{"id":"F2006B10853","name":"AD/INST/49 Amdt 1 - Rockwell Collins Air Data Computers","slug":"ad-inst-49-amdt-1-rockwell-collins-air-data-computers","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56349,"registerId":"commonwealth-F2006B10853-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/INST/49 Amdt 1 - Rockwell Collins Air Data Computers","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/INST/49 and issues the following AD under subregulation 39.1 (1) of CASR 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\n![](image.001.png)  \n\nInstruments and Automatic Pilots\n\nAD/INST/49\n\nAmdt 1\n\n  \nRockwell Collins Air Data Computers 6/2003\n\nApplicability: All Rockwell Collins air data computers (ADC) listed below; except ADC-85A computers part number 822-0370-113 or \\-123 with Rockwell Collins Service Bulletin (SB) 58 incorporated and installed on Saab 340 series aeroplanes.\n\n| Unit                            | Part Number  | Serial Number                              |\n| ------------------------------- | ------------ | ------------------------------------------ |\n| ADC-85                          | 622-8051-002 | All units                                  |\n| (Incorporating Rockwell Collins | 622-8051-003 |                                            |\n| Service Bulletin (SB) 58)       |              |                                            |\n| ADC-85A                         | 822-0370-113 | All units                                  |\n| (Incorporating SB 58)           | 822-0370-123 |                                            |\n|                                 | 822-0370-139 |                                            |\n|                                 | 822-0370-404 |                                            |\n|                                 | 822-0370-408 |                                            |\n| ADC-850D                        | 822-0389-133 | All up to and including                    |\n| (Incorporating SB 58)           |              | 3DGW (except for 1P6D, 22RC-22RF and 23WK- |\n|                                 |              | 3DGP)                                      |\n| ADC-850F                        | 822-1036-406 | All Units                                  |\n|                                 | 822-1036-418 |                                            |\n\nNote 1: These ADCs may be installed on, but not limited to, the following aeroplanes:\n\nUnit Aeroplane Model\n\nADC-85/ADC-85A\n\nADC-850D ADC-850F\n\n  \nAstra AIA\n\nChinese Y7 and Y8 Czech LET-610 DC-8\n\nFalcon 20F Piaggio P-180\n\nRaytheon B200, B300, C90A and 1900D Lear 60\n\nFalcon 20, 50 and 50EX\n\nRequirement: 1. Unless already accomplished, carry out the following actions in accordance with\n\nRockwell Collins SB 62, (ADC-85/85A/850C/850D/850E/850F-34-62), Revision No. 2, dated 7 March 2000, or SB 62, dated 25 October 1999, as applicable, together with the applicable Collins Computer Component Maintenance Manual and Collins Avionics Standard Shop Practices Instruction Manual:\n\n    Remove any affected ADC from the aeroplane.\n\n    b. As applicable, replace or reprogram parts or circuit card assemblies on central processing unit (CPU) circuit cards.\n\n    c. Test the ADC.\n\n2. Affected ADCs may not be installed on any aeroplane, except Saab 340 series aeroplanes, unless the modification and test required by Requirement 1.b. and c. have been accomplished.\n\nNote 2: Rockwell Collins Operator Bulletin 99-7, dated August 1999, contains information about an operational placard to install until accomplishment of the actions of this Directive. While not necessary to address the unsafe condition in this Directive, CASA highly recommends that the placard be installed.\n\nNote 3: FAA AD 2002-14-19 Amdt 39-12819 and FAA Special Airworthiness Information Bulletin CE-03-21 refer.\n\nCompliance: For Requirement 1 \\- Remains unchanged as ‘Within 12 months after the effective date of the original issue of this Directive’.\n\nFor Requirement 2 \\- As of the effective date of this Amendment. This Amendment becomes effective on 12 June 2003.\n\nBackground: The original issue of this Directive required replacement of any affected ADC with one that has a reprogrammed and tested CPU circuit card and circuit card assembly. The Directive was issued following a flight test that showed that these ADCs could display an unwarranted ADC flag in response to the aeroplane's \"Normal/Alternate Air\" static source selection capability. This could cause the flight crew to react to this incorrect flight information and possibly result in an unsafe operating condition.\n\nThis Amendment is issued following advice from the United States Federal Aviation Administration that Saab 340 series aeroplanes were not affected.\n\nThe original issue of this Directive became effective on 5 September 2002.\n\n![Signature of Jim Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 1 May 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 21 May 2003.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Yes. The amendment narrows the scope compared with the original AD by excluding certain ADC-85A units (part numbers 822-0370-113 or -123) that have Rockwell Collins Service Bulletin 58 incorporated and are installed on Saab 340 series aeroplanes. The Background states this change follows FAA advice that Saab 340 series aeroplanes were not affected. Mechanically, the AD still requires removal/reprogramming/replacement and testing of affected ADCs for other operators, but the explicit Saab 340 exception reduces the population of affected aircraft and therefore reduces the regulatory burden on those operators."},"complexity_factors":["Applicability table listing multiple unit models and several part numbers (some with serial-number limits)","One narrow exception carved out for Saab 340 series with specific ADC-85A part numbers incorporating SB 58","Single mandatory action set referencing an external manufacturer Service Bulletin (Rockwell Collins SB 62 Rev 2) and multiple Collins manuals","Two different compliance timings: Requirement 1 deadline (12 months from original AD) and Requirement 2 effective immediately on amendment date","Cross-references to FAA ADs and an operator bulletin (informational but relevant)","Technical nature of required work (remove, replace/reprogram CPU cards, test) which imposes operational and logistical complexity (parts, shop capabilities, downtime)"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Revokes the earlier Airworthiness Directive AD/INST/49 and issues an amended directive applying to specified Rockwell Collins Air Data Computers (ADCs) listed by unit, part number and (where limited) serial number. (See \"Applicability\" table in the AD.)\n- Requires removal of any affected ADC from the aircraft and, as applicable, replacement or reprogramming of parts or CPU circuit card assemblies, followed by testing, in accordance with Rockwell Collins Service Bulletin (SB) 62 (Revision 2, 7 March 2000, or the 25 October 1999 version) and the Collins maintenance/shop manuals. (Requirement 1.)\n- Prohibits installation of affected ADCs on any aeroplane (other than Saab 340 series aeroplanes) unless the modification and test in Requirement 1.b and 1.c have been completed. (Requirement 2.)\n- Recommends (but does not mandate) fitting an operational placard described in Rockwell Collins Operator Bulletin 99-7 until the modification/testing is done. (Note 2.)\n- Cross-references FAA documents for related information. (Note 3.)\n\n**Who this affects**\n\n- Aircraft operators, maintenance organisations and avionics shops that own or service the listed Rockwell Collins ADC models (ADC-85, ADC-85A, ADC-850D, ADC-850F and variants identified by the part numbers in the Applicability table). The AD lists multiple part numbers and, for some units, serial-number limits.\n- Rockwell Collins as supplier of the SB and reprogramming/parts.\n- Operators of Saab 340 series aeroplanes are partially excepted where specific ADC part numbers (ADC-85A part numbers 822-0370-113 or -123) have SB 58 incorporated and installed (those units are excluded from the AD’s applicability).\n\n**Why the action is required (stated purpose)**\n\n- The AD states it addresses an unsafe condition found in flight testing: affected ADCs could display an unwarranted ADC flag when the aeroplane’s static source selection (Normal/Alternate Air) was used. The incorrect indication could prompt inappropriate crew reactions. The AD therefore requires modification (reprogram or replace CPU cards) and testing to correct that condition. (Background; Requirement 1.)\n\n**Costs, incentives and trade-offs (practical effects)**\n\n- Who pays: aircraft operators and maintenance providers pay for removal, reprogramming/replacement, testing and downtime. Operators bear direct costs of parts, labour and aircraft out-of-service time. Rockwell Collins and authorised shops receive service work (revenue from repairs and reprogramming).\n- Who decides/controls implementation: CASA issued the directive (via its delegate). Compliance must follow the specified Rockwell Collins SB and Collins manuals, so technical discretion is limited by those documents and by the AD’s requirements.\n- Behaviour changes required: operators must either have affected ADCs modified and tested per SB 62, or they must not install affected ADCs on aircraft (other than Saab 340s with the specified SB 58 condition). Operators may temporarily fit placards as recommended until modification is complete.\n- Opportunity costs and operational impact: downtime for modification/testing can reduce aircraft availability; if replacement ADC stock is limited, operators may face scheduling delays or seek alternative suppliers or units. Maintenance shops may re-prioritise work to accommodate these AD-driven tasks.\n- Concentrated benefits vs diffuse costs: the safety benefit accrues to individual aircraft/crew/passengers; the immediate commercial benefit (work revenue) concentrates to maintenance providers and Rockwell Collins. Costs are spread across affected operators.\n- Implementation risk & compliance burden: the AD requires strict adherence to Rockwell Collins SB 62 and associated manuals; operators must ensure approved procedures are used and testing is documented. Any ambiguity in SB instructions or parts availability is a practical implementation risk.\n\n**Key cross-references and timing**\n\n- The AD requires completion of the modification/testing in Requirement 1 within 12 months of the original AD’s effective date (the original AD became effective 5 September 2002). Requirement 2 (the installation prohibition except for the Saab 340 exception) is effective as of the amendment’s effective date (12 June 2003). (See the Compliance section.)\n\n**Source claims vs observable trade-offs**\n\n- The AD’s stated purpose is safety correction of an erroneous ADC indication. That purpose is implemented by mandating hardware/software intervention (reprogram/replace CPU cards) and testing per the manufacturer’s service bulletin. The trade-off is clear: reduced risk of incorrect indications versus the costs and downtime required to implement the fix, and the need for operators to follow manufacturer procedures exactly. The AD narrows its application to exclude certain Saab 340 installations following FAA advice (see Background), which reduces the burden on those operators while keeping the mandated action for other operators.\n\n(References: Applicability table; Requirement 1 and 2; Notes 1–3; Compliance; Background.)"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original directive imposed modification requirements on all aircraft with affected ADCs. This amendment narrows the scope by creating a specific exemption for Saab 340 series aircraft, effectively reducing the directive's reach rather than expanding it. The change reflects updated technical understanding rather than mission creep."},"complexity_factors":["Multiple nested applicability conditions: specific part numbers, serial number ranges, and service bulletin incorporation status must all be checked","Cross-references to external technical documents: Rockwell Collins Service Bulletin 62 (two different versions), maintenance manuals, and shop practices manuals","Exception to exception structure: Saab 340 aircraft are excluded from the general rule, but only if they have specific ADC part numbers with SB 58 incorporated","Dual effective dates: original compliance deadline remains unchanged while new prohibition takes effect on amendment date","Technical aviation terminology throughout (ADC, CPU circuit cards, static source selection, placarding)","Reference to foreign regulatory documents (FAA AD 2002-14-19 and SAIB CE-03-21) for additional context"],"plain_english_summary":"This AD mandates removal and repair (replacement or reprogramming of CPU cards and testing) of certain Rockwell Collins Air Data Computers that can falsely display failure flags when switching static air sources—an error that could mislead flight crews. It affects operators of aircraft equipped with the specified ADC models and serials. The amendment exempts Saab 340 series aircraft from the modification."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-inst-49-amdt-1-rockwell-collins-air-data-computers","history":"/api/acts/ad-inst-49-amdt-1-rockwell-collins-air-data-computers/history","analysis":"/api/acts/ad-inst-49-amdt-1-rockwell-collins-air-data-computers/analysis","conflicts":"/api/acts/ad-inst-49-amdt-1-rockwell-collins-air-data-computers/conflicts","importantCases":"/api/acts/ad-inst-49-amdt-1-rockwell-collins-air-data-computers/important-cases","documents":"/api/acts/ad-inst-49-amdt-1-rockwell-collins-air-data-computers/documents"}}