03-9983. Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of the comment period.

SUMMARY:

This document proposes to revise an earlier proposed airworthiness directive (AD) that would apply to all Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. The earlier NPRM would have required you to repetitively replace the nose landing gear (NLG) drag link right-hand part every 4,000 landings until an improved design NLG drag link right-hand part is installed. This earlier proposed AD would also have required you to install an improved design NLG drag link right-hand part as terminating action for the repetitive replacements. The earlier NPRM resulted from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The manufacturer has established a more restrictive factor that is a better approximation of the fleet usage. Since this action imposes an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on this additional action.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before June 2, 2003.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2002-CE-51-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may view any comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except Federal holidays. You may also send comments electronically to the following address: [e-mail]. Comments sent electronically must contain “Docket No. 2002-CE-51-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Work 97 for Windows or ASCII text.

You may get service information that applies to this proposed AD from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: [phone]; facsimile: [phone]. You may also view this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD? The FAA invites comments on this proposed rule. You may submit whatever written data, views, or arguments you choose. You need to include the proposed rule's docket number and submit your comments to the address specified under the caption ADDRESSES. We will consider all comments received on or before the closing date. We may amend this proposed rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of this proposed AD action and determining whether we need to take additional rulemaking action.

Are there any specific portions of this proposed AD I should pay attention to? The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of this proposed rule that might suggest a need to modify the rule. You may view all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each contact we have with the public that concerns the substantive parts of this proposed AD.

How can I be sure FAA receives my comment? If you want FAA to acknowledge the receipt of your mailed comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2002-CE-51-AD.” We will date stamp and mail the postcard back to you.

Discussion

What events have caused this proposed 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 Models PC-12 and PC-12/45 airplanes. The FOCA reports that 3 aircraft experienced a failure of the nose landing gear (NLG) drag link assembly during cruise flight. The actuator attachment levers on the right-hand upper drag link part failed. In all cases, the NLG fell out due to gravity, and the emergency spring pack extended it forward and allowed safe landings

What are the consequences if the condition is not corrected? Structural failure of the NLG drag link right-hand part could result in either an unintended NLG extension during flight or the NLG not properly locking upon extension. This could lead to loss of airplane control during landing operations.

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 Models PC-12 and PC-12/45 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on December 18, 2002 (67 FR 77442). The NPRM proposed to require you to repetitively replace the nose landing gear (NLG) drag link right-hand part every 4,000 landings until an improved design NLG drag link right-hand part is installed. The NPRM also proposed to require you to install an improved design NLG drag link right-hand part as terminating action for the repetitive replacements.

You would have to accomplish the proposed actions in accordance with Service Bulletin No. 32-014, dated August 13, 2002.

Comment Issue No. 1: Landings Factor

What is the commenter's concern? The commenter requests correction of the proposed unknown landings factor (multiply time-in-service (TIS) by 0.5). The commenter explains that Pilatus has established for the Model PC-12 a factor of 45 minutes per landing (TIS divided by 0.75). Pilatus published this factor in Pilatus Aircraft Ltd. Service Bulletin 27-005, dated November 18, 1998, and the FOCA has approved this factor.

What is FAA's response to the concern? We concur with the commenter. Because revising this factor could increase the burden upon those owners/operators who do not keep track of landings, we will reopen the comment period and issue a supplemental NPRM.

Comment Issue No. 2: Correct Version of Temporary Revision No. 32-14

What is the commenter's concern? The commenter notes that there are two versions of Pilatus Maintenance Manual (MM) Temporary Revision No. 32-14, both dated June 4, 2002. However, neither is referenced differently, except that the older version has eight pages and the current version has seven pages. The current seven-paged version is the version that was forwarded by the FOCA. This current version shows revision bars on pages 4, 6, and 7. The commenter requests identifying Temporary Revision No. 32-14 with seven pages as the correct version to use for the AD.

What is FAA's response to the concern? We concur with the commenter and will note the correct version to use.

The Supplemental NPRM

How will the changes to the NPRM impact the public? The more restrictive unknown landings factor (0.75) goes beyond the scope of what was earlier proposed and imposes a greater burden on the public. Therefore, we are issuing a supplemental NPRM and reopening the comment period to allow the public additional time to comment.

How does the revision to 14 CFR part 39 affect this proposed AD? On July 10, 2002, FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to special flight permits, alternative methods of compliance, and altered products. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Cost Impact

How many airplanes would this proposed AD impact? We estimate that this proposed AD affects 265 airplanes in the U.S. registry.

What would be the cost impact of this proposed AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the proposed replacement with the same design part:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
6 workhours × $60 per hour = $360	$1,000	$1,360	$1,360 × 265 = $360,400.

We estimate the following costs to accomplish the proposed replacement with the improved design part:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
6 workhours × $60 per hour = $360	$2,200	$2,560	$2,560 × 265 = $678,400.

Compliance Time of This Proposed AD

What would be the compliance time of this proposed AD? The compliance time of this proposed AD is based on the number of landings rather than hours TIS.

Why is the compliance time of this proposed AD presented in landings? The reason for this type of compliance is that the area that is showing fatigue is the NLG drag link right-hand part. This area of the airplane is used during the landing operation. We have determined to base the compliance time for this proposed AD upon the number of landings.

Since airplane operators are not required to keep track of landings, we will provide a method of calculating hours TIS into landings.

Regulatory Impact

Would this proposed AD impact various entities? The regulations proposed herein would 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 proposed rule would not have federalism implications under Executive Order 13132.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed 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) if promulgated, 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 draft regulatory evaluation prepared for this action has been placed 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
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 airworthiness directive (AD) to read as follows:

Pilatus Aircraft Ltd.: Docket No. 2002-CE-51-AD

(a) What airplanes are affected by this AD? This AD affects Models PC-12 and PC-12/45 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 above airplanes must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to prevent structural failure of the nose landing gear (NLG) caused by fatigue damage to the NLG drag link right-hand part that develops over time. Such failure could result in either an unintended NLG extension during flight or the NLG not properly locking upon extension, which could lead to loss of airplane control during landing operations.

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

Actions	Compliance	Procedures
(1) Replace the nose landing gear (NLG) drag link right hand part, part number (P/N) 532.20.12.140 with: (i) the same P/N 532.20.12.140 or FAA-approved equivalent part number; or (ii) improved design NLG drag link right-hand part, P/N 532.20.12.289	Upon the accumulation of 4,000 landings on the nose landing gear (NLG) drag link right-hand part or within the next 100 landings after the effective date of this AD, whichever occurs later. Incorporation of the improved-design NLG drag link brace is terminating action for this AD	In accordance with Temporary Revision No. 32-14 (dated June 4, 2002, use version having seven pages) to Pilatus PC-12 Maintenance Manual 32-20-06.
(2) If replacement in paragraph (d)(1) is with the original style part, replace with: (i) the same P/N 532.20.12.140 or FAA-approved equivalent part number; or (ii) improved design NLG drag link right-hand part, P/N 532.20.12.289	Upon the accumulation of 4,000 landings. Incorporation of improved-design NLG drag link brace is terminating action for this AD	In accordance with Temporary Revision No. 32-14 (dated June 4, 2002, use version having seven pages) to Pilatus PC-12 Maintenance Manual 32-20-06.
(3) Unless already accomplished per paragraph (d)(1) or (d)(2), replace the NLG drag link right-hand part, P/N 532.20.12.140, with an improved design NLG drag link right-hand part, P/N 532.20.12.289 or FAA-approved equivalent part number. Installing the improved part terminates the repetitive replacement requirements of paragraph (d)(2) of this AD	At the third replacement required in paragraph (d)(2) of this AD	In accordance with Pilatus Aircraft Ltd. Service Bulletin No. 32-014, dated August 13, 2002, and the applicable maintenance manual.
(4) Do not install, on any affected airplane, an NLG drag link right-hand part that is not P/N 532.20.12.289 or FAA-approved equivalent part number	When an improved P/N 532.20.12.289 NLG drag link part is installed after the effective date of this AD	Not Applicable.

(e) What if I do not keep track of landings? The compliance times of this AD are presented in landings instead of hours time-in-service (TIS). If landings are not known, hours TIS may be used by dividing the numbers of hours TIS by the unknown landings factor (0.75).

Note 1:

For the purposes of this AD, 3,000 hours TIS would be equivalent to 4,000 landings (3,000 hours/0.75 = 4,000 landings).

(f) Can I comply with this AD in any other way? To use an alternative method of compliance or adjust the compliance time, follow the procedures in 14 CFR 39.13. Send these requests to the Standards Office Manager, Small Airplane Directorate. Contact Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone] for information on any already approved alternative methods of compliance.

(g) How do I get copies of the documents referenced in this AD? You may get copies of the documents referenced in this AD from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: [phone]; facsimile: [phone]; or from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: [phone]; facsimile: [phone]. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Note 2:

The subject of this AD is addressed in Swiss AD Number HB 2002-271, dated June 17, 2002.

Issued in Kansas City, Missouri, on April 15, 2003.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.