AD 96-19-15

This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B16 and CL-600-2B19 series airplanes, that requires a one-time inspection of the spring bungee assembly of the nose landing gear (NLG) to ensure proper torque of the collar and correct clearance between the collar and the body of the bungee, and replacement of the spring bungee assembly with a serviceable unit, if necessary. This amendment is prompted by reports of failure of the NLG to extend when the landing gear selector was placed in the "DOWN" position, and failure of the NLG doors to open when the NLG door switch was set in the "SAFETY/DOOR OPEN" position; these conditions may have been caused by a reduced stroke of the spring bungee. The actions specified by this AD are intended to prevent improper operation of the NLG door and consequent inability to extend the NLG due to a reduced stroke of the spring bungee.

Final rule

96-19-15 BOMBARDIER, INC. (Formerly Canadair): Amendment 39-9761. Docket 95-NM-247-AD.
Applicability: Model CL-600-2B16 (CL-601-3A and -3R), serial numbers 5100 through 5166, inclusive; and Model CL-600-2B19 (Regional Jet Series 100) series airplanes, serial numbers 7003 through 7048, inclusive; 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 (d) 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 improper operation of the nose landing gear (NLG) door and consequent inability to extend the NLG due to a reduced stroke of the spring bungee, accomplish the following:

(a) Within 90 days after the effective date of this AD: Perform a one-time inspection of the spring bungee assembly of the NLG to ensure proper torque of the collar and correct clearance between the collar and the body of the bungee; in accordance with Canadair Regional Jet Alert Service Bulletin A601R-32-037, Revision `A,' dated December 2, 1994 (for Model CL-600-2B19 series airplanes); or Canadair Challenger Service Bulletin 601-0454, dated May 15, 1995, as amended by Service Bulletin Information Sheet 601-0454, dated July 14, 1995 (for Model CL-600-2B16 series airplanes); as applicable.

(b) If improper torque of the collar is found, or if incorrect clearance between the collar and the body of the bungee is found: Prior to further flight, replace the spring bungee assembly with a serviceable (new or reworked) unit that has been inspected in accordance with Canadair Regional Jet Alert Service Bulletin A601R-32-037, Revision `A,' dated December 2, 1994 (for Model CL-600-2B19 series airplanes); or Canadair Challenger Service Bulletin 601-0454, dated May 15, 1995, as amended by Service Bulletin Information Sheet 601-0454, dated July 14, 1995 (for Model CL-600-2B16 series airplanes); as applicable. Accomplish the replacement in accordance with the applicable service bulletin.

(c) As of the effective date of this AD, no person shall install a spring bungee assembly having part number 600-86115-1 (for Model CL-600-2B16 series airplanes) or 600-86115-5/70 (for Model CL-600-2B19 series airplanes) on any airplane unless that assembly has been inspected and reworked, as necessary, in accordance with paragraph (a) 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, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

(e) 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.

(f) The inspection and replacement shall be done in accordance with Canadair Regional Jet Alert Service Bulletin A601R-32-037, Revision `A,' dated December 2, 1994; or CanadairChallenger Service Bulletin 601-0454, dated May 15, 1995, as amended by Service Bulletin Information Sheet 601-0454, dated July 14, 1995; as applicable. 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 Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Quebec H3C 3G9, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, Engine and Propeller Directorate, 10 Fifth Street, Third Floor, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on October 23, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Bombardier Model CL-600-2B16 and CL-600-2B19 series airplanes was published in the Federal Register on July 8, 1996 (61 FR 35691). That action proposed to require a one-time inspection of the spring bungee assembly of the nose landing gear (NLG) to ensure proper torque of the collar and correct clearance between the collar and the body of the bungee, and replacement of the spring bungee assembly with a serviceable (new or reworked) unit, if necessary.

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.

Conclusion
The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
TheFAA estimates that 101 Bombardier Model CL-600-2B16 and CL-600-2B19 series airplanes of U.S. registry will be affected by this AD, that it will take approximately 4 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $24,240, or $240 per airplane.

The 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.

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: