AD 95-26-10

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Jetstream Model 4101 airplanes, that currently requires repetitive purging of the hydraulic system and installation of a spoiler actuator that has been previously certified. That AD was prompted by a report of damage to the locking mechanisms on some pistons of the spoiler actuators. The actions specified by the AD are intended to prevent uncommanded extension of the lift spoiler in the event of loss of hydraulic pressure in the spoiler actuator. This amendment establishes an increased life limit for certain spoiler actuators, and provides an optional terminating action for the requirements of that AD. This amendment also limits the applicability of the rule to fewer airplanes.

Final rule

95-26-10 JETSTREAM AIRCRAFT, LIMITED: Amendment 39-9468. Docket 94-NM-237-AD. Supersedes AD 94-17-12, Amendment 39-9007.
Applicability: Model 4101 airplanes; having constructors numbers 41004 through 41015 inclusive, 41018 through 41026 inclusive, 41028 through 41030 inclusive, and 41032; 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 (d) of this AD 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 uncommanded extension of the lift spoiler in the event of loss of hydraulic pressure in the spoiler actuator, accomplish the following:

(a) Within 21 days after September 6, 1994 (the effective date of AD 94-17-12, amendment 39-9007), remove the spoiler actuators in accordance with Jetstream Alert Service Bulletin J41-A27-034, dated June 9, 1994, or Jetstream Alert Service Bulletin J41-A27-034, Revision 1, dated October 28, 1994. Following removal of the actuators, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD, in accordance with the service bulletin. Thereafter, repeat the requirements of this paragraph at intervals not to exceed500 landings.

(1) Prior to further flight, purge the hydraulic system to ensure that there is no contamination.

(2) Prior to further flight, install a spoiler actuator that has been previously certified and marked with an "R" after the serial number on the nameplate of the actuator.

(b) For spoiler actuators having Lucas Aerospace part number (P/N) TY1763-01A or P/N TY1763-01B: Prior to the accumulation of 5,000 total hours time-in-service on the spoiler actuator, or within 30 days after the effective date of this AD, whichever occurs later, replace the actuator with a new or serviceable part, in accordance with Jetstream Service Bulletin J41-A27-034, Revision 1, dated October 28, 1994. Thereafter, prior to the accumulation of 5,000 hours time-in- service on the spoiler actuator, replace the actuator with a new or serviceable part, in accordance with the service bulletin. Such replacement constitutes terminating action for the repetitive purging and repetitive installation requirements of paragraph (a) of this AD.

(c) Installation of improved spoiler actuators (Modification JM 41381) on the left and right wings, in accordance with Jetstream Service Bulletin J41-27-037, dated November 7, 1994, constitutes terminating action for the requirements of paragraphs (a) and (b) of this AD.

(d) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(e) Special flight permits may be issued in accordance with sections21.197 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.

(f) The actions shall be done in accordance with Jetstream Alert Service Bulletin J41-A27-034, dated June 9, 1994, or Jetstream Alert Service Bulletin J41-A27-034, Revision 1, dated October 28, 1994. The incorporation by reference of Jetstream Alert Service Bulletin J41-A27-034, dated June 9, 1994, 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 September 6, 1994 (59 FR 43025, August 22, 1994). The incorporation by reference of Jetstream Alert Service Bulletin J41-A27-034, Revision 1, dated October 28, 1994, 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, 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.

(g) This amendment becomes effective on February 8, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 94-17-12, amendment 39-9007 (59 FR 43025, August 22, 1994), which is applicable to certain Jetstream Model 4101 airplanes, was published in the Federal Register on September 8, 1995 (60 FR 46792). The action proposed to continue to require repetitive purging of the hydraulic system and installation of an actuator that has been previously certified marked with an "R" after the serial number. The action also proposed to establish an increased life limit for certain spoiler actuators, and provide an optional terminating action for the requirements of the AD. Additionally, the action proposed to limit the applicability of the rule to fewer airplanes.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

The commenter supports the proposedrule.

After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

The FAA estimates that approximately 17 airplanes of U.S. registry will be affected by this AD.

The repetitive purging and installation actions that are currently required by AD 94-17-12 take approximately 6 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact on U.S. operators of the actions currently required is estimated to be $6,120, or $360 per airplane.

Replacement of the spoiler actuator at the newly established life limit will add no new costs to affected operators. In fact, it will reduce the economic burden for most operators, since: (1) repetitive purging of the actuators will be eliminated, and (2) replacement of the actuators will not have to be accomplished as often as was previously required. Additionally, some of the replacement actuators will be provided to operators free of charge by the manufacturer.

Further, since this AD is applicable to fewer airplanes than was AD 94-17-12, the cost impact of the AD will be reduced by the amount of labor and parts costs that would previously have been applied to those additional airplanes.

The cost impact figures discussed above are 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 towarrant 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 USC 106(g), 40101, 40113, 44701.

39.13 - [Amended]
2. Section 39.13 is amended by removing amendment 39-9007 (59 FR 43025, August 22, 1994), and by adding a new airworthiness directive (AD), amendment 39-9468, to read as follows: