AD 96-20-09 ACTIVE

This amendment adopts a new airworthiness directive (AD), applicable to all Jetstream Model HS 748 series airplanes. This action requires a one-time inspection to ensure proper operation, positioning, and lubrication of the aileron, rudder, and elevator cable tensioners; gust lock levers; and cable pressure seals. It also requires a revision to the maintenance program to include these inspections on a repetitive basis. This amendment is prompted by reports of seizure and consequent jamming of the flight control cable tension regulators and gust lock mechanisms. The actions specified in this AD are intended to prevent the flight control cable tension regulators from jamming, which could result in the inability to achieve full deflection of the associated flight control surfaces, and lead to reduced controllability of the airplane.

Final rule; request for comments

96-20-09 JETSTREAM AIRCRAFT LIMITED (Formerly British Aerospace Commercial Aircraft, Limited): Amendment 39-9775. Docket 96-NM-198-AD.
Applicability: All Model HS 748 series airplanes, 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 request approval for an alternative method of compliance in accordance with paragraph (c ) 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 the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent the flight control cable tension regulators from jamming, which could result in the inability to achieve full deflection of the associated flight control surfaces, and lead to reduced controllability of the airplane, accomplish the following:

(a) Within 600 hours time-in-service or 6 months after the effective date of this AD, whichever occurs first, perform an inspection to ensure proper operation, positioning, and lubrication of the aileron, rudder, and elevator cable tensioners; gust lock levers; and cable pressure seals, in accordance with paragraphs A. and B.(1) through (27) of the Accomplishment Instructions of Jetstream Service Bulletin HS748-27-126, dated February 29, 1996. If any discrepancy is detected, prior to further flight, correct it in accordance with the service bulletin.

(b) Within 30 days after the effective date of this AD, revise the FAA-approved maintenance program to include a schedule of repetitive inspections to ensure proper operation, positioning, and lubrication of the aileron, rudder, and elevator cable tensioners; gust lock levers; and cable pressure seals; in accordance with Jetstream Service Bulletin HS748-27-126, dated February 29, 1996. The inspections are to be repeated every 12 months after the accomplishment of the inspection required by paragraph (a) of this AD. If any discrepancy is detected, it must be corrected in accordance with the service bulletin prior to further flight.

(c) 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-13.

NOTE 2: Information concerning the existence of approved alternativemethods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(d) 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.

(e) The inspection and correction of discrepancies shall be done in accordance with Jetstream Service Bulletin HS748-27-126, dated February 29, 1996. This incorporation by reference was 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, Inc., 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.

(f) This amendment becomes effective on October 25, 1996.

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified the FAA that an unsafe condition may exist on all Jetstream HS 748 series airplanes. The CAA advises that there have been reports indicating that it is possible for the aileron, rudder, and elevator cable tension regulators and gust locks to jam, leaving the associated primary control cable in a slack (untensioned) condition. Additionally, the CAA advises that the rear bulkhead and wing pressure seals could become displaced if grease has been applied to the flight control cables at these locations. These conditions, if not corrected, could result in the inability to achieve full deflection of the associated flight control surfaces, and consequently could lead to reduced controllability of the airplane.

Explanation of Relevant Service Information
Jetstream has issued Service Bulletin HS748-27-126, dated February 29, 1996, which describesprocedures for inspecting the aileron, rudder, and elevator cable tensioners and the gust lock levers to ensure that they operate properly. It also describes procedures for inspecting the cable pressure seals for correct positioning and contamination, and correction of any discrepancy found. The CAA classified this service bulletin as mandatory and issued British Airworthiness Directive 005-02-96 in order to assure the continued airworthiness of these airplanes in the United Kingdom.

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 21.19) 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 the Rule
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, this AD is being issued to prevent jamming of the flight control cables and consequent reduced controllability of the airplane. This AD requires, initially, a one-time inspection of the aileron, rudder, and elevator cable tensioners and gust lock levers to ensure that they operate properly. It also requires a one-time inspection of the cable pressure seals for correct positioning and contamination, and correction of any discrepancy. These actions are required to be accomplished in accordance with the service bulletin described previously.

Additionally, this AD requires that the FAA-approved maintenance program be revised to include these inspections and follow-on actions on a repetitive basis.

Cost Impact
None of the Model HS 748 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.

Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 4 work hours to accomplish the required actions, at an average labor charge of $60 per work hour. Based on these figures, the cost impact of this AD would be $240 per airplane.

Determination of Rule's Effective Date
Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal
Register.

Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 96-NM-198-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Impact
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 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, 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. 106(g), 40113, 44701.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 96-NM-198-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from Jetstream Aircraft, Inc., P.O. Box 16029, Dulles International Airport, Washington, DC 20041-6029. This information may be examined 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.

William Schroeder, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2141; fax (206) 227-1149.