AD 2002-22-03

This amendment adopts a new airworthiness directive (AD) that applies to certain PILATUS Aircraft Ltd. (Pilatus) Model PC-7 airplanes. This AD requires you to repetitively inspect the main landing gear front attachment brackets for cracks, and, if cracks are found, install improved-design brackets. Installing the improved-design brackets terminates the required inspections. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by this AD are intended to detect and correct cracks in the main landing gear front attachment brackets, which could result in failure of the brackets. Such failure could lead to the main landing gear leg detaching from the wing main spar.

Final rule.

2002-22-03 Pilatus Aircraft LTD.: Amendment 39-12927; Docket No. 2002-CE-28-AD.

(a) What airplanes are affected by this AD? This AD affects Model PC-7 airplanes, serial numbers 101 through 618, 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 main landing gear front attachment brackets, which could result in failure of the brackets. Such failure could lead to the main landing gear leg detaching from the wing main spar.

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

Compliance
Actions
Procedures
(1) Initial Inspection: At whichever of the following occurs later, unless already accomplished: (i) Upon the accumulation of 3,000 hours time-in-service (TIS) on the attachment brackets or 10 years after installation of the brackets, whichever occurs first; or (ii) within 90 days after December 20, 2002 (the effective date of this AD).
Inspect, using the Impedance-Plane Eddy-Current Inspection, both main landing gear front attachment brackets, part number (P/N) 111.34.07.105 and P/N 111.34.07.106 for cracks.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Pilatus PC-7 Service Bulletin No. 57-004, Revision No. 1, dated June 17, 2002; the ACCOMPLISHMENT INSTRUCTIONS section of Pilatus PC-7 Service Bulletin No. 57-005, dated September 10, 2001; and Pilatus PC-7 Maintenance Manual, Temporary Revision No. 05-10, dated September 10, 2001.
(2) Repetitive Inspections: Within 12 calendar months after the initial inspection required in paragraph (d)(1) of this AD and thereafter at intervals not to exceed 12 calendar months.
Inspection, using the Impedance-Plane Eddy-Current Inspection, both main landing gear front attachment brackets, P/N 111.34.07.105 and P/N 111.34.07.106 for cracks.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Pilatus PC-7 Service Bulletin No. 57-004, Revision No. 1, dated June 17, 2002; the ACCOMPLISHMENT INSTRUCTIONS section of Pilatus PC-7 Service Bulletin No. 57-005, dated September 10, 2001; and Pilatus PC-7 Maintenance Manual, Temporary Revision No. 05-10, dated September 10, 2001.
(3) Prior to further flight after the inspection in which the damage was found.
If a crack is found in any main landing gear front attachment bracket during any inspection required in this AD, replace with an improved bracket, P/N 557.10.09.045, P/N 557.10.09.046, or FAA-approved equivalent P/N. Repetitive inspections are still required on any P/N 111.34.07.105 and P/N 111.34.07.106 for cracks.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Pilatus PC-7 Service Bulletin No. 57-005, dated September 10, 2001.
(4) At any time as terminating action for the repetitive inspections. However, you must replace prior to further flight if you find cracks during any inspections required by this AD.
You may terminate the inspections required in paragraphs (d)(1) and (d)(2) of this AD when improved design main landing gear front attachment brackets, P/N 557.10.09.045, P/N 557.10.09.046, or FAA-approved equivalent P/Ns, are installed on both sides of the airplane.
In accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Pilatus PC-7 Service Bulletin No. 57-005, dated September 10, 2001.
(5) As of December 20, 2002 (the effective date of this AD).
Only install main landing gear brackets that are P/N 557.10.09.045, P/N 557.10.09.046, or FAA-approved equivalent P/Ns.
Not Applicable.

Note 1: If you find cracks on one side only, you are only required to replace the damaged side with the new improved-design bracket and continue the repetitive inspections required by paragraph (d)(2) of this AD. Repetitive inspections are still required onany installed bracket with either P/N 111.34.07.105 or P/N 111.34.07.106.

(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 Standards Office Manager.

Note 2: 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 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 Pilatus PC-7 Service Bulletin No. 57-004, Revision No. 1, dated June 17, 2002; Pilatus PC-7 Service Bulletin No. 57-005, dated September 10, 2001; and Pilatus PC-7 Maintenance Manual, Temporary Revision No. 05-10, dated September 10, 2001. 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 Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 6224; or from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: (303) 465-9099; facsimile: (303) 465-6040. 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 3: The subject of this AD is addressed in Swiss AD HB 2002-270, dated June 24, 2002.

(i) When does this amendment become effective ? This amendment becomes effective on December 20, 2002.

Discussion

What Events Have Caused This AD?

The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified FAA that an unsafe condition may exist on certain Pilatus Model PC-7 airplanes. The FOCA reports that an operator of a similar aircraft type design, which uses identical main landing gear support brackets, reported a single crack in one bracket. A fleet inspection of the operator's aircraft revealed stress corrosion cracking in more than 20 aircraft.

What Is the Potential Impact if FAA Took No Action?

Cracks in the main landing gear front attachment brackets could result in failure of the brackets. Such failure could lead to the main landing gear leg detaching from the wing main spar.

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 certain Pilatus Model PC-7 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 9, 2002 (67 FR 51794). The NPRM proposed to repetitively inspect the main landing gear front attachment brackets for cracks, and, if cracks are found, install improved-design brackets. Installing the improved-design brackets terminates the required inspections.

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 the NPRM.

Cost Impact

How Many Airplanes Does This AD Impact?

We estimate that this AD affects 14 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. operator
4 workhours x $60 = $240
No parts required
$240
$240 x 14 = $3,360.

The FAA has no method of determining the number of repetitive inspections each owner/operator would incur over the life of each of the affected airplanes so the cost impact is based on the initial inspection.

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

Labor cost
Parts cost
Total cost per airplane
80 workhours x $60 = $4,800 per side
$2,500 per side
$4,800 + $2,500 = $7,300 per side.

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: