{"id":"F2013L01751","name":"AD/B737/346 Amdt 1 — Cabin Altitude Warning Takeoff Briefing","slug":"ad-b737-346-amdt-1-cabin-altitude-warning-takeoff-briefing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":127805,"registerId":"commonwealth-F2013L01751-current","compilationNumber":null,"startDate":"2026-04-03","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/B737/346 Amdt 1 | Cabin Altitude Warning Takeoff Briefing | 20/2013 |\n| ------------------ | --------------------------------------- | ------- |\n\n| Applicability: | Boeing Model 737-100, -200, -200C, -300, -400, -500, -600, -700, -700C, -800,-900 and -900ER series aeroplanes. |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Revise the Limitations Section of the applicable Boeing 737 Aircraft Flight Manual (AFM) to include the following statement:“CABIN ALTITUDE WARNING TAKEOFF BRIEFINGWith the CABIN ALTITUDE and TAKEOFF CONFIG lights not installed, or installed but not activated:As part of the Takeoff Briefing before engine start for the first flight of the day or following any change of either flightcrew member, the pilot-in-command will ensure the Cabin Altitude Warning indications and procedures are briefed in accordance with the procedures contained in the Normal Procedures section of this manual.”2. Revise the Normal Procedures Section of the applicable Boeing 737 AFM to include the following statement:“CABIN ALTITUDE WARNING TAKEOFF BRIEFINGThe following briefing is important to further reduce the risk of flightcrew incapacitation due to hypoxia. Because of the dual purpose of the intermittent cabin altitude/takeoff configuration warning horn, this briefing serves to remind flightcrews that the sounding of the cabin altitude warning horn in flight requires immediate action, beginning with the immediate donning of oxygen masks. Upon completion of the applicable WARNING HORN—CABIN ALTITUDE OR CONFIGURATION non-normal checklist memory items, other alerts and indications on the flight deck (e.g., air/ground sensing system failures, equipment cooling OFF, etc.) may then be addressed. |\n\n| | Memory item cabin altitude warning indications and procedures must be briefed on airplanes in which the CABIN ALTITUDE and TAKEOFF CONFIG lights are not installed, or are installed but not activated. This will be included as an additional item on the Takeoff briefing before engine start for the first flight of the day, or following any change of either flightcrew member.The briefing must include the following items.- Whenever the intermittent warning horn sounds in flight:1. Immediately, don oxygen masks and set regulators to 100%.2. Establish crew communications.3. Do the CABIN ALTITUDE WARNING OR RAPID DEPRESSURIZATION checklist.- Both pilots must verify on the overhead Cabin Altitude Panel that the cabin altitude is stabilized at or below 10,000 feet before removing oxygen masks.”The above actions may be accomplished by inserting a copy of this Directive into the applicable AFM.The Requirement 1 and 2 AFM revisions may be removed from the applicable AFM when the information they contain is inserted in the AFM by a normal or temporary revision.Note: FAA AD 2008-23-07 Amdt 39-15728 refers. |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | For Requirements 1 and 2 - Within 120 days after the effective date of this Directive.Revising the AFM as per the approved FAA AMOC Letter 130S-09-134a dated28 April 2009 is an alternate means of complying with requirement 2 of this AD. |\n| | The effective date of this Amendment is 30 September 2013. |\n| Background: | The United States Federal Aviation Administration (FAA) had advised of the receipt of continuing reports that flightcrew have failed to recognize and react properly to the cabin altitude warning horn. This Directive is issued to prevent failure of the flightcrew to recognize and react to a valid cabin altitude warning horn, which could result in incapacitation of the flightcrew due to hypoxia (lack of oxygen in body) and consequent loss of aeroplane control. |\n\n| | Amendment 1 allows the revising of the AFM as per the approved FAA AMOC Letter 130S-09-134a dated 28 April 2009 as an alternate means of complying with requirement 2 of this AD.The original issue of this AD became effective on 25 November 2008. |\n| --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)\n\nPeter Nikolic \nDelegate of the Civil Aviation Safety Authority\n\n10 September 2013","sortOrder":0},{"sectionNumber":"AD/B737/346 Amdt 1","sectionType":"part","heading":"AD/B737/346 Amdt 1","content":"## AD/B737/346 Amdt 1","sortOrder":1},{"sectionNumber":"Cabin Altitude Warning Takeoff Briefing","sectionType":"part","heading":"Cabin Altitude Warning Takeoff Briefing","content":"## Cabin Altitude Warning Takeoff Briefing","sortOrder":2},{"sectionNumber":"20/2013","sectionType":"part","heading":"20/2013","content":"## 20/2013","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 does not widen the population of affected aeroplanes or alter the substantive safety requirement; it adds an alternate means of compliance by allowing the AFM revision to be accomplished via FAA AMOC Letter 130S-09-134a (28 April 2009). The original AD’s applicability and core briefing/checklist obligations remain unchanged."},"complexity_factors":["Prescriptive AFM text insertion: operators must revise both Limitations and Normal Procedures to include specified briefing text and memory items.","Wide applicability: covers a long list of Boeing 737 model variants, so many operators must act.","Operational implementation: requires changes to crew briefings and possibly training to ensure consistent use of the new memory items.","Compliance timeframe: 120-day deadline creates scheduling and administrative burden for airlines to amend AFMs and disseminate briefings.","Alternative compliance path: acceptance of an FAA AMOC (Letter 130S-09-134a dated 28 April 2009) adds options but requires regulatory coordination.","Enforcement and record-keeping: CASA oversight of AFM revisions and briefing adoption implies monitoring and potential audits."],"plain_english_summary":"This airworthiness directive requires operators of Boeing 737 series (-100 through -900ER) to update the Aircraft Flight Manual (AFM) so flight crews include a specific Cabin Altitude Warning takeoff briefing and memory items, and to ensure crews immediately don oxygen masks and follow the cabin altitude checklist if the warning horn sounds. Compliance is mandated within 120 days; an FAA-approved alternate means of compliance (AMOC) is permitted for one AFM revision item. The change responds to reports that crews missed cabin altitude warnings."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of the 2008 Airworthiness Directive. Amendment 1 simply adds an alternative compliance method (the FAA AMOC) without expanding the substantive requirements or applicability. The directive remains tightly focused on the specific safety issue of cabin altitude warning recognition for affected Boeing 737 aircraft."},"complexity_factors":["Single, specific technical requirement with clear applicability criteria (specific Boeing 737 models)","Two distinct but related compliance requirements (Limitations Section and Normal Procedures Section updates)","Conditional applicability based on aircraft configuration (lights not installed vs. installed but not activated)","One alternate means of compliance (AMOC) referenced","Straightforward compliance timeline (120 days from effective date)","No nested definitions, extensive cross-references, or complex conditional logic","Background and rationale clearly stated in plain language"],"plain_english_summary":"This CASA Airworthiness Directive requires operators of certain Boeing 737-100 through -900ER aircraft (where CABIN ALTITUDE and TAKEOFF CONFIG lights are absent or deactivated) to update flight manuals and add a mandatory pre-flight crew briefing on cabin altitude warnings. \n\nIt matters because the same horn can indicate hypoxic cabin depressurisation or takeoff config issues; pilots must don oxygen immediately, establish communications, run the checklist, and confirm cabin altitude ≤10,000 ft before removing masks."},"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-b737-346-amdt-1-cabin-altitude-warning-takeoff-briefing","history":"/api/acts/ad-b737-346-amdt-1-cabin-altitude-warning-takeoff-briefing/history","analysis":"/api/acts/ad-b737-346-amdt-1-cabin-altitude-warning-takeoff-briefing/analysis","conflicts":"/api/acts/ad-b737-346-amdt-1-cabin-altitude-warning-takeoff-briefing/conflicts","importantCases":"/api/acts/ad-b737-346-amdt-1-cabin-altitude-warning-takeoff-briefing/important-cases","documents":"/api/acts/ad-b737-346-amdt-1-cabin-altitude-warning-takeoff-briefing/documents"}}