{"id":"F2006B08904","name":"AD/DH 82/9 Amdt 1 - Datum Bolts","slug":"ad-dh-82-9-amdt-1-datum-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52426,"registerId":"commonwealth-F2006B08904-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DH 82/9 Amdt 1 - Datum Bolts","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nDH 82 (Tiger Moth) Series Aeroplanes\n\nAD/DH 82/9\n\nAmdt 1\n\n  \nDatum Bolts 10/98\n\nApplicability: Model DH82 and DH82A Moth aircraft.\n\nRequirement: Action in accordance with British Aerospace Technical News Sheet CT (Moth) No.\n\n28 Issue 2.\n\nNote: UK CAA AD 002-10-97 refers.\n\nCompliance: Unless already accomplished, within 25 hours time in service after 10 September 1998, or before 10 December 1998, whichever occurs first.\n\nThis amendment becomes effective on 10 September 1998.\n\nBackground: Moth aircraft have special bolts installed at certain fuselage joints which serve as “datum pins” when rigging the aircraft longitudinally. Although these bolts are similar in appearance, their material specifications differ. This Directive requires an inspection of the bolts installed at joint “E” (on some models) to determine the material specification.\n\nAmendment 1 is issued in response to Issue 2 of the Requirement document which introduces an additional one-time inspection and replacement, where necessary, of the fuselage Joint ‘E’ bolts on the opposite side of the aircraft to the datum bolts, and to allow the use of A25 bolts in lieu of obsolete specification AGS. 749 bolts.\n\nThe original issue of this airworthiness directive became effective on 12 November 1997.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The original 1997 directive only required inspection of datum bolts at Joint E. Amendment 1 expands the scope to include: (1) an additional one-time inspection of bolts on the opposite side of the fuselage, and (2) permission to use alternative modern bolts (A25) instead of obsolete specification bolts (AGS 749). This represents a modest expansion of safety coverage while also providing operational flexibility."},"complexity_factors":["Very short document (under 300 words)","Only 2 defined terms implicitly used (Joint 'E', datum bolts — both explained in plain English)","Single compliance pathway with clear deadline","No cross-references to other legislation (only references to technical documents: British Aerospace Technical News Sheet and UK CAA AD)","Simple conditional: 'unless already accomplished'","No nested exceptions or complex logical structures"],"plain_english_summary":"This CASA Airworthiness Directive mandates owners/operators of DH82/DH82A Tiger Moths inspect and, if necessary, replace fuselage datum bolts at Joint E (and the opposite side) because visually identical but different‑material bolts can fail. The amendment permits modern A25 bolts in place of obsolete AGS 749s, easing compliance.\n\nWork must be done within 25 flying hours after 10 September 1998 or by 10 December 1998, whichever is earlier."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Yes. Amendment 1 broadened the original directive by adding a one-time inspection and replacement, where necessary, of Joint E bolts on the side opposite the datum bolts and by permitting A25 bolts to replace obsolete AGS.749 bolts. ('introduces an additional one-time inspection and replacement ...' and 'allow the use of A25 bolts in lieu of obsolete specification AGS. 749 bolts.')"},"complexity_factors":["Narrow applicability to specific types — 'Applicability: Model DH82 and DH82A Moth aircraft.'","Technical inspection and potential part replacement required — 'This Directive requires an inspection of the bolts installed at joint “E” ... to determine the material specification.'","Short compliance window imposes scheduling pressure — 'within 25 hours time in service after 10 September 1998, or before 10 December 1998.'","Reliance on an external technical document for the mandated procedure — 'Action in accordance with British Aerospace Technical News Sheet CT (Moth) No. 28 Issue 2.'","Amendment expands the required work (opposite-side inspection and possible replacement) — 'introduces an additional one-time inspection and replacement, where necessary, of the fuselage Joint ‘E’ bolts on the opposite side of the aircraft to the datum bolts.'","Parts-specification and obsolescence consideration — 'allow the use of A25 bolts in lieu of obsolete specification AGS. 749 bolts.'","Compliance requires maintenance input and parts supply within the deadline (administrative and logistical burden implied by inspection/replacement requirement and deadline)."],"plain_english_summary":"This airworthiness directive requires operators of DH82 and DH82A Tiger Moth aeroplanes to inspect specific fuselage ‘datum’ bolts at joint E and replace them if they are the obsolete specification. It directs compliance with British Aerospace Technical News Sheet CT (Moth) No. 28 Issue 2 and must be done within 25 hours time-in-service after 10 September 1998 or by 10 December 1998. Amendment 1 adds a one-time inspection on the opposite side and permits using A25 bolts instead of obsolete AGS.749 bolts."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dh-82-9-amdt-1-datum-bolts","history":"/api/acts/ad-dh-82-9-amdt-1-datum-bolts/history","analysis":"/api/acts/ad-dh-82-9-amdt-1-datum-bolts/analysis","conflicts":"/api/acts/ad-dh-82-9-amdt-1-datum-bolts/conflicts","importantCases":"/api/acts/ad-dh-82-9-amdt-1-datum-bolts/important-cases","documents":"/api/acts/ad-dh-82-9-amdt-1-datum-bolts/documents"}}