AD 98-16-14

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AD Number:
98-16-14
Document Type:
AD Final Rules
Docket Number:
97-CE-112-AD
Subject Heading:
Airworthiness Directives; Pilatus Britten-Norman Ltd. BN-2, BN-2A, BN-2B, and BN-2T Series Airplanes
Subject:
Main Landing Gear Fitting Attachment Bolts, Nuts, and Washers
Status:
Current
Citation:
Federal Register: August 07, 1998 (Volume 63, Number 152)
Citation Publish Date:
08/07/1998
Effective Date:
09/21/1998
Make:
B-N Group Ltd.
Model:
BN-2 | BN-2A | BN-2A-2 | BN-2A-20 | BN-2A-21 | BN-2A-26 | BN-2A-27 | BN-2A-3 | BN-2A-6 | BN-2A-8 | B...Show more
Product Type:
Aircraft
Product Subtype:
Small Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 [63 FR 42205 No. 152 08/07/98]
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 98-16-14
CITATION:   [Federal Register: August 07, 1998 (Volume 63, Number 152)]

PAGE NUMBER:   [Page 42205]

DOCKET NUMBER:   97-CE-112-AD

AMENDMENT:   39-10690

AD NUMBER:   98-16-14

SUBJECT HEADING:   Airworthiness Directives; Pilatus Britten-Norman Ltd. BN-2, BN-2A, BN-2B, and BN-2T Series Airplanes

ACTION:   Final rule.

SUMMARY:   This amendment adopts a new airworthiness directive (AD) that applies to all Pilatus Britten-Norman Ltd. (Pilatus Britten-Norman) BN-2, BN-2A, BN-2B, and BN-2T series airplanes. This AD requires replacing the attachment bolts, nuts and washers of the lower fitting of the main landing gear (MLG), and adjusting the torque values of the nuts. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by this AD are intended to prevent the bolts that attach the lower fitting of the MLG to the nacelle from becoming threadbound, which could result in structural failure of the MLG with consequent loss of control of the airplane during takeoff, taxi, or landing operations.

DATES:   Effective September 21, 1998. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of September 21, 1998.

ADDRESSES:   Service information that applies to this AD may be obtained from Pilatus
Britten-Norman Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR; telephone:
44-1983 872511; facsimile: 44-1983 873246. This information may also be examined at the
Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention:
Rules Docket No. 97-CE-112-AD, Room 1558, 601 E. 12th Street, 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:   Mr. Roger Chudy, Aerospace Engineer, Small Airplane
Directorate, Aircraft Certification Service, 1201 Walnut, suite 900, Kansas City, Missouri 64106;
telephone: (816) 426-6934; facsimile: (816) 426-2169.


SUPPLEMENTARY INFORMATION:  
Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all Pilatus Britten-Norman BN-2, BN-2A, BN-2B, and BN-2T series airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on March 19, 1998 (63 FR 13379). The NPRM proposed to require replacing the washers on the attachment bolts of the lower fitting of the MLG. Accomplishment of the proposed action as specified in the NPRM would be in accordance with Pilatus Britten-Norman Service Bulletin BN2/SB.231, Initial Issue, dated October 17, 1996.

The NPRM was the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom.

After issuance of the NPRM, Pilatus Britten-Norman informed the FAA that Service Bulletin BN2/SB.231 has been revised to the Issue 2 status (dated October 1, 1997). This revision changes the procedures to specify replacing the attachment bolts and nuts of the lower fitting of the MLG instead of re-using the existing bolts and nuts. This service information also specifies procedures to adjust the torque loading values of the bolts.

In addition, the FAA has realized that the Model BN-2T-4R airplanes were inadvertently omitted from the proposed AD. At that time, the FAA determined that the Model BN-2T-4R airplanes are of similar type design to those currently listed in the NPRM.

This prompted the FAA to issue a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all Pilatus Britten-Norman BN-2, BN-2A, BN-2B, BN-2T, and BN-2T-4R series airplanes. This proposal was published in the Federal Register as a supplemental NPRM on May 28, 1998 (63 FR 29159). The supplemental NPRM proposed to also require replacing the attachment bolts and nuts of the lower fitting of the MLG and adjusting the torque values of the nuts. Accomplishment of the proposed action as specified in the supplemental NPRM would be in accordance with the service information previously referenced.

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

Comment Disposition
Pilatus Britten-Norman states that the proposed AD should not apply to the Model BN-2T-4R airplanes. These airplanes utilize a different type wing and an uprated landing gear construction from the rest of the affected models.

After re-examining all information related to this subject, the FAA concurs and has removed the Model BN-2T-4R airplanes from the final rule.

The FAA's Determination
After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Cost Impact
The FAA estimates that 80 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 3 workhours per airplane to accomplish this action, and that the average labor rate is approximately $60 an hour. Parts cost approximately $10 per airplane. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $15,200, or $190 per airplane.

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 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, 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 a new airworthiness directive (AD) to read as follows:

REGULATORY TEXT:  
98-16-14 PILATUS BRITTEN-NORMAN LTD: Amendment 39-10690; Docket No. 97-CE-112-AD.

Applicability: Models BN-2, BN-2A, BN-2A-3, BN-2A-6, BN-2A-8, BN-2A-2, BN-2A-9, BN-2A-20, BN-2A-21, BN-2A-26, BN-2A-27, BN-2B-20, BN-2B-21, BN-2B-26, BN-2B-27, and BN-2T airplanes, all serial numbers, 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 within the next 50 landings after the effective date of this AD, unless already accomplished.

NOTE 2: The compliance time of this AD is presented in landings instead of hours time-in-service (TIS). If the number of landings is unknown, hours TIS may be used by multiplying the number of hours TIS by 1.5.

To prevent the bolts that attach the lower fitting of the main landing gear (MLG) to the nacelle from becoming threadbound, which could result in structural failure of the MLG with consequent loss of control of the airplane during takeoff, taxi, or landing operations, accomplish the following:

(a) Replace the attachment bolts, nuts, and washers of the lower fitting of the MLG, in accordance with Pilatus Britten-Norman Service Bulletin No. BN2/SB.231, Issue 2, dated October 1, 1997.

(b) 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 an be accomplished.

(c) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri, 64106. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(d) Questions or technical information related to Pilatus Britten-Norman Service Bulletin BN2/SB.231, Issue 2, dated October 1, 1997, should be directed to Pilatus Britten-Norman Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR; telephone: 44-1983 872511; facsimile: 44-1983 873246. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

(e) The replacement required by this AD shall be done in accordance with Pilatus Britten-Norman Service Bulletin No. BN2/SB.231, Issue 2, dated October 1, 1997. 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 Pilatus Britten-Norman Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

NOTE 4: The subject of this AD is addressed in British AD No. 008-10-96, dated January 31, 1997.

(f) This amendment becomes effective on September 21, 1998.


FOOTER: