{"id":"F2008L00098","name":"AD/EC 120/17 - Seat Electrical Bonding Modification","slug":"ad-ec-120-17-seat-electrical-bonding-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":72229,"registerId":"commonwealth-F2008L00098-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter EC 120 Series Helicopters","sectionType":"division","heading":"Eurocopter EC 120 Series Helicopters","content":"### Eurocopter EC 120 Series Helicopters\n\n| AD/EC 120/17 | Seat Electrical Bonding Modification | 2/2008 DM |\n| ------------ | ------------------------------------ | --------- |\n\n| Applicability: | EC 120B Helicopters up to serial number 1523 inclusive, fitted with Sicma Type 159 energy absorbing seats.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Remove the electric bonding strap of Sicma Type 159 energy absorbing seats as instructed in Eurocopter Alert Service Bulletin No. 25A023.Note: EASA AD 2007-0311.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| Compliance:    | Within the next 110 Flight Hours but no later than 3 months, after the effective date of this Airworthiness Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n|                | This Airworthiness Directive becomes effective on 4 January 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| Background:    | The Sicma type 159 energy-absorbing seat is electrically bonded with a braided bonding strap. This bonding strap is secured to the base of the seat with a screw and nut assembly, the head which is in line with one of the two seat energy absorbers. In the event of a “crash” landing with very rapid deceleration and with a corpulent person occupying the seat, this screw may interfere with the “energy absorbing” function. This affects conformity with the EC120 certification requirements.An analysis made recently by Eurocopter shows that this “electrical bonding” braided strap is not necessary. Consequently, this Airworthiness Directive mandates the removal of the electrical bonding strap. |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n3 January 2008","sortOrder":0},{"sectionNumber":"AD/EC 120/17","sectionType":"part","heading":"AD/EC 120/17","content":"## AD/EC 120/17","sortOrder":1},{"sectionNumber":"Seat Electrical Bonding Modification","sectionType":"part","heading":"Seat Electrical Bonding Modification","content":"## Seat Electrical Bonding Modification","sortOrder":2},{"sectionNumber":"2/2008 DM","sectionType":"part","heading":"2/2008 DM","content":"## 2/2008 DM","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":2,"scope_assessment":{"changed":false,"description":"Scope is limited to EC120B helicopters up to serial 1523 with Sicma Type 159 seats and mandates removal of the electrical bonding strap to address a seat energy‑absorbing non‑conformity. The directive implements that corrective scope directly; no change from the instrument’s stated intent is indicated in the text."},"complexity_factors":["Narrow applicability: only EC120B helicopters up to serial number 1523 fitted with Sicma Type 159 seats","Single prescribed action: removal of the braided electrical bonding strap","Clear compliance window: within 110 flight hours or 3 months","Reliance on external technical instructions: work to be done per Eurocopter Alert Service Bulletin No. 25A023","Safety rationale tied to a specific failure mode (interference with energy absorber during high deceleration)","Operational scheduling burden for operators to implement the modification within the prescribed timeframe"],"plain_english_summary":"Requires removal of the braided electrical bonding strap fitted to Sicma Type 159 energy‑absorbing seats on Eurocopter EC120B helicopters up to serial number 1523. The strap can interfere with the seat’s energy‑absorbing function during very rapid decelerations, so operators must remove it per the manufacturer service bulletin to restore conformity with certification requirements.\n\nAircraft operators must carry out the removal within 110 flight hours or within 3 months of the directive becoming effective."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific safety defect in specific aircraft. It has not expanded beyond its original purpose of mandating a single safety modification."},"complexity_factors":["Single, specific mechanical action required (removal of one component)","Narrow applicability (only EC 120B helicopters up to serial number 1523 with specific seat type)","Clear compliance deadline (110 flight hours or 3 months)","No nested exceptions or conditional logic","Only one defined term of note ('Flight Hours' implied but not explicitly defined in text)","Straightforward background explanation without cross-references to other legislation","References only one external technical document (Eurocopter Alert Service Bulletin No. 25A023)"],"plain_english_summary":"Owners/operators of Eurocopter EC120B helicopters (S/N up to 1523) must remove a Sicma Type 159 seat electrical bonding strap per Eurocopter Alert Service Bulletin No. 25A023. CASA mandates removal within 110 flight hours or 3 months to prevent the strap’s retaining screw from impeding the seat’s energy‑absorbing crash mechanism. Eurocopter confirms the strap isn’t required, so removal eliminates a potential injury risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ec-120-17-seat-electrical-bonding-modification","history":"/api/acts/ad-ec-120-17-seat-electrical-bonding-modification/history","analysis":"/api/acts/ad-ec-120-17-seat-electrical-bonding-modification/analysis","conflicts":"/api/acts/ad-ec-120-17-seat-electrical-bonding-modification/conflicts","importantCases":"/api/acts/ad-ec-120-17-seat-electrical-bonding-modification/important-cases","documents":"/api/acts/ad-ec-120-17-seat-electrical-bonding-modification/documents"}}