{"id":"F2008L01245","name":"AD/A320/212 - Braking and Steering Control Unit","slug":"ad-a320-212-braking-and-steering-control-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":73483,"registerId":"commonwealth-F2008L01245-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus Industrie A319, A320 and A321 Ser","sectionType":"division","heading":"Airbus Industrie A319, A320 and A321 Series Aeroplanes","content":"### Airbus Industrie A319, A320 and A321 Series Aeroplanes\n\n| AD/A320/212 | Braking and Steering Control Unit | 5/2008 |\n| ----------- | --------------------------------- | ------ |\n\n```html\n

Applicability:

Aeroplane Models listed in Table 1 that are equipped with one conventional pre-Enhanced Manufacture and Maintainability (pre-EMM) Braking and Steering Control Unit (BSCU) part number (P/N):

a. C20216332292C (standard 7) installed by Airbus modification 24449 during production or by Airbus Service Bulletin (SB) A320-32-1124 whilst in service, or

b. C202163372D32 (standard 9) installed by modification 31106 during production or by SB A320-32-1227 or SB A320-32-1232 whilst service, or

c. C202163382D32 (standard 9.1) installed by modification 32500 during production or by SB A320-32-1254 whilst in service.

Table 1

A319-111
A319-112
A319-113
A319-114
A319-115

A319-131
A319-132
A319-133
A320-111
A320-211

A320-212
A320-214
A320-215
A320-216
A320-231

A320-232
A320-233
A321-111
A321-112
A321-131

A321-211
A321-212
A321-213
A321-231
A321-232

Requirement:

1. Modify or replace the BSCU in accordance with the instructions given in SB A320-32-1336, original issue, dated 19 September 2007, or later revision approved by the European Aviation Safety Agency (EASA) to install BSCU standard 10.

2. Remove Dunlop 46x16-20 tyres part numbers (P/N) 11659 T and 11661 T.

3. Dunlop 46x16-20 tyres P/N 11659 T and 11661 T may not be installed on any aeroplane equipped with a BSCU standard 10.

Note: EASA AD 2008-0048 refers.

Compliance:

For Requirement 1 - Before 30 September 2009.

For Requirement 2 - Before further flight after accomplishing Requirement 1.

\n```\n\n| | For Requirement 3 - As of the effective date of this Directive. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | This Airworthiness Directive becomes effective on 8 May 2008. |\n| Background: | The EASA has advised that during 2005 a lateral runway excursion occurred on an A320 aircraft. Such excursions are classified as hazardous with a large reduction in safety margins. Investigation has shown that the aircraft landed with the nose wheels rotated nearly 20 degrees from centre. During subsequent tests on the removed BSCU, a BSCU hardware failure was found, affecting the monitoring function, including the system reconfiguration management, and leading to a runaway of nose wheel steering.AD/A320/27 (Direction Générale de l’Aviation Civile of France Airworthiness Directive F-1992-117-025(B) Revision 1), mandated the BSCU upgrade in order to improve the steering logic, but this modification has shown not to be sufficient to address the identified failure mechanism.A software modification is now implemented in BSCU standard 10 which improves the system reconfiguration management when this failure mechanism is detected. BSCU standard 10 also includes other improvements as detailed in the associated Service Bulletin.This Directive mandates the modification or replacement of the BSCU standard 7, 9 or 9.1 by the BSCU standard 10. SB A320-32-1336 notes at paragraph 1.A.(2).(a) that BSCU standard 10 is not compatible with Dunlop 46x16-20 tyres P/N 11659 T and 11661 T therefore this Directive also requires that these tyres be removed when BSCU standard 10 is installed and prohibits the fitment of these tyres to aircraft with BCSU standard 10. |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n6 March 2008","sortOrder":0},{"sectionNumber":"AD/A320/212","sectionType":"part","heading":"AD/A320/212","content":"## AD/A320/212","sortOrder":1},{"sectionNumber":"Braking and Steering Control Unit","sectionType":"part","heading":"Braking and Steering Control Unit","content":"## Braking and Steering Control Unit","sortOrder":2},{"sectionNumber":"5/2008","sectionType":"part","heading":"5/2008","content":"## 5/2008","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Scope broadened from the prior BSCU upgrade mandate: the Background notes AD/A320/27 previously mandated a BSCU upgrade but that measure was insufficient. This Directive now specifically requires installation of BSCU standard 10 and also mandates removal and prohibition of specific Dunlop tyres when standard 10 is fitted (Background; Requirement 1–3). As drafted, operators (aircraft owners/operators) bear the cost and compliance burden of the hardware/software replacement and tyre changes, and must follow the referenced Service Bulletin (Requirement 1; Compliance)."},"complexity_factors":["Technical specificity of applicability: identifies particular BSCU part numbers and standards (Applicability: paragraphs a–c specify P/Ns C20216332292C, C202163372D32, C202163382D32).","Multiple mandated actions: modify/replace BSCU to standard 10; remove specified Dunlop tyres; prohibit re‑installation of those tyres (Requirement 1–3).","Cross‑document dependencies: requires compliance with SB A320‑32‑1336 (Requirement 1) and references EASA AD 2008‑0048 (Note), creating reliance on external approvals and revisions.","Staggered compliance deadlines: different timeframes for Requirement 1 (before 30 Sep 2009), Requirement 2 (before further flight after Requirement 1) and Requirement 3 (effective date) (Compliance).","Broad fleet coverage: applies to a wide list of A319/A320/A321 variants (Table 1), increasing operational reach and parts impact.","Parts compatibility constraint: BSCU standard 10 is explicitly incompatible with Dunlop 46x16‑20 tyres P/N 11659 T and 11661 T, forcing tyre changes where the BSCU is installed (Background; Requirement 3)."],"plain_english_summary":"Mandates that specified Airbus A319/A320/A321 aeroplanes fitted with certain pre‑EMM Braking and Steering Control Units (BSCUs) be upgraded or replaced with BSCU standard 10, and that two Dunlop tyre part numbers be removed and banned where standard 10 is fitted. Operators must follow Service Bulletin A320‑32‑1336 and meet set deadlines. The change addresses a BSCU failure that caused nose‑wheel steering runaway and directly affects maintenance tasks, parts compatibility and operator costs."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused scope addressing a specific safety-critical hardware/software failure mode. It does not represent scope creep from original intent."},"complexity_factors":["Multiple specific part numbers and standards referenced (7, 9, 9.1, 10)","Cross-reference to European Aviation Safety Agency (EASA) AD 2008-0048 and French DGAC directive","Conditional applicability based on production modifications vs in-service bulletins","Interdependent requirements (Requirement 2 depends on Requirement 1)","Technical aviation terminology (BSCU, EMM, Service Bulletin, part numbers)","Table of 25 specific aircraft models with variant numbers"],"plain_english_summary":"This CASA Airworthiness Directive requires operators of specified Airbus A319/A320/A321 aircraft with pre-EMM BSCU units (standards 7, 9, 9.1) to upgrade the Braking and Steering Control Unit to standard 10 to prevent nose-wheel steering “runaway” like the 2005 A320 runway excursion. It also bans certain Dunlop tyres incompatible with the upgraded BSCU.\n\nThe BSCU upgrade must be completed by 30 September 2009; the tyre removal ban is effective immediately and tyres must be removed before the next flight after upgrade."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-212-braking-and-steering-control-unit","history":"/api/acts/ad-a320-212-braking-and-steering-control-unit/history","analysis":"/api/acts/ad-a320-212-braking-and-steering-control-unit/analysis","conflicts":"/api/acts/ad-a320-212-braking-and-steering-control-unit/conflicts","importantCases":"/api/acts/ad-a320-212-braking-and-steering-control-unit/important-cases","documents":"/api/acts/ad-a320-212-braking-and-steering-control-unit/documents"}}