{"id":"F2006B04994","name":"AD/CESSNA 170/65 - Control Yoke Pivot Bolt","slug":"ad-cessna-170-65-control-yoke-pivot-bolt","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44894,"registerId":"commonwealth-F2006B04994-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 170/65 - Control Yoke Pivot Bolt","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)  \nCessna 170, 172, F172, FR172 and 175 Series Aeroplanes\n\nAD/CESSNA 170/65 Control Yoke Pivot Bolt 11/99 DM\n\nApplicability: The following serial numbers of Model 172R aircraft; that are equipped with a Cessna Modification Kit MK172-27-01 that was shipped sometime between September 21, 1998, and April 18,1999:\n\nSerial Numbers\n\n17280003 through 17280016, 17280018 through 17280060, 17280062, 17280063,\n\n17280065 through 17280071, 17280073 through 17280083, 17280085 through\n\n17280088, 17280090, 17280091, and 17280093 through 17280096.\n\nNote 1: Modification Kit MK172-27-01 was issued to reduce friction in the elevator control system.\n\nRequirement: Inspect the control yoke pivot bolt to assure positive clearance between the threaded end of the pivot bolt and the aileron direct cable in accordance with the Accomplishment Instructions section of Cessna Service Bulletin SB99-27-01, dated July 12 1999.\n\nIf positive clearance is not found, before further flight, accomplish the following in accordance with SB99-27-01:\n\n    Replace the control yoke pivot bolt; and,\n\n    b. Inspect the adjacent aileron control cables for damage and replace any damaged aileron control cable.\n\nAs of the effective date of this Directive, no person may incorporate on any aircraft, a Cessna Modification Kit MK172-27-01 that was shipped sometime between September 21, 1998, and April 18, 1999, unless a replacement control yoke pivot bolt is obtained from the manufacturer, and incorporated with the modification kit.\n\nNote 2: FAA AD 99-18-14 Amdt 39-11280 refers.\n\nCompliance: Within 25 hours time in service after 29 September 1999, unless already accomplished.\n\nThis Airworthiness Directive becomes effective on 29 September 1999.\n\nBackground: The FAA received information from the manufacturer of incorrect length control yoke pivot bolts supplied in certain Cessna Modification Kits MK172-27-01. The actions specified by this Directive are intended to prevent failure of an aileron control cable because of an incorrect length control yoke pivot bolt rubbing on one of these cables, which could result in loss of aileron control with loss of directional control of the aircraft.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This Directive is a targeted corrective safety measure responding to a specific manufacturing/shipping error (incorrect bolt length in a particular batch of modification kits). It does not broaden the regulatory scope beyond the original safety objective of ensuring safe control-cable operation; rather, it narrows focus to a defined set of kits/aircraft and prescribes corrective and preventative steps. It therefore does not represent a significant scope expansion beyond the instrument’s original safety purpose."},"complexity_factors":["Limited, well-defined applicability: multiple serial-number ranges and individual serial numbers (several clusters listed under Applicability)","Single principal technical requirement (inspect for positive clearance) with a single conditional corrective path (replace bolt and inspect/replace cables if clearance absent)","Cross-reference to one manufacturer service bulletin (Cessna SB99-27-01) for detailed accomplishment instructions","Forward-looking prohibition on incorporation of affected kits unless corrected bolt is installed (adds a procedural restriction beyond inspection)","A fixed and short compliance window (within 25 hours time in service after the effective date)","Reference to a related FAA AD (FAA AD 99-18-14) creating an external cross-reference"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Applies to certain Cessna Model 172R aeroplanes that received Cessna Modification Kit MK172-27-01 shipped between 21 September 1998 and 18 April 1999 (specific serial-number ranges are listed under \"Applicability\").\n- Requires an inspection of the control yoke pivot bolt to confirm there is positive clearance (a visible gap, not rubbing) between the threaded end of the pivot bolt and the aileron direct cable (see the \"Requirement\" section and Cessna Service Bulletin SB99-27-01 for how to inspect).\n- If the inspection shows there is not positive clearance, the aircraft must not fly again until the control yoke pivot bolt is replaced and adjacent aileron control cables are inspected and any damaged cables replaced (the AD makes replacement mandatory before further flight).\n- Prohibits installing any MK172-27-01 kit shipped in the date window above on any aircraft unless the replacement control yoke pivot bolt from the manufacturer is obtained and fitted with the kit (a forward-looking ban on incorporating affected kits without the corrective bolt).\n- Sets the compliance time as within 25 hours time in service after 29 September 1999 (the effective date of the Directive).\n\n**Who it affects**\n\n- Aircraft owners/operators of the specified Model 172R planes with the listed serial numbers and anyone who would fit an MK172-27-01 kit shipped in the specified date range.\n- Maintenance organisations, engineers and certificated mechanics who perform the inspection and replacement and who decide whether aircraft are legal to fly.\n- The manufacturer to the extent replacement bolts must be supplied for kits shipped in the stated date range.\n\n**Why it matters (stated purpose and practical effect)**\n\n- The FAA and manufacturer reported that some MK172-27-01 kits contained control yoke pivot bolts of incorrect length. Those bolts can rub on an aileron control cable and, over time, may lead to cable failure. The Directive requires inspection and corrective action to prevent possible loss of aileron control (see \"Background\").\n\n**Costs, incentives and trade-offs (practical effects and implementation risks)**\n\n- Who pays: Owners/operators bear the direct cost of inspection, any replacement bolt and labour, and replacement of any damaged aileron cables (Requirement). If replacement bolts are only available from the manufacturer, owners may face parts costs and potential delays.\n- Who decides: The Civil Aviation Safety Authority enforces the Directive; maintenance personnel decide on compliance actions at the aircraft level (Requirement / Compliance). Operators must ground aircraft that fail the inspection until corrective work is completed.\n- Behaviour changed: Operators must inspect affected aircraft within 25 flight hours and must not fit affected MK172-27-01 kits shipped in the given date window unless the corrective bolt is installed (Compliance; Requirement).\n- Compliance burden: Short-term inspections and possible parts/labour to replace pivot bolts and any damaged control cables; administrative effort to identify whether a particular aircraft or kit is within the affected serial-number/date ranges (Applicability; Requirement).\n- Supply / timing risk: If replacement bolts are to be sourced from the manufacturer, limited supply or delivery delay could keep aircraft out of service until parts arrive.\n- Opportunity cost: Aircraft downtime reduces available flight hours; maintenance resources diverted from other tasks.\n- Effects on private choice and market participants: Independent maintenance providers can perform the mandated inspections and replacements subject to access to the correct replacement bolts and the Service Bulletin instructions. The rule restricts which kits may be fitted unless corrected, which narrows contractors' immediate options when modifying aircraft (Requirement).\n\n**Implementation and enforcement notes**\n\n- The Directive cross-references Cessna Service Bulletin SB99-27-01 (Accomplishment Instructions) for the inspection and corrective procedures and refers to FAA AD 99-18-14 (Note 2). That means compliance is achieved by following the manufacturer's specified steps.\n- The Directive requires replacement and cable inspection \"before further flight\" if clearance is not found; this is a strict operational prohibition until the corrective work is done.\n\n**Net practical description**\n\n- In short: if your specific 172R has a MK172-27-01 kit shipped in the stated window, you must check the pivot bolt for clearance within 25 flight hours and replace the bolt (and any damaged cable) before flying if clearance is absent; you may not fit one of the affected kits unless you have and fit the correct replacement pivot bolt from the manufacturer (Applicability; Requirement; Compliance)."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific manufacturing defect in a specific modification kit for specific aircraft serial numbers. There is no evidence of scope creep; the directive remains tightly focused on the control yoke pivot bolt safety issue as originally identified."},"complexity_factors":["Single, specific technical issue (incorrect bolt length)","Limited applicability: only 78 specific aircraft serial numbers","Clear, step-by-step compliance requirements","Single cross-reference to FAA directive (Note 2)","No nested exceptions or conditional logic beyond the basic inspection/replace decision tree","Short document (under 400 words)","Only one defined term of note ('time in service') used in standard aviation sense"],"plain_english_summary":"This Airworthiness Directive orders inspections and remedial action for certain Cessna 172R aircraft fitted with MK172-27-01 modification kits (shipped Sep 1998–Apr 1999) because excessively long control yoke pivot bolts can rub and eventually sever aileron control cables. Owners must inspect for bolt–cable contact, replace bolts and inspect cables if contact is found, and only fit the kit with the manufacturer’s replacement bolt.\n\nIt affects listed 172R owners/operators, maintenance engineers, and anyone installing the kit — preventing loss of roll control and possible crashes."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-170-65-control-yoke-pivot-bolt","history":"/api/acts/ad-cessna-170-65-control-yoke-pivot-bolt/history","analysis":"/api/acts/ad-cessna-170-65-control-yoke-pivot-bolt/analysis","conflicts":"/api/acts/ad-cessna-170-65-control-yoke-pivot-bolt/conflicts","importantCases":"/api/acts/ad-cessna-170-65-control-yoke-pivot-bolt/important-cases","documents":"/api/acts/ad-cessna-170-65-control-yoke-pivot-bolt/documents"}}