# AD 2003-08-05: ASU No. 2 printed circuit board (PCB) - Type: Airworthiness directive - Status: Current - Products: Airbus Helicopters AS350B3 - Effective: May 19, 2003 - Published: April 14, 2003, 68 FR 17879–17880 - Issued: April 8, 2003 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-13116 - Docket: 2002-SW-05-AD - Registered aircraft: 646 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/21/52/2152fa9193907bd7cd8d9b20f86843a79ba2c0efd935c073ad07a8d84b69f80f (from https://www.govinfo.gov/content/pkg/FR-2003-04-14/pdf/03-9012.pdf) - Federal Register: https://www.federalregister.gov/documents/2003/04/14/03-9012/airworthiness-directives-eurocopter-france-model-as350b3-helicopters - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/656A86B875F84A1285256D080056BEAE.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/2003-08-05 ## Summary This amendment adopts a new airworthiness directive (AD) for the specified Eurocopter France (Eurocopter) model helicopters that requires inspecting the ASU No. 2 printed circuit board (PCB) to determine if the resistor R8 is installed, and if it is not installed, replacing the PCB with an airworthy PCB with that resistor installed. This amendment is prompted by the discovery of a PCB without a critical resistor that polarizes the voltage regulator that regulates electrical power to a critical warning light, a critical caution light, and the main rotor revolutions per minute (RPM) signal to the vehicle engine management display (VEMD). The actions specified by this AD are intended to prevent the malfunction of the two critical lights and the rotor RPM signal to the VEMD, failure of these components to timely alert the pilot to the associated malfunctions, further helicopter damage because of these malfunctions, and subsequent loss of control of the helicopter. ## The airworthiness directive 1. The authority citation for part 39 continues to read as follows: 2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: 2003-08-05 Eurocopter France: Amendment 39-13116. Docket No. 2002-SW-05-AD. Applicability: Model AS350B3 helicopters, serial numbers (S/N) 3062 and earlier, certificated in any category. Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required as indicated, unless accomplished previously. To prevent malfunction of the electrical circuits controlling the “BATT. TEMP.” red warning light, the “ENGINE CHIP” amber caution and the rotor revolutions-per-minute (RPM) signal output to the vehicle engine management display (VEMD), accomplish the following: (a) Within 15 hours time-in-service (TIS), inspect the ASU No. 2 printed circuit board (PCB), part number SE 03022, to determine if resistor R8 is installed. (b) If the resistor R8 is not installed, within 50 hours TIS, replace the PCB with an airworthy PCB that has a resistor R8 installed. Note 2: Eurocopter Service Bulletin No. 77.00.07, dated March 27, 2000, pertains to the subject of this AD. (c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group. (d) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished. (e) This amendment becomes effective on May 19, 2003. Note 4: The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 2001-319-083(A), dated July 25, 2001. ## Rule preamble ### Dates Effective May 19, 2003. ### For further information contact Carroll Wright, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations Group, Fort Worth, Texas 76193-0111, telephone (817) 222-5120, fax (817) 222-5961. ### SUPPLEMENTARY INFORMATION A proposal to amend 14 CFR part 39 to include an AD for Eurocopter Model AS350B3 helicopters was published in the Federal Register on January 21, 2003 (68 FR 2714). That action proposed to require, within 15 hours time-in-service (TIS), inspecting the ASU No. 2 PCB on helicopters with serial numbers 3062 and earlier to determine if the resistor R8 is installed, and if it is not installed, replacing the PCB with an airworthy PCB with resistor R8 installed within 50 hours TIS. The Direction Generale De L'Aviation Civile (DGAC), the airworthiness authority for France, notified the FAA that an unsafe condition may exist on Eurocopter Model AS350B3 helicopters. The DGAC advises that the absence of a resistor R8 on the ASU No. 2 boards can lead to a malfunction of the electric circuits supplying the “BATT. TEMP.” red warning light, the “ENGINE CHIP” amber caution light, and the rotor RPM signal output to the VEMD. Eurocopter has issued Service Bulletin No. 77.00.07, dated March 27, 2000, which specifies checking to determine if the resistor R8 is installed on the PCB within 25 hours time-in-service (TIS) and, if a resistor R8 is not installed, replacing the PCB with one that has a resistor R8 installed within 50 hours TIS. The DGAC classified this service bulletin as mandatory and issued AD No. 2001-319-083(A), dated July 25, 2001, to ensure the continued airworthiness of these helicopters in France. Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed. On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. However, for clarity and consistency in this final rule, we have retained the language of the NPRM regarding that material. The FAA estimates that 30 helicopters of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost $1,200. The manufacturer states in its service bulletin that PCB's will be replaced free of charge. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $37,800, if a PCB is replaced in the entire fleet and there is no free replacement by the manufacturer. The regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. ### Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H9EU](https://openairdocs.org/tcds/H9EU): Airbus Helicopters; names 1 of 10 models: AS350B3 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 646 (646 by airframe model, 0 by engine model) - Makers: Airbus Helicopters 347, Eurocopter 167, American Eurocopter 124, Eurocopter France 8 Models with the most aircraft: - [Airbus Helicopters AS350B3](https://openairdocs.org/model/airbus-helicopters-as350b3): 291 aircraft (airframe model) - [Eurocopter AS 350 B3](https://openairdocs.org/model/eurocopter-as-350-b3): 167 aircraft (airframe model) - [American Eurocopter AS350B3](https://openairdocs.org/model/american-eurocopter-as350b3): 124 aircraft (airframe model) - [Airbus Helicopters AS 350B3](https://openairdocs.org/model/airbus-helicopters-as-350b3): 56 aircraft (airframe model) - [Eurocopter France AS 350 B3](https://openairdocs.org/model/eurocopter-france-as-350-b3): 8 aircraft (airframe model) All 6 models: https://openairdocs.org/ad/2003-08-05/models.md Every aircraft: https://openairdocs.org/ad/2003-08-05/aircraft.md ## Related documents - [Proposed rule 2002-SW-05-AD](https://openairdocs.org/proposed/2002-SW-05-AD): Notice of proposed rulemaking (NPRM), published Jan 21, 2003 Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.