01-25048. Airworthiness Directives; British Aerospace Model HP.137 Jetstream Mk.1, Jetstream Series 200, Jetstream Series 3101, and Jetstream Model 3201 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to adopt a new airworthiness directive (AD) that would apply to all British Aerospace Model HP.137 Jetstream Mk.1, Jetstream Series 200, Jetstream Series 3101, and Jetstream Model 3201 airplanes that are equipped with certain main landing gear (MLG) radius rods. This proposed AD would require you to inspect the MLG radius rod cylinders for the required conductivity or hardness standard. This proposed AD would also require you to replace any MLG radius rod cylinder that does not meet this standard. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by this proposed AD are intended to prevent failure of the MLG due to incorrectly heat treated MLG radius rod cylinders. Such failure during takeoff, landing, or taxi operations, could lead to loss of airplane control.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before December 6, 2001.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-CE-34-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may view any comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except Federal holidays.

You may get service information that applies to this proposed AD from British Aerospace Regional Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland; telephone: [phone]; facsimile: [phone]. You may also view this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD? The FAA invites comments on this proposed rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments to the address specified under the caption ADDRESSES. We will consider all comments received on or before the closing date. We may amend this proposed rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of this proposed AD action and determining whether we need to take additional rulemaking action.

Are there any specific portions of this proposed AD I should pay attention to? The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of this proposed rule that might suggest a need to modify the rule. You may view all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each contact we have with the public that concerns the substantive parts of this proposed AD.

How can I be sure FAA receives my comment? If you want FAA to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2001-CE-34-AD.” We will date stamp and mail the postcard back to you.

Discussion

What events have caused this proposed AD? The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified FAA that an unsafe condition may exist on all British Aerospace Model HP.137 Jetstream Mk.1, Jetstream Series 200, Jetstream Series 3101, and Jetstream Model 3201 airplanes equipped with certain main landing gear (MLG) radius rods.

The CAA reports, that the manufacturer of the MLG radius rods, APPH Ltd., incorrectly heat treated a batch of radius rod cylinders, part number (P/N) 184811. Incorrect heat treatment of the MLG radius rod cylinder causes the part to be below required design strength. This results in reduced structural integrity of the part.

What are the consequences if the condition is not corrected? This condition, if not corrected, could result in failure of the MLG. Such failure during takeoff, landing, or taxi operations could lead to loss of airplane control.

Is there service information that applies to this subject? The following service bulletins apply to this subject:

—British Aerospace Alert Service Bulletin 32-A-JA-010740, Revision 2, Issued: July 23, 2001. This service bulletin specifies inspecting APPH Ltd. P/Ns 1847-A through 1847-L and 1862-A through 1862-L MLG radius rods;

—APPH Ltd. Service Bulletin No. 1847-32-08, dated July 2001. This service bulletin includes procedures for inspecting P/Ns 1847-A through 1847-L and 1848-A through 1848-F MLG radius rods for required conductivity or hardness standard; and

—APPH Ltd. Service Bulletin No. 1862-32-08, dated July 2001. This service bulletin includes procedures for inspecting P/Ns 1862-A through 1862-L and 1848-A through 1848-F MLG radius rods for conductivity or hardness standard.

What action did the CAA take? The CAA classified these service bulletins as mandatory and issued British AD Number 005-07-2001, not dated, in order to ensure the continued airworthiness of these airplanes in the United Kingdom.

Was this in accordance with the bilateral airworthiness agreement? These airplane models are manufactured in the United Kingdom 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 FAA informed of the situation described above.

The FAA's Determination and an Explanation of the Provisions of This Proposed AD

What has FAA decided? The FAA has examined the findings of the CAA; reviewed all available information, including the service information referenced above; and determined that:

—The unsafe condition referenced in this document exists or could develop on other British Aerospace Model HP.137 Jetstream Mk.1, Jetstream Series 200, Jetstream Series 3101, and Jetstream Model 3201 airplanes of the same type design that are equipped with the referenced MLG radius rods;

—The actions specified in the previously-referenced service information should be accomplished on the affected airplanes; and

—AD action should be taken in order to correct this unsafe condition.

What would this proposed AD require? This proposed AD would require you to inspect the MLG radius rods for the required conductivity or hardness standard and replace any rod that does not meet this standard.

Cost Impact

How many airplanes would this proposed AD impact? We estimate that this proposed AD affects 250 airplanes in the U.S. registry.

What would be the cost impact of this proposed AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the proposed inspection using the eddy current conductivity test:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
1 workhour per radius rod (2 per airplane) × $60 = $120	No parts required	$120	$30,000.

We estimate the following costs to accomplish the proposed inspection using the Rockwell hardness test:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
5 workhours per radius rod (2 per airplane) × $60 = $600	No parts required	$600	$150,000.

We estimate the following costs to accomplish any necessary replacements that would be required based on the results of the proposed inspection. We have no way of determining the number of airplanes that may need such replacement:

Labor cost for replacement of each main landing gear radius rod	Parts cost	Total cost per airplane
5 workhours × $60 = $300	$9,000	$9,300.

Are there differences between this proposed AD and the service information? British Aerospace Alert Service Bulletin 32-A-JA010740, Revision 2, Issued: July 23, 2001, specifies reporting the results of the inspections to British Aerospace Regional Aircraft. This proposed AD does not require this action. The FAA recommends that each owner/operator submit this information. We are including a note in this proposed AD to reflect this. British Aerospace and the British CAA will use this information to determine whether further action is necessary.

The FAA will evaluate the information from the British CAA and may initiate further rulemaking action.

Compliance Time of This Proposed AD

What is the compliance time of this proposed AD? The compliance time of this proposed AD is “within the next 30 calendar days after the effective date of this AD”.

Why is the compliance time presented in calendar time instead of hours time-in-service (TIS)? Failure of the MLG is an unsafe condition; however, it is not a direct result of airplane operation. The chance of this situation occurring is the same for an airplane with 10 hours TIS as it is for an airplane with 500 hours TIS. A calendar time for compliance will ensure that the unsafe condition is addressed on all airplanes in a reasonable time period.

Regulatory Impact

Would this proposed AD impact various entities? 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 proposed rule would not have federalism implications under Executive Order 13132.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed 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) 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 has been placed 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, under 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

[Amended]

2. FAA amends § 39.13 by adding a new airworthiness directive (AD) to read as follows:

British Aerospace: Docket No. 2001-CE-34-AD

(a) What airplanes are affected by this AD? This AD affects Model HP.137 Jetstream Mk.1, Jetstream Series 200, Jetstream Series 3101, and Jetstream Model 3201 airplanes, all serial numbers, that are:

(1) certificated in any category; and

(2) equipped with a main landing gear (MLG) radius rod, APPH Ltd. part number 1847-A through 1847-L, 1848-A through 1848-F, or 1862-A through 1862-L.

(b) Who must comply with this AD? Anyone who wishes to operate any of the above airplanes must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to prevent failure of the MLG due to incorrectly heat treated MLG radius rod cylinders. Such failure during takeoff, landing, or taxi operations could lead to loss of airplane control.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

Actions	Compliance	Procedures
(1) Inspect, using an eddy current conductivity tester, or the Rockwell hardness test, the left and right main landing gear (MLG) radius rods, part numbers (P/N) 1847-A through 1847-L, 1848-A through 1848-F, and 1862-A through 1862-L, for correct conductivity or hardness standard specified in the referenced service information	Within the next 30 calendar days after the effective date of this AD	In accordance with the Accomplishment Instructions section of British Aerospace Alert Service Bulletin 32-A-JA010740, Revision 2, Issued: July 23, 2001, APPH Ltd. Service Bulletin 1847-32-08, dated July 2001, APPH Ltd. Service Bulletin 1862-38-08, dated July 2001, and the applicable maintenance manual.
(2) If the results of the inspection are greater than 46% International Aluminum & Copper Standards (IACS) using the eddy current conductivity test, or less than 79 using the Rockwell hardness test, replace the MLG radius rod with an FAA-approved MLG radius rod meets the conductivity or hardness standard specified in the referenced service information	Within the next 90 calendar days after the inspection required in paragraph d(1) of this AD	In accordance with British Aerospace Alert Service Bulletin 32-A-JA010740, Revision 2, Issued: July 23, 2001, APPH Ltd. Service Bulletin 1847-32-08, dated July 2001, and APPH Ltd. Service Bulletin 1862-32-08, dated July 2001.
(3) If the results of the inspection are equal to or greater than 41.5% but less than or equal to 46% IACS using the eddy current conductivity test, or equal to or greater than 79 but less than or equal to 87 using the Rockwell hardness test, replace the MLG radius rod with an FAA-approved MLG radius rod that meets the conductivity or hardness requirements specified in the referenced service information	Within the next 180 calendar days after the inspection required in paragraph d(1) of this AD	In accordance with British Aerospace Alert Service Bulletin 32-A-JA010740, Revision 2, Issued: July 23, 2001, APPH Ltd. Service Bulletin 1847-32-08, dated July 2001, and APPH Ltd. Service Bulletin 1862-32-08, dated July 2001.
(4) If the results of the inspection are in the range of 36.5 and 41.5% using the eddy current conductivity test, or in the range of 87 and 90 using the Rockwell hardness test, no replacement of the MLG radius rod is required	Not applicable	In accordance with APPH Ltd. Service Bulletin 1847-32-08, dated July 2001, and APPH Ltd. Service Bulletin 1862-32-08, dated July 2001.
(5) Do not install, on any affected airplane, a P/N 1847-A through 1847-L, 1848-A through 1848-F, or 1862-A through 1862-L MLG radius rod, unless it has been inspected and is found to meet the conductivity or hardness standard specified in the service information	As of the effective date of this AD	In accordance with British Aerospace Alert Service Bulletin 32-A-JA010740, Revision 2, Issued: July 23, 2001.

Note 1:

The compliance time of this AD differs from that specified in British Aerospace Alert Service Bulletin 32-A-JA-010740, Revision 2, Issued July 23, 2001. This AD takes precedence over any other information.

Note 2:

British Aerospace Alert Service Bulletin 32-JA010740, Revision 2, Issued: July 23, 2001, specifies reporting the results of the inspections to British

Aerospace Regional Aircraft. The FAA highly recommends that each owner/operator submit this information. British Aerospace and the British Civil Airworthiness Authority (CAA) will use this information to determine whether further action is necessary. The FAA will evaluate the information from the British CAA and may initiate further rulemaking action.

(e) Can I comply with this AD in any other way? You may use an alternative method of compliance or adjust the compliance time if:

(1) Your alternative method of compliance provides an equivalent level of safety; and

(2) The Manager, Small Airplane Directorate, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

Note 3:

This AD applies to each airplane identified in paragraph (a) of this AD, regardless of whether it has been 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 (e) 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 you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? Contact Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

(g) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD.

(h) How do I get copies of the documents referenced in this AD? You may get copies of the documents referenced in this AD from British Aerospace Regional Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland; telephone: [phone]; facsimile: [phone]. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Note 4:

The subject of this AD is addressed in British AD Number 005-07-2001, not dated.

Issued in Kansas City, Missouri, on October 1, 2001.

Dorenda D. Baker,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.