AD 2001-26-22

This amendment adopts a new airworthiness directive (AD), applicable to certain BAE Systems (Operations) Limited Model Avro 146-RJ series airplanes, that requires a one-time inspection of the S4 and S5 static pipes of the pitot static system for discrepancies, and follow-on corrective actions, if necessary. This action is necessary to prevent failure of the S4 and S5 static pipes and consequent failure of the maximum differential pressure protection for the airplane, which could lead to the fuselage of the airplane being overstressed and result in reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

Final rule

2001-26-22 BAE Systems (Operations) Limited (Formerly British Aerospace Regional Aircraft): Amendment 39-12588. Docket 2001-NM-90-AD.

Applicability: Model Avro 146-RJ series airplanes, certificated in any category, on which modification HCM01080W is installed.

Note 1: This AD applies to each airplane 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 airplanes 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 (b) 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 toaddress it.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the S4 and S5 static pipes of the pitot static system and consequent failure of the maximum differential pressure protection for the airplane, which could lead to the fuselage of the airplane being overstressed and result in reduced structural integrity of the airplane, accomplish the following:

General Visual Inspection/Follow-On Corrective Actions

(a) Within 90 days after the effective date of this AD, do a general visual inspection of the S4 and S5 static pipes of the pitot static system for discrepancies (i.e., chafing, damage to pipes, inadequate clearance), per BAE Systems (Operations) Limited Inspection Service Bulletin ISB.34-338, dated February 14, 2001.

Note 2: For the purposes of this AD, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked."

(1) If any chafing is found, before further flight, do the applicable follow-on actions per the Accomplishment Instructions of the service bulletin. Where the service bulletin specifies to contact the manufacturer for disposition of certain repair conditions, the repair of those conditions is to be accomplished per a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority (or its delegated agent).

(2) If no chafing is found and the clearance between the static pipes and the adjacent avionics structure is less than 0.10 inch, before further flight, do the applicable follow-on actions per the Accomplishment Instructions of the service bulletin.

(3) If no chafing is found and a minimum clearance of 0.10 inch exists between the static pipes and the adjacent avionics structure, no further action is required by this AD.

Alternative Methods of Compliance

(b) 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, International Branch, ANM-116. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

Special Flight Permits

(c) 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 requirements of this AD can be accomplished.

Incorporation by Reference

(d) Except as provided by paragraph (a)(1) of this AD, the actions shall be done in accordance with BAE Systems (Operations) Limited Inspection Service Bulletin ISB.34-338, dated February 14, 2001. 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 British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 4: The subject of this AD is addressed in British airworthiness directive 008-02-2001.

Effective Date

(e) This amendment becomes effective on February 8, 2002.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain BAE Systems (Operations) Limited Model Avro 146-RJ series airplanes was published in the Federal Register on August 23, 2001 (66 FR 44311). That action proposed to require a one-time inspection of the S4 and S5 static pipes of the pitot static system for discrepancies, and follow-on corrective actions, if necessary.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

Revised Statement of Unsafe Condition

The commenter, the airplane manufacturer, requests that the FAA revise the wording of the statement of unsafe condition as it appears in several sections of the proposed AD. The proposed AD states the unsafe condition as "holes in the static pipes, erroneous input to the instrumentation and warning systems associated with the pilot's instruments, and consequent reduced controllability of the airplane." The commenter states that the consequence of holes in the static pipes is more accurately characterized as "erroneous input into instrumentation associated with the maximum differential pressure protection for the aircraft."

The FAA concurs. Upon further review of the detail of the design and function of the S4 and S5 static types, we agree that the primary purpose of the S4 and S5 static pipes is maintenance of the maximum differential pressure protection for the airplane. If these pipes fail, the maximum differential pressure protection will fail, which could lead to the fuselage of the airplane being overstressed and result in reduced structural integrity of the airplane. Therefore, we have revised the statement of unsafe condition in the Summary section and the body of this AD accordingly.

Explanation of Change to Applicability StatementThe applicability statement of the proposed AD reads, "Model Avro 146-RJ series airplanes * * * on which modification HCM01080W has been performed." For clarity, we have revised the wording of the applicability statement in this final rule to read, "Model Avro 146-RJ series airplanes * * * on which modification HCM01080W is installed."

Conclusion

After careful review of the available data, including the comment 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.

Cost Impact

The FAA estimates that 42 Model Avro 146-RJ series airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of this AD on U.S. operators is estimated to be $2,520, or $60 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

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 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 FederalAviation 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.

Sec. 39.13 [Amended]

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