{"id":"F2006B02828","name":"AD/B737/127Amdt 2 - Elevator Tab Push Rod Attachment","slug":"ad-b737-127amdt-2-elevator-tab-push-rod-attachment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42170,"registerId":"commonwealth-F2006B02828-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/127Amdt 2 - Elevator Tab Push Rod Attachment","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)  \n![](image.002.png)  \nBoeing 737 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B737/127 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\nAD/B737/127\n\nAmdt 2\n\n  \nElevator Tab Push Rod Attachment 1/2001\n\nApplicability: Model 737-100, \\-200, \\-200C, \\-300, \\-400, and \\-500 series aircraft, line numbers 1\n\nthrough 2939.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 2000-19-05 Amdt 39-11906.\n\nNote: Boeing Alert Service Bulletin 737-27A1205 and Service Letter 737-SL-27-118- D refer.\n\nCompliance: Within 24 months or 4,000 cycles after 25 January 2001, whichever occurs first.\n\nThis amendment becomes effective 25 January 2001.\n\nBackground: The FAA received two reports indicating that excessive high frequency airframe vibration occurred during flight on Model 737-200 and 737-300 series aircraft, which resulted in severe damage to the elevator, elevator tab, and elevator tab control mechanism. The actions specified in this Directive are intended to prevent detachment of an elevator tab pushrod due to a detached nut at either end attachment of a push rod.\n\nAmendment 1 added a requirement to replace all existing bolts and attachment nuts at the forward and aft end attachment of each elevator tab push rod with new bolts and self-locking castellated nuts with cotter pins.\n\nAmendment 2 is issued in response to a correction of the Requirement document which changes the compliance calendar time from 12 months to 24 months.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nAmendment 1 of this Airworthiness Directive became effective on 28 December 2000.\n\nThe original issue of this Airworthiness Directive became effective on 20 May 1999.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.003.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 6 December 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 20 December 2000.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 2 does not expand the substantive scope of the original directive. The AD has consistently targeted the same unsafe condition (risk of elevator tab push‑rod detachment) and requires the same corrective hardware replacement introduced by Amendment 1. Amendment 2 merely lengthens the calendar compliance period from 12 months to 24 months; it does not add new affected aircraft types, new work items, or additional obligations beyond those already specified in the Requirement (FAA AD 2000‑19‑05)."},"complexity_factors":["Short, targeted instrument (single specific hardware change) rather than broad regulatory regime","Cross-reference to external technical documents: FAA AD 2000‑19‑05 and Boeing service bulletin/service letter (requires reading external material for full technical detail)","Two compliance metrics (24 months or 4,000 cycles, whichever is earlier) — a conditional deadline based on time or utilisation","Limited amendment history (original AD, Amendment 1 added replacement requirement; Amendment 2 changes compliance time) — some historical layering","Applicability limited to particular models and line numbers (single applicability clause)","No large number of defined terms or nested exceptions in the AD text itself"],"plain_english_summary":"**What this directive does (mechanics)\n\n- Requires replacement of the bolts and attachment nuts at the forward and aft ends of each elevator-tab push rod on specified Boeing 737 series aircraft.  The replacement parts must be new bolts and self‑locking castellated nuts secured with cotter pins, and the work must be carried out in accordance with the technical instructions in FAA AD 2000‑19‑05 (which in turn refers to Boeing service documents).\n- Applies to Boeing 737‑100, ‑200, ‑200C, ‑300, ‑400 and ‑500 series aeroplanes, line numbers 1 through 2939 (see \"Applicability\").\n- Compliance time: complete the work within 24 months or 4,000 cycles after 25 January 2001, whichever comes first (see \"Compliance\").\n\nWhy the rule exists (stated rationale)\n\n- The FAA received reports of excessive high‑frequency airframe vibration in flight on some 737‑200 and 737‑300 aircraft that caused severe damage to the elevator assembly and its control mechanism.  The stated purpose of the AD is to prevent detachment of an elevator tab push rod caused by a detached nut at either end attachment (see \"Background\").\n\nWhat changed in this amendment\n\n- Amendment 2 does not change the required corrective action itself. It corrects the compliance calendar time in the Requirement document: the calendar deadline was changed from 12 months to 24 months (see \"Amendment 2\").  Amendment 1 had previously added the specific hardware replacement requirement (bolts and self‑locking castellated nuts with cotter pins).\n\nWho is affected and who pays\n\n- Directly affected: aircraft owners/operators of the listed Boeing 737 models (line 1–2939).  Maintenance organisations and licensed engineers who perform the work are also involved.\n- Who pays: the aircraft operator pays for parts, labour and the aircraft downtime required to perform the replacement and any associated inspections.  If an operator uses a third‑party maintenance provider, that provider charges for labour and may source parts (operators remain responsible for compliance).\n\nPractical implications, incentives and trade‑offs\n\n- Safety vs cost/time: the measure imposes a discrete parts-and‑labour cost and causes aircraft downtime, while reducing the risk of push‑rod detachment and consequent elevator damage.  Operators with high utilisation may hit the 4,000‑cycle trigger sooner than the 24‑month calendar date, which shifts the timing of the expense.\n- Maintenance scheduling: operators can minimise operational disruption by combining the replacement with scheduled heavy maintenance.  The AD’s cross‑reference to FAA AD and Boeing service documents determines the exact procedure and parts specification; operators and maintenance providers must follow those externally referenced instructions.\n- Supply and certification: the requirement for specific hardware (self‑locking castellated nuts and cotter pins) means parts must meet applicable certification or procurement standards.  If parts are scarce, there is a risk of scheduling delays.\n- Market effects: the AD creates short‑term demand for the specified hardware and for maintenance labour. It does not alter ownership, competition or contract freedom except that operators must meet a regulatory requirement; independent approved maintenance organisations can perform the work provided they follow the prescribed technical instructions.\n- Enforcement and records: CASA enforces compliance (the directive is issued under CAR 1998 subregulation 39.1(1)). Operators must retain maintenance records showing compliance.\n\nImplementation risks and burdens\n\n- The technical task is straightforward hardware replacement but requires correct parts and certified maintenance.  Main burdens are parts cost, labour hours and aircraft downtime.  There is minor implementation risk if parts or approved maintenance slots are not available within the compliance window.\n\nRelevant sections cited\n\n- Applicability: lists models and line numbers.\n- Requirement: references FAA AD 2000‑19‑05 as the technical instruction.\n- Compliance: sets the 24‑month or 4,000‑cycle deadline.\n- Background: describes the vibration reports and the safety concern.\n- Amendment notes: Amendment 1 added the replacement requirement; Amendment 2 extended the calendar compliance time from 12 to 24 months.\n"},"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":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of addressing elevator tab push rod safety. The only change is an extension of the compliance deadline from 12 to 24 months, which does not alter the substantive safety requirements or the affected aircraft population."},"complexity_factors":["Very short document (approximately 400 words)","Only 3 defined applicability criteria (aircraft models and line numbers)","Single requirement referencing an external technical document (FAA AD 2000-19-05)","Simple compliance condition (time OR flight cycles, whichever first)","No nested exceptions or conditional logic","Clear linear structure: Applicability → Requirement → Compliance → Background"],"plain_english_summary":"This CASA safety order requires operators of Boeing 737-100 to -500 series to inspect and replace bolts and nuts at the elevator tab push-rod attachment with self-locking castellated nuts secured by cotter pins, to prevent nut loosening and possible push-rod detachment that could lead to loss of control.  \n\nAmendment 2 extends the compliance window to 24 months (or 4,000 flight cycles) from 25 January 2001, giving operators more time to complete the work."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-127amdt-2-elevator-tab-push-rod-attachment","history":"/api/acts/ad-b737-127amdt-2-elevator-tab-push-rod-attachment/history","analysis":"/api/acts/ad-b737-127amdt-2-elevator-tab-push-rod-attachment/analysis","conflicts":"/api/acts/ad-b737-127amdt-2-elevator-tab-push-rod-attachment/conflicts","importantCases":"/api/acts/ad-b737-127amdt-2-elevator-tab-push-rod-attachment/important-cases","documents":"/api/acts/ad-b737-127amdt-2-elevator-tab-push-rod-attachment/documents"}}