### 47194 Federal Register / Vol. 75, No. 150 / Thursday, August 5, 2010 / Rules and Regulations

(954) 359–3826; e-mail structure@embraer.com.br; at the applicable time specified in paragraph (f)(3)(i) or (f)(3)(ii) of this AD. The report must include the inspection results, a description of any discrepancies found, the airplane serial number, and the number of landings and flight hours on the airplane.

(i) If the inspection was done on or after the effective date of this AD: Submit the report within 30 days after the inspection.

(ii) If the inspection was accomplished prior to the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

FAA AD Differences

Note 1: This AD differs from the MCAI and/or service information as follows:

(1) Although Brazilian Airworthiness Directive 2008–10–02, effective October 21, 2008, does not include a reporting requirement, the service bulletins identified in paragraph (f)(1) of this AD do specify reporting findings to EMBRAER. This AD requires that operators report the results of the inspections to EMBRAER because the required inspection report will help determine the extent of the corrosion in the affected fleet, from which we will determine if further corrective action is warranted. This difference has been coordinated with Age ˆ ncia Nacional de Aviac

 ̧ a  ̃ o Civil (ANAC). (2) Brazilian Airworthiness Directive 2008– 10–02, effective October 21, 2008, allows replacement of the affected APU mounting rods by ‘‘new ones bearing a new P/N [part number] approved by ANAC. ’’ However, paragraph (f)(1)(ii) of this AD requires replacing the affected mounting rod only with a new mounting rod having the same part number. Operators may request approval of an alternative method of compliance in order to install a new part number in accordance with the procedures specified in paragraph (g)(1) of this AD. This difference has been coordinated with ANAC.

Other FAA AD Provisions

(g) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM–116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Todd Thompson, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057–3356; telephone (425) 227–1175; fax (425) 227–1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq. ), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120–0056.

(4) Special Flight Permits: Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the airplane can be modified (if the operator elects to do so), except if two or more center mounting rods or rod ends are heavily corroded or broken, a special flight permit is not permitted.

Related Information

(h) Refer to MCAI Brazilian Airworthiness Directive 2008–10–02, effective October 21, 2008; EMBRAER Service Bulletin 145–49– 0034, Revision 01, dated September 8, 2008; and EMBRAER Service Bulletin 145LEG–49– 0008, Revision 02, dated September 8, 2008; for related information.
Material Incorporated by Reference

(i) You must use EMBRAER Service Bulletin 145–49–0034, Revision 01, dated September 8, 2008; or EMBRAER Service Bulletin 145LEG–49–0008, Revision 02, dated September 8, 2008; as applicable; to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Empresa Brasileira de Aeronautica S.A. (EMBRAER), Technical Publications Section (PC 060), Av. Brigadeiro Faria Lima, 2170–Putim–12227–901 Sa  ̃ o Jose dos Campos–SP–BRASIL; telephone: +55 12 3927–5852 or +55 12 3309–0732; fax: +55 12 3927–7546; e-mail: distrib@embraer.com.br; Internet: http://www.flyembraer.com.

(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call
425–227–1221.

(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202–741–6030, or go
to: http://www.archives.gov/federal

_register/ code

_ of

_ federal

_regulations/ ibr

_locations.html. Issued in Renton, Washington, on July 16,
2010. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2010–18398 Filed 8–4–10; 8:45 am]

**BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION** 

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0046; Directorate Identifier 2009–NM–086–AD; Amendment**  **39–16383; AD 2010–16–06]**

**RIN 2120–AA64**

**Airworthiness Directives; The Boeing Company Model 737–300, –400, –500,**  **–600, –700, and –800 Series Airplanes**

**AGENCY :**  Federal Aviation Administration (FAA), DOT.

**ACTION :**  Final rule.

**SUMMARY :**  We are adopting a new airworthiness directive (AD) for certain Model 737–300, –400, –500, –600, –700, and –800 series airplanes. This AD requires inspecting to verify the part number of the low-pressure flex-hoses of the crew oxygen system installed under the oxygen mask stowage boxes located within the flight deck, andreplacing the flex-hose with a new nonconductive low-pressure flex-hose if necessary. This AD results from reports of low-pressure flex-hoses of the crew oxygen system that burned through due to inadvertent electrical current from a short circuit in the audio select panel. We are issuing this AD to prevent inadvertent electrical current, which can cause the low-pressure flex-hoses of the crew oxygen system to melt or burn, causing oxygen system leakage and smoke or fire.

**DATES :**  This AD is effective September 9,
2010.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of September 9, 2010.

**ADDRESSES :**  For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, Washington 98124– 2207; telephone 206–544–5000, extension 1; fax 206–766–5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone 800–647–5527) is the Document Management Facility,


### 47195 Federal Register / Vol. 75, No. 150 / Thursday, August 5, 2010 / Rules and Regulations

U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

**FOR FURTHER INFORMATION CONTACT :**  Susan L. Monroe, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM–150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 917–6457; fax (425) 917–6590.

**SUPPLEMENTARY INFORMATION :** 

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model 737–300, –400, –500, –600, –700, and –800 series airplanes. That NPRM was published in the Federal Register on January 22, 2010 (75 FR 3662). That NPRM proposed to require inspecting to verify the part number of the low-pressure flex-hoses of the crew oxygen system installed under the oxygen mask stowage boxes located within the flight deck, andreplacing the flex-hose with a new nonconductive low-pressure flex-hose if
necessary.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received. Support of NPRM

Boeing concurs with the contents of the NPRM. Request for Clarification of Cup-Type Oxygen Mask Applicability

All Nippon Airways requests that the FAA clarify the NPRM by including a note stating that the cup-type oxygen mask at the observer seat position is not included in the applicability statement of the NPRM, as stated in a note in the Accomplishment Instructions of Boeing Service Bulletin 737–35A1053, Revision 1, dated June 1, 2000.

We agree that clarification is necessary. Boeing Service Bulletin 737– 35A1053, Revision 1, dated June 1, 2000, provides information that describes the applicable parts and equipment. ADs do not identify parts and equipment that are not applicable; therefore, the cup-type oxygen mask is not included in the applicability statement. No change has been made to the AD in this regard. Request To Extend Compliance Time

The Air Transport Association on behalf of its member American Airlines, requests that the 36-month compliance time be extended to 72 months to allow accomplishment during heavy maintenance. American Airlines states that this extended compliance time would be consistent with the apparent urgency being placed on this inspection by the FAA, which has waited over ten years since the original release of the service bulletin to issue the NPRM. American Airlines also states that the compliance urgency should also take into account that the proposed AD results from reports of hoses that burned through on a Model 757 airplane due to electrical current from a short circuit in the audio selector panel with no mention of reports of burned-through hoses on properly maintained Model 737 airplanes.

We do not agree. American Airlines provides no technical justification for extending the compliance time. In developing an appropriate compliance time, we considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of the required actions. Further, we arrived at the compliance time with manufacturer concurrence. In consideration of all of these factors, we determined that the compliance time, as proposed, represents an appropriate interval in which the inspections can be done in a timely manner within the fleet, while still maintaining an adequate level of safety. If additional data are presented that would justify a longer compliance time, we may consider further rulemaking on this issue. No change has been made to the AD in this regard. Request for Clarification of Conductive Oxygen Hose Part Numbers

The Air Transport Association on behalf of its member American Airlines, requests clarification regarding the conductive oxygen hose part numbers in Table 1 of the NPRM and the applicable airplane models. American Airlines states that the NPRM requires inspections for five conductive hose part numbers regardless of model applicability, and does not differentiate between part numbers that are applicable to Model 737–300, –400, and –500 series airplanes, and those applicable to Models 737–600, –700, and –800 series airplanes. American Airlines states that if an operator who flies only Model 737–800 series airplanes has accomplished Boeing Service Bulletin 737–35A1058, Revision 1, dated June 1, 2000, for Model 737– 800 airplanes prior to the effective date of the NPRM, the operator would now be required to perform another inspection to look for the part numbers in Boeing Service Bulletin 737– 35A1053, Revision 1, dated June 1, 2000, which does not apply to Model 737–800 airplanes. American Airlines asserts that this places undue burden and expense on the operator.

We agree that clarification is needed regarding the conductive hose part numbers. We have changed Table 1 of this final rule to identify part numbers for only Model 737–300, –400, and –500 series airplanes. Table 2 has been added to this final rule to identify part numbers for Model 737–600, –700, and –800 series airplanes.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD. Explanation of Change to Costs of Compliance

Since issuance of the NPRM, we have increased the labor rate used in theCosts of Compliance from $80 per workhour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate. Costs of Compliance

We estimate that this AD will affect 851 airplanes of U.S. registry. We also estimate that it will take 1 work-hour per product to comply with this AD.The average labor rate is $85 per workhour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $72,335, or $85 per product. Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. ‘‘ Subtitle VII: Aviation Programs, ’’ describes in more detail the scope of the Agency’s authority.

We are issuing this rulemaking under the authority described in ‘‘ Subtitle VII, Part A, Subpart III, Section 44701: General requirements. ’’ Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition


### 47196 Federal Register / Vol. 75, No. 150 / Thursday, August 5, 2010 / Rules and Regulations

that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings

This AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment

■ Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: **PART 39—AIRWORTHINESS DIRECTIVES** 

■ 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

**§ 39.13 [Amended]**

■ 2. The FAA amends § 39.13 by adding the following new AD: 2010–16–06 The Boeing Company: Amendment 39–16383. Docket No. FAA–2010–0046; Directorate Identifier 2009–NM–086–AD.

Effective Date

(a) This airworthiness directive (AD) is effective September 9, 2010.

Affected ADs

(b) None.
Applicability

(c) This AD applies to the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD, certificated in any category.

(1) The Boeing Company Model 737–300, –400, and –500 series airplanes, as identified in Boeing Service Bulletin 737–35A1053, Revision 1, dated June 1, 2000.

(2) The Boeing Company Model 737–600, –700, and –800 series airplanes, as identified in Boeing Service Bulletin 737–35A1058, Revision 1, dated June 1, 2000.
Subject

(d) Air Transport Association (ATA) of America Code 35: Oxygen.

Unsafe Condition

(e) This AD results from reports of lowpressure flex-hoses of the crew oxygen system that burned through due to inadvertent electrical current from a short circuit in the audio select panel. The Federal Aviation Administration is issuing this AD to prevent inadvertent electrical current, which can cause the low-pressure flex-hoses of the crew oxygen system to melt or burn, resulting in oxygen system leakage and smoke or fire.
Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Inspection and Replacement

(g) Within 36 months after the effective date of this AD, do an inspection todetermine whether any low-pressure flexhose of the crew oxygen system installed under the oxygen mask stowage box in the flight deck has a part number identified in Table 1 or Table 2 of this AD, as applicable. A review of airplane maintenance records is acceptable in lieu of this inspection if the part number of the low-pressure flex-hoses of the crew oxygen system can be conclusively determined from that review.

(1) For any hose having a part number identified in Table 1 or Table 2 of this AD, as applicable, before further flight, replace the hose with a new or serviceable part, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737– 35A1053, Revision 1, dated June 1, 2000; or Boeing Service Bulletin 737–35A1058, Revision 1, dated June 1, 2000; as applicable.

(2) For any hose not having a part number identified in Table 1 or Table 2 of this AD no further action is required by this paragraph.



### TABLE 

### 1—A PPLICABLE 

### P ART 

### N UMBERS FOR 

### M ODEL 

### 737–300, –400, AND 

### –500 S ERIES 

### A IRPLANES

Boeing specification part No. Equivalent Boeing supplier part Nos.

Puritan bennett Hydraflow

10–60174–31 .......................................................................... 173470–31 .............................................................................. 37001–31 10–60174–35 .......................................................................... 173470–35 .............................................................................. 37001–35 10–60174–46 .......................................................................... Not Applicable ............................ ............................................ 37001–46 60B50059–99 ......................................................................... Not Applicable ............................. ........................................... 38001–99



### TABLE 

### 2—A PPLICABLE 

### P ART 

### N UMBERS FOR 

### M ODEL 

### 737–600, –700, AND 

### –800 S ERIES 

### A IRPLANES

Boeing specification part No. Equivalent Boeing supplier part Nos.

Puritan bennett Hydraflow

10–60174–31 .......................................................................... 173470–31 .............................................................................. 37001–31 10–60174–35 .......................................................................... 173470–35 .............................................................................. 37001–35 60B50059–124 ....................................................................... Not Applicable .............................. .......................................... 38001–124

Parts Installation

(h) As of the effective date of this AD, no person may install a crew oxygen hose with a part number identified in Table 1 or Table 2 of this AD, as applicable, on any airplane. Actions Accomplished According to Previous Issue of Service Bulletins

(i) Actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737–35A1053, dated September 2, 1999; or Boeing Alert Service Bulletin 737–35A1058, dated September 2, 1999; as applicable; are considered acceptable for compliance with the corresponding actions specified in this
AD.
Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the


### 47197 Federal Register / Vol. 75, No. 150 / Thursday, August 5, 2010 / Rules and Regulations

authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to Attn: Susan L. Monroe, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM– 150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057–3356; telephone (425) 917–6457; fax (425) 917–6590. Or, e-mail information to 9–ANM–Seattle-ACO–AMOC– Requests@faa.gov.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.
Material Incorporated by Reference

(k) You must use Boeing Service Bulletin 737–35A1053, Revision 1, dated June 1, 2000; or Boeing Service Bulletin 737– 35A1058, Revision 1, dated June 1, 2000; as applicable; to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, Washington 98124–2207; telephone 206–544–5000, extension 1; fax 206–766– 5680; e-mail me.boecom@boeing.com ; Internet https://www.myboeingfleet.com

.

(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call

425–227–1221.

(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202–741–6030, or go

to: http://www.archives.gov/federal

_register/ code

_ of

_ federal

_regulations/ ibr

_locations.html.
Issued in Renton, Washington, on July 16,

2010. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2010–18624 Filed 8–4–10; 8:45 am]

**BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION** 

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0758; Directorate Identifier 2010–SW–004–AD; Amendment**  **39–16385; AD 2010–16–08]**

**RIN 2120–AA64**

**Airworthiness Directives; Schweizer Aircraft Corporation (Schweizer) Model**  **269D Helicopters**

**AGENCY :**  Federal Aviation Administration (FAA), Department of Transportation (DOT).

**ACTION :**  Final rule; request for
comments.

**SUMMARY :**  This amendment adopts a new airworthiness directive (AD) for the Schweizer Model 269D helicopters. This action requires installing a Scroll Housing Blade Containment Shielding Kit on each helicopter. This amendment is prompted by 21 reports of the blades of the oil cooler impeller separating, one of which punctured the engine and transmission oil cooler resulting in loss of engine oil pressure. The actions specified in this AD are intended to protect the oil cooler from uncontained oil cooler impeller blades that could damage the oil cooler and result in loss of engine and transmission oil pressure, and subsequent loss of control of the helicopter.

**DATES :**  Effective August 20, 2010.

Comments for inclusion in the Rules Docket must be received on or before October 4, 2010.

**ADDRESSES :**  Use one of the following addresses to submit comments on this AD:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

• Fax: 202–493–2251.

• Mail: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

• Hand Delivery: U.S. Department of Transportation, Docket Operations, M– 30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You may get the service information identified in this AD from Schweizer Aircraft Corporation, Elmira/Corning Regional Airport, 1250 Schweizer Road, Horseheads, NY 14845, telephone (607) 739–3821, fax: (607) 796–2488, e-mail address schweizer@sacusa.com , or at http://www.sacusa.com/support

. Examining the Docket: You may examine the docket that contains the AD, any comments, and other information on the Internet at http:// www.regulations.gov, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone (800) 647– 5527) is located in Room W12–140 on the ground floor of the West Building at the street address stated in the

**ADDRESSES** section. Comments will be available in the AD docket shortly after receipt.

**FOR FURTHER INFORMATION CONTACT :**  Richard P. Fiesel, Aviation Safety Engineer, FAA, New York Aircraft Certification Office, Airframe and Propulsion Branch, 1600 Stewart Ave., suite 410, Westbury, New York 11590, telephone (516) 228–7304, fax (516)
794–5531.

**SUPPLEMENTARY INFORMATION :**  This amendment adopts a new AD for the Schweizer Model 269D helicopters. This action requires installing a certain Scroll Housing Blade Containment Shielding Kit on each helicopter. This amendment is prompted by 21 reports of the blades of the oil cooler impeller separating and damaging the oil cooler. One failure resulted in an emergency landing when the crew experienced vibration and loss of oil pressure. Further investigation revealed that a portion of a fan impeller blade damaged the oil cooler resulting in a loss of oil. This condition, if not corrected, could result in loss of engine and transmission oil pressure and subsequent loss of control of the helicopter.

We have reviewed Schweizer Service Bulletin No. DB–031, dated September 1, 2009 (SB), which specifies installing a Scroll Housing Blade Containment Shielding Kit, part number (P/N) SA– 269DK–048 on each Model 269D helicopter. The manufacturer developed the containment kit after a recent incident in which separation of a blade due to fatigue cracks at the root of the blade resulted in damage to the oil cooler and loss of engine oil pressure. The SB states that the containment kit will prevent the escape of any separated impeller blades from the scroll assembly and relieve the operator of daily and 25- hour time-in-service (TIS) inspections. The SB also states that future inspections of the cooling impeller will be done at 100-hour TIS intervals per the maintenance manual.

This unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is being issued to prevent failure of the oil cooler, loss of engine and transmission