01-28809. Airworthiness Directives; British Aerospace Models HP.137 Jetstream Mk.1, Jetstream Series 200, and Jetstream Series 3101 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); Reopening of the comment period.

SUMMARY:

This document proposes to revise an earlier proposed airworthiness directive (AD) that applies to British Aerospace Models HP.137 Jetstream Mk.1, Jetstream Series 200, and Jetstream Series 3101 airplanes. This proposed AD would supersede Airworthiness Directive (AD) 98-13-03, which currently requires repetitive inspections of the main landing gear (MLG) hinge fittings, support angles, and attachment bolts and requires eventual installation of improved design MLG hinge fittings as terminating action for the repetitive inspections of the hinge fittings and attachment bolts. AD 98-13-03 specifies repetitive inspections of the support angles for those airplanes with the improved design MLG hinge fittings installed and exempts from the applicability those airplanes with the improved design MLG hinge fittings installed. The earlier NPRM would have retained the requirements of AD 98-13-03 and would have removed the applicability exemption of those Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes with the improved design MLG hinge fittings installed. British Aerospace has informed us that it will not provide the improved design MLG hinge fittings free of charge. Since the cost burden has changed from the manufacturer to the owners/operators of the affected airplanes, we are reopening the comment period to allow the public the chance to comment on this additional cost burden.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before December 21, 2001.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-58-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? We specifically invite 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 us to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2000-CE-58-AD.” We will date stamp and mail the postcard back to you.

Discussion

Has FAA taken any action on the main landing gear (MLG) hinge fittings, support angles, and attachment bolts on British Aerospace Models HP.137 Jetstream Mk.1, Jetstream Series 200, and Jetstream Series 3101 airplanes to this point? On June 8, 1998, FAA issued AD 98-13-03, Amendment 39-10591 (63 FR 33532, June 19, 1998). This AD currently requires the following on the above-referenced airplanes:

—Repetitive inspections of the MLG hinge fitting, support angles, and attachment bolts, and repairing or replacing any part that is cracked; and

—Eventual installation of improved design MLG hinge fittings, part number (P/N) 1379133B1 and 1379133B2 (Modification 5218), as terminating action for the repetitive inspections of the hinge fittings and attachment bolts. This AD specifies repetitive inspections of the support angles for those airplanes with the improved design MLG hinge fittings installed. However, the applicability of AD 98-13-03 exempts those airplanes with the improved design MLG hinge fittings installed from the actions of the AD.

Accomplishment of these actions is required in accordance with the following service information:

—British Aerospace Jetstream Mandatory Service Bulletin (MSB) No. 7/5, which includes procedures for inspecting the left and right main landing gear hinge attachment nuts to the auxiliary and aft spars for signs of relative movement between the nuts and hinge fitting on Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes. This MSB incorporates the following effective pages:

Pages	Revision level	Date
2 and 4	Original Issue	Mar. 31, 1982.
1 and 3	Revision 1	May 23, 1988.

—British Aerospace MSB No. 7/8, which includes procedures for inspecting the MLG hinge fitting for cracks, and repairing cracked hinge fittings on Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes. This MSB incorporates the following effective pages:

Pages	Revision level	Date
2, 5, 6, 7, and 8	Revision 2	Jan. 6, 1983.
1, 3, and 4	Revision 3	May 23, 1988.

—Jetstream Alert Service Bulletin (ASB) 32-A-JA 850127, which includes procedures for inspecting the MLG hinge fitting and support angle for cracks on Jetstream Series 3101 airplanes. This ASB incorporates the following effective pages:

Pages	Revision level	Date
5 through 14	Original Issue	April 17, 1985.
1 through 4	Revision 2	Nov. 11, 1994.

—Jetstream Service Bulletin (SB) 57-JM 5218, which includes procedures for installing improved design MLG hinge fittings, P/N 1379133B1 and 1379133B2 (Modification 5218), on Models HP.137 Jetstream Mk.1, Jetstream Series 200, and certain Jetstream Series 3101 airplanes. This SB incorporates the following effective pages:

Pages	Revision level	Date
11, 12, 17, 18, 19, 21, 22, 23, 24, 27, 28, 29, 30, and 31	Revision 1	Sept. 29, 1987.
20	Revision 3	Jan. 29, 1990.
13 and 14	Revision 4	Oct. 31, 1990.
1 through 10, 15, 16, 25, and 26	Revision 5	July 28, 1997.

The actions of AD 98-13-03 are consistent with our aging commuter aircraft policy, which briefly states that, when a modification exists that could eliminate or reduce the number of required critical inspections, the modification should be incorporated. This policy is based on our determination that reliance on critical repetitive inspections on airplanes utilized in commuter service carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections.

The alternative to installing improved design MLG hinge fittings would be to repetitively inspect this area for the life of the airplane.

What has happened since AD 98-13-03 to initiate this action? Since AD 98-13-03 became effective, FAA has received comments regarding the applicability. The applicability of AD 98-13-03 exempts those airplanes with the improved design MLG hinge fittings installed as of the effective date of the AD. However, those airplanes that have the improved design MLG hinge fittings incorporated after the effective date of the AD are subject to repetitive inspections of the MLG support angles. Our intent was to require the inspections of the MLG support angles regardless of when the improved design MLG hinge fittings are incorporated.

Therefore, we then determined that the exemption of those airplanes with the improved design MLG hinge fittings installed should be removed, and that all affected airplanes should have the MLG support angles repetitively inspected.

Has FAA taken any action to this point? We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain British Aerospace Models HP.137 Jetstream Mk.1, Jetstream Series 200, and Jetstream Series 3101 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on July 18, 2001 (66 FR 37435). The NPRM proposed to supersede AD 98-13-03. The NPRM also proposed to:

—Retain the requirement of repetitively inspecting the main landing gear (MLG) hinge fittings, support angles, and attachment bolts and the requirement of repairing any cracked part;

—Require eventual installation of improved design MLG hinge fittings as terminating action for the repetitive inspections of the hinge fittings and attachment bolts; and

—Require repetitive inspections of the MLG support angles on all affected airplanes, even those with the improved design MLG hinge fittings installed.

Was the public invited to comment? The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment:

Comment Issue No. 1: Change or Clarify the Applicability for the Model Jetstream 3101 Series Airplanes

What is the commenter's concern? Two commenters question FAA's intent for the Model Jetstream 3101 Series airplanes, as follows:

—One commenter states that the AD should not require repetitive inspections of the support angles on the Model Jetstream 3101 Series airplanes once Modification JM5218 is incorporated. This commenter explains that this is explained in the most recent revised pages (Revision 5) of Jetstream SB 57-JM 5218.

—Another commenter states that we should have extended the applicability to all serial numbers of the Jetstream 3101 Series airplanes if we wanted the support angles of all post-modification 5218 MLG fittings inspected. British Aerospace incorporated these fittings at the factory beginning with serial number 696. The applicability of the NPRM covered Model Jetstream 3101 Series airplanes up to serial number 695.

What is FAA's response to the concern? We concur that the AD should reflect that the repetitive inspections of the support angles do not apply to Model Jetstream Series 3101 airplanes that have Modification JM5218 incorporated. At the time of issuing the NPRM, we did not have the revised pages (Revision 5) of that service bulletin.

We are changing this proposed AD to reflect this change.

Making this change also takes care of the concern for requiring the inspections on those Model Jetstream Series 3101 airplanes that have serial number of 696 or higher. Since these airplanes had Modification JM5218 incorporated at the factory, the repetitive inspections of the support angles are not necessary.

The need for the repetitive inspections of the support angles on Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes still exists.

Comment Issue No. 2: Change the Cost Information To Reflect That British Aerospace Will Not Provide MLG Fittings Free of Charge

What is the commenter's concern? One commenter states that, because British Aerospace considers Modification JM5218 optional, the company is not providing the MLG fittings at no cost, as indicated in the NPRM. The current cost of these parts is $14,000 per airplane.

What is FAA's response to the concern? The FAA will revise the Cost Impact section of the final rule AD to reflect this change. Because this shifts the cost burden of these improved design MLG hinge fittings from the manufacturer to the owner/operator, we will reopen the comment period for this proposed AD.

Comment Issue No. 3: Require the Incorporation of Modification JM5218 to Reflect the Aging Aircraft Policy

What is the commenter's concern? One commenter states that FAA should mandate the incorporation of Modification JM5218 in order to be consistent with the agency's aging aircraft policy. This policy briefly states that, when a modification exists that could eliminate or reduce the number of required critical inspections, the modification should be incorporated. The policy is based on FAA's determination that reliance on critical repetitive inspections on airplanes utilized in commuter service carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections.

What is FAA's response to the concern? Paragraph (d)(3) of the NPRM currently requires installing improved design MLG hinge fittings, part number (P/N) 1379133B1 (or FAA-approved equivalent P/N) and P/N 1379133B2 (or FAA-approved equivalent P/N) upon accumulating 20,000 landings on each MLG hinge fitting or within the next 50 landings after June 8, 1998 (the effective date of AD 98-13-03), whichever occurs later. These installations are Modification JM5218 so the commenter's concern is already incorporated in the NPRM.

We will add a statement in this proposed AD to indicate that these installations and Modification JM5218 are the same.

The FAA's Determination

What has FAA decided? After examining the circumstances and reviewing all available information related to the incidents described above, we have determined that:

—The unsafe condition exists or could develop on British Aerospace Models HP.137 Jetstream Mk.1, Jetstream Series 200, and Jetstream Series 3101 airplanes;

—The comment period should be reopened to allow the public the opportunity to comment on the change in the cost impact; and

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

The Supplemental NPRM

How will the changes to the NPRM impact the public? Since British Aerospace is not providing the MLG fittings free of charge as indicated in the NPRM, the $14,000 burden for these parts is on the owners/operators of the affected airplanes. Because this shifts the cost burden of these improved design MLG hinge fittings from the manufacturer to the owner/operator, we will reopen the comment period for this proposed AD.

What are the provisions of the supplemental NPRM? The provisions of this supplemental NPRM are the same as previously published.

Cost Impact

How many airplanes does this AD impact? We estimate that this AD affects 236 airplanes in the U.S. registry.

What is the cost impact of this AD on owners/operators of the affected airplanes? The FAA estimates that this AD will affect 71 airplanes in the U.S. registry. We estimate the following costs to accomplish the actions:

	Labor cost	Parts cost	Per airplane cost	Fleet cost
Initial Inspection	61 workhours × $60 per hour = $3,660	Not Applicable	$3,660 per airplane	71 airplanes × $3,660 = $259,860.
Hinge Fitting Installation	210 workhours × $60 per hour = $12,600	$14,000 per airplane	$26,600 per airplane	71 airplanes × $26,600 per hour = $1,888,600.
Repetitive Support Angle Inspections	10 workhours × $60 per hour = $600 per inspection	Not applicable	$600 per airplane per inspection	71 airplanes × $600 = $42,600 per inspection.

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 removing Airworthiness Directive (AD) 98-13-03, Amendment 39-10591 (63 FR 33532, June 19, 1998), and by adding a new AD to read as follows:

British Aerospace: Docket No. 2000-CE-58-AD; Supersedes AD 98-13-03, Amendment 39-10591.

(a) What airplanes are affected by this AD? This AD affects the following airplane models and serial numbers that are certificated in any category:

Model	Serial No.
HP.137 Jetstream Mk.1	All serial numbers
Jetstream Series 200	All serial numbers
Jetstream Series 3101	601 through 695 that do not have Jetstream Service Bulletin 57-JM 5218 incorporated (using the applicable Revision 4 or Revision 5 pages)

(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 detect, correct, and prevent future fatigue cracking of the main landing gear (MLG), which could result in structural failure of the MLG and consequent loss of airplane control during takeoff, landing, or taxi operations.

Note 1:

The compliance times of this AD are presented in landings. If you do not keep the total number of landings, then you may multiply the total number of airplane hours time-in-service (TIS) by 0.75.

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

Actions	Compliance	Procedures
(1) For the Models HP.137 Jetstream Mk.1 and Jetstream 200 Series airplanes, accomplish the following if part number (P/N) 1379133B1 (or FAA-approved equivalent P/N) and P/N 1379133B2 (or FAA-approved equivalent P/N) MLG hinge fittings are not installed. These installations are Modification 5218: (i) Inspect the MLG hinge attachment nuts to auxiliary and aft spars on both the left and right MLG for signs of fuel leakage or signs of relative movement between the nuts and hinge fitting (ii) If any signs of fuel leakage or relative movement between the nuts and hinge fitting are found during any inspection required by paragraph (d)(1)(i) of this AD, resecure the MLG hinge fitting to auxiliary spar (iii) You may terminate the above inspections when Modification 5218 is incorporated. The repetitive inspections of the MLG hinge support angles as required by paragraph (d)(2) of this AD are still required	Inspect within the next 50 landings after June 8, 1998 (the effective date of this AD 98-13-03) or within 200 landings after the last inspection required by AD 98-13-03, whichever occurs later, and thereafter at intervals not to exceed 200 landings. Resecure the MLG hinge fitting prior to further flight after the applicable inspection	Use the service information presented in paragraph (e)(1) of this AD.
(2) For all airplanes regardless of the MLG hinge fitting installed, inspect the MLG hinge support angles for cracks. If any crack(s) is/are found in the support angles, replace the cracked MLG hinge fitting(s) with a P/N 1379133B1 (or FAA-approved equivalent P/N) or P/N 1379133B2 (or FAA-approved equivalent P/N) fitting (i) For all airplanes: you may terminate the repetitive inspection requirement of paragraphs (d)(1)(i) and (d)(1)(ii) of this AD after incorporating Modification JM5218 on both sides of the airplane (ii) For the Jetstream 3101 Series airplanes: the repetitive inspections of the MLG support angles required by paragraph (d)(2) of this AD are no longer required after incorporating Modification JM5218 on both sides of the airplane (iii) If Modification JM5218 is incorporated on both sides of a Jetstream 3101 Series airplane in accordance with the provisions of AD 98-13-03, then the intent of paragraph (d)(3) of this AD is met and paragraph (d)(4) of this AD is the only paragraph that applies (iv) For the affected Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes: the repetitive inspections of the MLG support angles required by paragraph (d)(2) of this AD are still required after incorporating Modification JM5218	Inspect upon accumulating 4,000 landings on the MLG fitting or within the next 50 hours TIS after the effective date of this AD, whichever occurs later, unless already accomplished, and thereafter at intervals not to exceed 400 hours TIS. Accomplish any necessary replacement prior to further flight after the inspection where the cracked support angle(s) is/are found	Inspect in accordance with the service information presented in paragraph (e)(2) or (e)(3) of this AD, as applicable. Replace in accordance with the service information presented in paragraph (e)(4) of this AD.
(3) For all airplanes, install improved design MLG hinge fittings, P/N 1379133B1 (or FAA-approved equivalent P/N) and P/N 1379133B2 (or FAA-approved equivalent P/N). These installations are Modification JM5218 (i) For all airplanes: you may terminate the repetitive inspection requirement of paragraphs (d)(1)(i) and (d)(1)(ii) of this AD after incorporating Modification JM5218 on both sides of the airplane (ii) For the Jetstream 3101 Series airplanes: the repetitive inspections of the MLG support angles required by paragraph (d)(2) of this AD are no longer required after incorporating Modification JM5218 on both sides of the airplane (iii) If Modification JM5218 is incorporated on both sides of a Jetstream 3101 Series airplane in accordance with the provisions of AD 98-13-03, then the intent of paragraph (d)(3) of this AD is met and paragraph (d)(4) of this AD is the only paragraph that applies (iv) For the affected Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes: the repetitive inspections of the MLG support angles required by paragraph (d)(2) of this AD are still required after incorporating Modification JM5218	Upon accumulating 20,000 landings on each MLG hinge fitting or within the next 50 landings after June 8, 1998 (the effective date of AD 98-13-03), whichever occurs later, unless already accomplished	In accordance with the service information presented in paragraph (e)(4) of this AD.
(4) Do not install, on any affected airplane, MLG hinge fittings that are not P/N 1379133B1 (or FAA-approved equivalent P/N) or P/N 13790133B2 (or FAA-approved equivalent P/N)	As of the effective date of this AD	Not applicable.

(e) What service information applies to this AD? You must accomplish the actions of this AD in accordance with the following service bulletins:

(1) British Aerospace Jetstream Mandatory Service Bulletin No. 7/5, which applies to the affected Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes and incorporates the following pages:

Pages	Revision level	Date
2 and 4	Original Issue	Mar. 31, 1982.
1 and 3	Revision 1	May 23, 1988.

(2) British Aerospace Mandatory Service Bulletin No. 7/8, which applies to the affected Models HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes and incorporates the following effective pages:

Pages	Revision level	Date
2, 5, 6, 7, and 8	Revision 2	Jan. 6, 1983.
1, 3, and 4	Revision 3	May 23, 1988.

(3) Jetstream Alert Service Bulletin 32-A-JA 850127, which applies to the affected Jetstream Series 3101 airplanes and incorporates the following effective pages:

Pages	Revision level	Date
5 through 14	Original Issue	April 17, 1985.
1 through 4	Revision 2	Nov. 11, 1994.

(4) Jetstream Service Bulletin 57-JM 5218, which applies to all of the affected airplanes and incorporates the following effective pages:

Pages	Revision level	Date
11, 12, 17, 18, 19, 21, 22, 23, 24, 27, 28, 29, 30, and 31	Revision 1	Sept. 29, 1987.
20	Revision 3	Jan. 29, 1990.
13 and 14	Revision 4	Oct. 31, 1990.
1 through 10, 15, 16, 25, and 26	Revision 5	July 28, 1997.

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

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

(ii) 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.

(2) Alternative methods of compliance approved in accordance with

AD 98-13-03, which is superseded by this AD, are approved as alternative methods of compliance with this AD.

Note 2:

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(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 you have not eliminated the unsafe condition, specific actions you propose to address it.

(g) 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].

(h) 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.

(i) How do I get copies of the documents referenced in this AD? You may obtain 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 examine these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

(j) Does this AD action affect any existing AD actions? This amendment supersedes AD 98-13-03, Amendment 39-10591.

Issued in Kansas City, Missouri, on November 13, 2001.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.