AD 94-26-04

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Jetstream Model 4101 airplanes, that currently requires inspections to detect damage of the ball bearings in the aileron quadrants, replacement of damaged ball bearings with new ball bearings, and adjustment to the secondary stops. This amendment requires installation of new swivel bearings in the aileron quadrants, which, when accomplished, will terminate the inspection requirement. This amendment is prompted by the development of a modification that eliminates the need to inspect repetitively. The actions specified by this AD are intended to prevent failure of the bearings in the aileron quadrants, which could result in reduced controllability of the airplane.

Final rule.

94-26-04 JETSTREAM AIRCRAFT LIMITED: Amendment 39-9100. Docket 94-NM-25-AD. Supersedes AD 93-25-10, Amendment 39-8849.
Applicability: Model 4101 airplanes having constructors numbers 41004 and subsequent; on which Modification JM41307A or JM41307B has not been installed previously; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, 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 use the authority provided in paragraph (e) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the bearings in the aileron quadrants, which could result in reduced controllability of the airplane, accomplish the following:

(a) Within 7 days after March 28, 1994 (the effective date of AD 93-25-10, Amendment 39-8849), perform a detailed visual inspection to detect damage of the bearings in the aileron quadrant in the pilot's and co-pilot's aileron control, in accordance with Jetstream Aircraft Limited Alert Service Bulletin J41-A-27-026, Revision 1, dated December 7, 1993; or Revision 2, dated January 17, 1994.

(1) If no damaged bearing is found, repeat the inspection, thereafter, at intervals not to exceed 7 days.

(2) If any damaged bearing isfound, prior to further flight, replace the damaged bearing with a new bearing in accordance with the service bulletin, and repeat the inspection, thereafter, at intervals not to exceed 7 days.

NOTE 2: Paragraph (a) of this AD restates the requirement for an initial and repetitive inspections contained in paragraph (a) of AD 93-25-10. Therefore, for operators that have previously accomplished at least the initial inspection in accordance with AD 93-25-10, paragraph (a) of this AD requires that the next scheduled inspection be performed within 7 days after the last inspection performed in accordance with paragraph (a) of AD 93-25-10.

(b) Within 7 days after March 28, 1994 (the effective date of AD 93-25-10, Amendment 39-8849), adjust the aileron secondary stop in the pilot's and co-pilot's aileron control system in accordance with Jetstream Aircraft Limited Alert Service Bulletin J41-A-27-026, Revision 1, dated December 7, 1993; or Revision 2, dated January 17, 1994.

NOTE 3: Paragraph (b) of this AD restates the requirement to adjust the aileron secondary stop contained in paragraph (b) of AD 93-25-10. As allowed by the phrase "unless accomplished previously," if that requirement of AD 93-25-10 has been accomplished previously, this AD does not require that it be repeated.

(c) Within 7 days after March 28, 1994 (the effective date of AD 93-25-10, Amendment 39-8849), revise the Abnormal Procedures Section of the FAA-approved Airplane Flight Manual (AFM) to include the following. This may be accomplished by inserting a copy of this AD in the AFM.

"Where abnormal aileron control backlash is experienced by one pilot, the other pilot should assume control of the aircraft without using the disconnect facility. The disconnect facility should only be used in accordance with published procedures in cases of control restrictions or jamming."

NOTE 4: Paragraph (c) of this AD restates the requirement for an AFM revision contained in paragraph(c) of AD 93-25-10. As allowed by the phrase "unless accomplished previously," if that requirement of AD 93-25-10 has been accomplished previously, this AD does not require that it be repeated.

(d) Within 180 hours time-in-service after the effective date of this AD, install new swivel bearings in the left and right aileron quadrants (Modification JM41307A) in accordance with Jetstream Service Bulletin J41-27-027, dated January 17, 1994. Accomplishment of this modification constitutes terminating action for the requirements of this AD. The AFM revision required by paragraph (c) of this AD may be removed following accomplishment of this modification.

(e) 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, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

NOTE 5: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(f) 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.

(g) The actions shall be done in accordance with Jetstream Service Bulletin J41-27-027, dated January 17, 1994; and Jetstream Alert Service Bulletin J41-A-27-026, Revision 1, dated December 7, 1993, or Jetstream Alert Service Bulletin J41-A-27-026, Revision 2, dated January 17, 1994, as applicable. Revision 2 of Jetstream Alert Service Bulletin J41-A-27-026 contains the following list of effective pages:

Service Bulletin
Referenced and Date

Page Number
Revision Level
Shown on Page
Date
Shown on Page

J41-A-27-026
Revision 2
1-3

2
January 17, 1994
January 17, 1994
4-9
1
December 7, 1993

The incorporation by reference of Jetstream Alert Service Bulletin J41-A-27-026, Revision 1, dated December 7, 1993, was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51 as of March 28, 1994 (59 FR 11531, March 11, 1994). The incorporation by reference of the remainder of the service bulletins listed above is 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 Jetstream Aircraft, Incorporated, P.O. Box 16029, Dulles International Airport, Washington, DC 20041-6029. 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.

(h) This amendment becomes effective on January 26, 1995.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-25-10, Amendment 39-8849 (59 FR 11531, March 11, 1994), which is applicable to certain Jetstream Model 4101 airplanes, was published in the Federal Register on May 4, 1994 (59 FR 23031). The action proposed to require installation of new swivel bearings in the left and right aileron quadrants (Modification JM41307A) as terminating action for the currently required inspections.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

The FAA has recently reviewed the figures it has used over the past several years in calculating the economic impact of AD activity. In order to account for various inflationary costs in the airline industry, the FAA has determined that it is necessary to increase the labor rate used in these calculations from $55 per work hour to $60 per work hour. The economic impact information below has been revised to reflect this increase in the specified hourly labor rate.

As a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. Under these circumstances, at least one operator appears to have incorrectly assumed that its airplane was not subject to an AD. On the contrary, all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been added to this final rule to clarify this requirement. The FAA has determined that this addition will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 8 airplanes of U.S. registry will be affected by this AD.

The inspections that were previously required by AD 93-25-10, and retained in this amendment, take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the total cost impact of these inspection requirements on U.S. operators is estimated to be $480, or $60 per airplane, per inspection cycle.

The adjustment to the secondary stops that were previously required by AD 93-25-10, and retained in this amendment, take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures,the total cost impact of this adjustment requirement on U.S. operators is estimated to be $480, or $60 per airplane. The FAA estimates that all affected U.S. operators have already accomplished this action; therefore, the future cost impact of this requirement is minimal.

The installation of new swivel bearings (Modification JM41307A) that will be required by this amendment will take approximately 10 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operator. Based on these figures, the total cost impact of the modification requirement of this AD on U.S. operators is estimated to be $4,800, or $600 per airplane.

The total 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 regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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 atthe 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 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

39.13 - [Amended]
2. Section 39.13 is amended by removing amendment 39-8849 (59 FR 11531, March 11, 1994), and by adding a new airworthiness directive (AD), amendment 39-9100 to read as follows: