2019-09689. Airworthiness Directives; Learjet Inc. Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Learjet Inc. Model 60 airplanes. This proposed AD was prompted by a report of a reverse thrust command accelerating the airplane instead of decelerating the airplane. The acceleration with reverse thrust commanded occurred when the thrust reverser doors were in the stowed position instead of the deployed position. This proposed AD would require installing a Thrust Reverser (T/R) Voice Command Warning System (VCWS) to alert the crew of a T/R malfunction. We are proposing this AD to address the unsafe condition on these products.

DATES:

We must receive comments on this proposed AD by June 27, 2019.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Learjet Inc., MS 53, P.O. Box 7707, Wichita, Kansas 67277-7707; telephone: (toll free) 1-866-538-1247; [phone]; internet: https://my.businessaircraft.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].

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-2019-0204; 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 NPRM, the regulatory evaluation, any comments received, and other information. The street address for Docket Operations (phone: [phone]) is listed above. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

James Galstad, 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:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2019-0204; Product Identifier 2018-CE-042-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this NPRM. We will consider all comments received by the closing date and may amend this NPRM because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this NPRM.

Discussion

We received a report of a high-speed rejected takeoff involving a Learjet Model 60 airplane that occurred when all four main landing gear (MLG) tires blew out during the takeoff roll. The tires blew out due to internal heat damage consistent with under-inflation, overloading, or a combination of both. Subsequently, damage from tires caused damage to various components, including the MLG squat switches, brake hydraulic tubes, wheel speed sensor wiring, and anti-skid components. In the event of squat switch wiring failures, thrust reverser operation can be adversely affected. During the subject accident, forward thrust occurred when the thrust reverser doors stowed due to the failure, and at the same time the crew was still commanding reverse thrust. Squat switch wiring can also be damaged by other external factors, such as bird strikes or deer strikes.

We consider this NPRM to be the third of three ADs that are related to each other, and collectively address unsafe conditions that might result from damage to critical components on the landing gear or in the wheel well that affect the braking, spoiler, and thrust reverser systems. AD 2010-11-11, Amendment 39-16316 (75 FR 32255, June 8, 2010), was issued to prevent tire failure, and AD 2013-13-09, Amendment 39-17497 (78 FR 39574, July 2, 2013), was issued to prevent failure of the braking system or adverse operation of the spoiler and reverse thruster system due to external damage, particularly from tire failure, which could result in loss of control of the airplane. This proposed AD would require installing a T/R VCWS to alert the crew of a T/R malfunction. We are proposing this AD to mitigate failure of the engine thrust reverser system.

This condition, if not addressed, could result in the airplane overrunning the runway or a runway excursion.

Related Service Information Under 1 CFR Part 51

We reviewed Bombardier Learjet 60 Service Bulletin SB 60-78-9, dated June 25, 2018. The service bulletin contains procedures for installing a T/R VCWS to alert the pilot of a T/R malfunction. 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.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would require installing the T/R VCWS.

Costs of Compliance

We estimate that this proposed AD affects 289 airplanes of U.S. registry.

We estimate the following costs to comply with this proposed AD:

Estimated costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Install a T/R VCWS	20 work-hours × $85 per hour = $1,700	$28,274	$29,974	$8,662,486

According to the manufacturer, some of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate.

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.

We are 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

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify this proposed regulation:

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

(2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

(3) Will not affect intrastate aviation in Alaska, and

(4) 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

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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 (AD):

Learjet Inc.: Docket No. FAA-2019-0204; Product Identifier 2018-CE-042-AD.

(a) Comments Due Date

We must receive comments by June 27, 2019.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Learjet Inc. Model 60 airplanes, serial numbers 60-001 through 60-430, certificated in any category.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 78, Engine Exhaust.

(e) Unsafe Condition

This AD was prompted by a report of a reverse thrust command accelerating the airplane instead of decelerating the airplane because the engine thrust reverser doors were stowed instead of deployed. We are issuing this AD to mitigate failure of the engine thrust reverser system. The unsafe condition, if not addressed, could result in the airplane overrunning the runway or a runway excursion.

(f) Compliance

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

(g) Install a Thrust Reverser Voice Command Warning System

Within the next 1,200 hours time-in-service or within the next 48 months after the effective date of this AD, whichever occurs first, install a Thrust Reverser Voice Command Warning System and perform a functional test in accordance with sections 3.A. through 3.C. of the Accomplishment Instructions in Bombardier Learjet 60 Service Bulletin SB 60-78-9, dated June 25, 2018.

(h) 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 certification office, send it to the attention of the person identified in paragraph (i) 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.

(i) Related Information

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

(2) For service information identified in this AD, contact Learjet Inc., MS 53, P.O. Box 7707, Wichita, Kansas 67277-7707; telephone: (toll free) 1-866-538-1247; [phone]; internet: https://my.businessaircraft.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].

Issued in Kansas City, Missouri, on May 3, 2019.

Melvin J. Johnson,

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