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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 99-NE-47-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

This document proposes to adopt a new airworthiness directive (AD), applicable to Allison Engine Company 250-C18 and -C20 series turboshaft engines. This proposal would require a one-time visual inspection of the fuel nozzle screen for contamination. If contamination is found, this proposal would require, prior to further flight, replacement of the fuel nozzle screen with a serviceable screen, visual inspection of the entire fuel system for contamination, and repair, if necessary. In addition, this proposal would require reporting the results of the one-time inspection to the Federal Aviation Administration (FAA) to determine if repetitive inspections should be required by future rulemaking. This proposal is prompted by a report of fuel system contamination that caused blockage of the fuel nozzle screen. This blockage of the fuel nozzle screen caused an in-flight engine shutdown, autorotation, and forced landing. The actions specified by the proposed AD are intended to prevent an in-flight engine shutdown due to blockage of the fuel nozzle screen, which can result in autorotation and forced landing. 

# DATES:

Comments must be received by June 26, 2000. 

# ADDRESSES:

Submit comments to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-47-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: “9-ane-adcomment@faa.gov”. Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. 

# FOR FURTHER INFORMATION CONTACT:

John Tallarovic, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, Small Airplane Directorate, 2300 E. Devon Ave., Des Plaines, IL 60018; telephone (847) 294-8180, fax (847) 294-7834. 

# SUPPLEMENTARY INFORMATION:

## Comments Invited 

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. 

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. 

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 99-NE-47-AD.” The postcard will be date stamped and returned to the commenter. 

## Availability of NPRMs 

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-47-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

## Discussion 

The Federal Aviation Administration (FAA) has received a report of a McDonnell Douglas Helicopter Systems 369D helicopter with an Allison Engine Company Model 250-C20B turboshaft engine that lost power at approximately 150 feet and autorotated to a forced landing. The subsequent investigation revealed contamination at the fuel pump filter, fuel control unit screen, and the fuel nozzle screen. Three additional loss of power events dating back to 1994 have been associated with some level of fuel system contamination. In each case, the fuel nozzle screen was contaminated. This condition, if not corrected, could result in an in-flight engine shutdown due to blockage of the fuel nozzle screen, which can result in autorotation and forced landing. 

## Proposed Actions 

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require a one-time visual inspection of the fuel nozzle screen for contamination at the next scheduled 300-hour inspection or after 300 hours time-in-service from the effective date of the AD, whichever occurs first. If contamination is found, this proposal would require, prior to further flight, replacement of the fuel nozzle screen with a serviceable screen, visual inspection of the entire fuel system for contamination, and repair, if necessary. These proposed actions have been coordinated with the Rotorcraft Directorate of the FAA. In addition, this proposal would require reporting the results of the one-time inspection to the FAA to determine if repetitive inspections may be required by future rulemaking. The actions would be required to be accomplished in accordance with the service information described previously. 

## Economic Analysis 

                    There are approximately 14,000 engines of the affected design in the worldwide fleet. The FAA estimates that 6,000 engines installed on rotorcraft of US registry would be affected by this proposed AD, that it would take approximately 1 work hour per engine                           ( print page 24136)                        to accomplish the visual inspection of the fuel nozzle screen, and that the average labor rate is $60 per work hour. Required parts would cost approximately $150 per engine. If the fuel nozzle screen is contaminated, it must be replaced and the entire fuel system must be inspected. The FAA estimates these actions to take 8 work hours, with a parts cost of $2,600 per engine. Based on these figures, the total cost impact of the proposed AD on US operators is estimated to be $1,814,400.                 

## Regulatory Impact 

This proposal does not have federalism implications, as defined in Executive Order No. 13132, because it would 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposal. 

                    For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order No. 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption                     **ADDRESSES**                    .                 

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

## The Proposed Amendment 

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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

2. Section 39.13 is amended by adding the following new airworthiness directive:

**Allison Engine Company:**                                 Docket No. 99-NE-47-AD.                            

*Applicability:*                                 Allison Engine Company 250-C18 series and 250-C20 series turboshaft engines, installed on, but not limited to the following rotorcraft: AGUSTA Models A109, A109A, A109AII, A109C; Bell Helicopter Textron Models 47, 206, 206A, 206B, 206L, 206L-1, 206L-4; Enstrom Helicopter Models TH-28, 480; Eurocopter Canada Limited Model BO 105 LS A-3; Eurocopter France Models AS355E, AS355F, AS355F1, AS355F2; Eurocopter Deutschland Models BO-105A, BO-105C, BO-105S, BO-105LS A-1; Hiller Aviation Model FH-1100; McDonnell Douglas Helicopter Company Models 369D, 369E, 369F, 369H, 369HM, 369HS, 369HE, 369FF, 500N; Rogerson Hiller Corp. Model UH-12E; Schweizer Aircraft Corporation Model 269D.                            

# Note 1:

This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines 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 (f) 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 in-flight engine shutdown due to blockage of the fuel nozzle screen, which can result in autorotation and forced landing, accomplish the following: 

## One-Time Inspection 

(a) At the next scheduled 300-hour inspection, or 300 hours time-in-service (TIS) after the effective date of this AD, whichever occurs first, visually inspect the fuel nozzle screen for contamination. 

## Fuel Nozzle Screen Replacement 

(b) If the fuel nozzle screen is contaminated, prior to further flight replace the fuel nozzle screen with a serviceable screen. 

## Fuel System Inspection and Repair 

(c) If the fuel nozzle screen is contaminated, prior to further flight visually inspect and clean the following engine components: 

(1) Fuel pump filter.

(2) Gas Producer fuel control inlet filter.

(3) Fuel control unit.

(4) Governor Filter.

(5) High pressure fuel filter, if applicable. 

(d) If the fuel nozzle screen is contaminated, prior to further flight visually inspect and clean the aircraft fuel system. 

## Reporting Requirement 

(e) Within 5 calendar days of the inspection performed in accordance with paragraph (a) of this AD, report the results of the inspection to John Tallarovic, Aerospace Engineer, Chicago Aircraft Certification Office, at 2300 E. Devon Ave., Des Plaines, IL 60018; telephone 847-294-8180, fax 847-294-7834, Internet john.m.tallarovic@faa.gov. Reporting requirements have been approved by the Office of Management and Budget and assigned OMB Control Number 2120-0056. 

## Alternative Methods of Compliance 

(f) 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, Chicago Aircraft Certification Office. Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Chicago Aircraft Certification Office. 

# Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Chicago Aircraft Certification Office.

## Ferry Flights 

(g) 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 rotorcraft to a location where the requirements of this AD can be accomplished.

Issued in Burlington, Massachusetts, on April 18, 2000. 

Ronald L. Vavruska, 

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. 

[FR Doc. 00-10291 Filed 4-24-00; 8:45 am] 

BILLING CODE 4910-13-P