{"id":"F2009L00514","name":"AD/F100/93 - On-Ground Wing Leading Edge Heating System","slug":"ad-f100-93-on-ground-wing-leading-edge-heating-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":77174,"registerId":"commonwealth-F2009L00514-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Fokker F100 (F28 Mk 100) Series Aeroplan","sectionType":"division","heading":"Fokker F100 (F28 Mk 100) Series Aeroplanes","content":"### Fokker F100 (F28 Mk 100) Series Aeroplanes\n\n| AD/F100/93 | On-Ground Wing LeadingEdge Heating System | 3/2009 |\n| ---------- | ----------------------------------------- | ------ |\n\n| Applicability: | F28 Mark 0070 and Mark 0100 aircraft, all serial numbers. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | Note 1: Aircraft with serial numbers 11496, 11518, 11562, 11566, 11567, 11568, 11571, 11572, 11575, 11579, 1581, 11582 and 11583 are known to have been delivered with an On-Ground Wing Leading Edge Heating System (OGWLEHS) installed, although this may have since been removed or deactivated. |\n| Requirement: | Install an OGWLEHS in accordance with the Accomplishment Instructions of Fokker (Pro Forma) SBF100-30-018 or Revision 1 or later revision approved by the European Aviation Safety Agency (EASA) and the associated Appendix (identified by Roman numerals I through VIII) as applicable to aircraft serial number. |\n| | Note 2: After modification of an aircraft as required this Directive, safe winter operation of the aircraft remains an operational responsibility. The system will certainly aid in keeping wing leading edges free of ice, frost and snow accumulation, but it does not replace the required procedures to prevent take-off with contaminated wings. Consequently, modification of the aircraft as required by this Directive does not relieve the operator from the responsibility to maintain the clean aircraft concept as required by regulation. This includes appropriate inspections whenever icing conditions exist, as well as the application of de-icing and/or antiicing fluids based on the decision logic in an approved winter operation program. When the aircraft is operated in accordance with the approved Aircraft Flight Manual (AFM), the actual use of wing leading edge heating on the ground may - only under certain specific conditions described in the AFM - relieve the operator of the requirement to perform a tactile inspection of the upper surface of the wing leading edge after treatment with de-icing and/or anti-icing fluid, as applicable. |\n| | Note 3: In an operational environment where ground-icing conditions as defined in the AFM can be completely excluded over the full calendar year and the operator’s complete operating network, the operator may consider submitting an application to obtain an exemption for the actions required by this Directive. |\n| | Note 4: EASA AD 2009-0008 refers. |\n| Compliance: | Within 24 calendar months after the effective date of this Directive. |\n\n| | This Airworthiness Directive becomes effective on 12 March 2009. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Background: | Subsequent to a fatal accident with a Fokker F28 Mark 0100 in 1993, the last few aircraft from the production line were fitted with an OGWLEHS, which activates the wing antiicing system on the ground when engine anti-icing is selected ON. The standard wing anti-icing system, if selected ON, operates only during flight.This modification, which provides an additional safety feature during winter operation, was also made available as an option to in-service aircraft through Pro-Forma Service Bulletin SBF100-30-018 in 1997.During the last few years, at least two serious winter operation events with F28 Mark 0100 aircraft are known to have occurred, associated with leading edge ice contamination, as a result of which the two aircraft were written off.Apparently, the required inspections for wing contamination by ice, frost or snow and the associated de-/anti-icing treatments are not always fully complied with in the actual operational environment. As a consequence, a clean aircraft prior to take-off cannot be taken for granted.If these events would have been directly attributable to design-related causes, this occurrence rate would be beyond the acceptable limit for continuing airworthiness. However, these events are established to have been caused by operational (human) factors instead. Nevertheless, the potential of further accidents due to similar causes can be more effectively reduced by a single design change, rather than by additional operational measures (however necessary) to improve the operational assurance of a clean aircraft take-off.It is highly probable that the two aircraft losses referred to above would not have occurred if the aircraft had been equipped with an OGWLEHS. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n27 January 2009","sortOrder":0},{"sectionNumber":"AD/F100/93","sectionType":"part","heading":"AD/F100/93","content":"## AD/F100/93","sortOrder":1},{"sectionNumber":"On-Ground Wing LeadingEdge Heating Syste","sectionType":"part","heading":"On-Ground Wing LeadingEdge Heating System","content":"## On-Ground Wing Leading \nEdge Heating System","sortOrder":2},{"sectionNumber":"3/2009","sectionType":"part","heading":"3/2009","content":"## 3/2009","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":4,"scope_assessment":{"changed":true,"description":"This directive converts a previously optional modification (the OGWLEHS was available as an optional service bulletin SBF100‑30‑018 from 1997) into a mandatory requirement for the entire applicable fleet (Requirement; Background). The scope therefore expanded from an optional retrofit for in‑service aircraft to a fleet‑wide mandatory installation, while still allowing a narrow exemption for operators that can demonstrate no ground‑icing conditions across their network (Note 3). The directive thus broadens regulatory reach from voluntary compliance to enforced mandatory compliance, with serial‑specific installation details controlled by appended instructions."},"complexity_factors":["Single clear mandatory action (install OGWLEHS) with a single 24‑month compliance window (Compliance & Requirement).","Applicability to all serial numbers of two Marks but with a list of serial numbers already delivered with the system (Note 1) — serial‑specific appendices (I–VIII) determine detailed work scope (Requirement).","External reference to Fokker Pro‑Forma SBF100‑30‑018 and any later revision approved by EASA (Requirement) — introduces dependency on external documents and regulatory approval.","Operator responsibilities and conditional relief (AFM‑dependent tactile inspection exemption) create conditional logic (Note 2).","Exemption pathway for operators with no ground‑icing across network (Note 3) adds case‑by‑case regulatory discretion.","References to another AD (EASA AD 2009‑0008) create cross‑referencing to broader regulatory material (Note 4).","Moderate number of operational notes and background history to interpret scope and intent (Notes & Background)."],"plain_english_summary":"**What this directive does (mechanically)**\n\n- Requires that an On‑Ground Wing Leading Edge Heating System (OGWLEHS) be installed on Fokker F28 Mark 0070 and Mark 0100 aircraft (all serial numbers) within 24 calendar months of the directive's effective date (see “Requirement” and “Compliance”).\n- The installation must follow the Accomplishment Instructions of Fokker (Pro‑Forma) SBF100‑30‑018 or Revision 1 (or a later revision approved by the European Aviation Safety Agency (EASA)) and the associated Appendix (I–VIII) that applies to each aircraft serial number (see “Requirement”).\n\n**Who is affected**\n\n- Aircraft owners and operators of Fokker F28 Mark 0070 and Mark 0100 series aeroplanes (all serial numbers). Some listed serial numbers are already known to have been delivered with the system installed (Note 1), but the directive applies fleet‑wide regardless of current equipment status.\n- The regulator (Civil Aviation Safety Authority) enforces the directive; EASA must approve later revisions of the referenced service bulletin.\n\n**Why it matters (stated purpose and how it works)**\n\n- The AD responds to a history of fatal and serious accidents associated with wing leading‑edge contamination in winter. The OGWLEHS activates the wing anti‑icing system on the ground (when engine anti‑icing is selected ON), whereas the standard wing anti‑icing operates only in flight. The regulator’s stated view is that the retrofit is a single design change likely to reduce the risk arising from operational non‑compliance with de‑icing/inspection procedures (see “Background”).\n\n**Operational effect and limits**\n\n- The system helps keep wing leading edges free of ice, frost and snow, but it does not replace the operator’s responsibility for the clean‑aircraft concept (i.e. inspections, tactile checks and de‑/anti‑icing as required) (Note 2).\n- In limited cases and only under conditions described in the Aircraft Flight Manual (AFM), use of the OGWLEHS on the ground may relieve the operator from performing a tactile inspection of the upper surface of the wing leading edge after fluid treatment. This relief is conditional and AFM‑specific (Note 2).\n- Operators who can demonstrate that ground‑icing conditions never occur across their entire operating network for the whole year may apply for an exemption from the AD (Note 3).\n\n**Who pays and who decides**\n\n- Aircraft owners/operators bear the direct cost of purchasing and installing the OGWLEHS, plus any associated downtime, maintenance and training costs. The regulator (CASA) enforces compliance with the AD; EASA approves revisions to the referenced service bulletin.\n\n**Costs, incentives and trade‑offs**\n\n- Costs: retrofit kit procurement, engineering and labour for installation, possible grounding time, ongoing maintenance, and crew training for operation of the new system.\n- Benefits: reduced likelihood of take‑offs with contaminated wing leading edges, potentially lowering accident risk attributed to operational lapses.\n- Incentives: because the retrofit is mandated, costs are concentrated on aircraft owners/operators while safety benefits are diffuse (affecting crew and passengers). The AD includes a narrowly framed exemption pathway for operators with demonstrable absence of ground‑icing conditions.\n- Risk of substitution/complacency: the directive explicitly retains operator responsibilities to inspect and de‑/anti‑ice as required; however, installation may change operational behaviour (e.g. reliance on the heated system rather than stricter ground procedures), so the AD preserves regulatory requirements to counter that risk (Note 2).\n\n**Implementation and compliance risks**\n\n- Availability of approved kits and qualified maintenance facilities may constrain timely compliance for some operators.\n- The installation scope varies by serial number (Appendices I–VIII apply per serial), creating fleet‑specific work scopes.\n- If operators delay modification, the intended safety gain is postponed; non‑compliance creates regulatory exposure.\n\n**Cross‑references and approvals**\n\n- The directive references and depends on Fokker Pro‑Forma SBF100‑30‑018 (and later EASA‑approved revisions) and refers to EASA AD 2009‑0008 (Note 4).\n\n**Net practical effect**\n\n- Operators must retrofit the specified heating system within 24 months or seek an exemption. The directive imposes direct installation and compliance costs on operators while preserving existing operational responsibilities for preventing take‑off with contaminated wings (Requirement; Notes 1–3; Compliance; Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive maintains its original, narrow scope: mandating a specific safety modification for one aircraft type following known accidents. The operational notes and exemption provision are integral to the safety regulation rather than scope creep."},"complexity_factors":["Single, clearly defined modification requirement with specific technical reference (Fokker Service Bulletin SBF100-30-018)","Straightforward applicability clause covering two aircraft marks and all serial numbers","Simple compliance deadline (24 months from effective date)","Limited conditional logic — only one exemption pathway (Note 3) and one operational relief condition (Note 2)","No nested definitions or extensive cross-referencing to other legislation — only reference is to EASA AD 2009-0008 and the Aircraft Flight Manual","Background narrative is lengthy but explanatory rather than legally operative"],"plain_english_summary":"This CASA Airworthiness Directive mandates that all Fokker F100 (F28 Mk 0070/0100) operators install an on‑ground wing leading edge heating system to prevent ice/frost/snow build‑up before takeoff. It makes the optional late‑production safety modification mandatory within 24 months, while stressing it does not replace de‑icing inspections and procedures. Operators never exposed to ground‑icing year‑round may seek an exemption."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-93-on-ground-wing-leading-edge-heating-system","history":"/api/acts/ad-f100-93-on-ground-wing-leading-edge-heating-system/history","analysis":"/api/acts/ad-f100-93-on-ground-wing-leading-edge-heating-system/analysis","conflicts":"/api/acts/ad-f100-93-on-ground-wing-leading-edge-heating-system/conflicts","importantCases":"/api/acts/ad-f100-93-on-ground-wing-leading-edge-heating-system/important-cases","documents":"/api/acts/ad-f100-93-on-ground-wing-leading-edge-heating-system/documents"}}