05-20779. Airworthiness Directives; Rolls-Royce Corporation (Formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) 250-B and 250-C Series Turboshaft and Turboprop Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for certain RRC 250-B and 250-C series turboshaft and turboprop engines. That AD currently requires a onetime inspection of the fuel nozzle screen for contamination, and if contamination is found, inspection and cleaning of the entire aircraft fuel system before further flight. That AD also requires replacing the fuel nozzle with a new design fuel nozzle, at the next fuel nozzle overhaul or by June 30, 2006, whichever occurs first. This proposed AD would require the same actions, but would add additional part numbers (P/Ns) to the list of affected fuel nozzles. This proposed AD would also explain that the existing AD, as worded, allows certain part number (P/N) fuel nozzles back into service. Those fuel nozzles must not be allowed back into service. This proposed AD results from the discovery that several P/Ns of fuel nozzles were inadvertently left out of AD 2004-24-09. We are proposing this AD to minimize the risk of sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle.

DATES:

We must receive any comments on this proposed AD by December 19, 2005.

ADDRESSES:

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

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2004-NE-10-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: [phone].
• By e-mail: [e-mail].

You can get the service information identified in this proposed AD from Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206-0420; telephone [phone]; fax [phone].

You may examine the AD docket at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

John Tallarovic, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des Plaines, IL 60018-4696; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2004-NE-10-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

On November 22, 2004, we issued AD 2004-24-09, Amendment 39-13885 (69 FR 69807, December 1, 2004). That AD requires a onetime inspection of the fuel nozzle screen for contamination, and if contamination is found, inspection and cleaning of the entire aircraft fuel system before further flight. That AD also requires replacing the fuel nozzle with a new design fuel nozzle, at the next fuel nozzle overhaul or by June 30, 2006, whichever occurs first. That AD was the result of 10 reports of engine power loss with accompanying collapse of the fuel nozzle screen, due to fuel contamination. That condition, if not corrected, could result in sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle.

Actions Since AD 2004-24-09 Was Issued

Since AD 2004-24-09 was issued, we discovered that several RRC and Parts Manufacturer Approval (PMA) fuel nozzle part numbers were inadvertently left out of the AD. Additionally, we discovered that certain RRC fuel nozzles are only identified by their vendor part number. Because AD 2004-24-09 defined a serviceable fuel nozzle as a nozzle that has a P/N not specified in, or addressed by, that AD, it is possible that operators could return to service fuel nozzles, P/Ns 6874959, 6894610, and 6898531, and then record being in compliance with AD 2004-24-09. In those cases, the minimizing of the risk of sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle, has not been achieved. We have added these additional RRC, PMA, and vendor part numbers to this proposed AD.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would minimize the risk of sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle. This proposed AD requires:

• A onetime inspection of the screens in certain P/N fuel nozzles for contamination within 50 operating hours after the effective date of the proposed AD; or
• A onetime inspection of the screens in certain P/N fuel nozzles for contamination within 150 operating hours after January 5, 2005, unless already done using AD 2004-24-09; and
• If contamination is found, inspecting and cleaning the entire aircraft fuel system, before further flight; and
• Replacing the fuel nozzles listed in this AD with a new design fuel nozzle, at the next fuel nozzle overhaul or by June 30, 2006, whichever occurs first.

Costs of Compliance

There are about 15,000 RRC 250-B and 250-C series turboshaft and turboprop engines of the affected design in the worldwide fleet. We estimate that 10,000 engines installed on aircraft of U.S. registry would be affected by this proposed AD. We also estimate that it would take about one work hour per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. In addition, operators can either replace the fuel nozzle with a new one at a cost of about $2,595 or have the existing nozzle overhauled at a cost of about $850. We estimate that about 80% of the fuel nozzles will be overhauled and 20% will be replaced with a new nozzle. Therefore, we estimate that the required parts would cost, on average, about $1,200 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $12,650,000.

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

Regulatory Findings

We have determined that this proposed AD will not have federalism implications under Executive Order 13132. This proposed 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 the regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the 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.

We prepared a summary of the costs to comply with this proposed AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2004-NE-10-AD” in your request.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 removing Amendment 39-13885 (69 FR 69807, December 1, 2004), and by adding a new airworthiness directive to read as follows:

Rolls-Royce Corporation: Docket No. 2004-NE-10-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by December 19, 2005.

Affected ADs

(b) This AD supersedes AD 2004-24-09.

Applicability

(c) This AD applies to Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) 250-B and 250-C series turboshaft and turboprop engines in the following Table 1:

-B15A

-B15E

-B15G

-B17

-B17B

-B17C

-B17D

-B17E

-B17F

-B17F/1

-B17F/2

-C18

-C18A

-C18B

-C18C

-C20

-C20B

-C20C

-C20F

-C20J

-C20R

-C20R/1

-C20R/2

-C20R/4

-C20S

-C20W

-C28

-C28B

-C28C

-C30

-C30G

-C30G/2

-C30M

-C30P

-C30R

-C30R/1

-C30R/3

-C30R/3M

-C30S

-C30U

-C40B

-C47B

-C47M

These engines are installed on, but not limited to, the aircraft listed in the following Table 2:

Table 2.—Engines Installed On, But Not Limited To

Manufacturer	Model
Agusta	A109, A109A, A109AII, and A109C.
Bell Helicopter Textron	47, 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, 407, and 430.
B-N Group	BN-2T and BN-2T-4R.
Enstrom	TH28, 480; and 480B.
Eurocopter Canada Limited	BO 105 LS A-3.
Eurocopter France	AS355E, AS355F, AS355I, and AS355F2.
Eurocopter Deutschland	BO-105A, BO-105C, BO-105S, and BO-105LS A-1.
Hiller Aviation	FH-1100.
McDonnell Douglas	369D, 369E, 369F, 369H, 369HE, 369HM, 369HS, 369FF, and 500N.
Schweizer	TH269D.
SIAI Marchetti s.r.l.	SF600 and SF600A.
Sikorsky	S-76A.

Unsafe Condition

(d) This AD results from the discovery that several part numbers (P/Ns) of fuel nozzles were inadvertently left out of AD 2004-24-09. That AD, as worded, allows certain P/N fuel nozzles back into service. Those fuel nozzles must not be allowed back into service. We are issuing this AD to minimize the risk of sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle.

Compliance

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

(f) Perform a onetime inspection of the screens in fuel nozzles as follows:

(1) For fuel nozzles with a P/N listed in Table 3 of this AD, inspect the screen for contamination within 50 operating hours after the effective date of this AD.

Table 3.—Fuel Nozzles To Be Inspected Within 50 Operating Hours

Manufacturer	P/N	Corresponding RRC vendor P/N
RRC	6874959	5232815
	6894610	5233465
	6898531	5233585
Delevan Inc. (PMA)	49445	N/A
	47069	N/A
	47101	N/A

(2) For fuel nozzles with a P/N listed in Table 4 of this AD, inspect the screen for contamination within 150 operating hours after January 5, 2005.

Table 4.—Fuel Nozzles To Be Inspected Within 150 Operating Hours

Manufacturer	P/N	Corresponding RRC vendor P/N
RRC	6852020	5232480
	6890917	5233333
	6899001	5233600

(g) Before further flight, inspect and clean the entire aircraft fuel system if you find any contamination on the screen.

(h) At the next fuel nozzle overhaul after the effective date of this AD, or by June 30, 2006, whichever occurs first, do the following:

(1) Remove from service fuel nozzles listed in Table 3 and Table 4 of this AD.

(2) Replace with a serviceable fuel nozzle.

Definition

(i) For the purposes of this AD, a serviceable fuel nozzle is defined as a nozzle that has a P/N not specified in, or addressed by, this AD.

Previous Credit

(j) Previous credit is given for onetime inspections of fuel nozzles, RRC P/Ns 6852020, 6890917, and 6899001 using AD 2004-24-09.

Alternative Methods of Compliance

(k) The Manager, Chicago Aircraft Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(l) Information related to the subject of this AD can be found in Rolls-Royce Corporation Alert Commercial Engine Bulletins (CEBs), all at Revision 1, and all dated August 30, 2004, listed in the following Table 5:

Table 5.—Related Alert Commercial Engine Bulletins

CEB-A-313	CEB-A-73-5029.
CEB-A-73-2075	CEB-A-73-6041.
CEB-A-1394	TP CEB-A-183.
CEB-A-73-3118	TP CEB-A-1336.
CEB-A-73-4056	TP CEB-A-73-2032.

Issued in Burlington, Massachusetts, on October 11, 2005.

Ann C. Mollica,

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