Document Headings

                    Document headings vary by document type but may contain                    the following:                  
                -                       the agency or agencies that issued and signed a document                    
                -                       the number of the CFR title and the number of each part                      the document amends, proposes to amend, or is directly                      related to                    
                -                       the agency docket number / agency internal file number                    
                -                       the RIN which identifies each regulatory action listed in                      the Unified Agenda of Federal Regulatory and Deregulatory                      Actions                    

                    See the                                          Document Drafting Handbook                                        for more details.                  

###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2021-0795; Project Identifier 2019-CE-054-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Daher Aerospace (type certificate previously held by SOCATA) Models TB 20 and TB 21 airplanes. This AD was prompted by mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as cracks on the main landing gear (MLG) legs. This proposed AD would require repetitively inspecting the MLG and performing all applicable corrective actions. The FAA is proposing this AD to address the unsafe condition on these products.

# DATES:

The FAA must receive comments on this proposed AD by November 1, 2021.

# 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                          https://www.regulations.gov.                          Follow the instructions for submitting comments.                    
      - Fax: (202) 493-2251.
      -  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 Daher Aircraft Inc., Pompano Beach Airpark, 601 NE 10th Street, Pompano Beach, FL 33060; phone: (954) 893-1400; website:                         *www.tbm.aero.*                         You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (816) 329-4148.                    

## Examining the AD Docket

                    You may examine the AD docket at                     *https://www.regulations.gov*                     by searching for and locating Docket No. FAA-2021-0795; 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 MCAI, any comments received, and other information. The street address for Docket Operations is listed above.                

# FOR FURTHER INFORMATION CONTACT:

                        Gregory Johnson, Aviation Safety Engineer, FAA, General Aviation & Rotorcraft Section, International Validation Branch, 901 Locust, Room 301, Kansas City, MO 64106; phone: (720) 626-5462; fax: (816) 329-4090; email:                         *gregory.johnson@faa.gov*.                    

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    The FAA invites 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-2021-0795; Project Identifier 2019-CE-054-AD” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend the proposal because of those comments.                

                    Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to                     *https://www.regulations.gov,*                     including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this proposed AD.                

## Confidential Business Information

CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Gregory Johnson, Aviation Safety Engineer, FAA, General Aviation & Rotorcraft Section, International Validation Branch, 901 Locust, Room 301, Kansas City, MO 64106. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

## Background

The European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2019-0274, dated November 6, 2019 (referred to after this as “the MCAI”), to address an unsafe condition on all Daher Aerospace (formerly SOCATA) Models TB 20 and TB 21 airplanes. The MCAI states:

Occurrences have been reported of finding cracks on MLG legs of TB 20 and TB 21 aeroplanes.

                        This condition, if not detected and corrected, could lead to structural failure of an MLG leg and consequent MLG collapse, possibly resulting in damage to the aeroplane and injury to occupants.                              ( print page 51841)    

To address this potential unsafe condition, DAHER Aerospace issued the [service bulletin] SB to provide inspection instructions.

For the reasons described above, this [EASA] AD requires repetitive special detailed inspections (SDI) using magnetic particle method of the affected MLG area, and, depending on findings, accomplishment of applicable corrective action(s).

                    You may examine the MCAI in the AD docket at                     *https://www.regulations.gov*                     by searching for and locating Docket No. FAA-2021-0795.                

## Related Service Information Under 1 CFR Part 51

                    The FAA reviewed Daher Service Bulletin SB 10-154-32, dated September 2019. The service information contains procedures for repetitively inspecting the MLG area for cracks and performing any rework and repair. 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

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI and service information referenced above. The FAA is issuing this NPRM after determining the unsafe condition described previously is likely to exist or develop on other products of the same type design.

## Proposed AD Requirements

This proposed AD would require accomplishing the actions specified in the service information already described.

## Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 52 airplanes of U.S. registry. The FAA also estimates that it would take about 8 work-hours per airplane to perform the magnetic particle inspection that would be required by this proposed AD. The average labor rate is $85 per work-hour.

Based on these figures, the FAA estimates the inspection cost of this proposed AD on U.S. operators to be $35,360, or $680 per airplane, per inspection cycle.

In addition, the FAA estimates that any necessary rework would take 12 work-hours and require parts costing $400, for a cost of $1,420 per airplane. The FAA has no way of determining the number of airplanes that may need these actions. If the reworked MLG area is found damaged during a follow-on magnetic particle inspection, because the damage may vary considerably from airplane to airplane, the FAA has no way of estimating this repair cost.

## 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

The FAA 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) Would not affect intrastate aviation in Alaska, and

(3) Would 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 

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

**Daher Aeropsace (Type Certificate Previously Held by SOCATA):**                         Docket No. FAA-2021-0795; Project Identifier 2019-CE-054-AD.                    

## (a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by November 1, 2021.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to Daher Aerospace (type certificate previously held by SOCATA) Models TB 20 and TB 21 airplanes, all serial numbers, certificated in any category.

## (d) Subject

Joint Aircraft System Component (JASC) Code 3200, Landing Gear System.

## (e) Unsafe Condition

This AD was prompted by mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as cracks on the main landing gear (MLG) legs. The FAA is issuing this AD to prevent structural failure of an MLG leg and consequent collapse of the MLG. The unsafe condition, if not addressed, could result in damage to the airplane and injury to occupants.

## (f) Compliance

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

## (g) Repetitive Inspections

                        (1) Before the MLG exceeds 16,000 landings since first installation on an airplane or within 200 landings after the effective date of this AD, whichever occurs later, and thereafter at intervals not to exceed 3,200 landings, accomplish the magnetic particle inspection on each MLG for cracks in the left-hand and right-hand MLG leg and take all applicable corrective actions before further flight in accordance with the Description of Accomplishment Instructions in Daher Service Bulletin SB 10-154-32, dated September 2019, except you are not required to contact the manufacturer. Instead, repair using a method approved by the Manager, International Validation Branch, FAA; the European Union Aviation Safety Agency (EASA); or Daher Aerospace's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature. For a                               ( print page 51842)                            repair to be approved as required by this paragraph, the approval letter must specifically refer to this AD.                    

(2) For the purposes of this AD, any maneuver resulting in weight on the MLG for any duration of time after initial takeoff counts as a landing. If the number of landings for the MLG is unknown, multiply the number of airframe hours by a factor of 3.6 and round up to the nearest whole landing.

## (h) Alternative Methods of Compliance (AMOCs)

                        (1) The Manager, General Aviation & Rotorcraft Section, International Validation 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 Related Information or email:                         *9-AVS-AIR-730-AMOC@faa.gov.*

(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 Gregory Johnson, Aviation Safety Engineer, FAA, General Aviation & Rotorcraft Section, International Validation Branch, 901 Locust, Room 301, Kansas City, MO 64106; phone: (720)-626-5462; fax: (816) 329-4090; email:                         *gregory.johnson@faa.gov.*

                        (2) Refer to European Union Aviation Safety Agency (EASA) AD 2019-0274, dated November 6, 2019, for more information. You may examine the EASA AD in the AD docket at                         *https://www.regulations.gov*                         by searching for and locating Docket No. FAA-2021-0795.                    

                        (3) For service information identified in this AD, contact Daher Aircraft Inc., Pompano Beach Airpark, 601 NE 10th Street, Pompano Beach, FL 33060; phone: (954) 893-1400; website:                         *www.tbm.aero.*                         You may view this referenced service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (816) 329-4148.                    

Issued on September 8, 2021.

Ross Landes,

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

[FR Doc. 2021-19962 Filed 9-16-21; 8:45 am]

BILLING CODE 4910-13-P