 340-7310231-1 terminates the inspection requirements of the Directive; installing a reworked part does not , instead inspections continue under the stated intervals (Requirement 3 and 4).
• Temporal compliance expressed in operational units: The Directive measures compliance windows in landings (not days, flight hours, or calendar time). Initial inspection within 10 landings after 11 May 2006; reinspection within 600 landings; recurring inspections not to exceed 2,400 landings; reinspection within 600 landings after installation of a reworked part (Compliance clause).
• Immediate grounding trigger: If a crack is detected during any inspection the Directive requires replacement "before further flight" (Requirement 2 and Compliance clause). That creates an immediate operational constraint linked to airworthiness.

The Directive cross-references earlier technical materials , General Dynamics Service Bulletin 640 (340D) No. 32-7 and Convair Service Engineering Report No. 340-44A/440-44A , as sources for the inspection locus and acceptable repair/replacement parts. The background statement frames the safety purpose as preventing possible NLG collapse from fatigue cracking; that is the stated safety risk motivating the inspection and replacement regime.

The Directive identifies the affected population precisely and therefore narrows who must act. The named obligations fall on operators of the specified aircraft and anyone responsible for their maintenance and airworthiness. Specifically:

• Aircraft owners/operators of Convair Model 340 and Model 440 aeroplanes are within scope. The Applicability clause explicitly includes "Model 340 and 440 aircraft, and any such model aircraft converted to turbopropeller power," so both original-configuration and converted examples are captured.
• Maintenance organisations, technicians and persons carrying out NDI on those aircraft are affected because the Directive prescribes inspection methods (dye penetrant, eddy current or ultrasonic) and disallows disassembly for this inspection (Requirement 1).
• Engineering/parts managers and procurement personnel who source replacement drag struts are affected. The Directive limits acceptable replacements to new P/N 340-7310231-1 or "serviceable parts (items 1 through 4, Convair Service Engineering Report No. 340-44A/440-44A, dated 16 June 1961)" (Requirement 2). These references constrain what parts can be installed to comply.
• Flight operations and maintenance planners are affected because compliance is measured in landings and because a detected crack requires replacement "before further flight" (Compliance clause and Requirement 2). Planners must track landing counts, schedule inspections within the specified landing windows, and manage aircraft availability.
• Regulators and delegated CASA officers are affected in the sense that the Directive is an instrument under their administration; in the provided text David Villiers, Delegate of CASA, signs and issues the AD (29 March 2006).

The Directive does not, in the provided text, impose obligations on parties outside that chain (for example, it does not directly command suppliers beyond specifying accepted P/Ns). The Directive also does not list exemptions, alternative methods of compliance, or approvals for equivalent inspection techniques beyond the three NDI methods named. There is no listing of penalties, approvals, or an appeals process in the text; accordingly, those administrative processes (if they exist) are not present in this document and would need to be sought elsewhere if relevant.

The Directive sets out precise operational duties and the conditional rights that result from particular actions. The main duties and conditional rights derived from the text are:

Duties

• Perform an external visual inspection of all listed part numbers (P/N 340-5210103, 5215103, or 340-7310231) of the nose landing gear drag strut upper left hand segments for cracking in the area depicted in General Dynamics SB 640 (340D) No. 32-7, view A-A (Requirement 1).
• Use only the specified NDI methods , dye penetrant, eddy current, or ultrasonic , for that inspection (Requirement 1).
• If a crack is detected, replace the drag strut with either a new P/N 340-7310231-1 or with serviceable parts as defined by items 1 through 4 in Convair Service Engineering Report No. 340-44A/440-44A dated 16 June 1961. Replacement is required "before further flight" whenever a crack is found (Requirement 2; Compliance clause).
• Repetitively inspect at intervals not to exceed 2,400 landings if no crack is found (Requirement 3; Compliance clause).
• When a reworked part is installed, perform an inspection within 600 landings after installation and continue inspections at intervals not exceeding 2,400 landings (Requirement 4; Compliance clause).
• Meet the initial inspection deadline: unless already accomplished, perform the initial inspection within 10 landings after 11 May 2006; reinspect within 600 landings of the initial inspection unless already accomplished (Compliance clause).

Rights and conditional effects

• Installing a new P/N 340-7310231-1 confers a specific right: the Directive’s inspection requirements are terminated for that component ("If a new P/N 340-7310231-1 part is used as a replacement, the inspection requirements of this Directive are terminated." Requirement 3). That is a discrete regulatory benefit tied to fitting a new approved part.
• Installing a reworked part does not confer termination; it leaves the operator subject to continued inspections under the same landing-count intervals (Requirement 4).
• The Directive specifies inspection methods and references figures and service bulletins as the technical authority for where and how to inspect, which constrains maintenance discretion to the procedures and areas referenced (Requirement 1, references to SB 32-7 and Convair Service Engineering Report).

Not included in the text

• The Directive text does not set out appeal rights, alternative method of compliance (AMOC) procedures, or explicit enforcement penalties in this document. It also does not specify who bears the direct monetary cost , although the duties unambiguously impose work and replacement obligations on operators , nor does it specify reporting requirements such as mandatory service difficulty reporting in this text.

Practically, the duties create operational obligations (inspection, record-keeping of landed counts, action before further flight on cracked parts) and the right to cease inspections as a direct consequence of installing the specified new P/N part.

The provided Directive text does not include explicit penalty, sanction, or enforcement provisions. It is an Airworthiness Directive that prescribes technical and operational requirements, provides an effective date (11 May 2006), and is signed by a CASA delegate (David Villiers, 29 March 2006). Absent in the text are:

• any monetary fines or administrative penalty clauses;
• any criminal sanctions;
• details of monitoring, audit, or reporting mechanisms tied specifically to this Directive; and
• explicit enforcement steps such as grounding orders, certificates suspension, or escalation procedures set out in the instrument itself.

Because the text does not specify enforcement mechanisms, the Directive must be read as a prescriptive regulatory requirement where the immediate obligations (inspection within 10 landings, replacement before further flight if a crack is found, recurrent inspections not to exceed 2,400 landings) take effect from the stated effective date. The instrument records its formal origin (CASA delegate signature) which, in administrative practice, indicates regulatory authority to require compliance; however, the text provided does not describe the legal consequences of non‑compliance.

The document does reference an FAA Airworthiness Directive (FAA AD 73-18-01 Amdt 39-1705) in a note, indicating technical alignment or cross-reference to a prior FAA action, but it does not import penalties from that FAA AD into this text. Enforcement practices, reporting obligations and sanctions (if any) must therefore be located in the broader regulatory framework or in other CASA instruments and cannot be inferred from this document alone. Users operating under this Directive who need precise enforcement and penalty information should consult CASA’s enforcement and regulatory instruments beyond the AD text, because those instruments are not reproduced here.

The Directive cross-references and relies on several pre-existing technical documents and one external airworthiness directive; the interaction mechanism is by reference. The explicit cross-references and interactions in the text are:

• General Dynamics Service Bulletin (SB) 640 (340D) No. 32-7, dated 20 June 1973: The area for inspection is specified as depicted in Figure 1, view A-A of this Service Bulletin. The Directive therefore imports the drawing/figure for the locus of inspection and the interpretation of that figure for maintenance work (Requirement 1).
• Convair Service Engineering Report No. 340-44A/440-44A, dated 16 June 1961: The Directive references "serviceable parts (items 1 through 4)" in that Convair report as acceptable replacement materials when a crack is detected. Thus, the Convair report supplies acceptable repair/replacement part definitions to the Directive (Requirement 2).
• FAA AD 73-18-01 Amdt 39-1705: The Directive contains a note stating "FAA AD 73-18-01 Amdt 39-1705 refers." That indicates the CASA AD aligns with or is related to a prior FAA AD on the same subject. The text does not state whether the FAA AD is incorporated or whether compliance with one satisfies the other; it merely records the reference.

Interaction by reference imposes operational consequences:

• Inspectors and maintainers must consult the specified Service Bulletin and Convair Engineering Report for technical details, diagrams and part itemisation. The effectiveness of the Directive therefore depends in part on access to and interpretation of those referenced documents.
• The Directive does not specify alternative methods of compliance or amendments to the referenced documents; it treats them as technical authorities for inspection location and acceptable replacement parts.
• The note referencing the FAA AD indicates coordination with international airworthiness practice, but it does not import foreign regulatory penalties, nor does it state cross‑jurisdictional enforcement mechanisms.

Absent from the text are references to domestic legislative provisions that authorise issuance of Airworthiness Directives, or to CASA’s enforcement powers or dispute resolution processes. Those statutory and procedural instruments, which would govern enforcement, penalties, or administrative review, are not in the provided text and must be consulted separately if needed. The Directive therefore interacts with other technical sources (service bulletin, engineering report, FAA AD) by reference for procedural and technical content, while the instrument itself remains silent in this text about the wider legal enforcement architecture.

The Directive text as provided includes limited explicit amendment history. The document identifies the Directive as "AD/CONVAIR/8" and twice repeats the identifier and title headings, ending with the date code "5/2006." The key time-stamped items in the document are:

• The Directive’s effective date is stated as 11 May 2006 (Compliance clause: "This Airworthiness Directive becomes effective on 11 May 2006.").
• The signature block records David Villiers as Delegate of the Civil Aviation Safety Authority and a date of 29 March 2006. That indicates the delegate executed the instrument on that date.
• The header and table label the Directive as AD/CONVAIR/8 and the date shorthand "5/2006," which aligns with the effective date month and year.

The Directive also references prior technical publications with their publication dates:

• General Dynamics Service Bulletin 640 (340D) No. 32-7, dated 20 June 1973 (Requirement 1).
• Convair Service Engineering Report No. 340-44A/440-44A, dated 16 June 1961 (Requirement 2).
• FAA AD 73-18-01 Amdt 39-1705 is cited (no date given in this text, though the numbering suggests an FAA action from 1973), but the Directive treats it as a related reference; the text labels it as a referential note.

No later amendments or version changes to AD/CONVAIR/8 itself are recorded in the provided material. The document does not include an amendment log, revocation, supersession, or any notation that it replaces or was replaced by another AD. Thus, based solely on the text here, the relevant issuance timeline for AD/CONVAIR/8 is: delegate signing 29 March 2006, effective date 11 May 2006, with the AD identified as 5/2006.

If users require a complete amendment history beyond these entries , for example, any subsequent CASA revisions, withdrawals, or superseding directives , they must consult CASA records or later instruments because none are present in this excerpt.

The Directive text contains no litigation history, references to legal challenges, or case citations. It does not name any judicial decisions, nor does it record administrative appeals or contested enforcement actions. The only external legal-technical reference is to the FAA AD 73-18-01 Amdt 39-1705 and to older manufacturer service documents; no subsequent judicial review or litigation matters are recorded.

Therefore, based solely on this document:

• There is no record within the Directive of any litigation, judicial review, or tribunal action challenging the Directive or its technical requirements.
• There are no citations to cases or legal precedent in the text.

Practitioners seeking litigation history or judicial interpretation relevant to this AD will need to search judicial and administrative records, CASA enforcement files, or industry legal databases for cases involving AD/CONVAIR/8, Convair 340/440 NLG drag strut issues, or related FAA AD enforcement. That information is not provided in the Directive itself.

The Directive contains several precise technical and timing features that can produce compliance traps if not carefully followed. The main "gotchas," grounded in the instrument language, are:

• Narrow part‑number scope: Only the three listed P/Ns (340-5210103, 5215103, 340-7310231) are subject to the inspection requirement. If operators rely on different part-number records or have parts re-marked or re‑identified, they must ensure serials and P/Ns are correctly matched to the AD’s list (Requirement 1).
• Applicability includes converted aircraft: The Applicability clause expressly includes Model 340 and 440 aircraft converted to turbopropeller power. Conversions do not exclude the aircraft; conversion status will not exempt an aircraft from inspection obligations (Applicability clause).
• Inspection location mandated by figure: The inspection area is defined by Figure 1, view A-A, in General Dynamics SB 640 (340D) No. 32-7. Practitioners must obtain and interpret that figure correctly; the AD’s instruction to inspect "in the area depicted by Figure 1, view A-A" ties the inspection to a diagram rather than a textual description (Requirement 1).
• Disassembly not required but NDI methods required: The Directive explicitly states disassembly of the strut is not required, while listing dye penetrant, eddy current or ultrasonic as acceptable methods. Inspectors must use one of those NDI techniques but are not to disassemble for the inspection , mixing up this procedural requirement could lead to non-compliance or unnecessary work (Requirement 1).
• Tight initial inspection window: Unless already accomplished, the initial inspection must be done within 10 landings after 11 May 2006. That is a tight operational window if an aircraft has many short sectors or is in continuous traffic. Operators must track landings precisely and not substitute flying hours or calendar days for landings (Compliance clause).
• Reinspection timing complexity: The Directive has layered landing-count obligations , initial within 10 landings after the effective date, reinspection within 600 landings of the initial inspection unless already done, and recurrent inspections at intervals not to exceed 2,400 landings. For reworked replacements, the reinspection clock is 600 landings after installation, and thereafter at intervals not exceeding 2,400 landings. Miscalculating these landing windows may create inadvertent non-compliance (Requirements 3 and 4; Compliance clause).
• Replacement choice changes obligations: Installing a new P/N 340-7310231-1 terminates the inspection requirements. Installing a reworked part does not; it requires inspections to continue. That creates an operational trade-off: a single capital expenditure on a new approved part removes recurring inspection obligations. Operators should be aware that installing a reworked part does not provide the same regulatory relief (Requirement 3 and 4).
• "Before further flight" replacement duty: A detected crack triggers a replacement requirement "before further flight" (Requirement 2; Compliance clause). That creates an immediate operational safety stop; it is not sufficient to schedule replacement on the next planned maintenance day , the aircraft must not continue flying in that configuration after detection.
• Reference to older technical documents: The Directive relies on documents from 1961 and 1973 (Convair report and General Dynamics SB). Access to those original documents and correct interpretation of their figures and itemised parts is essential; absence of those documents could leave technicians unclear as to the precise inspection locus or acceptable serviceable parts (Requirement 1 and 2).
• No alternative compliance path stated: The AD does not specify an AMOC process within its text or any alternative inspection techniques beyond the three NDI methods. If an operator believes an alternative approach is acceptable, the Directive text as provided does not give an internal route for that alternate method.

Each of these specifics is drawn from the AD language. They create operational and administrative friction points: part-number matching, accurate landing-count tracking, access to referenced service documents, managing repair vs replacement choices, and immediate grounding obligations where cracks are found. Those who manage compliance should plan to address these items practically , e.g. by ensuring parts inventories, NDI capability, and landing-count record-keeping are in place , because the Directive ties airworthiness to those concrete actions and measurements.

Compliance with the Directive requires concrete steps tied to the instrument’s enumerated Requirements and Compliance timings. The following stepwise actions implement the Directive as written:

1. Confirm applicability

   • Identify all aircraft in the fleet that are Convair Model 340 or Model 440, including those converted to turbopropeller power, per the Applicability clause. Do not assume conversions exempt aircraft.

2. Locate and verify relevant parts

   • For each applicable aircraft, identify whether the nose landing gear drag strut upper left hand segment fitted is one of these P/Ns: 340-5210103, 5215103, or 340-7310231. Log serial numbers and installation records to establish whether the AD applies to that specific unit (Requirement 1).

3. Obtain referenced technical materials

   • Acquire General Dynamics Service Bulletin 640 (340D) No. 32-7 (20 June 1973) to determine the exact inspection area (Figure 1, view A-A). Obtain Convair Service Engineering Report No. 340-44A/440-44A (16 June 1961) to identify "serviceable parts (items 1 through 4)" to be used if a crack is detected (Requirement 1 and 2).

4. Schedule and perform the initial inspection within the AD’s landing-count window

   • If the initial inspection has not been performed already, arrange for an external visual inspection of each specified P/N component within 10 landings after 11 May 2006 (Compliance clause). Use dye penetrant, eddy current or ultrasonic inspection methods and do not disassemble the strut for this inspection (Requirement 1).

5. Record and react to findings

   • If no crack is found, record the inspection and schedule a reinspection within 600 landings of the initial inspection (Compliance clause).
   • If a crack is found, replace the drag strut with either: a) a new P/N 340-7310231-1, which, once fitted, terminates the Directive’s inspection requirements for that component; or b) a serviceable part as defined in Convair Service Engineering Report No. 340-44A/440-44A (items 1-4), understanding that installation of a reworked part does not terminate inspections and triggers an inspection within 600 landings of installation (Requirement 2 and 4; Compliance clause).
   • Do not operate the aircraft further with a cracked part; replacement is required "before further flight" (Requirement 2; Compliance clause).

6. Maintain ongoing inspection schedule

   • If no crack was detected, inspect repetitively at intervals not to exceed 2,400 landings (Requirement 3; Compliance clause).
   • If a reworked part is installed as replacement, inspect within 600 landings after installation and then at intervals not to exceed 2,400 landings thereafter (Requirement 4; Compliance clause).

7. Administrative and record-keeping actions

   • Record dates, landing counts at time of inspection, NDI method used, inspector identity and qualifications, findings, and any replacement parts installed including P/N and reference to Convair report items if serviceable parts are used. The AD measures compliance in landings, so maintain landing-count tracking systems that can support proving compliance.
   • Retain copies of inspections and replacement documentation in maintenance records tied to the individual aircraft and component.

8. Consider procurement and operational choices that affect future obligations

   • If the operator wants to cease recurring inspections on a given strut, plan to procure and fit a new P/N 340-7310231-1, because installation of that specific new part is the only action in the Directive that terminates inspection requirements (Requirement 3). Evaluate availability, cost and lead time for that part relative to the burden of recurring inspections.

9. Ensure qualified personnel and methods

   • Use personnel qualified to carry out dye penetrant, eddy current or ultrasonic inspections. The AD does not allow disassembly for this inspection, so plan NDI activities accordingly and ensure access to equipment and expertise.

10. Follow referenced technical figures and parts lists

    • Conduct inspections in the precise area shown in SB 640 Figure 1, view A-A; use Convair report items 1-4 as the definition of serviceable parts when replacing a cracked strut. Failure to align inspection location with the referenced figure or to use the prescribed replacement parts may produce non-compliance.

11. Check for other regulatory communications

    • Note the AD references FAA AD 73-18-01 Amdt 39-1705; consider reviewing that FAA AD and any related manufacturer communications for technical clarification or historical context. The AD itself, however, sets the binding CASA requirements.

12. If uncertain, seek CASA guidance

    • The AD text does not describe an internal process for alternative methods of compliance or appeals. If a technical question arises that cannot be resolved by the SB or Convair report referenced, consider contacting CASA for clarification because the Directive provides mandatory requirements without listing alternative paths in its text.

Following these steps aligns aircraft maintenance and operations with the Directive’s mandatory inspections, defined repair/replacement options, and the landing-count-based compliance windows the instrument establishes.