{"id":"F2007L01049","name":"AD/PMC/50 - RPM Restriction and Life Limit","slug":"ad-pmc-50-rpm-restriction-and-life-limit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":64989,"registerId":"commonwealth-F2007L01049-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Propellers - Variable Pitch - McCauley","sectionType":"division","heading":"Propellers - Variable Pitch - McCauley","content":"### Propellers - Variable Pitch - McCauley\n\n| AD/PMC/50 | RPM Restriction and Life Limit | 6/2007 TX |\n| --------- | ------------------------------ | --------- |\n\n```html\n

Applicability:

McCauley Propeller Systems models 3A32C406/82NDB-X and D3A32C409/82NDB-X propellers herein referred to as C406 and C409 propellers, respectively.

These propellers are installed on, but not limited to, the aeroplanes in the following Table 1:

Table 1 - Aeroplanes That Propellers Are Installed On, But Not Limited To

Aeroplane models

With engine model

Beech:

A35, B35, C35, D35, E35, F35, G35, H35, J35, K35, M35, N35, P35, S35, V35, V35A, V35B, 35-33, 35-A33, 35-B33, 35-C33, 35-C33A, E33, E33A, E33C, F33, F33A, F33C, 36, A36, A45, and D45.

Teledyne Continental Motors (TCM) IO-520 series and IO-550 series reciprocating engines.

Beech:

A36TC, B36TC, S35, V35A, V35B

TCM TSIO-520 series reciprocating engines.

Navion:

A (L-17B, C), B, D, E, F, G, and H

TCM IO-550 and TSIO-520 series reciprocating engines.

Requirement:

1. Install a placard on the instrument panel as close to the tachometer as possible, that states, in 1/8 inch-high or higher characters, ''Continuous operation between 2,350-2,450 RPM at or above 24'' manifold pressure is prohibited''. The placard shall have red letters, on a white contrasting background with a red border.

2. For propellers with unknown total hours time-in-service (TIS), or 10,000 or more hours total TIS on the effective date of this AD, remove the propeller from service.

\n```\n\n| | 3. For propellers with fewer than 10,000 hours total TIS on the effective date of this AD do the following:a. Perform an inspection of the propeller blades and repair if necessary, using paragraphs 2.B. through 2.F. of Accomplishment Instructions of McCauley Propeller Systems Alert Service Bulletin (ASB) No. ASB248, dated 19 April 2005.b. Life-limit-stamp the letter ''L'' on the propeller hub and blades, using paragraph 3 of Accomplishment Instructions of McCauley Propeller Systems ASB No. ASB248.c. Remove the propeller from service.Note: FAA AD 2007-08-04 Amdt 39-15021 dated 4 April 2007 refers. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | 1. Within 10 hours TIS after the effective date of this AD.2. Within 50 hours TIS after the effective date of this AD.3a. Within 100 hours after the effective date of this AD, thereafter, within every 100 hours TIS or at next annual inspection, whichever occurs first.3b. At the next propeller overhaul or next major propeller disassembly after the effective date of this AD.3c. Upon reaching the life limit of 10,000 hours total TIS. |\n| | This Airworthiness Directive becomes effective on 20 April 2007. |\n| Background: | This AD requires adding an operational revolutions per minute (RPM) restriction on the C406 and C409 propellers, and installing an RPM restriction placard in the cockpit. This AD also adds a 10,000-hour total TIS life limit for these propellers. This AD also removes from service any propeller that has 10,000 hours or more total TIS, or that has unknown total TIS. Also, this AD requires initial and repetitive propeller blade inspections for damage, and repair if necessary. This AD results from testing by the manufacturer that identified stress conditions that affect the fatigue life and damage tolerance of C406 and C409 propellers, when installed on TCM IO-520, TSIO-520, or IO-550 reciprocating engines. The issuing of this AD is intended to prevent blade or hub failure that could result in separation of a propeller blade and loss of control of the aeroplane. |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n16 April 2007","sortOrder":0},{"sectionNumber":"AD/PMC/50","sectionType":"part","heading":"AD/PMC/50","content":"## AD/PMC/50","sortOrder":1},{"sectionNumber":"RPM Restriction and Life Limit","sectionType":"part","heading":"RPM Restriction and Life Limit","content":"## RPM Restriction and Life Limit","sortOrder":2},{"sectionNumber":"6/2007 TX","sectionType":"part","heading":"6/2007 TX","content":"## 6/2007 TX","sortOrder":3}],"analysis":{"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":"The instrument expands regulatory constraints beyond advisory guidance by imposing an operational RPM restriction, a firm 10,000‑hour TIS life limit, and mandatory removals for propellers with unknown hours (Requirement 1–2). It also converts manufacturer inspection guidance into compulsory, repetitive regulatory obligations and requires life‑limit stamping and specific placarding (Requirement 3a–3b). These changes shift costs and operational decisions to aircraft owners/operators (Compliance; Background)."},"complexity_factors":["Multiple action types required: placard installation, inspections, repairs, life‑limit stamping, and removal from service (Requirement 1–3).","Staggered, short compliance deadlines (10, 50, 100 hours TIS and at next overhaul/annual inspection) creating operational scheduling pressure (Compliance).","Applicability limited to specific McCauley models and listed aeroplane/engine combinations, requiring fleet‑level identification and record checks (Applicability; Table 1).","Life‑limit and unknown TIS rule forces immediate removals for some units, producing potential premature replacement costs (Requirement 2; Background).","Repetitive inspection obligation (initial and every 100 hours or at annual) increases recurring maintenance workload and tracking requirements (Requirement 3a; Compliance).","Mandatory physical marking ('L' stamping) ties maintenance action to component identity and resale/overhaul procedures (Requirement 3b).","Prescriptive placard specifications (size, colour, wording, location) impose a precise compliance standard with little administrative discretion (Requirement 1).","Interplay with manufacturer's Alert Service Bulletin for inspection/repair methods requires reliance on external technical instructions (Requirement 3a reference to ASB248)."],"plain_english_summary":"This directive requires installing a cockpit placard with a new RPM operating restriction, sets a 10,000-hour total time‑in‑service (TIS) life limit for McCauley C406 and C409 propellers, removes propellers with unknown or ≥10,000 hours, and mandates initial and recurring blade inspections and repairs. It applies to those propellers installed on specified Beech and Navion aeroplanes. The authority says the measures are to prevent blade or hub fatigue failure; operators bear the costs and short‑deadline compliance burden."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing specific fatigue and damage tolerance issues in McCauley C406/C409 propellers. The requirements (RPM restriction, life limit, and inspection regime) directly target the identified safety risk without expanding into unrelated operational areas."},"complexity_factors":["Single, clearly defined applicability section with specific model numbers and aircraft types","Three distinct, numbered requirements with straightforward compliance deadlines (10, 50, and 100 hours time-in-service)","Cross-reference to only one external document (McCauley Alert Service Bulletin ASB248)","No nested exceptions or conditional logic — requirements apply based solely on known/unknown flight hours","Simple binary compliance paths: either propeller has <10,000 hours TIS (inspect and life-limit) or ≥10,000 hours/unknown (remove from service)","Standard aviation terminology used throughout (TIS, manifold pressure, RPM) but explained in context"],"plain_english_summary":"This AD mandates safety measures for McCauley variable‑pitch propellers (C406/C409) on certain Beechcraft Bonanza/Debonair and Navion aircraft with Continental IO‑520/TSIO‑520/IO‑550 engines. It requires an RPM/manifold‑pressure placard limiting operation, a 10,000 flight‑hour retirement limit (immediate removal if exceeded or unknown), and recurring blade inspections with life‑limit marking.\n\nIt responds to fatigue cracking found in testing — the measures reduce risk of in‑flight propeller or blade failure and loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pmc-50-rpm-restriction-and-life-limit","history":"/api/acts/ad-pmc-50-rpm-restriction-and-life-limit/history","analysis":"/api/acts/ad-pmc-50-rpm-restriction-and-life-limit/analysis","conflicts":"/api/acts/ad-pmc-50-rpm-restriction-and-life-limit/conflicts","importantCases":"/api/acts/ad-pmc-50-rpm-restriction-and-life-limit/important-cases","documents":"/api/acts/ad-pmc-50-rpm-restriction-and-life-limit/documents"}}