{"id":"F2008L00491","name":"AD/J4100/2 - Nose Landing Gear Capsule","slug":"ad-j4100-2-nose-landing-gear-capsule","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119301,"registerId":"commonwealth-F2008L00491-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"BAe Systems (Operations) Jetstream 4100 ","sectionType":"division","heading":"BAe Systems (Operations) Jetstream 4100 Series Aeroplanes","content":"### BAe Systems (Operations) Jetstream 4100 Series Aeroplanes\n\n| AD/J4100/2 | Nose Landing Gear Capsule | 4/2008 DM |\n| ---------- | ------------------------- | --------- |\n\n| Applicability: | Jetstream Aircraft Ltd, British Aerospace Regional Aircraft Ltd, British Aerospace (Operations) Ltd and British Aerospace (Commercial Aircraft) Ltd. Jetstream 4100 Series aeroplanes.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Carry out an initial inspection of the Nose Landing Gear (NLG) capsule in accordance with Paragraph 2B of SB J41-A32-082 Revision 2 or later approved revision.2. If the check for free movement of the capsule is not satisfactory, remove the NLG and install a serviceable unit and inspect in accordance with Paragraph 2.B. of Service Bulletin J41 -A32-082 Revision 2 or later approved revision.3. Repeat the actions detailed in Requirements 1 and 2 of this AD.4. Modify the aircraft in accordance with Paragraph 2.B. of Service BulletinJ41-A32-084 Revision 0 or later approved revision.Paragraph 2.B, of Service Bulletin J41-A32-084 Revision 0 requires a check for free movement of the capsule, this is to be performed in accordance with Paragraph 2B of SB J41-A32-082 rev 2 or later approved revision.Note: EASA AD 2006-0131 dated 18 May 2006 refers.                                                                                                                                                              |\n| Compliance:    | 1. Prior to exceeding the greater of either: 400 flight hours since the AD effective date or 800 flight hours from the last inspection in accordance with SBJ41-A32-082 Revision 1, but this is not to exceed 3000 fight hours from the last inspection in accordance with SB J41- A32-082 Revision 1. (3000 flight hours being the repeat interval defined in SB Revision 1).2. Before further flight after the effective date of this AD.3. For aircraft without Service Bulletin J41-A32-084 Revision 0 or later approved revision embodied, (Modification JM41670), repeat at an interval not exceeding 800 flight hours.For aircraft with Service Bulletin J41-A32-084 Revision 0 or later approved revision embodied, (Modification JM41670), repeat at an interval not exceeding 3000 flight hours.                                                                                                                                                                                                                                        |\n|                | 4. Within 30 days after the effective date of this AD; where there is a need to fit a replacement gear to an aircraft; orPrior to 30 June 2012, whichever occurs first after the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n|                | This Airworthiness Directive becomes effective on 20 February 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| Background:    | Service Bulletin J41-A32-082 revision 1 was issued following two incidents where the nose landing gear failed to fully extend. Repeat inspections of the NW shortening mechanism where required to detect binding at the capsule bearings.Following a third incident in 2005 where the nose landing gear failed to fully extend on an aircraft that had been inspected in accordance with J41-A32-082 rev 1, a review identified that changes were necessary to ensure the inspection would detect NLG assemblies at risk of seizure. The changes comprise a modified ‘freefall’ test and a reduced repeat inspection frequency, these being introduced in revision 2 of the SB. This AD is required to fully address the unsafe condition previously identified.In addition, modification JM41670 (Service Bulletin J41-32-084) has been developed. This installs a nose landing gear with modified bearings and lubrication provisions in the shortening mechanism. Embodiment of this modification also allows a revised inspection frequency. |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n14 February 2008","sortOrder":0},{"sectionNumber":"AD/J4100/2","sectionType":"part","heading":"AD/J4100/2","content":"## AD/J4100/2","sortOrder":1},{"sectionNumber":"Nose Landing Gear Capsule","sectionType":"part","heading":"Nose Landing Gear Capsule","content":"## Nose Landing Gear Capsule","sortOrder":2},{"sectionNumber":"4/2008 DM","sectionType":"part","heading":"4/2008 DM","content":"## 4/2008 DM","sortOrder":3}],"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":false,"description":"This AD maintains its original scope as a targeted safety directive addressing a specific mechanical failure mode in the Jetstream 4100 nose landing gear. The document reflects the natural evolution of the safety response (from inspection to modification) rather than scope creep."},"complexity_factors":["Multiple cross-references to external Service Bulletins (SB J41-A32-082 and SB J41-A32-084) without reproducing their full content","Nested conditional compliance deadlines (four different timing requirements depending on flight hours, modification status, and effective date)","Technical aviation terminology requiring specialist knowledge (e.g., \"NLG capsule\", \"shortening mechanism\", \"freefall test\")","Dual-path compliance structure (inspection regime vs. modification regime) with different repeat intervals for each","Reference to EASA AD 2006-0131 indicating harmonisation with European regulations"],"plain_english_summary":"This AD requires owners/operators of Jetstream 4100 series aircraft to address a nose landing-gear capsule seizure hazard that can prevent full gear extension. It mandates recurring inspections for free movement and removal/repair if a capsule fails.\n\nThe aim is to prevent nose-gear collapse or forced landings by catching defects early and ultimately mandating a modification (improved bearings and lubrication) that resolves the root cause and reduces inspection frequency."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"The AD tightens and formalises the earlier Service Bulletin regime by requiring the revised inspection method introduced in SB J41‑A32‑082 Revision 2 (modified 'freefall' test and reduced repeat frequency) and by mandating embodiment of or compliance alternatives tied to modification JM41670 (SB J41‑A32‑084). It therefore expands the original SB scope by making the revised checks and specified compliance windows mandatory to address the identified NLG binding/seizure risk (see Background; Requirements; Compliance)."},"complexity_factors":["Multiple referenced Service Bulletin revisions (J41‑A32‑082 rev 1 and rev 2; J41‑A32‑084 rev 0) requiring attention to correct revision.","Conditional repeat intervals: different intervals apply depending on whether modification JM41670 (SB J41‑A32‑084) is embodied (800 flight hours vs 3000 flight hours).","Interplay with prior inspections: compliance measured against last inspection performed under SB J41‑A32‑082 Revision 1 (limits such as 400/800/3000 flight hours introduce look‑back calculations).","Fixed compliance deadlines and events (effective date 20 Feb 2008; modification deadline referenced as prior to 30 June 2012; inspection before further flight in some cases).","Technical inspection criteria (check for 'free movement' and a modified 'freefall' test) require specific procedures from the Service Bulletins.","Mandatory remedial action if check is unsatisfactory (remove and install a serviceable NLG) plus requirement to document and repeat inspections.","Cross‑reference to an EASA AD (adds an external regulatory source to consider)."],"plain_english_summary":"This Airworthiness Directive requires operators of Jetstream 4100 series aeroplanes to inspect the nose landing‑gear (NLG) capsule for free movement, replace any unserviceable NLG, and implement a specified modification where required. Inspections and modification must follow Service Bulletins J41‑A32‑082 (Rev 2) and J41‑A32‑084 (Rev 0) and be repeated at the mandated intervals (see Requirement and Compliance). Operators pay for the inspections, repairs and any modification; CASA set the AD effective 20 February 2008 and prescribes the compliance windows."}},"importantCases":[],"_links":{"self":"/api/acts/ad-j4100-2-nose-landing-gear-capsule","history":"/api/acts/ad-j4100-2-nose-landing-gear-capsule/history","analysis":"/api/acts/ad-j4100-2-nose-landing-gear-capsule/analysis","conflicts":"/api/acts/ad-j4100-2-nose-landing-gear-capsule/conflicts","importantCases":"/api/acts/ad-j4100-2-nose-landing-gear-capsule/important-cases","documents":"/api/acts/ad-j4100-2-nose-landing-gear-capsule/documents"}}