2020-14886. Airworthiness Directives; Daher Aircraft Design, LLC (Type Certificate Previously Held by Quest Aircraft Design, LLC), Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for all Daher Aircraft Design, LLC (type certificate previously held by Quest Aircraft Design, LLC), Model KODIAK 100 airplanes. This AD was prompted by reports of cracks found in certain nose landing gear (NLG) forks. This AD requires a one-time inspection to determine if an affected NLG fork is installed, repetitive inspections of the affected NLG fork for cracks, repetitive inspections of the shimmy damper bracket for looseness, and of the shimmy damper system for damaged components if an affected NLG fork is installed, and rework/replacement of parts as necessary. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective August 17, 2020.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of August 17, 2020.

ADDRESSES:

For service information identified in this final rule, contact Kodiak Aircraft Company, Inc., 1200 Turbine Drive, Sandpoint, Idaho 83864; phone: [phone] or 1 [phone]; email: [e-mail]; internet: http://Kodiak.aero/​support. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the FAA, call 816-329-4148. It is also available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2018-0180.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2018-0180; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, the regulatory evaluation, any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Wade Sullivan, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Quest Aircraft Design, LLC (type certificate now held by Daher Aircraft Design, LLC), Model KODIAK 100 airplanes. The NPRM published in the Federal Register on March 8, 2018 (83 FR 9820). The NPRM was prompted by reports of cracks on the NLG fork on Model KODIAK 100 airplanes. The NPRM proposed to require a one-time inspection to determine if an affected NLG fork is installed, repetitive inspections of the affected NLG fork for cracks, repetitive inspections of the shimmy damper bracket for looseness if an affected NLG fork is installed, and rework/replacement of parts as necessary. The FAA is issuing this AD to prevent separation of the NLG fork and consequent reduced control on landing. If the NLG fork separates on an unimproved surface, the risk of the NLG digging in and the airplane overturning on the ground increases.

Since the FAA issued the NPRM, the type certificate holder for the Model KODIAK 100 airplane changed from Quest Aircraft Design, LLC (Quest), to Daher Aircraft Design, LLC. This final rule reflects that change and updates the contact information to obtain service documentation.

Comments

The FAA gave the public the opportunity to participate in developing this final rule. The following presents the comments received on the NPRM and the FAA's response to each comment.

Request To Revise Proposed AD To Lessen Economic Impact

Quest requested numerous changes to paragraphs (h), (i), and (j) of the proposed AD. In support, Quest stated that these changes would address all sources of shimmy and lessen the economic impact to operators in international locations where nondestructive testing (NDT) inspection methods are less accessible.

First, Quest requested that the FAA change paragraphs (h)(1) and (i)(1) of the proposed AD to require the initial inspections only if there is shimmy. Quest stated that its analysis and review of the NLG fork determined that extended shimmy with the existing design (type A NLG fork) could result in fatigue cracks at the locations reported.

The FAA disagrees with this request because there is no regulatory requirement for all pilots to report a nosewheel shimmy event. If the initial inspections were conditional on reported shimmy events, the unsafe condition would go unaddressed each time a pilot forgot or neglected to report an event.

Quest also requested that the FAA revise the service information that would be required throughout the proposed AD to allow later revisions.

The FAA disagrees with this request. Requiring the use of a service document that does not yet exist at the time an AD is published violates 1 CFR 51.1(f), regarding approval by the Director of the Federal Register of a publication incorporated by reference. In order for operators to use later revisions of a referenced document (issued after the publication of the AD), either the AD must be revised to reference the specific later revisions, or operators must request approval to use a later revision as an alternative method of compliance (AMOC) using the procedures in paragraph (l) of this AD.

Quest requested that the FAA revise paragraph (h)(2) of the proposed AD to remove the identification of the replacement part so that replacement of a cracked NLG fork is not limited to NLG fork P/N 100-410-7013 (type B).

The FAA disagrees. The type B NLG fork, P/N 100-410-7013, is the only replacement option that has been shown to address the unsafe condition. The FAA disagrees with relying solely on the repetitive inspections without requiring replacement with the type B NLG fork if a crack is found. If a different option provides an acceptable level of safety, an operator may request an AMOC using the procedures in paragraph (l) of this AD.

Quest requested that the FAA revise paragraph (i)(1) of the proposed AD to change the requirement to inspect the shimmy damper bracket for looseness using revision 21 of the maintenance manual to a requirement to perform the nosewheel shimmy system troubleshooting procedure in revision 24 (or later) of the maintenance manual. In support of this request, Quest stated that shimmy can result from a wide range of factors, and thus a less focused procedure is more appropriate.

The FAA disagrees with this request. The FAA has determined that the procedures to inspect the shimmy damper bracket and replace damaged components adequately address the unsafe condition. Performing the entire nosewheel shimmy system troubleshooting procedure in Revision 24 goes beyond what is required and is not necessary to address the unsafe condition.

Quest further requested that the FAA revise paragraph (j) of the proposed AD to require replacement of the NLG fork using the procedures in the maintenance manual, instead of the procedures in Quest Field Service Instruction FSI-147.

The FAA partially agrees. Replacing an NLG fork with a type B NLG fork may be accomplished using the Quest maintenance manual or other standard maintenance practices. The FAA has changed paragraph (j) of this AD accordingly.

Request To Extend the Repetitive Inspection Intervals

Quest, New Tribes Mission (Papua New Guinea) Ltd (New Tribes Mission), and SIL Aviation requested that the FAA extend the repetitive inspection intervals for the NDT inspection of the NLG fork. In the NPRM, the FAA proposed a 100-hour TIS interval; the commenters requested an interval ranging from 200 to 1,000 hours TIS. According to New Tribes Mission, extending the repetitive interval would align with other scheduled Kodiak inspection items and still provide a measure of assurance that no cracks are forming, while reducing labor time and costs and increasing aircraft availability for operators. Quest stated that the 30-second duration of a severe shimmy occurrence used in its original analysis was extraordinarily long, and suggested that half that duration would still provide a reasonable and conservative number for analysis and allow increasing the repetitive inspection interval to 200 hours TIS.

The FAA agrees with the analysis supporting an increase in the repetitive inspection intervals to 200 hours TIS and has revised paragraphs (h)(1) and (i)(1) of this AD accordingly. The FAA has determined there is insufficient data to support increasing the repetitive inspection intervals beyond 200 hours TIS. The FAA will consider a further extension of this repetitive interval, via further rulemaking or approval of an AMOC, if analysis of the nosewheel shimmy and the effect of the NLG gravel deflectors shows that safety would be ensured by a longer interval.

Request To Extend Repetitive Interval Based on Shimmy Documentation

Quest requested that the FAA allow a longer repetitive inspection interval of 800 hours TIS for operators that implement a shimmy-occurrence documentation procedure and where no severe shimmy (longer than 3 seconds per landing) occurs. The commenter suggested that it was important for international operators to include this option in the AD instead of through an AMOC because of the various international regulations and associated complexities in obtaining approvals.

The FAA disagrees with this request. Although the engineering analysis provided by Quest suggests that cracks are more likely to develop in airplanes that experience nosewheel shimmy, there is no regulatory requirement for all pilots to report or record a shimmy event. Even if an operator were to adopt and implement a procedure, there is no reliable way to determine if an airplane has experienced a previous shimmy event. A new owner of an airplane would have no way of determining if the airplane had experienced a shimmy event with the previous owner based on a review of the maintenance records. The FAA has not changed this AD based on this comment.

Request To Limit Applicability to Airplanes With NLG Gravel Deflector

New Tribes Mission and SIL Aviation requested that the FAA limit the applicability of the proposed AD to airplanes with a supplemental type certificate (STC) for an NLG gravel deflector installed. The commenters stated that the four instances of cracking on the NLG fork were limited to airplanes of the same operator, operated in the same location, with an STC for an NLG gravel deflector installed. New Tribes Mission noted that the extra weight of the gravel deflector could exacerbate the effects of the shimmy. Both commenters stated that other operators in similar locations and conditions, with airplanes that had accumulated more hours TIS and landings but without the gravel deflector installed, have not reported any signs of cracking on airplanes.

The FAA does not agree with this request. Although Quest's analysis suggests that nosewheel shimmy contributes to the cracking, there is insufficient data to make that conclusion specifically for airplanes with the gravel deflector installed. Should Quest complete a shimmy analysis of the effect of the NLG gravel deflectors, the FAA will determine whether to take further rulemaking action.

The FAA has not changed this AD based on this comment.

Request To Allow Credit for Inspections Already Completed

Quest requested that the FAA provide relief from the initial requirement to perform an NDT inspection within 25 hours if an operator has previously complied with the inspection. Quest stated that such operators should not be required to perform another “initial” inspection.

Paragraph (f) of this AD requires compliance unless already done. Thus, the AD already allows operators to take credit for the initial NDT inspection if it is done before the effective date of the AD. Operators must then repeat the inspection at intervals not to exceed 200 hours TIS. No changes to this AD are necessary based on this comment.

Comments Regarding the Type of Inspection

SIL Aviation and New Tribes Mission stated that the NDT inspection methods required by the AD are not readily available and/or are cost prohibitive. SIL Aviation noted that the type of inspection would be very costly to its operation. The FAA infers that these commenters would like the AD to allow the inspection using a different method.

The FAA acknowledges the commenters' concerns about the costs associated with this AD. However, the FAA has determined that the required actions in this AD are necessary to address the unsafe condition. The FAA considered several possible NDT methods and determined that the inspection options (fluorescent penetrant, dye penetrant, or eddy current inspection) for the inspection required by this AD are the most cost effective and simple to perform in the field while still providing an adequate level of safety. The dye penetrant kits are available from several sources. Under the provisions of paragraph (l) of this AD, operators may request approval of an AMOC for a different inspection method if that method provides the same or higher level of crack detection.

Other Changes to the Proposed AD

In the NPRM, the FAA proposed that paragraph (h)(2) require replacing a cracked NLG fork by following section 5. Instructions in Quest Aircraft Field Service Instruction FSI-147, Revision 00 (not dated), and paragraph (i)(3) require replacing damaged components by following pages 32_110 and 32_111, section 3252, Shimmy Damper, in Chapter 32, Landing Gear, of Quest Aircraft Company Kodiak 100 Maintenance Manual, Revision No. 21, dated February 15, 2017. The FAA has revised paragraphs (h)(2) and (i)(3) in this AD to remove the incorporation by reference of the specified service information to allow the actions to be done using standard maintenance practices.

The FAA has also clarified the proposed requirements in paragraph (i). Paragraph (i)(1) of the proposed AD specified inspecting the shimmy damper bracket for looseness by following pages 32_110 and 32_111, section 3252, Shimmy Damper, found in Chapter 32, Landing Gear, of Quest Aircraft Company Kodiak 100 Maintenance Manual, Revision No. 21, dated February 15, 2017. Section 3252 contains a broader inspection procedure of the shimmy damper system and not only an inspection of the bracket for looseness. Paragraph (i)(3) of the proposed AD then specified corrective action for damaged components in the shimmy damper system as a result of the inspection in paragraph (i)(1). The FAA has revised paragraph (i)(1) in this AD to clarify that the entire inspection of the shimmy damper system is required.

Conclusion

The FAA reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule with the changes described previously and minor editorial changes. The FAA has determined that these changes:

• Αre consistent with the proposal in the NPRM for addressing the unsafe condition; and
• Do not add any burden upon the public than was already proposed in the NPRM.

The FAA also determined that these changes will not increase the economic burden on any operator or increase the scope of this final rule.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Quest Aircraft Field Service Instruction FSI-147, Revision 00, Release Date January 29, 2018, which provides instructions for inspection and, if necessary, replacement of the NLG fork. The FAA reviewed pages 32_110 and 32_111, section 3252, Shimmy Damper, in Chapter 32, Landing Gear, of Quest Aircraft Company Kodiak 100 Maintenance Manual, Revision No. 21, dated February 15, 2017, which contains procedures for inspecting the shimmy damper system. The FAA also reviewed Quest Aircraft Field Service Instruction FSI-146, Revision 00, Release Date April 18, 2017, which provides instructions for modifying the shimmy damper attach bracket. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.

Costs of Compliance

The FAA estimates that this AD affects 116 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Determine if type A or type B NLG fork is installed	1 work-hour × $85 per hour = $85	Not applicable	$85	$9,860

The FAA estimates the following costs to do any necessary additional inspections, replacements, and modifications that would be required based on the results of the NLG fork type determination. The FAA has no way of determining the number of airplanes that might need these inspections, replacements, and modifications:

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Inspection of the NLG fork for cracks	4 work-hours × $85 per hour = $340	Not applicable	$340 per inspection cycle.
Replacement of the NLG fork	4 work-hours × $85 per hour = $340	$7,002.36	$7,342.36.
Inspection of the shimmy damper system including the bracket	1 work-hour × $85 per hour = $85	Not applicable	$85 per inspection cycle.
Rework of the shimmy damper bracket	4 work-hours × $85 per hour = $340	$127.33	$467.33.

The FAA has received no definitive data that would enable the agency to provide cost estimates for replacing damaged components specified in this AD.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.

The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

This AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Will not affect intrastate aviation in Alaska, 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.

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 FAA amends 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. The FAA amends § 39.13 by adding the following new airworthiness directive:

2020-13-01 Quest Aircraft Design, LLC: Amendment 39-21146; Docket No. FAA-2018-0180; Project Identifier 2017-CE-043-AD.

(a) Effective Date

This airworthiness directive (AD) is effective August 17, 2020.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Daher Aircraft Design, LLC (type certificate previously held by Quest Aircraft Design, LLC), Model KODIAK 100 airplanes, all serial numbers, certificated in any category.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 32, Landing Gear.

(e) Unsafe Condition

This AD was prompted by reports from the manufacturer of fatigue cracks on the nose landing gear (NLG) fork. The FAA is issuing this AD to detect and prevent fatigue cracking of the NLG fork. The unsafe condition, if not corrected, could result in separation of the NLG fork with consequent reduced control on landing. If the NLG fork separates on an unimproved surface, the risk of the NLG digging in and the airplane overturning on the ground increases.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Inspection for Type of NLG Fork

Within 25 hours time-in-service (TIS) after August 17, 2020 (the effective date of this AD), inspect the airplane to determine if an NLG fork part number (P/N) 100-410-7001 (type A) or an NLG fork P/N 100-410-7013 (type B) is installed. If you determine that an NLG fork P/N 100-410-7013 (type B) is installed during the inspection, no further action is required by this AD. If a review of the maintenance records can identify the P/N NLG fork that is installed, you may use a maintenance records review in lieu of inspecting the airplane to determine if an NLG fork P/N 100-410-7001 (type A) or an NLG fork P/N 100-410-7013 (type B) is installed.

(h) Inspection of the NLG Fork for Cracks

(1) If you determine that an NLG fork P/N 100-410-7001 (type A) is installed during the inspection required by paragraph (g) of this AD, within 25 hours TIS after August 17, 2020 (the effective date of this AD) and thereafter at intervals not to exceed 200 hours TIS, do a fluorescent penetrant, dye penetrant, or open-hole eddy current inspection of the NLG fork for cracks by following section 5. Instructions in Quest Aircraft Field Service Instruction FSI-147, Revision 00, Release Date January 29, 2018.

(2) If you find any cracks of the NLG fork during any inspection required by paragraph (h)(1) of this AD, before further flight, replace the NLG fork with an NLG fork P/N 100-410-7013 (type B). Replacement of the NLG fork with an NLG fork P/N 100-410-7013 (type B) terminates the repetitive inspections required by paragraphs (h)(1) and (i)(1) of this AD.

(i) Inspection of the Shimmy Damper Bracket

(1) If you have not replaced an NLG fork P/N 100-410-7001 (type A) per the initial inspection and replacement requirements in paragraph (h) of this AD, then within 25 hours TIS after August 17, 2020 (the effective date of this AD) and thereafter at intervals not to exceed 200 hours TIS (until the NLG fork is replaced with a P/N 100-410-7013 (type B) fork), inspect the shimmy damper bracket for looseness, and inspect the shimmy damper system for damaged (loose, leaking, corroded, or worn) components, by following pages 32_110 and 32_111, section 3252, Shimmy Damper, found in Chapter 32, Landing Gear, of Quest Aircraft Company Kodiak 100 Maintenance Manual, Revision No. 21, dated February 15, 2017.

(2) If a loose shimmy damper bracket is found during any inspection required by paragraph (i)(1) of this AD, rework the shimmy damper bracket with interference-fit bolts by following Quest Aircraft Field Service Instruction FSI-146, Revision 00, Release Date April 18, 2017. Reworking the shimmy damper bracket with the interference-fit bolts terminates the repetitive inspections required by paragraph (i)(1) of this AD.

(3) If any other damaged components are found in the shimmy damper system during any inspection required by paragraph (i)(1) of this AD, before further flight, replace the damaged components.

(j) Optional Terminating Action

In lieu of the NLG fork and shimmy damper bracket inspections required by paragraphs (h)(1) and (i)(1) of this AD, you may replace the NLG fork P/N 100-410-7001 (type A) with an NLG fork P/N 100-410-7013 (type B). This replacement terminates the inspection requirements of this AD, and no further actions are required.

(k) Restriction of NLG Fork P/N 100-410-7001 (Type A) Installation

Once an NLG fork P/N 100-410-7013 (type B) is installed on an airplane, do not install an NLG fork P/N 100-410-7001 (type A). If an NLG fork P/N 100-410-7013 (type B) is removed from the airplane for any reason (for example, to install floats), you must reinstall an NLG fork P/N 100-410-7013 (type B) when operating with wheels.

(l) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Seattle ACO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in paragraph (m) of this AD. Information may also be emailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(m) Related Information

For more information about this AD, contact Wade Sullivan, Aerospace Engineer, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: [phone]; email: [e-mail].

(n) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(i) Pages 32_110 and 32_111, section 3252, Shimmy Damper, Chapter 32, Landing Gear, of Quest Aircraft Company Kodiak 100 Maintenance Manual, Revision No. 21, dated February 15, 2017.

(ii) Quest Aircraft Field Service Instruction FSI-146, Revision 00, Release Date April 18, 2017.

Note 1 to paragraph (n)(2)(ii) of this AD:

The Release Date is a pen-and-ink addition that appears only on the Revision Notice transmitted with FSI-146.

(iii) Quest Aircraft Field Service Instruction FSI-147, Revision 00, Release Date January 29, 2018.

Note 2 to paragraph (n)(2)(iii) of this AD:

The Release Date is a pen-and-ink addition that appears only on the Revision Notice transmitted with FSI-147.

(3) For service information identified in this AD, contact Kodiak Aircraft Company, Inc., 1200 Turbine Drive, Sandpoint, Idaho 83864; phone: [phone] or 1 [phone]; email: [e-mail]; internet: http://Kodiak.aero/​support.

(4) You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the FAA, call [phone].

(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email [e-mail], or go to https://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued on June 9, 2020.

Ross Landes,

Deputy Director for Regulatory Operations, Compliance & Airworthiness Division, Aircraft Certification Service.