AD/CONVAIR/19 - NLG Actuating Cylinder Rod End Eyebolt

The AD rests on a small set of technical and regulatory concepts, each stated in the text and used to allocate inspection burden and remedial action.

Applicability identifies the narrow fleet subset subject to the directive: Model 340 and Model 440 Convair-type aircraft, including those converted to turbopropeller power. The component in focus is a single part number, Peacock C50137-2, described as the nose landing gear actuating cylinder rod end eyebolt (Applicability, Requirement).

A material distinction in the AD is modification status, defined by compliance with Convair Service Engineering Report No. 6820-240-23/340-45/440-45 dated 24 August 1962. The AD sets separate inspection timing and recurrence for eyebolts modified per that report versus eyebolts that have not been modified (Requirement, Compliance). That engineering report therefore functions as the dividing line for maintenance history categorisation.

Inspection technique is specified: a dye penetrant method applied to the threaded area that has been machined for the relief radius (Requirement). The AD does not elaborate procedural detail beyond naming the method and the precise area to inspect. The dye penetrant inspection is the diagnostic tool mandated by the AD to detect cracking. The AD uses a binary diagnostic outcome: cracked or not cracked. If cracking is detected, mandatory replacement before further flight is triggered (Requirement).

The term "serviceable eyebolt of the same part number" defines allowable replacement hardware. The AD requires replacement with a unit of the same P/N C50137-2 and does not permit substituting a different part number in lieu without further reference (Requirement). It also states that if unmodified eyebolts are used as replacements, the inspection intervals applicable to unmodified eyebolts apply thereafter (Requirement).

The AD is time-based for recurrence, using hours time in service as the metric. For unmodified eyebolts the initial-inspection window and recurring interval are expressed as 225 hours initial unless an inspection occurred within the last 775 hours, then at 1,000-hour recurring intervals. For modified eyebolts the initial-inspection window is 1,000 hours unless an inspection occurred within the last 4,500 hours, with recurring inspections not to exceed 5,500 hours (Compliance). The Background statement attributes the directive to FAA reports of cracks, and the Note cross-references FAA AD 63-15-04, signalling an international regulatory linkage.

The AD directly binds operators and maintainers of Convair Model 340 and Model 440 airframes, and any Model 340/440 aircraft converted to turbopropeller power, for which the NLG actuating cylinder rod end eyebolt part number C50137-2 is installed (Applicability). That includes aircraft owners, aircraft operators, maintenance organisations, and certifying staff who perform or approve maintenance, inspection, and replacement actions on those aircraft.

Maintenance personnel and maintenance control organisations are the parties that must perform the dye penetrant inspections specified by the AD, applied to the threaded area machined for the relief radius on the eyebolt, because the AD prescribes both the inspection method and the area to inspect (Requirement). Where cracking is discovered, the operator, via maintenance personnel, must replace the eyebolt with a serviceable unit of the same P/N before the aircraft is released for further flight (Requirement). Those actions will be captured in the aircraft maintenance logbooks and records in whichever manner CASA requires for conformity with airworthiness directives, although the text of the AD itself does not describe logbook entries.

Owners and operators bear the cost and scheduling consequences of the mandated inspections and any replacements. The AD’s compliance windows, stated in hours time in service (Compliance), determine when an operator must schedule inspections relative to the effective date of 11 May 2006, or relative to prior inspections accomplished within the specified look-back windows. For example, an operator with an unmodified eyebolt that was inspected within 775 hours prior to 11 May 2006 can defer the initial AD inspection until later, in accordance with the look-back allowance; conversely, if no recent inspection exists, the operator must inspect within 225 hours time in service after 11 May 2006 (Compliance).

The AD also affects supply chain decisions. Replacement is constrained to a "serviceable eyebolt of the same part number" C50137-2, so procurement officers must source that part number when replacement is required (Requirement). The AD further affects future maintenance choices because if an operator installs an unmodified eyebolt as a replacement, the AD requires the shorter inspection regime applicable to unmodified eyebolts to apply thereafter (Requirement). That creates an operational incentive to track whether replacement units are modified per Convair Service Engineering Report No. 6820-240-23/340-45/440-45 or unmodified, because the modification status changes inspection cadence (Requirement, Compliance).

Regulators and their delegates are also implicated, insofar as the AD is issued by the Civil Aviation Safety Authority delegate and becomes effective on a specified date; those bodies will oversee compliance and may expect operators to demonstrate adherence, though the AD text itself does not set out enforcement mechanisms or penalties in its body (signature block; effective date).

The AD establishes a set of affirmative duties for operators and maintenance personnel. The primary duties are:

• Identification: Determine whether the eyebolt installed is Peacock part number C50137-2 and whether it has been modified in accordance with Convair Service Engineering Report No. 6820-240-23/340-45/440-45 dated 24 August 1962, because different inspection timing applies depending on modification status (Applicability, Requirement).

• Inspection: Perform a dye penetrant inspection of the unmodified or modified eyebolt, focused on the threaded area that has been machined for the relief radius (Requirement). The AD prescribes that inspection method and inspection area as the diagnostic procedure.

• Timing compliance: For unmodified eyebolts the initial inspection must occur within 225 hours time in service after 11 May 2006 unless an inspection has already been completed within the last 775 hours; after the initial inspection the recurrence must not exceed 1,000 hours time in service (Compliance). For modified eyebolts the initial inspection must occur within 1,000 hours time in service after 11 May 2006 unless an inspection has already been completed within the last 4,500 hours; subsequent inspections must not exceed intervals of 5,500 hours time in service (Compliance).

• Remedial action: If cracking is detected during any inspection, before further flight replace the cracked eyebolt with a serviceable eyebolt of the same part number C50137-2, and continue the repetitive inspections thereafter (Requirement). The AD does not permit flying with a cracked eyebolt.

• Replacement consequence: If an operator replaces an eyebolt with an unmodified unit, the AD requires that the inspection periods applicable to unmodified eyebolts are applicable to that replaced unit (Requirement).

Rights, strictly as stated or implied in the AD, are limited but practically important:

• Operators retain the choice of replacement hardware consistent with the AD. The AD permits replacement with a "serviceable eyebolt of the same part number." The AD does not mandate a specific manufacturer or serial-number traceability number within its text, only the part number requirement (Requirement).

• Operators may rely on prior inspections to meet initial-inspection windows where the AD allows a look-back. For unmodified eyebolts the AD recognises inspections done within the last 775 hours, and for modified eyebolts those done within the last 4,500 hours, allowing operators to count a qualifying prior inspection toward compliance instead of repeating immediately (Compliance).

The AD does not explicitly provide procedural rights such as an appeals process or an alternative means of compliance within its text. It also does not define "serviceable" in the body of the AD. The AD does, however, reference external documents (the Convair Service Engineering Report and FAA AD 63-15-04) which operators will need to consult to determine modification status and to understand the historical FAA action that prompted this directive (Requirement; Note; Background).

The AD text does not articulate specific penalties, sanctions, or enforcement procedures within its four corners. It states that the directive "becomes effective on 11 May 2006" and is signed by a Delegate of the Civil Aviation Safety Authority (signature block), establishing the issuing authority and the effective date, but it does not include express penalty provisions, infringement schedules, or administrative fine amounts.

Given the document is an airworthiness directive issued by the Civil Aviation Safety Authority delegate, regulatory enforcement and any consequential administrative or compliance action would be expected to be exercised by the regulator under its statutory powers. The AD itself, however, contains no enforcement provisions, no procedural rules about notices of non-compliance, and no specified schedule of penalties. The AD requires actions that have immediate operational effect , for example, replacing cracked eyebolts "before further flight" (Requirement) , so an aircraft found to be in non-compliance with the directive would present a safety-of-flight issue. The AD does not describe how non-compliance findings are to be recorded or processed.

Because the AD references FAA activity , noting that the FAA received reports of cracks and cross-referencing FAA AD 63-15-04 , it embeds an international safety rationale, but it does not transform or restate U.S. enforcement mechanisms; only CASA's issuance and effective date are explicit in the text (Background; Note; signature).

Practically, the absence of penalty language in the AD means readers must look to the statutory and regulatory framework under which CASA issues ADs for the concrete enforcement mechanisms and sanctions. The AD’s text contains no litigation history, enforcement actions, or examples of administrative enforcement steps. Therefore, to determine the enforcement consequences of non-compliance, an operator or maintenance organisation must consult the governing aviation legislation and CASA regulatory material outside this AD.

The AD explicitly interacts with two external documents. First, it conditions the distinction between two eyebolt populations on modification in accordance with Convair Service Engineering Report No. 6820-240-23/340-45/440-45 dated 24 August 1962 (Requirement). The Convair report therefore functions as an incorporated reference point for the AD: whether an eyebolt is "modified" under that report determines which compliance schedule applies. That creates a direct normative link where operators must consult the Convair engineering report to establish maintenance history and the correct compliance regime.

Second, the AD references FAA material. The Background states that the FAA received reports of cracks in certain nose landing gear actuating cylinder rod end eyebolts (Background). The AD also contains a note that reads "FAA AD 63-15-04 Amdt 584 Part 507 refers" (Requirement, Note). That reference ties the CASA AD to an earlier FAA AD; it signals that the FAA action and associated findings informed CASA’s directive, and it indicates operators should consult FAA AD 63-15-04 for related content or historical context.

Beyond those two documents, the AD does not cite or amend other Australian statutes, regulations, or CASA instrument numbers within its text. It does not itself purport to alter any other legislative text. Enforcement, oversight, or record-keeping mechanisms are not set out in the AD; they will be governed by the broader regulatory framework under which CASA operates, but that framework is not recited or amended in this document.

The AD’s focus on a particular P/N and a particular engineering report creates a dependency: compliance requires operators to reconcile component identification and modification history with the Convair report. Because the AD does not define what constitutes a "serviceable eyebolt," or set out alternative means of compliance or equivalent procedures, any operator seeking to rely on an alternative inspection method or alternate part-number solution would need to look outside the AD to CASA procedural rules or to request specific approvals through whatever CASA processes apply for alternative compliance. The AD itself contains no such mechanism.

The text of the AD provides the following dates and identifiers: the AD number is AD/CONVAIR/19, titled "NLG Actuating Cylinder Rod End Eyebol t," and carries the date code "5/2006" (header). The body states that the AD "becomes effective on 11 May 2006" (Compliance statement), and the signature block is dated 31 March 2006, signed by David Villiers, Delegate of the Civil Aviation Safety Authority. The AD cross-references FAA AD 63-15-04 and cites Convair Service Engineering Report No. 6820-240-23/340-45/440-45 dated 24 August 1962.

Within the supplied AD text there are no recorded prior amendments, supersessions, or subsequent amendments. The document does not present a history list, nor does it state that it supersedes or is superseded by any CASA AD. It does not include any amendment notes or trailing clauses referencing amending instruments. The only reference to other regulatory instruments is to the FAA AD and the Convair engineering report already discussed.

Consequently, the amendment history as supplied is limited: initial issue signed 31 March 2006, effective 11 May 2006, AD/CONVAIR/19, code 5/2006. No later amendment dates, repeal clauses, or version histories are included in the text provided. To discover any amendments, revocations, or continuing effect beyond what is dated here, a reader would need to consult subsequent CASA records or consolidated AD indexes outside this document.

The AD text contains no litigation history, no court decisions, and no references to judicial proceedings. It does not name any cases, litigation outcomes, or legal challenges. The only legal signatory is the Delegate of the Civil Aviation Safety Authority, who issued the AD (signature block). The AD’s Background links the safety concern to FAA reports of cracks, and the Note refers to FAA AD 63-15-04, but no litigation or dispute record is included or referenced.

Therefore, within this instrument there is no recorded litigation history to analyse. Any legal challenges, enforcement proceedings, or disputes arising from compliance with this AD would be external to the text supplied and would need to be located and reviewed in separate legal or regulatory records. The document itself provides no case names, no references to tribunal or court decisions, and no accounts of contested enforcement actions.

The AD’s brevity contains several operational and interpretative pitfalls that operators and maintainers must attend to carefully.

1. Modification status is determinative. The AD distinguishes between eyebolts "modified in accordance with Convair Service Engineering Report No. 6820-240-23/340-45/440-45, dated 24 August 1962" and those that have not been so modified (Requirement). Operators must therefore obtain and apply that specific Convair engineering report to determine whether an eyebolt qualifies as modified for the purposes of the AD. The AD itself does not define the modification in technical detail; it references the report as the defining standard. Failure to correctly classify a unit could result in application of an incorrect inspection schedule.

2. Inspection area specificity. The AD requires dye penetrant inspection "where the threaded area is machined for the relief radius" (Requirement). That is a narrowly described locus for inspection; maintenance staff must be precise in locating and inspecting the machined relief radius on the threaded portion. Generic eyebolt inspection that does not specifically assess that machined area may not satisfy the AD.

3. Single-method prescription. The AD mandates the dye penetrant method for inspection (Requirement). It does not state alternative non-destructive inspection methods or permit equivalent techniques within the AD text. If an operator believes another method would be equivalent or preferable, the AD contains no process for substitution; such an operator would need to seek external approval, which is not described in this AD.

4. "Serviceable" is not defined. The AD requires replacement with a "serviceable eyebolt of the same part number" (Requirement). The AD does not define the criteria for serviceability within its text. Maintenance organisations will need to rely on existing serviceability definitions in their quality and airworthiness procedures or seek clarification from CASA, as necessary.

5. Consequence of installing unmodified replacements. The AD expressly states that if unmodified eyebolts are used as replacements, the Requirement 1 inspection periods (the shorter intervals applicable to unmodified eyebolts) apply (Requirement). This means that a replacement decision affects the long-term inspection cadence. Operators replacing a failed modified eyebolt with an unmodified unit accept a transition to the more frequent inspection regime, which has ongoing time and resource implications.

6. Look-back windows and record requirements. The AD allows prior inspections to satisfy the initial-inspection requirement where those prior inspections fall within specified look-back windows (775 hours for unmodified; 4,500 hours for modified) (Compliance). Operators must be able to prove the prior inspection and its date/time-in-service to use that allowance. Absent adequate maintenance records, an operator may be required to perform the initial inspection within the shorter window.

7. Narrow P/N focus. Only Eyebolt Peacock part number C50137-2 is covered by the AD (Applicability). If alternative parts are present, either different part numbers or different designs, the AD as written does not directly regulate them. However, operators should not assume that alternate parts are acceptable replacement options because the AD requires replacement with the same part number where cracking is found (Requirement).

8. Effective date and scheduling. The AD becomes effective on 11 May 2006 (Compliance). Operators must map their aircraft hours-in-service against that date and against any prior inspections to determine the correct initial compliance deadlines. Scheduling inspections in a fleet environment requires careful hours tracking.

9. Cross-reference reliance. The AD cross-references FAA AD 63-15-04 (Note) and relies on the Convair engineering report for modification definition (Requirement). Operators will need to obtain and analyse those documents for consistent application. The AD does not reproduce their content, so critical details may reside outside the AD itself.

10. No enforcement detail in text. Because the AD does not set out enforcement mechanisms or penalty schedules, operators cannot deduce from the AD text alone how regulators will handle non-compliance. Practical compliance decisions should assume that the AD’s mandatory "before further flight" replacement requirement will be treated as a safety-critical obligation.

These "gotchas" are not speculative; they arise directly from the AD’s textual choices: narrowly defined applicability and part-number focus, the use of an external engineering report to define modification status, prescription of a single inspection technique and area, and look-back allowances tied to maintenance records.

The AD prescribes a clear sequence of steps. Below is a compliance checklist constructed strictly from the AD text, to be applied by operators and maintenance organisations for aircraft within the stated applicability.

1. Confirm applicability. Verify the aircraft is a Convair Model 340 or Model 440, or a conversion of those models to turbopropeller power, and that the nose landing gear actuating cylinder rod end eyebolt installed is Peacock part number C50137-2 (Applicability).

2. Establish modification status. Obtain Convair Service Engineering Report No. 6820-240-23/340-45/440-45 dated 24 August 1962, and determine whether the eyebolt on the aircraft has been modified in accordance with that report. This classification determines which compliance timetable applies (Requirement).

3. Review inspection history. Check maintenance records to see if a qualifying inspection was performed before 11 May 2006 and whether that inspection falls within the look-back windows specified for unmodified or modified eyebolts. For unmodified eyebolts, an inspection done within 775 hours prior to 11 May 2006 counts; for modified eyebolts, an inspection done within 4,500 hours prior counts (Compliance).

4. Schedule initial inspection per status. If no qualifying prior inspection exists:

   • For unmodified eyebolts: perform the initial dye penetrant inspection within 225 hours time in service after 11 May 2006 (Compliance).
   • For modified eyebolts: perform the initial dye penetrant inspection within 1,000 hours time in service after 11 May 2006 (Compliance).

5. Conduct the inspection method as specified. Perform a dye penetrant inspection focused on the threaded area machined for the relief radius (Requirement). Ensure inspection personnel apply the dye penetrant technique to that machined area as the AD specifies.

6. Act on findings. If cracking is detected during any inspection, replace the cracked eyebolt before further flight with a serviceable eyebolt of the same part number C50137-2 (Requirement). Record the replacement in maintenance records. The AD specifies replacement with the same P/N as the unit removed.

7. Apply replacement consequences. If the replacement eyebolt is unmodified, carry forward the Requirement 1 inspection periods (the unmodified inspection timing and recurrent intervals) from the time of installation (Requirement). In practice that means the operator must schedule subsequent inspections according to the unmodified schedule even if the previously removed unit had been modified.

8. Implement recurrent inspections. After the initial inspection, continue repetitive inspections at the intervals specified:

   • Unmodified eyebolts: not to exceed 1,000 hours time in service between inspections (Compliance).
   • Modified eyebolts: not to exceed 5,500 hours time in service between inspections (Compliance).

9. Maintain records. Ensure maintenance and inspection records document part numbers, modification status per the Convair report, inspection methods and dates, hours time in service at inspection, and any replacements made. The AD’s look-back allowances require proof of prior inspections to take advantage of extended initial windows.

10. Consult referenced documents. Obtain and retain a copy of Convair Service Engineering Report No. 6820-240-23/340-45/440-45 dated 24 August 1962 to verify modification status and interpret the AD’s distinction between modified and unmodified units. Similarly consult FAA AD 63-15-04 as referenced in the AD for historical context or further details that may assist in maintenance decisions (Requirement; Note; Background).

11. Act before further flight when necessary. Where the AD requires replacement "before further flight" in the event of detected cracking, ensure the aircraft is grounded until the replacement is installed and the aircraft is released in accordance with applicable maintenance release procedures (Requirement).

12. Engage regulator if uncertain. Where definitions in the AD are ambiguous (for example "serviceable" or equivalence of alternative inspection methods), seek guidance or approval from the Civil Aviation Safety Authority, noting that the AD was issued by the Authority’s delegate and is effective from 11 May 2006 (signature block; effective date).

13. Program maintenance planning. Given the hours-based recurrence intervals, integrate the inspection schedule into the aircraft’s time-in-service tracking and maintenance planning systems to ensure inspections occur within prescribed intervals and to avoid inadvertent non-compliance.

This compliance pathway follows the AD’s text: identification of applicability and P/N, classification by Convair modification status, performance of dye penetrant inspection at the specified machined location, mandatory replacement before further flight where cracking is present, and adherence to the hours-based inspection recurrence schedules. Operators should ensure that the referenced Convair report and the FAA AD 63-15-04 are available to maintenance personnel for definitive interpretation.