{"id":"F2009L03054","name":"AD/B737/278 Amdt 1 - Elevator Input Torque Tube Assembly","slug":"ad-b737-278-amdt-1-elevator-input-torque-tube-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":80650,"registerId":"commonwealth-F2009L03054-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/278 Amdt 1 | Elevator Input Torque Tube Assembly | 10/2009 DM |\n| ------------------ | ----------------------------------- | ---------- |\n\n```html\n

Applicability:

Boeing Model 737 aeroplanes as listed in Table 1 below.

Table 1: Affected B737 Aeroplanes.

Boeing aeroplane models -

As identified in Boeing
Alert Service Bulletin-

737-100, -200, -200C, -300, -400, and -500 series aeroplanes

737-27A1274, dated 17 February 2005, or later FAA approved revision.

737-600, -700, -700C, -800 and -900 series aeroplanes

737-27A1271, dated 16 December 2004, or later FAA approved revision.

Requirement:

Modify the elevator input torque tube assembly by doing all the actions in accordance with the Accomplishment Instructions of the applicable service bulletin in Table 1 of this AD.

Note: FAA AD 2005-26-03 Amdt 39-14424 refers.

Compliance:

Within 60 months after 16 March 2006.

The compliance time remains unchanged by this issue of the Directive.

This Amendment becomes effective on 7 August 2009.

Background:

This AD resulted from a report of a restriction in the pilot's elevator input control system. Although the cause of the incident was indeterminate, a design review performed on the elevator input torque tube assembly in the course of the investigation discovered possible failure modes that could lead to a jam of the elevator control system. The actions detailed in this AD are intended to prevent loss of elevator control and consequent reduced controllability of the aeroplane.

\n```\n\n| | Amendment 1 is issued to allow use of a later FAA approved Boeing Alert Service Bulletin, as specified in Table 1, as an alternate method of compliance. |\n| --- | -------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png) \nDavid Villiers \nDelegate of the Civil Aviation Safety Authority\n\n4 August 2009","sortOrder":0},{"sectionNumber":"AD/B737/278 Amdt 1","sectionType":"part","heading":"AD/B737/278 Amdt 1","content":"## AD/B737/278 Amdt 1","sortOrder":1},{"sectionNumber":"Elevator Input Torque Tube Assembly","sectionType":"part","heading":"Elevator Input Torque Tube Assembly","content":"## Elevator Input Torque Tube Assembly","sortOrder":2},{"sectionNumber":"10/2009 DM","sectionType":"part","heading":"10/2009 DM","content":"## 10/2009 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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment does not alter the required modification or the compliance deadline; it only expands acceptable means of compliance by allowing a later FAA‑approved Boeing Alert Service Bulletin as an alternate method (as reflected in Table 1). This broadens the documentary/technical route to compliance without changing who must act or the deadline."},"complexity_factors":["Technical mechanical modification required to a flight‑control torque tube (requires qualified maintenance/parts and shop time).","Cross‑reference dependence on Boeing Alert Service Bulletins and FAA AD 2005‑26‑03 (external documents determine exact work).","Applicability spans multiple 737 series models with different SB numbers (model‑specific procedures).","Fixed compliance window (retroactive deadline), creating scheduling/operational costs for operators.","Amendment permits use of a later FAA‑approved SB as an alternate method of compliance (adds limited regulatory flexibility).","Enforcement delegated to CASA; compliance recordkeeping and inspection burden on operators."],"plain_english_summary":"Requires modification of the elevator input torque tube assembly on specified Boeing 737 models, carried out in accordance with the Boeing Alert Service Bulletin identified in the Directive. Aircraft owners/operators pay for and arrange the work; the Civil Aviation Safety Authority (via its delegate) enforces completion. The stated purpose is to address possible failure modes that could jam elevator controls and reduce controllability. Compliance must be completed within 60 months after 16 March 2006; this amendment allows use of a later FAA‑approved Boeing Alert Service Bulletin as an alternate method of compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope. It is a minor administrative update that expands the permitted methods of compliance to include later revisions of the referenced service bulletins, without altering the substantive safety requirement or the affected aircraft population."},"complexity_factors":["Single, specific technical requirement (modify one assembly)","Clear applicability table listing affected aircraft models","Straightforward compliance deadline (60 months from fixed date)","Minimal cross-referencing (only to Boeing service bulletins and FAA AD 2005-26-03)","No nested exceptions or conditional logic","Short document (approximately 300 words of substantive content)","Only 2 defined technical references (the Boeing service bulletins)"],"plain_english_summary":"This CASA Airworthiness Directive mandates modification of the elevator input torque tube assembly on Boeing 737-100 through -900 series aircraft to eliminate a potential elevator jam that could cause loss of control. It affects all owners/operators of those 737 models. Amendment 1 permits compliance using a later FAA‑approved Boeing service bulletin, giving operators an approved alternative method."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-278-amdt-1-elevator-input-torque-tube-assembly","history":"/api/acts/ad-b737-278-amdt-1-elevator-input-torque-tube-assembly/history","analysis":"/api/acts/ad-b737-278-amdt-1-elevator-input-torque-tube-assembly/analysis","conflicts":"/api/acts/ad-b737-278-amdt-1-elevator-input-torque-tube-assembly/conflicts","importantCases":"/api/acts/ad-b737-278-amdt-1-elevator-input-torque-tube-assembly/important-cases","documents":"/api/acts/ad-b737-278-amdt-1-elevator-input-torque-tube-assembly/documents"}}