AD 2002-24-09

This amendment adopts a new airworthiness directive (AD) that applies to all Pilatus Britten-Norman Limited (Pilatus Britten-Norman) BN2T and BN2T-4R series airplanes. This AD requires you to repetitively inspect the left and right engine-mounting frame for cracks and replace the frame if cracks are found. 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 detect and correct cracks in the left and right engine- mounting frame, which could lead to engine mount failure. Such failure could result in separation of the engine from the airplane.

Final rule.

2002-24-09 Pilatus Britten-Norman Limited: Amendment 39-12974; Docket No. 2002-CE-34-AD.

(a) What airplanes are affected by this AD? This AD affects Models BN2T, and BN2T-4R airplanes, all serial numbers, that are certificated in any category.

(b) Who must comply with this AD? Anyone who wishes to operate any of the airplanes identified in paragraph (a) of this AD must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to detect and correct cracks in the left and right engine-mounting frame, which could lead to engine mount failure. Such failure could result in separation of the engine from the airplane.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

Actions
Compliance
Procedures
(1) Inspect the left and right turbine
engine-mounting frame, part number (P/N) NB-20-6853, or FAA-approved equivalent part number, for cracks.Initially upon accumulating 1,000 hours time-in-service (TIS) on the engine mounting frame or within the next 50 hours TIS after January 27, 2003 (the effective date of this AD), whichever occurs later.
If no cracks are found on the initial inspection, repetitively inspect
every 100 hours TIS.

In accordance with Britten-Norman
Service Bulletin No. SB 282, Issue 2, dated June 1, 2002.

(2) If cracks are found during any
inspection required in paragraph (d)(1) of this AD, replace the mounting frame with a new frame, P/N NB-20-6853, or FAA-approved equivalent part number.

Prior to further flight after the inspection in which any crack and/or
damage is found. After installing the new frame, inspect as required
in paragraph (d)(1) of this AD.

In accordance with Britten-Norman
Service Bulletin No. SB 282, Issue 2, dated June 1, 2002

(e) Can I comply with this AD in any other way? You may use an alternative method of compliance or adjust the compliance time if:(1) Your alternative method of compliance provides an equivalent level of safety; and
(2) The Standards Office Manager, Small Airplane Directorate, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standards Office Manager.

Note 1: This AD applies to each airplane identified in paragraph (a) of this AD, 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 (e) 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 you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? Contact Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4059; facsimile: (816) 329-4090.

(g) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD.

(h) Are any service bulletins incorporated into this AD by reference? Actions required by this AD must be done in accordance with Britten-Norman Service Bulletin No. SB 282, Issue 2, dated June 1, 2002. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You may get copies from Pilatus Britten-Norman Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR; telephone: +44 (0) 1983 872511; facsimile: +44 (0) 1983 873246. You may view copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC.

Note 2: The subject of this AD is addressed in British AD 002- 05-2002, not dated.

(i) When does this amendment become effective? This amendment becomes effective on January 27, 2003.

Discussion

What events have caused this AD? The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified FAA that an unsafe condition may exist on all Pilatus Britten-Norman BN2T and BN2T-4R Series airplanes. The CAA reports that the manufacturer has reported six occurrences of cracks in the left and right turbine engine-mounting frame detected during routine inspections by operators of aircraft used on parachute drop or pilot training operations.

What is the potential impact if FAA took no action? These cracks could lead to engine mount failure with consequent separation of the engine from the airplane.

Has FAA taken any action to this point? We issued 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 BN2T and BN2T-4R series airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on September 17, 2002 (67 FR 58544). The NPRM proposed to require you to repetitively inspect the left and right engine-mounting frame for cracks and replace the frame if cracks are found.

Was the public invited to comment? The FAA encouraged interested persons to participate in the making of this amendment. We did not receive any comments on the proposed rule or on our determination of the cost to the public.

FAA's Determination

What is FAA's final determination on this issue? After careful review of all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. We have determined that these minor corrections:

--Provide the intent that was proposed in the NPRM for correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already proposed in theNPRM.

Cost Impact

How many airplanes does this AD impact? We estimate that this AD affects 6 airplanes in the U.S. registry.

What is the cost impact of this AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the inspection:

Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
4 workhours x $60 per hour = $240
No cost for parts
$240
6 x $240 = $1,440.

We estimate the following costs to accomplish any necessary replacements that will be required based on the results of the inspection. We have no way of determining the number of airplanes that may need such replacement:

Labor cost
Parts cost
Total cost per airplane
30 workhours x $60 per hour = $1,800 per frame
$5,400
$7,200.

Regulatory Impact

Does this AD impact various entities? The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

Does this AD involve a significant rule or regulatory action? 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, under 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. FAA amends 39.13 by adding a new AD to read as follows: