02-3163. Airworthiness Directives; British Aerospace Model HP.137 Jetstream Mk.1, Jetstream Series 200, and Jetstream Series 3101 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment supersedes Airworthiness Directive (AD) 98-13-03, which currently requires repetitive inspections of the main landing gear (MLG) hinge fittings, support angles, and attachment bolts on British Aerospace Model HP.137 Jetstream Mk.1, Jetstream Series 200, and Jetstream Series 3101 airplanes. AD 98-13-03 also 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. This AD retains the requirements of AD 98-13-03 and removes the applicability exemption of those Model HP.137 Jetstream Mk.1 and Jetstream Series 200 airplanes with the improved design MLG hinge fittings installed. The actions specified by this AD are intended to detect, correct, and prevent future fatigue cracking of the MLG, which could result in structural failure of the MLG and consequent loss of airplane control during takeoff, landing, or taxi operations.

DATES:

This AD becomes effective on April 2, 2002.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of April 2, 2002.

ADDRESSES:

You may get the service information referenced in this AD from British Aerospace Regional Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland; telephone: [phone]; facsimile: [phone]. You may view this information at the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-58-AD, 901 Locust, Room 506, Kansas City, Missouri 64106; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

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:

Discussion

Has FAA Taken any Action on the Main Landing Gear (MLG) Hinge Fittings, Support Angles, and Attachment Bolts on British Aerospace Model 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 Model 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	March 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 Model 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	January 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	November 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 Model 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	September 29, 1987.
20	Revision 3	January 29, 1990.
13 and 14	Revision 4	October 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 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.

Consequently, 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.

Based on comments received on this NPRM, we made minor changes to the proposed action. Another comment indicated that the manufacturer was not providing parts to accomplish the proposed action free of charge as previously referenced. Because this shifts the cost burden of these improved design MLG hinge fittings from the manufacturer to the owner/operator, we reopened the comment period for this proposed AD and issued a supplemental NPRM.

This supplemental NPRM was published in the Federal Register on November 19, 2001 (66 FR 57890). We received no comments on this supplemental NPRM.

FAA's Determination

What Is FAA's Final Determination on This Issue?

We carefully reviewed all available information related to the subject presented above and determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial changes. We have determined that these changes:

—Provide the intent that was proposed in the NPRM for correcting the unsafe condition; and

—Do not add any additional burden upon the public than was already proposed in the NPRM.

Cost Impact

How Many Airplanes Does This AD Impact?

We estimate that this AD affects 71 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 = $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

Does This AD Impact Various Entities?

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.

Does This AD Involve a Significant Rule or Regulatory Action?

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 copy of the final 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
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under 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. 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:

2002-03-02 British Aerospace: Amendment 39-12643; 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 airplanes identified in paragraph (a) of this AD 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 incorporate 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 inspection 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 AD 98-13-03) or within 200 landings TIS after the last inspection required by 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 (h)(1)(i) 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 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 each MLG hinge fitting or within the next 50 hours TIS after April 2, 2002 (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 (h)(1)(ii) or (h)(1)(iii) of this AD, as applicable. Replace in accordance with the service information presented in paragraph (h)(1)(iv) 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 incorporate 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 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.	Inspect in accordance with the service information presented in paragraph (h)(1)(iv) 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 1379133B2 (or FAA-approved equivalent P/N).	As of April 2, 2002 (the effective date of this AD).	Not Applicable.

(e) Can I comply with this AD in any other way?

(1) 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, Standards Office, 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, Standards Office, 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 (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) Are any service bulletins incorporated into this AD by reference?

(1) Actions required by this AD must be done in accordance with the following:

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

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

(ii) 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	January 6, 1983.
1, 3, and 4	Revision 3	May 23, 1988.

(iii) 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	November 11, 1994.

(iv) 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	September 29, 1987.
20	Revision 3	January 29, 1990.
13 and 14	Revision 4	October 31, 1990.
1 through 10, 15, 16, 25, and 26	Revision 5	July 28, 1997.

(2) The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51.

(3) You can get copies from British Aerospace Regional Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland. You can look at copies at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

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

(j) When does this amendment become effective? This amendment becomes effective on April 2, 2002.

Issued in Kansas City, Missouri, on February 5, 2002.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.