34560 Federal Register / Vol. 69, No. 119 / Tuesday, June 22, 2004 / Rules and Regulations 

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 Rules 

Docket at the location provided under 

the caption ADDRESSES.

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety.

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:

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. Section 39.13 is amended by adding 

the following new airworthiness 

directive:

2004–12–19 Airbus: Amendment 39–13680. 

Docket 2003–NM–63–AD.

Applicability: Model A319, A320, and 

A321 series airplanes, certificated in any 

category; except those airplanes on which 

Airbus Modification 30737 has been 

accomplished in production (reference 

Airbus Service Bulletin A320–24–1099, 

Revision 02, dated February 11, 2003, in 

service). 

Compliance: Required as indicated, unless 

accomplished previously. 

To prevent ignition of the input filter 

capacitors of the transformer rectifier unit 

(TRU) in position 2 of the avionics 

compartment, which could potentially result 

in smoke in the cockpit, accomplish the 

following: 

Replacement 

(a) Prior to the accumulation of 15,000 total 

flight hours, or within 16 months after the 

effective date of this AD, whichever occurs 

later, replace the TRU, part number Y005–2, 

with a new TRU, part number Y005–3, in 

accordance with the Accomplishment 

Instructions of Airbus Service Bulletin A320–

24–1099, Revision 02, dated February 11, 

2003. 

(b) Replacements accomplished before the 

effective date of this AD per Airbus Service 

Bulletin A320–24–1099, dated March 5, 

2002; or Revision 01, dated July 26, 2002; are 

considered acceptable for compliance with 

the corresponding action specified in this 

AD. 

Parts Installation 

(c) As of the effective date of this AD no 

person shall install a TRU, part number 

Y005–2, within position 2 of the avionics 

compartment on any airplane. 

Alternative Methods of Compliance 

(d) In accordance with 14 CFR 39.19, the 

Manager, International Branch, ANM 116, 

Transport Airplane Directorate, FAA, is 

authorized to approve alternative methods of 

compliance (AMOCs) for this AD. 

Incorporation by Reference 

(e) Unless otherwise specified in this AD, 

the actions shall be done in accordance with 

Airbus Service Bulletin A320–24–1099, 

Revision 02, dated February 11, 2003. This 

incorporation by reference was approved by 

the Director of the Federal Register in 

accordance with 5 U.S.C. 552(a) and 1 CFR 

part 51. Copies may be obtained from Airbus, 

1 Rond Point Maurice Bellonte, 31707 

Blagnac Cedex, France. Copies may be 

inspected at the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue, SW., Renton, 

Washington; or 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.

Note 1: The subject of this AD is addressed 

in French airworthiness directive 2002–

554(B), dated November 13, 2002.

Effective Date 

(f) This amendment becomes effective on 

July 27, 2004.

Issued in Renton, Washington, on June 9, 

2004. 

Kalene C. Yanamura, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service.

[FR Doc. 04–13701 Filed 6–21–04; 8:45 am] 

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. 2001–NE–50–AD; Amendment 

39–13681; AD 2004–13–01] 

RIN 2120–AA64 

Airworthiness Directives; Dowty 

Aerospace Propellers Type R321/4–82–

F/8, R324/4–82–F/9, R333/4–82–F/12, 

and R334/4–82–F/13 Propeller 

Assemblies

AGENCY: Federal Aviation 

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes 

an existing airworthiness directive (AD) 

that applies to Dowty Aerospace 

Propellers (Dowty) Type R334/4–82–F/

13 propeller assemblies. That AD 

currently requires a one-time ultrasonic 

inspection of propeller hubs, part 

number (P/N) 660709201, for cracks. 

This amendment requires initial and 

repetitive ultrasonic inspections of 

propeller hubs, P/N 660709201, that are 

installed on airplanes, and for hubs and 

propellers in storage, initial ultrasonic 

inspection of propeller hubs before 

placing in service. Propeller hubs, P/N 

660709201, are installed on Type R321/

4–82–F/8, R324/4–82–F/9, R333/4–82–

F/12, and R334/4–82–F/13 propeller 

assemblies. This amendment results 

from the manufacturer’s reevaluation of 

potential hub failure on Type R321/4–

82–F/8, R324/4–82–F/9, R333/4–82–F/

12, and R334/4–82–F/13 propeller 

assemblies. We are issuing this AD to 

prevent propeller hub failure due to 

cracks in the hub, which could result in 

loss of control of the airplane.

DATES: Effective July 27, 2004. The 

incorporation by reference of certain 

publications listed in the regulations is 

approved by the Director of the Federal 

Register as of July 27, 2004.

ADDRESSES: The service information 

referenced in this AD may be obtained 

from Dowty Aerospace Propellers, 

Anson Business Park, Cheltenham Road 

East, Gloucester GL 29QN, UK; 

telephone 44 (0) 1452 716000; fax 44 (0) 

1452 716001. This information may be 

examined, by appointment, at the 

Federal Aviation Administration (FAA), 

New England Region, Office of the 

Regional Counsel, 12 New England 

Executive Park, Burlington, MA; or 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.

FOR FURTHER INFORMATION CONTACT:

Frank Walsh, Aerospace Engineer, 

Boston Aircraft Certification Office, 

FAA, Engine and Propeller Directorate, 

telephone (781) 238–7158, fax (781) 

238–7170.

SUPPLEMENTARY INFORMATION: A 

proposal to amend part 39 of the Federal 

Aviation Regulations (14 CFR part 39) 

by superseding AD 2002–01–28, 

Amendment 39–12623 (67 FR 4351, 

January 30, 2002), that applies to Dowty 

Type R334/4–82–F/13 propeller 

assemblies was published in the Federal 

Register on April 28, 2003 (68 FR 

22339). That action proposed to require 

initial and repetitive ultrasonic 

inspections of propeller hubs, P/N 

660709201, that are installed on 

airplanes, and for hubs and propellers 

in storage, initial ultrasonic inspection 

of propeller hubs before placing in 

service. That action proposed to perform 

Federal Register / Vol. 69, No. 119 / Tuesday, June 22, 2004 / Rules and Regulations 34561

inspections in accordance with Dowty 

Mandatory Service Bulletin (MSB) No. 

61–1119, Revision 3, dated March 8, 

2002; MSB No. 61–1124, Revision 1, 

dated October 8, 2002; MSB No. 61–

1125, Revision 1, dated October 9, 2002; 

and MSB No. 61–1126, Revision 1, 

dated October 9, 2002. The Civil 

Aviation Authority (CAA), which is the 

airworthiness authority for the United 

Kingdom (UK), classified these service 

bulletins as mandatory and issued CAA 

UK AD No. 003–11–2001, dated 

November 30, 2001; CAA UK AD No. 

009–05–2002, dated April 15, 2003; 

CAA UK AD No. 010–05–2002, dated 

April 15, 2003; and CAA UK AD No. 

011–05–2002, dated April 15, 2003 in 

order to ensure the airworthiness of 

these Dowty Propellers in the UK. 

Comments 

Interested persons have been afforded 

an opportunity to participate in the 

making of this amendment. Due 

consideration has been given to the 

comments received. 

Request To Increase the Initial 

Inspection Interval 

One commenter states that the initial 

inspection interval in the NPRM of 50 

hours is unrealistically short to 

complete the inspection on a large, 

geographically wide-spread fleet. The 

commenter believes that the initial 

inspection interval should be increased 

to 200 hours. 

We do not agree that we need to 

change the compliance time for the 

initial inspection. Dowty issued an MSB 

on May 7, 2002, and directed operators 

to conduct the initial inspection. Dowty 

also stated that the calendar compliance 

time for that inspection was within six 

months after the issue date of that MSB. 

Based on the issuance date of that MSB, 

all propellers should already be 

inspected. We have not changed the AD.

Request To Increase the Repetitive 

Inspection Interval 

One commenter requests that the 

repetitive inspection interval in the 

NPRM be increased from 1,000 hours to 

2,000 hours based on the fact that only 

one crack was found in their fleet. 

We do not agree. Dowty based the 

compliance time on an engineering 

evaluation of the 16 cracks found by this 

inspection. Five cracks were found on 

the same propeller model as flown by 

the commenter. We have not changed 

the AD. 

Credit for Previous Inspections on All 

Models 

One commenter states that the 

previous inspections on the propeller 

should be applicable to all models, not 

just the R334/4–82–F13 propeller. 

We agree. We have changed the 

Applicability in the Regulatory text of 

the AD by adding Dowty Propeller 

Types R321/4–82–F/8, R324/4–82–F/9, 

and R333/4–82–F/12. 

Request To Clarify the Economic 

Analysis Paragraph 

One commenter states that the FAA 

underestimated the cost of the AD to 

U.S. operators. The commenter also 

provides additional information to 

better estimate the cost of the 

inspection. 

We agree. Our revised estimate retains 

the 11 work hours per propeller and 

modifies the part cost from $1,650 per 

propeller to $300 per propeller. In 

addition, we increased the estimated 

number of airplanes from 10 airplanes 

to 50 airplanes and raised the labor rate 

to $65 per hour. Based on these 

revisions, the total cost for the 

inspection for U.S. operators will be 

about $126,875 for the fleet of affected 

airplanes. 

Clarification of CAA ADs Related to 

This AD 

We inadvertently left out three CAA 

UK ADs in Note 3 of the NRPM 

supersedure. We have added the three 

CAA UK ADs in Note 3 of the AD. 

After careful review of the available 

data, including the comments noted 

above, the FAA has determined that air 

safety and the public interest require the 

adoption of the rule with the changes 

described previously. The FAA has 

determined that these changes will 

neither increase the economic burden 

on any operator nor increase the scope 

of the AD. 

Bilateral Agreement Information 

These propeller models are 

manufactured in the UK and are Type 

certificated for operation in the United 

States under the provisions of Section 

21.29 of the Federal Aviation 

Regulations (14 CFR 21.29) and the 

applicable bilateral airworthiness 

agreement. Pursuant to this bilateral 

airworthiness agreement, the CAA has 

kept the FAA informed of the situation 

described above. The FAA has 

examined the findings of the CAA, 

reviewed all available information, and 

determined that AD action is necessary 

for products of this type design that are 

certificated for operation in the United 

States. 

Economic Analysis 

There are about 275 airplanes with 

propellers of the affected design in the 

worldwide fleet. The FAA estimates that 

there are about 125 Dowty Propellers 

Type R321/4–82–F/8, R324/4–82–F/9, 

R333/4–82–F/12, and R334/4–82–F/13 

installed on airplanes of U.S. registry 

that would be affected by this AD. The 

FAA also estimates that it would take 

approximately 11 work hours per 

propeller to perform one inspection and 

replacement, and that the average labor 

rate is $65 per work hour. Required 

shipping and parts would cost 

approximately $300 per propeller. 

Based on these figures, the total cost of 

the AD to known U.S. operators is 

estimated to be $126,875. 

Regulatory Analysis 

This final rule does not have 

federalism implications, as defined in 

Executive Order 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 final rule. 

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 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. A final evaluation has 

been prepared for this action and it 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, Incorporation by reference, 

Safety.

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:

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. Section 39.13 is amended by 

removing Amendment 39–12623 (67 FR 

34562 Federal Register / Vol. 69, No. 119 / Tuesday, June 22, 2004 / Rules and Regulations 

4351, January 30, 2002) and by adding a 

new airworthiness directive, 

Amendment 39–13681, to read as 

follows:

2004–13–01 Dowty Aerospace Propellers:

Amendment 39–13681. Docket No. 

2001–NE–50–AD. Supersedes AD 2002–

01–28, Amendment 39–12623. 

Applicability 

This airworthiness directive (AD) applies 

to Dowty Aerospace Propellers (Dowty) Type 

R321/4–82–F/8, R324/4–82–F/9, R333/4–82–

F/12, and R334/4–82–F/13 propeller 

assemblies with propeller hubs part number 

(P/N) 660709201. These propeller assemblies 

are installed on, but not limited to, 

Construcciones Aeronauticas, S.A. (CASA) 

212, British Aerospace Regional Aircraft 

Jetstream Models 3101 and 3201, Fairchild 

Aircraft, Inc., Merlin IIIC, and Merlin IVC/

Metro III airplanes.

Note 1: This AD applies to each propeller 

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 

propellers 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 

Compliance with this AD is required as 

indicated, unless already done. 

To prevent propeller hub failure due to 

cracks in the hub, which could result in loss 

of control of the airplane, do the following: 

Initial Ultrasonic Inspection 

(a) Within 50 flight hours time-in-service 

(TIS) after the effective date of this AD, or 

within 60 days after the effective date of this 

AD, whichever occurs earlier, perform an 

initial ultrasonic inspection of the rear wall 

of the rear half of the propeller hub for cracks 

in accordance with Appendix A of the 

applicable Dowty Mandatory Service Bulletin 

(MSB) listed in the following Table 1:

TABLE 1.—APPLICABLE MSB FOR

PROPELLER TYPE

Propeller assembly type Applicable MSB 

(1) R334/4–

82–F/13.

MSB No. 61–1119, Revision 

3, dated March 8, 2002. 

(2) R333/4–

82–F/12.

MSB No. 61–1124, Revision 

1, dated October 8, 2002. 

(3) R321/4–

82–F/8.

MSB No. 61–1125, Revision 

1, dated October 9, 2002. 

(4) R324/4–

82–F/9.

MSB No. 61–1126, Revision 

1, dated October 9, 2002 

(b) For hubs and propellers in storage, 

perform an initial ultrasonic inspection of the 

rear wall of the rear half of the propeller hub 

for cracks, before placing in service, in 

accordance with Appendix A of the 

applicable Dowty MSB listed in Table 1 of 

this AD.

(c) Propeller hubs, P/N 660709201, used on 

Type R334/4–82–F/13 propeller assemblies 

that have been previously inspected using a 

Dowty MSB listed in Table 1 or earlier issue 

of those MSBs, are considered to be in 

compliance with paragraph (a) of this AD. 

Repetitive Ultrasonic Inspections 

(d) Thereafter, within 1,000 flight hours 

TIS after each ultrasonic inspection, perform 

an ultrasonic inspection of the rear wall of 

the rear half of the propeller hub for cracks 

in accordance with Appendix A of the 

applicable Dowty MSB listed in Table 1 of 

this AD. 

Inspection Reporting Requirements 

(e) For each inspection, record the 

inspection data on a copy of Appendix B of 

the applicable MSB listed in Table 1 of this 

AD, and report the findings to the Manager, 

Boston Aircraft Certification Office, FAA, 

Engine and Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 

01803–5299 within 10 days after the 

inspection. Reporting requirements have 

been approved by the Office of Management 

and Budget (OMB) 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, Boston 

Aircraft Certification Office. Operators must 

submit their request through an appropriate 

FAA principal Maintenance Inspector, who 

may add comments and then send it to the 

Manager, Boston 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 Boston 

Aircraft Certification Office.

Special Flight Permits 

(g) Special flight permits may be issued in 

accordance with §§ 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 requirements of this AD 

can be done. 

Documents That Have Been Incorporated by 

Reference 

(h) The inspections must be done in 

accordance with the following Dowty 

Aerospace Propellers mandatory service 

bulletins:

Document No. Pages Revision Date 

MSB No. 61–1119 .................................................................................................................................. 1 ............... 3 .............. Mar. 8, 2002. 

2 ............... 2 ............... Dec. 6, 2001. 

Appendix A ............................................................................................................................................. 1 .............. 1 ............... Nov. 27, 2001. 

2 ............... Original .... Nov. 1, 2001. 

3–6 ........... 1 ............... Nov. 27, 2001. 

Appendix B ............................................................................................................................................. 1 .............. Original .... Nov. 1, 2001. 

Appendix C ............................................................................................................................................. All ............ Original .... Nov. 27, 2001. 

Appendix D ............................................................................................................................................. All ............ Original .... Dec. 6, 2001. 

Total pages: 29.

MSB No. 61–1124 .................................................................................................................................. 1 ............... 1 .............. Oct. 8, 2002. 

2–3 ........... Original .... May 7, 2002. 

Appendix A ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix B ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix C ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix D ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Total pages: 30.

MSB No. 61–1125 .................................................................................................................................. 1 ............... 1 .............. Oct. 9, 2002. 

2–3 ........... Original .... May 7, 2002. 

Appendix A ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix B ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix C ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix D ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Total pages: 30.

MSB No. 61–1126 .................................................................................................................................. 1 ............... 1 .............. Oct. 9, 2002. 

2–3 ........... Original .... May 7, 2002. 

Federal Register / Vol. 69, No. 119 / Tuesday, June 22, 2004 / Rules and Regulations 34563

Document No. Pages Revision Date 

Appendix A ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix B ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix C ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Appendix D ............................................................................................................................................. All ............ Original .... May 7, 2002. 

Total pages: 30.

This incorporation by reference was 

approved by the Director of the Federal 

Register in accordance with 5 U.S.C. 552(a) 

and 1 CFR part 51. Copies may be obtained 

from Dowty Propellers, Anson Business Park, 

Cheltenham Road East, Gloucester GL 29QN, 

UK; telephone 44 (0) 1452 716000; fax 44 (0) 

1452 716001. Copies may be inspected at the 

FAA, New England Region, Office of the 

Regional Counsel, 12 New England Executive 

Park, Burlington, MA; or 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.

Note 3: The subject of this AD is also 

addressed in CAA UK AD No. 003–11–2001, 

dated November 30, 2001; CAA UK AD No. 

009–05–2002, dated April 15, 2003; CAA UK 

AD No. 010–05–2002, dated April 15, 2003; 

and CAA UK AD No. 011–05–2002, dated 

April 15, 2003.

Effective Date 

(i) This amendment becomes effective on 

July 27, 2004.

Issued in Burlington, Massachusetts, on 

June 10, 2004. 

Francis A. Favara, 

Acting Manager, Engine and Propeller 

Directorate, Aircraft Certification Service.

[FR Doc. 04–13773 Filed 6–21–04; 8:45 am] 

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2004–18024; Directorate 

Identifier 2003–NE–39–AD; Amendment 39–

13684; AD 2004–13–03] 

RIN 2120–AA64 

Airworthiness Directives; Rolls-Royce 

(1971) Limited, Bristol Engine Division 

Model Viper Mk.601–22 Turbojet 

Engine

AGENCY: Federal Aviation 

Administration (FAA), DOT.

ACTION: Final rule; request for 

comments. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for RollsRoyce (1971) Limited, Bristol Engine 

Division (RR) Model Viper Mk.601–22 

turbojet engines. This AD requires 

reducing the life of certain 1st stage 

turbine rotor blades from 7,000 hours 

time-in-service (TIS) to 4,600 hours TIS, 

and provides a drawdown schedule for 

blades that have already exceeded the 

new reduced life limit. This AD results 

from the manufacturer’s investigations 

into failures of 1st stage turbine rotor 

blades. We are issuing this AD to 

prevent multiple failures of 1st stage 

turbine rotor blades that could result in 

a dual-engine shutdown.

DATES: Effective July 7, 2004. 

We must receive any comments on 

this AD by August 23, 2004.

ADDRESSES: Use one of the following 

addresses to submit comments on this 

proposed AD. 

• DOT Docket Web site: Go to http:/

/dms.dot.gov and follow the instructions 

for sending your comments 

electronically. 

• Government-wide rulemaking Web 

site: Go to http://www.regulations.gov

and follow the instructions for sending 

your comments electronically. 

• Mail: Docket Management Facility; 

U.S. Department of Transportation, 400 

Seventh Street, SW., Nassif Building, 

Room PL–401, Washington, DC 20590–

001. 

• Fax: (202) 493–2251. 

• Hand Delivery: Room PL–401 on 

the plaza level of the Nassif Building, 

400 Seventh Street, SW., Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

You can get the service information 

identified in this AD from Rolls-Royce 

Limited, Bristol Engines Division, 

Technical Publications Department 

CLS–4, P.O. Box 3, Filton, Bristol, BS34 

7QE England; telephone 117–979–1234, 

fax 117–979–7575. 

You may examine the comments on 

this AD in the AD docket on the Internet 

at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Ian 

Dargin, Aerospace Engineer, Engine 

Certification Office, FAA, Engine and 

Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803–

5299; telephone (781) 238–7178; fax 

(781) 238–7199.

SUPPLEMENTARY INFORMATION: The Civil 

Aviation Authority (CAA), which is the 

airworthiness authority for the United 

Kingdom (UK), recently notified the 

FAA that an unsafe condition may exist 

on RR model Viper Mk.601–22 turbojet 

engines. The CAA advises that 

inspections of 1st stage turbine rotor 

blades, part numbers (P/Ns) V926000, 

V926293, and V926319, from engines 

that were returned from the field have 

identified cracks in the blade airfoil at 

an increasing rate. Under the current 

requirements to replace the blades at 

7,000 hours TIS, the risk of dual-engine 

shutdowns is unacceptable. Reducing 

the class B life of these 1st stage turbine 

blades, recommended in Chapter 5 of 

the engine manual, from 7,000 hours 

TIS to a mandatory life limit of 4,600 

hours TIS reduces the risk of dualengine shutdowns. 

Relevant Service Information 

We have reviewed and approved the 

technical contents of RR Alert Service 

Bulletin (ASB) 72–A184, dated January 

2001, that describes procedures for 

managing engine configurations to 

reduce the risk of dual-engine 

shutdowns. The CAA classified this 

service bulletin as mandatory and 

issued AD 004–01–2001 in order to 

ensure the airworthiness of these RR 

engines in the UK. 

Differences Between This AD and the 

Service Information 

RR ASB 72–A184, dated January 

2001, specifies the date of receipt of the 

ASB as the baseline for the compliance 

time. This AD specifies the effective 

date of this AD as the baseline for the 

compliance time. 

Bilateral Airworthiness Agreement

This engine model is manufactured in 

the UK and is type certificated for 

operation in the United States under the 

provisions of section 21.29 of the 

Federal Aviation Regulations (14 CFR 

21.29) and the applicable bilateral 

airworthiness agreement. Under this 

bilateral airworthiness agreement, the 

CAA has kept the FAA informed of the 

situation described above. We have 

examined the findings of the CAA, 

reviewed all available information, and 

determined that AD action is necessary 

for products of this type design that are 

certificated for operation in the United 

States.