AD/CONVAIR/26 - Main Landing Gear Lockpins

Key technical concept: the element controlled by the AD is the piston upper bearing retaining lockpin(s) in the main landing gear assembly. The AD identifies two factual states of the gear relevant for scheduling: main landing gears "known to have a single lockpin configuration or unknown lockpin configuration" and main landing gears "known to have more than a single lockpin configuration" (the "Compliance" text). The AD’s inspection and interval requirements differ by these factual states.

Inspection vs corrective action: the AD separates the obligation to inspect from the obligation to take remedial action. The "Requirement" block directs operators to inspect the piston upper bearing retaining lockpins. It then directs replacement where lockpins are "loose or damaged." The AD states explicitly that replacement of loose or damaged lockpins must occur "before further flight after the effective date of this AD" (the "Compliance" block). The AD therefore imposes both a scheduled condition-monitoring task (inspection) and a mandatory immediate remedy for adverse findings (replacement before flight).

Initial windows and repeat intervals: the AD provides different initial windows and repeat intervals depending on the configuration:

• For single or unknown lockpin configuration: initial inspection within the next 300 hours time in service (TIS) from the effective date, unless such inspection was already done within the last 1200 hours TIS; thereafter inspections at intervals not to exceed 1500 hours TIS (the "Compliance" block).

• For gear known to have more than a single lockpin configuration: initial inspection within 1000 hours TIS from the effective date, unless already done within the last 2000 hours TIS; thereafter inspections at intervals not to exceed 3000 hours TIS (the "Compliance" block).

A rework option: the AD authorises extending the repetitive inspection intervals to 8000 hours TIS when rework is carried out "per Paragraph 2B, General Dynamics/Convair Service Bulletin No. 32-5, dated 3 September 1971, or later FAA approved revision" (the "Compliance" block). That creates a trade-off: do periodic inspections more frequently, or perform a manufacturer-stated rework to reduce inspection frequency.

Cross-reference: the AD contains a Note that "FAA AD 71-21-04 Amdt 39-1308 refers" (the "Requirement" block). That indicates the CASA AD both aligns with and cites prior FAA regulatory action as relevant background or authority for the required measures.

Form and effect: the AD is short and focused on a single identified failure mode , failure of lockpins retaining the piston upper bearing, with the failure outcome identified as "possible subsequent loss of the piston assembly from the main landing gear" (the "Requirement" and "Background" blocks). The instruction set is procedural (inspect, replace, or rework) and time-limited (specific TIS windows and intervals), not performance-based.

The AD applies to Models 340 and 440 aeroplanes of the General Dynamics/Convair series, as stated in the "Applicability" block. That identifies the population of aircraft that must follow the directive: registered aircraft of those types in Australian jurisdiction to which CASA’s ADs apply. The AD further differentiates obligations within that population by the factual condition of the main landing gear lockpin configuration, so operators must determine whether a given aeroplane’s main landing gear is "known to have a single lockpin configuration," "known to have more than a single lockpin configuration," or has an "unknown" configuration (the "Compliance" block).

Primary responsible parties are therefore the aircraft owners and operators (the AD’s procedural commands , inspect and replace , fall to those who operate and maintain the aeroplanes). Aircraft maintenance organisations and technicians engaged to perform the inspections, replacements, or the Service Bulletin rework (Paragraph 2B of Service Bulletin No. 32-5) are operationally affected because they will be asked to execute the inspection, identify lockpin condition, and perform replacements or rework in accordance with the AD.

The CASA delegate (James Coyne, signed 13 September 2006) is the issuing official recorded in the AD, and the AD becomes effective on 26 October 2006 (the "Compliance" block). The AD thus places time-limited compliance obligations on operators and maintenance providers from that effective date.

Indirectly affected parties include any lessee, purchaser, or prospective buyer of Models 340 and 440 aeroplanes who must take account of the AD’s maintenance and inspection obligations when assessing operational readiness. The AD’s reference to FAA AD 71-21-04 and to the General Dynamics/Convair Service Bulletin No. 32-5 also engages manufacturers, their authorised service centres, and FAA-approved revision processes if an operator seeks to rely on later FAA-approved revisions of the Service Bulletin to obtain the extended inspection interval (the "Requirement" and "Compliance" blocks).

Duties

• Inspect the piston upper bearing retaining lockpin(s) on the main landing gear in accordance with the timing and conditions set out in the "Compliance" block. The timing is conditional on whether the main landing gear is known to have a single lockpin configuration (or is of unknown configuration) or is known to have more than a single lockpin configuration, and whether recent inspections were already completed within specified prior TIS windows.

• Replace any loose or damaged lockpin(s). The AD’s "Requirement" block states replacement if loose or damaged lockpins are discovered; the "Compliance" block states remedial action is required "Before further flight after the effective date of this AD."

• Observe the specified repetitive inspection intervals after the initial inspections (1500 hours TIS for single/unknown configuration; 3000 hours TIS for more-than-single configuration), unless the operator has performed the stipulated rework that allows a longer interval (the "Compliance" block).

Rights and options (explicit in the AD)

• The AD permits operators to extend the repetitive inspection intervals to 8000 hours TIS if the operator accomplishes the rework described in Paragraph 2B of General Dynamics/Convair Service Bulletin No. 32-5 dated 3 September 1971, or a later FAA approved revision (the "Compliance" block). This is an explicit operational option provided by the AD: operators may perform a manufacturer-specified rework to reduce inspection frequency.

• The AD also explicitly recognises prior inspections: where inspections were "already accomplished within the last 1200 hours" or "already accomplished within the last 2000 hours" (for the two configuration categories respectively), the initial inspection window is shortened or may be treated as already satisfied (the "Compliance" block). That gives a limited credit for recent maintenance actions.

How duties are structured in time

• The AD sets an effective date (26 October 2006) and then prescribes when the initial inspections must be done relative to that date, and how frequently thereafter inspections must be repeated. It also requires immediate replacement of defective lockpins before further flight after the effective date (the "Compliance" block).

What the AD does not state as a duty

• The AD itself does not set out record-keeping, reporting obligations to CASA, or specific technician qualifications; it also does not specify the exact inspection method or acceptance criteria beyond identifying a lockpin as "loose or damaged." The AD does reference the manufacturer service bulletin and the FAA AD as contextual material (the "Requirement" and "Compliance" blocks), which may contain detailed procedures, but the AD text itself remains succinct about the tasks and intervals.

The text of this AD does not specify monetary penalties, infringement procedures, or criminal sanctions. It is titled and presented as an Airworthiness Directive issued by the Civil Aviation Safety Authority and is signed by a CASA delegate (James Coyne, 13 September 2006), and it records an effective date (26 October 2006). The AD therefore functions as a mandatory regulatory instruction, but the AD document as provided does not articulate the enforcement mechanisms or specific sanctions for non-compliance within its own text.

What the AD does supply relevant to enforcement:

• It prescribes mandatory tasks and firm timing: inspect within specified hours in service, repeat at fixed intervals, replace any loose or damaged lockpin(s) before further flight, and optionally perform the Service Bulletin rework to extend intervals. Failure to meet those prescribed times or to replace defective components could leave an aircraft in an unairworthy condition given the AD’s safety rationale ("to prevent failure of the lockpins and subsequent release of the piston assembly from the main landing gear," the "Background" block). The AD therefore creates a regulatory standard of maintenance and repair for the specified aircraft.

What it does not say:

• The AD does not set out the procedural steps for CASA enforcement actions, nor does it list civil penalty amounts, de-registration steps, or other administrative remedies. It likewise does not specify reporting obligations back to CASA or to the FAA. The document contains no express provision for how CASA will verify compliance, audit operators, or require documentary proof.

Practical implication for operators

• Given the AD’s mandatory prescriptions and effective date, operators must implement the inspections and remedial work within the specified windows. The AD’s silence on penalties in the text does not negate that it is a directive issued by CASA; practical enforcement and any penalties would arise under the broader statutory or regulatory regime that empowers CASA to issue and enforce ADs. The AD itself, however, does not enumerate those enforcement particulars.

The AD explicitly cross-references two external materials: FAA AD 71-21-04 Amdt 39-1308 (note in the "Requirement" block) and General Dynamics/Convair Service Bulletin No. 32-5 dated 3 September 1971 (with allowance for a later FAA approved revision) in the "Compliance" block. Those references create two distinct interactions:

• Regulatory alignment with FAA action. The AD’s Note that "FAA AD 71-21-04 Amdt 39-1308 refers" signals that CASA’s directive is operating in the context of existing FAA airworthiness action on the same issue. That suggests the CASA AD is consistent with, and points to, historical FAA regulatory findings and remedies dealing with the same failure mode.

• Reliance on a manufacturer Service Bulletin for a maintenance rework pathway. The AD permits extending inspection intervals to 8000 hours TIS "when rework has been accomplished per Paragraph 2B, General Dynamics/Convair Service Bulletin No. 32-5, dated 3 September 1971, or later FAA approved revision." That explicitly conditions the longer interval on completion of a manufacturer-specified rework, and on that rework being either the dated SB paragraph or an FAA-approved later revision. This creates an interaction between CASA’s AD, manufacturer technical data, and FAA review/approval processes.

What the AD does not state about interactions with other laws

• The AD does not identify other Australian statutory or regulatory instruments (for example the specific Civil Aviation Act provisions or Civil Aviation Safety Regulations) within its text. It also does not specify reporting or certification steps that might be required under other regulations. The AD is narrowly focused on the inspection and replacement/rework tasks for the Convair models and on the timing.

Implications for cross-jurisdictional operators

• Operators that operate the same aircraft under oversight by multiple civil aviation authorities will need to ensure compliance with CASA’s AD as drafted, and may reasonably refer to the cited FAA AD and the manufacturer Service Bulletin for technical procedure or for FAA-approved revision language that the AD explicitly permits. The AD’s reference to "later FAA approved revision" creates an explicit bridge so that an FAA-approved update to the Service Bulletin can be relied on for the extended inspection interval.

The AD document itself records the following temporal and document history items within its text:

• AD identification and date block: AD/CONVAIR/26, Main Landing Gear Lockpins, dated 11/2006 (top of the document).

• Issuance signature and date: signed by James Coyne, Delegate of the Civil Aviation Safety Authority, with the date 13 September 2006 indicated under the signature block.

• Effective date: the AD text states "This Airworthiness Directive becomes effective on 26 October 2006" within the "Compliance" block.

• Cross-references to prior external items: the AD’s "Requirement" block contains the Note "FAA AD 71-21-04 Amdt 39-1308 refers." The "Compliance" block references General Dynamics/Convair Service Bulletin No. 32-5 dated 3 September 1971 and allows reliance on "later FAA approved revision."

The AD text does not list any prior amendments to AD/CONVAIR/26 itself, nor does it specify any subsequent amendments or revocations. The AD therefore appears as a single-issue directive adopted in late 2006, referencing older FAA and manufacturer materials as the technical underpinning for its requirements.

What the AD does not contain regarding amendments

• There is no amendment log, no version history, no replacement text, and no transitional or sunset provisions recorded in the presented document. If operators require an amendment record, revocation, or later CASA updates, those would need to be sought in CASA’s AD database or in later instruments; the provided text contains no such entries.

The AD text contains no mention of litigation, appeals, or tribunal outcomes. There are no cases, determinations, or recorded disputes referenced in the instrument. The document is a single administrative directive; it does not provide or summarise any judicial or administrative review history.

Consequently, from the face of this document:

• There is no litigation history reported, and no description of any legal challenge to this AD within the text.

If a practitioner needs actual case history or references to administrative appeals concerning this AD, they must consult CASA records, court databases, or the relevant administrative review bodies. The instrument itself provides no litigation detail.

Several detail-level points in the AD’s short text can generate operational confusion if not read precisely.

1. Distinct schedules tied to "known" configuration and to "unknown" configuration. The AD treats "single lockpin configuration" and "unknown lockpin configuration" together for scheduling purposes, with a more aggressive inspection cadence (initial within 300 hours TIS unless inspected within the last 1200 hours; repeat at intervals not to exceed 1500 hours). By contrast, main landing gears "known to have more than a single lockpin configuration" are subject to a slower cadence (initial within 1000 hours unless inspected within the last 2000 hours; repeat at intervals not to exceed 3000 hours). Operators must determine and document which category each aircraft falls into; the AD’s text does not define how to establish "known" beyond the plain meaning, so a one-time physical verification of lockpin configuration will be required to apply the correct schedule.

2. Credit for recent inspections. The initial inspection windows are conditional on whether an inspection "was already accomplished within the last 1200 hours" (single/unknown) or "within the last 2000 hours" (more-than-single). Operators must have maintenance records that show the timing of any prior inspection to take advantage of that credit. The AD text grants the credit but does not specify how records must be retained or presented.

3. Ambiguity of numbering in the Compliance block. The AD sets out a numbered list under "Compliance" that appears to contain two numbered items. The first numbered paragraph contains the initial and repetitive inspection schedules for the two configuration categories. The second numbered paragraph reads "Before further flight after the effective date of this AD." Interpreting the text sensibly: the "Before further flight" requirement corresponds to the replacement action directed in the "Requirement" block ("If loose or damaged lockpin(s) are discovered, replace lockpins(s)"), but the AD’s layout could cause operational confusion about whether other actions are also required "before further flight." Practitioners should therefore read the Requirement and Compliance blocks together: inspection is scheduled as timed tasks; any replacement of loose/damaged lockpins must be effected before the next flight after discovery or after the effective date where discovery occurs.

4. Rework option tied to a specific paragraph and an old Service Bulletin date. The AD allows extension to an 8000 hour interval only "when rework has been accomplished per Paragraph 2B, General Dynamics/Convair Service Bulletin No. 32-5, dated 3 September 1971, or later FAA approved revision." That creates two operational points: the rework must conform to a specific paragraph of a dated Service Bulletin, and if an operator intends to rely on a later FAA-approved revision, that FAA approval must be demonstrable. The AD does not itself quote the rework content; operators must source and apply the exact Service Bulletin paragraph and/or an FAA-approved revision to qualify for the longer interval.

5. Tight remedial timing for unsafe findings. The AD requires replacement of loose or damaged lockpins "Before further flight after the effective date of this AD." That gives no room to defer replacement pending parts availability; operations that discover a loose or damaged lockpin must not fly the aircraft until replacement is made. Operators will need to plan for parts and technician availability to avoid grounding disruption.

6. Narrow scope of the AD. The AD applies only to Convair Models 340 and 440. An operator must ensure they have correctly identified the airframe model and that the AD applies to the specific aircraft variant. No extension to other types is specified.

7. No procedural detail in the AD text. The AD does not supply a step-by-step inspection procedure or detailed acceptance criteria beyond the identification of a lockpin as "loose or damaged." Operators will need to consult the referenced FAA AD, the manufacturer Service Bulletin, or maintenance manuals for precise inspection techniques and criteria.

8. Effective date vs signature date. The AD is signed on 13 September 2006 but becomes effective on 26 October 2006. Operators must plan around the effective date for initial windows and avoid confusion between issue/signature date and effective date.

Follow the AD’s text literally; the AD contains a small set of discrete, time-bound tasks. The AD’s "Requirement" and "Compliance" blocks are the operative provisions. The following steps restate and sequence those obligations to produce an actionable compliance checklist grounded in the AD language.

1. Confirm applicability and aircraft identity

• Verify the aeroplane is a General Dynamics/Convair Model 340 or Model 440. The AD’s "Applicability" block limits the directive to these models. If the aircraft is not one of those models, the AD does not apply.

2. Determine main landing gear lockpin configuration

• Establish whether each main landing gear assembly is "known to have a single lockpin configuration," "known to have more than a single lockpin configuration," or if the configuration is "unknown." This is required because the AD sets different initial inspection windows and repeat intervals depending on that factual category (the "Compliance" block). If configuration is unknown, treat the gear as in the single/unknown group for scheduling purposes.

3. Schedule and perform the initial inspection within the AD’s windows

• If the gear is single or unknown configuration:
  • Inspect the piston upper bearing retaining lockpin(s) within the next 300 hours time in service (TIS) from the AD effective date, unless an inspection was already accomplished within the last 1200 hours TIS (the "Compliance" block). If the operator can demonstrate an inspection was done within the last 1200 hours, the initial inspection requirement may be treated as satisfied for the moment.
• If the gear is known to have more than a single lockpin configuration:
  • Inspect the piston upper bearing retaining lockpin(s) within the next 1000 hours TIS from the AD effective date, unless an inspection was already accomplished within the last 2000 hours TIS (the "Compliance" block).

4. Execute remedial replacements if defects found

• If any lockpin(s) are discovered to be "loose or damaged" during an inspection, replace the lockpin(s). The AD’s "Requirement" block directs replacement where loose or damaged lockpins are discovered. The "Compliance" block requires replacement "Before further flight after the effective date of this AD." Therefore, do not permit the aircraft to operate with loose/damaged lockpins past the time of discovery.

5. Implement the repetitive inspection regime

• After the initial inspection, repeat inspections at the prescribed intervals:
  • For single/unknown configuration: no more than every 1500 hours TIS.
  • For more-than-single configuration: no more than every 3000 hours TIS.
• If the operator performs the specified rework (see step 6), the repetitive interval may be extended to 8000 hours TIS (the "Compliance" block).

6. Optional rework to extend inspection intervals

• If the operator wishes to extend the repetitive inspection interval to 8000 hours TIS, ensure the rework has been accomplished "per Paragraph 2B, General Dynamics/Convair Service Bulletin No. 32-5, dated 3 September 1971, or later FAA approved revision" (the "Compliance" block). Obtain and follow the exact Service Bulletin paragraph (or a later FAA-approved revision), and document completion. Reliance on a later FAA approved revision is explicitly permitted by the AD text.

7. Consult referenced documents for technical procedure

• The AD is concise and does not detail inspection technique, acceptance criteria for "loose or damaged," or the Service Bulletin rework procedure. Practitioners should obtain and follow the detailed inspection and rework procedures from:
  • General Dynamics/Convair Service Bulletin No. 32-5 (Paragraph 2B), dated 3 September 1971, and any later FAA-approved revision relied upon for the 8000 hour interval.
  • FAA AD 71-21-04 Amdt 39-1308, referenced in the AD’s Note, for historical regulatory context and possibly procedural content.
• The AD text itself references these documents; the AD’s compliance option to use later FAA-approved revisions makes those documents the technical source for the rework.

8. Plan operationally for parts and downtime

• Because the AD requires replacement of loose/damaged lockpins "before further flight," operators must ensure access to appropriate replacement lockpins and qualified maintenance personnel to avoid extended aircraft grounding. The AD does not provide parts lists or procurement instructions; these must follow manufacturer specifications and supply channels.

9. Record and demonstrate compliance

• The AD gives prescribed timing conditions that rely on prior inspection history (credit if inspected within specified prior hours). Operators will need to be able to demonstrate, from maintenance records, the timing of prior inspections or the completion of the rework if they claim credit or rely on the extended interval. The AD text itself does not specify record formats or reporting procedures, but the reliance on prior inspections and on a Paragraph 2B rework requires some means of documentary proof to apply the AD’s timing options.

10. Observe the AD effective date

• The AD is effective on 26 October 2006. Calculate the inspection initial windows and the "next X hours" from that effective date as the AD prescribes. If an inspection was already done within the last 1200 or 2000 hours (as relevant), that prior inspection may satisfy the initial requirement per the AD text.

Summary sequencing (compact)

• Identify model and lockpin configuration (single/unknown vs more-than-single).
• Verify any qualifying recent inspections (within 1200/2000 hours) to claim credit.
• Schedule and perform the initial inspection within 300/1000 hours as applicable.
• Replace any loose/damaged lockpin(s) before further flight.
• Repeat inspections at the AD-prescribed intervals (1500/3000 hours), unless rework per Service Bulletin Paragraph 2B is completed, in which case intervals may be extended to 8000 hours.
• Keep maintenance records that substantiate inspection dates and any rework performed.

Note that the AD gives operators the explicit technical and timing options; it does not provide detailed inspection methodology or record-keeping clauses, so compliance practitioners should obtain the referenced FAA AD and the stated Service Bulletin paragraph for procedural detail and for documentary support of any extended-interval claims.