{"id":"F2006L02862","name":"AD/AL 250/85 Amdt 1 - Fuel Nozzle Screen","slug":"ad-al-250-85-amdt-1-fuel-nozzle-screen","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":60101,"registerId":"commonwealth-F2006L02862-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Allison Turbine Engines - 250 Series","sectionType":"division","heading":"Allison Turbine Engines - 250 Series","content":"### Allison Turbine Engines - 250 Series\n\n| AD/AL 250/85 Amdt 1 | Fuel Nozzle Screen | 10/2006 |\n| ------------------- | ------------------ | ------- |\n\n```html\n

Applicability:

Rolls Royce Corporation (Allison) 250-B and 250-C series turboshaft and turboprop engines as listed in Table 1 of this Directive.

TABLE 1. - 250-B AND 250-C SERIES TURBOSHAFT
AND TURBOPROP ENGINES AFFECTED

-B15A

-B15E

-B15G

-B17

-B17B

-B17C

-B17D

-B17E

-B17F

-B17F/1

-B17F/2

- C10

-C10B

-C10C

-C18

-C18A

-C18B

-C18C

-C20

-C20B

-C20C

-C20F

-C20J

-C20R

-C20R/1

-C20R/2

-C20R/4

-C20S

-C20W

-C28

-C28B

-C28C

-C30

-C30G

-C30G/2

-C30M

-C30P

-C30R

-C30R/1

-C30R/3

-C30R/3M

-C30S

-C30U

-C40B

-C47B

-C47M

Requirement:

1. Perform a onetime inspection of the screens in fuel nozzles for contamination.

2. If you find contamination on the screen, inspect and clean the entire aircraft fuel system.

3. Remove from service fuel nozzles listed in Table 3 and Table 4 of this AD and replace with a serviceable fuel nozzle.

For the purposes of this AD, a serviceable fuel nozzle is defined as a nozzle that has a part number (P/N) not specified in, or addressed by, this AD.

\n```\n\n```html\n

Information pertaining to this subject can be found in Rolls-Royce Corporation Alert Commercial Engine Bulletins (CEBs), all at Revision 1, and all dated 30 August 2004, listed in the following Table 2:

Table 2. - Related Alert Commercial Engine Bulletins

CEB-A-313

CEB-A-73-5029

CEB-A-73-2075

CEB-A-73-6041

CEB-A-1394

TP CEB-A-183

CEB-A-73-3118

TP CEB-A-1336

CEB-A-73-4056

TP CEB-A-73-2032

Note: FAA AD 2006-16-04 Amdt 39-14704 dated 27 July 2006 refers. This AD supersedes FAA AD 2004-24-09.

Compliance:

1. For fuel nozzles with a P/N listed in Table 3 of this AD, within 50 operating hours after the effective date of this AD, unless previously accomplished.

Table 3. - Fuel Nozzles To Be Inspected Within 50 Operating Hours

Manufacturer

P/N

Corresponding RRC vendor P/N

RRC

6874959

5232815

6894610

5233465

6898531

5233585

Goodrich Delavan (Parts Manufacturer Approval (PMA))

47069

N/A

47101

N/A

49445

N/A

For fuel nozzles with a P/N listed in Table 4 of this AD, within 150 operating hours after 17 March 2005 (the effective date of the original issue of this AD), unless previously accomplished.

\n```\n\n```html\n

Table 4. - Fuel Nozzles To Be Inspected Within 150 Operating Hours

Manufacturer

P/N

Corresponding
RRC vendor P/N

RRC

6852020

5232480

\"\"

6890917

5233333

\"\"

6899001

5233600

2. Before further flight after the effective date of this AD.

3. At the next fuel nozzle overhaul after the effective date of this Directive.

This Amendment becomes effective on 28 September 2006.

Background:

This Directive required a onetime inspection of the fuel nozzle screen for contamination, and if contamination is found, inspection and cleaning of the entire aircraft fuel system before further flight. This Directive also required replacing the fuel nozzle with a new design fuel nozzle.

This Directive resulted from 10 reports of engine power loss with accompanying collapse of the fuel nozzle screen, due to fuel contamination. This Directive was issued to minimize the risk of sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle.

This amendment is prompted by the discovery that several part numbers (P/Ns) of fuel nozzles were inadvertently left out of AD/AL 250/85. That AD, as worded, allows certain P/N fuel nozzles back into service. Those fuel nozzles must not be allowed back into service. The intention of this AD is to minimize the risk of sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle.

The original issue of this AD became effective on 17 March 2005.

\n```\n\n![](image.003.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n14 August 2006","sortOrder":0},{"sectionNumber":"AD/AL 250/85 Amdt 1","sectionType":"part","heading":"AD/AL 250/85 Amdt 1","content":"## AD/AL 250/85 Amdt 1","sortOrder":1},{"sectionNumber":"Fuel Nozzle Screen","sectionType":"part","heading":"Fuel Nozzle Screen","content":"## Fuel Nozzle Screen","sortOrder":2},{"sectionNumber":"10/2006","sectionType":"part","heading":"10/2006","content":"## 10/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment expanded the set of nozzle part numbers covered by the original AD. The AD text states the amendment was prompted by discovery that several P/Ns were inadvertently omitted from AD/AL 250/85, which could have allowed those nozzles back into service. The amendment closes that gap by listing the additional P/Ns (Tables 3 & 4) and thereby increases the population of nozzles and engines subject to mandatory inspection and removal, restoring the original safety intent (Background; Requirement ¶3; Tables 3 & 4)."},"complexity_factors":["Multiple lists/tables to check: Table 1 (engine models), Table 2 (related CEBs), Table 3 and Table 4 (specific fuel nozzle P/Ns).","Different compliance timings and triggers: 50 operating hours for Table 3 P/Ns; 150 operating hours (from original AD date) for Table 4 P/Ns; additional instructions 'before further flight' and 'at next nozzle overhaul' (nested timing conditions).","Defined term that affects scope: 'serviceable fuel nozzle' defined by exclusion (any P/N not specified or addressed by the AD).","Cross‑references to external technical documents (multiple Rolls‑Royce CEBs) and to FAA ADs for technical guidance.","Relatively short directive text but with conditional obligations (inspect → if contaminated then clean entire fuel system → remove/replace listed P/Ns) increasing interpretive steps.","Numerous specific part numbers (several RRC and Goodrich/PMA P/Ns) requiring inventory checks by operators and MROs."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Applies to Rolls‑Royce Corporation (Allison) 250‑B and 250‑C series turboshaft and turboprop engines listed in Table 1 of the Directive (see Applicability).\n- Requires a one‑time inspection of the fine wire/mesh screen inside each fuel nozzle to check for fuel contamination (Requirement ¶1; Tables 3 & 4).\n- If contamination is found on a nozzle screen, the AD requires inspection and cleaning of the entire aircraft fuel system before further flight (Requirement ¶2).\n- Requires removal from service and replacement of specific fuel nozzle part numbers (P/Ns) listed in Table 3 and Table 4 with a “serviceable” fuel nozzle (Requirement ¶3). The AD defines a serviceable nozzle as one having a P/N not listed in or addressed by the AD.\n- Sets different compliance windows depending on the nozzle P/N: for nozzles in Table 3, inspect within 50 operating hours after the AD’s effective date; for nozzles in Table 4, inspect within 150 operating hours after 17 March 2005 (the original AD effective date). The AD also includes instructions about before‑further‑flight and next‑overhaul actions where stated (Compliance section; Tables 3 & 4).\n- Cross‑references Rolls‑Royce Alert Commercial Engine Bulletins (CEBs) and a related FAA AD for technical information (Table 2 and Note).\n\n**Who is affected**\n\n- Aircraft owners/operators and maintenance organisations that operate aircraft powered by the listed Allison 250‑B and 250‑C series engines.\n- Parts suppliers, MROs (maintenance, repair and overhaul shops) and inventory managers who stock or install the specified fuel nozzle P/Ns.\n\n**Why it matters (official rationale and technical risk)**\n\n- Background in the AD: there were reports (10 in total) of engine power loss associated with collapse of the fuel nozzle screen caused by fuel contamination. The AD's stated purpose is to reduce the risk of sudden engine power loss or uncommanded engine shutdown by ensuring contaminated screens are found and contaminated/nozzle P/Ns that permit failure are removed from service (Background).\n\n**Practical effects, costs, incentives and trade‑offs**\n\n- Direct compliance costs fall on aircraft operators and maintenance providers: they must perform the inspections, potentially clean the aircraft fuel system, and replace prohibited nozzles with serviceable ones. These impose labour time, parts procurement and aircraft down‑time costs (Requirement; Compliance).\n- The action is primarily a one‑time requirement (inspection) with replacement mandated for specific P/Ns; therefore ongoing recurrent costs are limited unless contamination is discovered or additional overhauls are required earlier than planned.\n- Supply‑side risk: if many operators must replace the same nozzle P/Ns, there may be short‑term demand for replacement nozzles, which can raise prices or cause delays in returning aircraft to service. The AD does not provide parts supply or provisioning measures (Table 3 & 4; Requirement).\n- Effect on competition and independent MROs: independent shops must follow the AD when servicing affected engines; the AD’s P/N listings and the definition of “serviceable” may shift demand toward P/Ns not listed in the AD (including OEM or approved PMA parts). The AD does not mandate a single supplier but does cross‑reference RRC vendor P/Ns for identification (Tables 3 & 4).\n- Implementation risk is moderate but manageable: the required tasks are conventional (inspection, cleaning, part replacement). The main operational risk is aircraft downtime while inspections/replacements are completed, and the time required to source replacement nozzles if stock is limited.\n- Recordkeeping and enforcement: operators and maintenance organisations must ensure compliance is documented to satisfy regulators and to demonstrate airworthiness (Compliance; Requirement).\n\n**How the AD changes behaviour**\n\n- Operators will schedule and perform a one‑time fuel nozzle screen inspection within the AD’s time windows, clean the system if contamination is found, and replace certain nozzle P/Ns with allowed P/Ns. Maintenance supply choices will be constrained by the AD’s P/N lists.\n\n**Reference to source claims**\n\n- Mechanical requirements: (Requirement ¶1–3; Tables 3 & 4).\n- Applicability and affected engine models: (Applicability; Table 1).\n- Technical background and reason for issue: (Background — reports of engine power loss due to screen collapse).\n- Cross‑references to Rolls‑Royce CEBs and FAA AD: (Table 2 and Note).\n\n"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: addressing fuel nozzle screen contamination in Allison 250-series engines. The amendment does not expand scope but corrects an error in the original 2005 directive by adding fuel nozzle part numbers that were inadvertently omitted. The safety objective (preventing engine power loss due to fuel contamination) and the affected engine population remain unchanged from the original intent."},"complexity_factors":["Multiple compliance deadlines based on different tables (50 hours vs 150 hours vs 'before further flight' vs 'next overhaul')","Extensive tabular data: 47 engine models in Table 1, 6 fuel nozzle part numbers in Table 3, 3 part numbers in Table 4","Cross-references to 10 separate Rolls-Royce Commercial Engine Bulletins (CEBs)","Conditional logic: different actions required depending on whether contamination is found","Definition of 'serviceable fuel nozzle' requires negative inference (part numbers NOT listed in the AD)","References to superseded FAA ADs (2004-24-09 and 2006-16-04) creating international regulatory context","Amendment structure requires understanding of what changed from original AD/AL 250/85 (2005)"],"plain_english_summary":"This AD legally requires inspections and replacements of fuel nozzles on Rolls‑Royce/Allison 250‑B and 250‑C series engines after contamination was found that can collapse nozzle screens and cause sudden engine power loss or failure. It affects aircraft owners/operators and maintenance organisations using those engines.\n\nYou must inspect nozzle screens (one‑time), clean the fuel system if contamination is found, and replace specified nozzles with serviceable parts within the stated operating‑hour deadlines (50 hrs for high‑risk, 150 hrs for others) and before further flight. The amendment corrects a prior oversight."},"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-al-250-85-amdt-1-fuel-nozzle-screen","history":"/api/acts/ad-al-250-85-amdt-1-fuel-nozzle-screen/history","analysis":"/api/acts/ad-al-250-85-amdt-1-fuel-nozzle-screen/analysis","conflicts":"/api/acts/ad-al-250-85-amdt-1-fuel-nozzle-screen/conflicts","importantCases":"/api/acts/ad-al-250-85-amdt-1-fuel-nozzle-screen/important-cases","documents":"/api/acts/ad-al-250-85-amdt-1-fuel-nozzle-screen/documents"}}