Airworthiness Directives; BAE Systems (Operations) Limited Model BAe 146 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all BAE Systems (Operations) Limited Model BAe 146 series airplanes. This proposal would require repetitive detailed inspections of the inside of each air conditioning sound-attenuating duct, and corrective actions as necessary. This action is necessary to prevent impairment of the operational skills and abilities of the flightcrew caused by the inhalation of agents released from oil or oil breakdown products, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 17, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-94-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-94-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1175; fax (425) 227-1149.

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 shall identify the Rules Docket number and be submitted in triplicate 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 action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-94-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, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-94-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on all BAE Systems (Operations) Limited Model BAe 146 series airplanes. The CAA advises that incidents have been reported involving impaired performance of the flightcrew. The impaired performance may have resulted from the flightcrew's inhalation of agents released from the breakdown of oil, which leaked and contaminated the environmental control system; or from unidentified cabin/flight deck odors. The preliminary investigations did not provide substantiating evidence indicating that the inhalation of oil or oil breakdown products could impair flightcrew performance. However, more extensive investigations are being done to determine the nature of any agents that may be released into the cabin/flight deck environments and to identify any necessary corrective actions. While these investigations are being done, oil leaks and cabin/flight deck odors should be regarded as potential threats to flight safety. The possibility of odors and toxic fumes entering the cabin/flight deck, if not corrected, could result in impairment of the operational skills and abilities of the flightcrew, caused by the inhalation of agents released from oil or oil breakdown products, which could result in reduced controllability of the airplane.

Explanation of Relevant Service Information

BAE Systems (Operations) Limited has issued Inspection Service Bulletin ISB.21-156, dated October 31, 2002, which describes procedures for repetitive inspections of each air conditioning sound-attenuating duct for the presence of oil contamination, and corrective action as necessary. These procedures include inspecting for signs of contamination on the inside of the mixing chamber duct/filter housing of each air conditioning sound-attenuating duct. The service bulletin also includes the criteria for distinguishing between normal contamination and oil contamination on the inside of the ducts to determine if a duct should be considered contaminated. The rejection criteria include:

• Squeezing the inner and outer skins of the sound-attenuating duct together. Any evidence of oil seepage through the inner surface of the duct is unacceptable.
• Using the sense of smell. Any strong and obvious odor of oil, sweaty socks, “locker rooms,” or rancid cheese may indicate the presence of oils or oil breakdown products. The service bulletin recommends that operators determine if any odor from the duct is consistent with previous flightcrew or passenger complaints of odor in the flight deck/cabin.

The corrective actions include replacing any contaminated sound-attenuating duct with new parts, and cleaning the mixing chamber duct/filter housing.

The CAA classified this service bulletin as mandatory and issued British airworthiness directive 003-10-2002 to ensure the continued airworthiness of these airplanes in the United Kingdom.

Related AD

The FAA has issued a related AD, AD 2004-05-11, amendment 39-13506 (69 FR 11297, March 10, 2004), which is applicable to all BAE Systems (Operations) Limited Model BAe 146 series airplanes. Among other things, that AD requires repetitive general visual inspections of the inside of the condenser regenerative air ducts, air cycle machine turbine outlet, and the jet pump ducts on each air conditioning pack to detect oil and/or oil breakdown products. This action proposes a detailed inspection of the inside of each of the four air conditioning sound-attenuating ducts for the presence of contamination from oil and/or oil breakdown products on the same model airplanes.

FAA's Conclusions

This airplane model is manufactured in the United Kingdom 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. 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.

Explanation of Requirements of Proposed AD

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Among the British Airworthiness Directive, Service Bulletin, and Proposed AD

The British airworthiness directive and the service bulletin both specify that the inspection should be done at the next “A-check,” or within 500 flights after November 30, 2002; and repeated at every “C-check.” Because “A-check” and “C-check” schedules vary among operators, this proposed AD would require accomplishment of the inspection within 120 days or 500 flight cycles after the effective date of this proposed AD, whichever is first, and repetitive inspections thereafter at intervals not to exceed 4,000 flight cycles. We find that a compliance time of 120 days or 500 flight cycles after the effective date of the AD, whichever is first, and repetitive inspections thereafter at intervals not to exceed 4,000 flight cycles, are appropriate for affected airplanes to continue to operate without compromising safety. Although the Accomplishment Instructions of the service bulletin specify to report inspection results to the manufacturer, this proposed AD does not require that action.

Clarification of Type of Inspection

The British airworthiness directive and the service bulletin specify that operators do an inspection of the inside of each air conditioning sound-attenuating duct. This proposed AD requires a “detailed” inspection. Note 1 has been included in this proposed AD to define this type of inspection.

Interim Action

This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.

Cost Impact

We estimate that 20 airplanes of U.S. registry would be affected by this proposed AD, and that it would take approximately 5 work hours per airplane to accomplish the proposed inspections. The average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $6,500, or $325 per airplane, per inspection cycle.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed 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 proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed 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) 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.