{"id":"F2009L00050","name":"AD/CESSNA 170/85 - Alternate Static Air Source Selector Valve Placard","slug":"ad-cessna-170-85-alternate-static-air-source-selector-valve-placard","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76455,"registerId":"commonwealth-F2009L00050-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Cessna 170, 172, F172, FR172 and 175 Ser","sectionType":"division","heading":"Cessna 170, 172, F172, FR172 and 175 Series Aeroplanes","content":"### Cessna 170, 172, F172, FR172 and 175 Series Aeroplanes\n\n| AD/CESSNA 170/85 | Alternate Static Air SourceSelector Valve Placard | 3/2009 TX |\n| ---------------- | ------------------------------------------------- | --------- |\n\n```html\n

Applicability:

Aeroplane models listed in Table 1 of this AD, that:

1. Were initially delivered from the manufacturer between 1 January 1993, and
31 March 2008, unless the modification/rework required in AD/CESSNA 170/83 has been done and the aeroplane remains in compliance with that AD; or

2. Have a alternate static air selector valve part number (P/N) 2013142-18 installed as a replacement part anytime after 1 January 1993, unless the modification/rework required in AD/CESSNA 170/83 has been done and the aeroplane remains in compliance with that AD.

Table 1 - Aeroplanes that Could Have the Affected Part Installed

172

172M

F172K

R172E (USAF T-41B)
(USAF T-41C and D)

172A

172N

F172L

R172F (USAF T-41)

172B

172P

F172M

R172G (USAF T-41C or D)

172C

172Q

F172N

R172H (USAF T-41D)

172D

172R

F172P

R172J

172E

172S

FR172E

R172K

172F (USAF T-41A)

172RG

FR172F

175

172G

F172D

FR172G

175A

172H (USAF T-41A)

F172E

FR172H

175B

172I

F172F

FR172J

175C

172K

F172G

FR172K

172L

F172H

P172D

\n```\n\n| | Note 1: The affected part was shipped from Cessna Parts Distribution (CPD) between 1 January 1993 and 31 March 2008.Note 2: P/N 2013142-18 replaced P/Ns 2013142-9, -13, and -17. |\n| ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement: | 1. For all affected aeroplanes that are not equipped for flight under instrument flight rules (IFR) - Inspect the alternate static air source selector valve to assure that the part number identification placard is not obstructing the port.2. For all affected aeroplanes that are equipped for flight under IFR:a. Inspect the alternate static air source selector valve to assure that the part number identification placard is not obstructing the port; orb. Fabricate a placard that incorporates the following words (using at least1/8-inch letters) and install this placard on the instrument panel within the pilot’s clear view:“IFR OPERATION IS PROHIBITED” and “USE OF THE ALTERNATE STATIC AIR SOURCE IS PROHIBITED.”3. For all affected aeroplanes that are equipped for flight under IFR - If placards were installed in accordance with Requirement 2b of this AD, inspect the alternate static air source selector valve to assure that the part number identification placard is not obstructing the port.After doing the inspection, remove the placards installed in accordance with Requirement 2b of this AD before further flight.4. For all affected aeroplanes - If the alternate static air source selector valve port is found obstructed by the part number identification placard during the inspection detailed in Requirements 1, 2a, and 3 of this AD, remove the placard from the valve body, discard the placard, and assure that the port is open and unobstructed.5. For all affected aeroplanes - When a replacement valve is needed, only install a P/N 2013142-18 alternate static air source selector valve that has been inspected and the port is found free from obstruction.The procedures required to accomplish this AD are detailed in Cessna Single Engine Service Bulletin SB08-34-02, Revision 1, dated 6 October 2008; Cessna Caravan Service Bulletin CAB08-04, Revision 1, dated 6 October 2008; Cessna Single Engine Service Bulletin SEB08-5, dated 13 October 2008; or Cessna Multi-engine Service Bulletin MEB08-6, dated 13 October 2008, as applicable.Note 3: FAA AD 2008-26-10 Amdt 39-15776 dated 15 December 2008 refers. |\n\n| Compliance: | For Requirement 1 - Within the next 100 hours time-in-service (TIS) after the effective date of this AD or within the next 4 months after the effective date of this AD, whichever occurs first.For Requirement 2a - Within the next 10 days after the effective date of this AD.For Requirement 2b - Before further flight after the effective date of this AD.For Requirement 3 - Within the next 100 hours TIS after the effective date of this AD or within the next 4 months after the effective date of this AD whichever occurs first.For Requirement 4 - Before further flight after the inspection required in Requirements 1, 2a, and 3 of this AD.For Requirement 5 - As of 10 days after the effective date of this AD. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | This Airworthiness Directive becomes effective on 16 January 2009. |\n| Background: | Reports of improper installation of the part number (P/N) identification placard on P/N 2013142-18 alternate static air source selector valves prompted the issue of AD/CESSNA 170/83 in response to the United States Federal Aviation Administration (FAA) issuing AD 2008-10-02.Since then the FAA has received reports of 15 aeroplanes not previously affected by AD 2008-10-02 with a P/N 2013142-18 installed and the alternate static air source selector valve port was found obstructed by the P/N identification placard.The Civil Aviation Safety Authority (CASA) has no way of determining which aeroplanes have the remaining problem alternate static air source selector valve assemblies installed without having all of the affected aeroplanes and spares stock inspected.The FAA has been informed that all P/N 2013142-18 alternate static air source selector valves shipped from Cessna Parts Distribution between 1 January 1993, and 31 March 2008, may have port obstruction caused by the P/N identification placard.This condition, if not corrected, could result in the altimeter, airspeed, and vertical speed indicators displaying erroneous indications. This could cause the pilot to react to incorrect flight information and possibly result in loss of control. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n8 January 2009","sortOrder":0},{"sectionNumber":"AD/CESSNA 170/85","sectionType":"part","heading":"AD/CESSNA 170/85","content":"## AD/CESSNA 170/85","sortOrder":1},{"sectionNumber":"Alternate Static Air SourceSelector Valv","sectionType":"part","heading":"Alternate Static Air SourceSelector Valve Placard","content":"## Alternate Static Air Source \nSelector Valve Placard","sortOrder":2},{"sectionNumber":"3/2009 TX","sectionType":"part","heading":"3/2009 TX","content":"## 3/2009 TX","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope addressing a specific manufacturing defect in a single part number (P/N 2013142-18) across defined Cessna aircraft models. The directive does not expand beyond its original safety purpose of ensuring unobstructed alternate static air source valves."},"complexity_factors":["Multiple conditional applicability criteria with exceptions (manufacture date range OR replacement part installation, both subject to exemption from prior AD compliance)","Differentiated requirements based on aircraft equipment type (VFR vs IFR-capable)","Nested compliance timelines varying by requirement (10 days, before further flight, 100 hours time-in-service or 4 months)","Cross-reference to prior AD (AD/CESSNA 170/83) for exemption determination","Reference to four separate Cessna service bulletins for procedural guidance","Table of 44 specific aircraft model variants requiring parsing","Circular logic in Requirement 3 (inspecting after installing placards under Requirement 2b, then removing those placards)"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection and corrective action on the alternate static air source selector valve of certain Cessna 170/172/F172/FR172/175 aircraft (built 1 Jan 1993–31 Mar 2008 or fitted with replacement valve P/N 2013142‑18) because a part‑number placard can block a static port. Owners/operators must inspect and remove any obstructing placard before further flight; IFR aircraft face shorter compliance times or temporary instrument‑panel placards. The defect can cause false altimeter/airspeed/VSI readings and create a serious flight‑safety hazard."},"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":6,"scope_assessment":{"changed":true,"description":"This AD expands the set of affected aeroplanes compared with the earlier AD/CESSNA 170/83 by capturing any listed models that may have P/N 2013142-18 shipped from Cessna Parts Distribution between 1 January 1993 and 31 March 2008 or installed as a replacement after 1 January 1993, unless already modified/reworked per AD/CESSNA 170/83 (see Applicability and Background). It also adds immediate, IFR-specific placarding and inspection steps and an explicit prohibition on installing replacement P/N 2013142-18 valves unless inspected (Requirements 2, 3 and 5; Compliance)."},"complexity_factors":["Broad model list (many Cessna 170/172/175 variants listed in Table 1) increases identification effort for owners/operators.","Date- and source-based applicability (valves shipped from CPD 1 Jan 1993–31 Mar 2008, or installed after 1 Jan 1993) requires record checks of parts provenance.","Multiple conditional branches: different actions for non-IFR vs IFR-equipped aeroplanes and for replacement valves (see Requirements 1–5).","Staggered compliance deadlines with short and medium timeframes (10 days; before further flight; next 100 hours TIS or 4 months) create scheduling complexity (see Compliance table).","Operational constraint for IFR-equipped aeroplanes: temporary placard prohibiting IFR and alternate-static use, then removal after inspection (Requirement 2b and 3).","Mandated procedures reference multiple manufacturer service bulletins (SB08-34-02 Rev 1, CAB08-04 Rev 1, SEB08-5, MEB08-6) which operators must obtain and follow.","Enforcement and safety consequence linkage: placard obstruction can cause erroneous altimeter/airspeed/vertical speed indications—requires conservative removal before flight if found (Background; Requirements 4–5).","Compliance cost and operational impact fall on owners/operators (inspections, possible valve replacement, temporary placarding), with regulator (CASA) oversight.","Interdependency with a prior AD (AD/CESSNA 170/83) and FAA ADs requires cross-referencing maintenance/airworthiness records to determine exemption status."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of listed Cessna 170/172/175 series aircraft with alternate static selector valve P/N 2013142‑18 (shipped from Cessna Parts Distribution 1 Jan 1993–31 Mar 2008 or installed after 1 Jan 1993) to inspect the valve for a part-number placard blocking the static-port, remove any obstruction, and follow temporary placard rules for IFR‑equipped aeroplanes. It also prohibits installing replacement P/N 2013142‑18 valves unless inspected and found unobstructed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-170-85-alternate-static-air-source-selector-valve-placard","history":"/api/acts/ad-cessna-170-85-alternate-static-air-source-selector-valve-placard/history","analysis":"/api/acts/ad-cessna-170-85-alternate-static-air-source-selector-valve-placard/analysis","conflicts":"/api/acts/ad-cessna-170-85-alternate-static-air-source-selector-valve-placard/conflicts","importantCases":"/api/acts/ad-cessna-170-85-alternate-static-air-source-selector-valve-placard/important-cases","documents":"/api/acts/ad-cessna-170-85-alternate-static-air-source-selector-valve-placard/documents"}}