{"id":"F2006B05798","name":"AD/PA-31/93 Amdt 2 - Main Landing Gear Inboard Door Hinge","slug":"ad-pa-31-93-amdt-2-main-landing-gear-inboard-door-hinge","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135713,"registerId":"commonwealth-F2006B05798-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/93 Amdt 2 - Main Landing Gear Inboard Door Hinge","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/PA-31/93 Amdt 1 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nPiper PA-31 Series Aeroplanes\n\nAD/PA-31/93\n\nAmdt 2\n\n  \nMain Landing Gear Inboard Door Hinge 4/2001\n\n| Applicability: | Model      | Serial Numbers                                                                                                       |\n| -------------- | ---------- | -------------------------------------------------------------------------------------------------------------------- |\n|                | PA-31      | 31-2 through 31-900 and 31-7300901 through 31-8312019.                                                               |\n|                | PA-31-300  | 31-2 through 31-900 and 31-7300901 through 31-8312019.                                                               |\n|                | PA-31-350  | 31-5001 through 31-5004 and 31-7305005 through 31-8553002.                                                           |\n|                | PA-31-325  | 31-7400990, 31-7512001 through 31-8312019.                                                                           |\n|                | PA-31P     | 31P-1 though 31P-109 and 31P-7300110 through 31P-7730012.                                                            |\n|                | PA-31T     | 31T-7400002 through 31T-8120104                                                                                      |\n|                | PA-31T1    | 31T-7804001 through 31T-8104073; 31T-8104101; 31T-8304001 through 31T-8304003; and 31T-1104004 through 31T- 1104017. |\n|                | PA-31T2    | 31T-8166001 through 31T8166076 and 31T-1166001 through 31T-1166008.                                                  |\n|                | PA-31T3    | 31T-8275001 through 31T-8475001 and 31T-5575001.                                                                     |\n|                | PA-31P-350 | 31P-8414001 through 31P-8414050.                                                                                     |\n\nRequirement: 1. For aircraft with any MLG inboard door hinge assembly that is Piper part number 47529-32 (or FAA or CASA-approved equivalent part number), accomplish the following in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980.\n\n    Inspect all hinges and hinge attachment angles in the MLG inboard door hinge assembly; and\n\n    b. Replace any cracked MLG inboard door hinge assembly with a Piper part number 47529-32 assembly (or FAA or CASA-approved equivalent part number).\n\n    2. For aircraft with any aluminium MLG inboard door hinge assembly that is not Piper part number 47529-32 (or FAA or CASA-approved equivalent part number) or any other assembly that is not made of steel, accomplish the following in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980\n\n    Inspect all hinges and hinge attachment angles in the MLG inboard door hinge assembly; and\n\n    b. Replace any cracked MLG inboard door hinge assembly with a Piper part number 47529-32 assembly (or FAA or CASA-approved equivalent part number).\n\nCompliance: 1. Inspect upon accumulating 2,000 hours time-in-service on the MLG inboard door hinge assembly or within the next 100 hours time in service after 19 April 2001, whichever occurs later; and thereafter at intervals not to exceed 2,000 hours TIS. Accomplish the replacement, if necessary, before further flight after the inspection.\n\n2. Inspect at the next inspection required by the previous issue of this Directive or within the next 100 hours time-in-service after 19 April 2001 whichever occurs first, and thereafter at intervals not to exceed 100 hours TIS. Accomplish the replacement, if necessary, before further flight after the inspection where the cracked assembly was found.\n\nThis amendment becomes effective on 19 April 2001.\n\nBackground: Instances of main landing gear inboard door hinge failure have occurred on local aircraft.\n\nAmendment 1 was in response to a new FAA AD which was prompted by reports of cracks in the improved design MLG inboard door hinge assemblies on the affected aircraft. This AD retains the current repetitive inspections (contained in FAA AD 80- 26-05) and requires inspection on the improved design parts.\n\nAmendment 2 is issued to include CASA-approved parts as an alternative to the Piper and FAA-approved parts.\n\nAmendment 1 of this Airworthiness Directive became effective on 22 March 2001.\n\nThe original issue of this Airworthiness Directive became effective on 30 September 1980.\n\n![](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 9 March 2001\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 21 March 2001","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original 1980 directive addressed a specific unsafe condition with specific hinges. Amendment 1 (March 2001) expanded scope to cover 'improved design' parts that were themselves cracking. Amendment 2 (this version) further expands the regulatory scope by adding 'CASA-approved' parts as acceptable alternatives to Piper and FAA-approved parts, effectively broadening the compliance options while maintaining the same safety intent. The directive has evolved from a simple inspection/replacement order to a more complex instrument accommodating multiple approval pathways."},"complexity_factors":["Multiple aircraft models and extensive serial number ranges (10 model variants with non-contiguous serial number ranges)","Two distinct compliance tracks with different inspection intervals (2,000 hours vs 100 hours) depending on hinge material and part number","Cross-reference to external technical document (Piper Service Bulletin No. 682) for detailed instructions","Conditional timing logic ('whichever occurs later' / 'whichever occurs first')","Nested definitions of approved parts (Piper part number OR FAA-approved equivalent OR CASA-approved equivalent)","Amendment history references (original 1980 issue, Amendment 1 in 2001, now Amendment 2) requiring understanding of what changed"],"plain_english_summary":"This CASA Airworthiness Directive targets specific Piper PA-31 series aircraft after cracks were found in landing-gear inboard door hinges that could detach or interfere with gear operation. Owners/operators must inspect hinges at set intervals and replace any cracked assemblies with approved steel parts (Piper P/N 47529-32 or CASA/FAA‑approved equivalents). The amendment permits Australian-approved replacement parts, giving local operators more flexibility while preserving landing safety."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Amendment 2 modifies the acceptable replacement parts by explicitly adding CASA‑approved parts as alternatives to Piper and FAA‑approved parts; otherwise it retains the inspection and replacement requirements introduced earlier (Background; Requirement)."},"complexity_factors":["Extensive applicability list: multiple PA-31 variants with many serial-number ranges to determine if an aircraft is affected (Applicability).","Two distinct inspection regimes depending on hinge assembly part number and material (steel vs aluminium/not PN 47529-32) (Requirement; Compliance).","Different compliance triggers and intervals using hours‑in‑service and date-based cutoffs, including “whichever occurs first/later” phrasing that affects scheduling (Compliance).","Mandatory replacement before further flight if cracks are found, creating immediate operational disruption and potential costs (Requirement; Compliance).","Reference to an external document (Piper Service Bulletin No. 682) for inspection instructions, requiring operators to obtain and follow that bulletin (Requirement).","Allowance of replacement with Piper part or FAA‑ or CASA‑approved equivalents introduces approval-path complexity for parts sourcing and certification (Requirement; Background).","Revocation and reissue of a previous amendment means operators must reconcile prior compliance actions against the new requirements and dates (Intro; Background)."],"plain_english_summary":"This amendment revokes the prior AD and requires inspections and replacement of main landing gear inboard-door hinge assemblies on specified Piper PA-31 series aircraft. Inspections must follow Piper Service Bulletin No. 682, and cracked parts must be replaced with Piper part 47529-32 or FAA- or CASA‑approved equivalents (Requirement; Compliance; Background).\n\nAircraft owners/operators pay for inspections and replacements. CASA (the delegate) sets the timing and acceptable parts; inspections occur at 2,000‑hour or 100‑hour intervals depending on part type, and replacements must be done before further flight (Compliance)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-93-amdt-2-main-landing-gear-inboard-door-hinge","history":"/api/acts/ad-pa-31-93-amdt-2-main-landing-gear-inboard-door-hinge/history","analysis":"/api/acts/ad-pa-31-93-amdt-2-main-landing-gear-inboard-door-hinge/analysis","conflicts":"/api/acts/ad-pa-31-93-amdt-2-main-landing-gear-inboard-door-hinge/conflicts","importantCases":"/api/acts/ad-pa-31-93-amdt-2-main-landing-gear-inboard-door-hinge/important-cases","documents":"/api/acts/ad-pa-31-93-amdt-2-main-landing-gear-inboard-door-hinge/documents"}}