2019-18427. Airworthiness Directives; Learjet, Inc. Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA is superseding Airworthiness Directive (AD) 2017-11-09 for certain Learjet, Inc. (Learjet), Model 60 airplanes. AD 2017-11-09 required a one-time fluorescent dye penetrant inspection of the fuselage skin for corrosion, additional related inspections and corrective actions as necessary, and reporting the inspection results to the FAA. This AD clarifies the compliance time for the inspection and corrects an error in the inspection area of the fuselage skin. This AD was prompted by the identification of an error in the fluorescent dye penetrant inspection of the fuselage skin and an ambiguity in the compliance time for the fluorescent dye penetrant inspection. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective October 2, 2019.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of May 22, 2017 (82 FR 18084, April 17, 2017).

ADDRESSES:

For service information identified in this final rule, contact Learjet, Inc., One Learjet Way, Wichita, KS 67209-2942; telephone: [phone]; fax: [phone]; email: [e-mail]; internet: http://www.bombardier.com. You may view this service information at the FAA, Policy and Innovation Division, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the FAA, call [phone]. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-0046.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-0046; 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:

Tara Shawn, Aerospace Engineer, Wichita ACO Branch, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [phone]; fax: [phone]; email: [e-mail] or [e-mail].

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2017-11-09, Amendment 39-18908 (82 FR 24462, May 30, 2017) (“AD 2017-11-09”). AD 2017-11-09 applied to certain serial-numbered Learjet Model 60 airplanes with either a dorsal-mounted oxygen bottle or with a retained oxygen line fairing installed on top of the fuselage after removing the dorsal-mounted oxygen bottle. AD 2017-11-09 required a one-time fluorescent dye penetrant inspection of the fuselage skin for corrosion and reporting the results of the inspection to the FAA. AD 2017-11-09 resulted from an evaluation by the design approval holder that indicated the upper fuselage skin under the aft oxygen line fairing is subject to multi-site damage. The FAA issued AD 2017-11-09 to detect and correct corrosion of the fuselage skin, which could result in reduced structural integrity of the airplane.

AD 2017-11-09 superseded AD 2017-08-07, Amendment 39-18856 (82 FR 18084, April 17, 2017) (“2017-08-07”). AD 2017-11-09 retained all of the actions of AD 2017-08-07 but revised the applicability to include only those airplanes with a dorsal-mounted oxygen bottle or airplanes with a retained the oxygen line fairing installed on top of the fuselage after removing the dorsal-mounted oxygen bottle. AD 2017-11-09 was prompted by the FAA's determination that only certain airplanes listed in the applicability of AD 2017-08-07 were affected by the unsafe condition.

The NPRM published in the Federal Register on February 8, 2019 (84 FR 2793). The NPRM was prompted by the FAA's identification of an error in the area of the fluorescent dye penetrant inspection requirement. AD 2017-11-09 required a fluorescent penetrant inspection of the fuselage skin between stringer (S)-2L and S-2R. Bombardier Learjet 60 Service Bulletin (SB) 60-53-19, Revision 3, dated August 29, 2016, specifies inspecting only out to the fairing end caps, which is a smaller area.

The FAA also identified an ambiguity in the compliance time for the inspection of the fuselage skin. Paragraphs (g)(1) through (3) of AD 2017-11-09 do not specify that the date used for compliance is either the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever date is earlier.

The FAA is issuing this AD to correct the error of the inspection area and clarify the compliance times for the fluorescent dye penetrant inspection of the fuselage skin. The actions of this AD will detect and correct corrosion of the fuselage skin, which could result in reduced structural integrity of the airplane.

Comments

The FAA gave the public the opportunity to participate in developing this AD. The FAA received no comments on the NPRM or on the determination of the cost to the public.

Conclusion

The FAA reviewed the relevant data and determined that air safety and the public interest require adopting this AD as proposed except for minor editorial changes. It has determined that these minor changes:

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

Related Service Information Under 1 CFR Part 51

The FAA reviewed Bombardier Learjet 60 Service Bulletin (SB) 60-53-19, Revision 3, dated August 29, 2016. This service information was previously approved for incorporation by reference in AD 2017-08-07 and retained in AD 2017-11-09. The service information describes procedures for inspections of the fuselage crown skin for corrosion and, as necessary, related investigative inspections and corrective actions. 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 284 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
Inspection (retained action from AD 2017-11-09)	46 work-hours × $85 per hour = $3,910	$265	$4,175	$1,185,700
Reporting (retained action from AD 2017-11-09)	1 work-hour × $85 per hour = $85	0	85	24,140

This AD adds no additional economic burden. The FAA has not received definitive data that would enable us to provide cost estimates for the on-condition actions specified in this AD. According to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. The FAA does not control warranty coverage for affected individuals. As a result, it has included all known costs in the cost estimate.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a currently valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

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.

This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to small airplanes, gliders, balloons, airships, domestic business jet transport airplanes, and associated appliances to the Director of the Policy and Innovation Division.

Regulatory Findings

The FAA determined that 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 removing Airworthiness Directive (AD) 2017-11-09, Amendment 39-18908 ( 82 FR 24462, May 30, 2017), and adding the following new AD:

2019-17-01 Learjet, Inc.: Amendment 39-19721; Docket No. FAA-2019-0046; Product Identifier 2018-CE-040-AD.

(a) Effective Date

This AD is effective October 2, 2019.

(b) Affected ADs

This AD replaces AD 2017-11-09, Amendment 39-18908 (82 FR 24462, May 30, 2017) (“AD 2017-11-09”).

(c) Applicability

This AD applies to Learjet, Inc., Model 60 airplanes, certificated in any category, having serial numbers 60-002 through 60-430 inclusive, and having a configuration identified in paragraph (c)(1) or (2) of this AD.

(1) Airplanes with a dorsal-mounted oxygen bottle.

(2) Airplanes that have had the dorsal mounted oxygen bottle removed but have retained the oxygen line fairing installed on top of the fuselage.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

This AD was prompted by an evaluation by the design approval holder indicating that the upper fuselage skin under the aft oxygen line fairing is subject to multi-site damage. The FAA is issuing this AD to detect and correct corrosion of the fuselage skin, which could result in reduced structural integrity of the airplane.

(f) Compliance

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

(g) Inspection of the Fuselage Skin, Related Investigative Inspections, and Corrective Actions

At the applicable compliance times specified in paragraphs (g)(1) through (3) of this AD, do the fluorescent dye penetrant inspection of the fuselage skin for corrosion. Before further flight, do all related investigative and corrective actions. Follow the Accomplishment Instructions of Bombardier Learjet 60 Service Bulletin 60-53-19, Revision 3, dated August 29, 2016, (SB 60-53-19, Revision 3) except as required by paragraph (h) of this AD.

(1) As of May 22, 2017 (the effective date of AD 2017-08-07, Amendment 39-18856 (82 FR 18084, April 17, 2017) (“2017-08-07”), which was superseded by AD 2017-11-09), any airplanes with more than 12 years since the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever date is earlier: Inspect within 12 months after May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by 2017-11-09).

(2) As of May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by AD 2017-11-09), any airplanes with more than 6 years but equal to or less than 12 years since the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever date is earlier: Inspect within 24 months after May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by AD 2017-11-09).

(3) As of May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by AD 2017-11-09), any airplanes with 6 years or less since the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever date is earlier: Inspect within 36 months after May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by AD 2017-11-09).

(h) Retained Service Information Exception, With No Changes

This paragraph restates the requirements of paragraph (h) of AD 2017-11-09, with no changes. Where SB 60-53-19, Revision 3, specifies contacting Learjet, Inc., for appropriate action: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD.

(i) Retained Reporting, With No Changes

This paragraph restates the requirements of paragraph (i) of AD 2017-11-09, with no changes. At the applicable time specified in paragraph (i)(1) or (i)(2) of this AD: Submit a report of the findings (both positive and negative) of the inspection required by the introductory text of paragraph (g) of this AD to: [e-mail]; or Ann Johnson, Wichita ACO Branch, 1801 Airport Road, Wichita, KS 67209. The report must include the name of the owner, the address of the owner, the name of the organization incorporating Learjet 60 Service Bulletin 60-53-19, the date that inspection was completed, the name of the person submitting the report, the address, telephone number, and email of the person submitting the report, the airplane serial number, the total time (flight hours) on the airplane, the total number of landings on the airplane, whether corrosion was detected, whether corrosion was repaired, the structural repair manual (SRM) chapter and revision used (if repaired), and whether corrosion exceeded the minimum thickness specified in Bombardier Learjet 60 SB 60-53-19 (and specify the SRM chapter and revision, if used as an aid to determine minimum thickness).

(1) If the inspection was done on or after May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by AD 2017-11-09): Submit the report within 30 days after the inspection.

(2) If the inspection was done before May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by AD 2017-11-09): Submit the report within 30 days after May 22, 2017 (the effective date of AD 2017-08-07, which was superseded by AD 2017-11-09).

(j) Credit for Previous Actions

This AD allows credit for the actions required in the introductory text of paragraph (g) if completed before the effective date of this AD using the Accomplishment Instructions in Learjet 60 SB 60-53-19, dated November 23, 2015; Learjet 60 SB 60-53-19 Revision 1, dated April 4, 2016; or Learjet 60 SB 60-53-19 Revision 2, dated April 18, 2016.

(k) Paperwork Reduction Act Burden Statement

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 1 hour per response, including the time for reviewing instructions, completing and reviewing the collection of information. All responses to this collection of information are mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to the FAA at: 800 Independence Ave. SW, Washington, DC 20591, Attn: Information Collection Clearance Officer, AES-200.

(l) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Wichita 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 ACO Branch, send it to the attention of the person identified in paragraph (m)(1) of this AD.

(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.

(3) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by a Learjet, Inc., Designated Engineering Representative (DER), or a Unit Member (UM) of the Learjet Organization Designation Authorization (ODA), that has been authorized by the Manager, Wichita ACO Branch, to make those findings. To be approved, the repair, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(4) AMOCs approved previously for AD 2017-08-07 or AD 2017-11-09 are approved for the corresponding requirements in paragraph (g) of this AD.

(m) Related Information

For more information about this AD, contact Tara Shawn, Aerospace Engineer, Wichita ACO Branch, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [phone]; fax: [phone]; email: [e-mail] or [e-mail].

(n) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) 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.

(3) The following service information was approved for IBR on May 22, 2017, (82 FR 18084, April 17, 2017).

(i) Bombardier Learjet 60 Service Bulletin 60-53-19, Revision 3, dated August 29, 2016.

(ii) [Reserved]

(4) For service information identified in this AD, contact Learjet, Inc., One Learjet Way, Wichita, KS 67209-2942; telephone: [phone]; fax: [phone]; email: [e-mail]; internet: http://www.bombardier.com.

(5) You may view this service information at the FAA, Policy and Innovation Division, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the FAA, call [phone].

(6) 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, call 202-741-6030, or go to: http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued in Kansas City, Missouri, on August 20, 2019.

Melvin J. Johnson,

Aircraft Certification Service, Deputy Director, Policy and Innovation Division, AIR-601.