# AD 2020-12-10: Tail Rotor Blades

- Type: Airworthiness directive
- Status: Current
- Products: Bell Textron 205A, 205A-1, 205B, 212, 412, 412CF and 412EP
- Effective: July 16, 2020
- Published: June 11, 2020, 85 FR 35555–35557
- Issued: June 5, 2020
- Issued as: Final rule
- Supersedes: [AD 2011-12-08](https://openairdocs.org/ad/2011-12-08)
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- ATA chapter: 53 · Fuselage
- Amendment: 39-21145
- Docket: FAA-2018-0866 (https://www.regulations.gov/docket/FAA-2018-0866)
- Registered aircraft: 206 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/fc/f7/fcf7eefcfe3a7e5ef4e2dad693f1936e047dec11b47a30c8f807317d92e47472 (from https://www.govinfo.gov/content/pkg/FR-2020-06-11/pdf/2020-12592.pdf)
- Federal Register: https://www.federalregister.gov/documents/2020/06/11/2020-12592/airworthiness-directives-bell-textron-inc-type-certificate-previously-held-by-bell-helicopter
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9B9BB8522E5A84AD86258584003F57CF.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/2020-12-10

## Summary

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. This AD was prompted by reports of cracks of the upper splice fittings. This AD requires repetitive detailed inspections and open hole high frequency eddy current (HFEC) inspections of the upper splice fittings for cracks and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.

## The airworthiness directive

1. The authority citation for part 39 continues to read as follows:

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

AD 2020-12-10 The Boeing Company: Amendment 39-19919; Docket No. FAA-2019-0990; Product Identifier 2019-NM-122-AD.

### (a) Effective Date

This AD is effective July 28, 2020.

### (b) Affected ADs

None.

### (c) Applicability

This AD applies to all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes, certificated in any category.

### (d) Subject

Air Transport Association (ATA) of America Code 53, Fuselage.

### (e) Unsafe Condition

This AD was prompted by reports of cracking in particular areas of the bulkhead structure at body station (BS) 2598. The FAA is issuing this AD to address fatigue cracking of the BS 2598 bulkhead structure, which could adversely affect the structural integrity of the bulkhead and the horizontal stabilizer support structure, and result in loss of controllability of the airplane.

### (f) Compliance

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

### (g) Required Actions

Except as specified by paragraph (h) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020.

Note 1 to paragraph (g):

Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 747-53A2899, Revision 1, dated April 7, 2020, which is referred to in Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020.

### (h) Exceptions to Service Information Specifications

  (1) For purposes of determining compliance with the requirements of this AD: Where Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020, uses the phrase “the original issue date of Requirements Bulletin 747-53A2899 RB,” this AD requires using “the effective date of this AD.”

  (2) Where Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020, specifies contacting Boeing for repair instructions: This AD requires doing the repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD.

### (i) Credit for Previous Actions

This paragraph provides credit for the actions specified in paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Requirements Bulletin 747-53A2899 RB, dated April 5, 2019.

### (j) 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 (k)(1) of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@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.

  (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 The Boeing Company Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO Branch, FAA, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

### (k) Related Information

  (1) For more information about this AD, contact Eric Lin, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3523; email: eric.lin@faa.gov.

  (2) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (l)(3) and (4) of this AD.

### (l) 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.

    (i) Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020.

    (ii) [Reserved]

  (3) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; phone: 562-797-1717; internet: https://www.myboeingfleet.com.

  (4) You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.

  (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 fedreg.legal@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

## Rule preamble

### Dates

This AD is effective July 28, 2020.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of July 28, 2020.

### Addresses

For service information identified in this final rule, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; phone: 562-797-1717; internet: https://www.myboeingfleet.com. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. It is also available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-0990.

### For further information contact

Eric Lin, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3523; email: eric.lin@faa.gov.

### 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 The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. The NPRM published in the Federal Register on December 31, 2019 (84 FR 72260). The NPRM was prompted by reports of cracks of the upper splice fittings. The NPRM proposed to require repetitive detailed inspections and open hole HFEC inspections of the upper splice fittings for cracks and applicable on-condition actions.

The FAA is issuing this AD to address fatigue cracking of the body station (BS) 2598 bulkhead structure, which could adversely affect the structural integrity of the bulkhead and the horizontal stabilizer support structure, and result in loss of controllability of the airplane.

### Comments

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

### Request To Clarify the Unsafe Condition

Boeing requested that the FAA clarify the unsafe condition statement in the NPRM, and reword it to read similarly to the unsafe condition statement in AD 2014-14-03, Amendment 39-17898 (79 FR 41120, July 15, 2014) (“AD 2014-14-03”). Boeing pointed out that AD 2014-14-03 was prompted by reports of cracking in similar areas of the bulkhead structure at BS 2598. Boeing also pointed out that cracking of the bulkhead splice fitting would not be expected to result in loss of the horizontal stabilizer. Boeing also mentioned that the requested change would maintain consistent wording between ADs that are prompted by cracking in similar areas.

The FAA agrees for the reasons provided and has reworded the unsafe condition statement in this AD accordingly.

### Change to the Service Information

Since the NPRM was published, the manufacturer has published a new revision to the service information. Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020, corrects the bulletin approval statement and clarifies the description of Group 2 airplanes. The FAA has updated this AD to refer to Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020, as the appropriate source of service information for the required actions, as all substantive requirements remain unchanged. Additionally, the FAA has added paragraph (i) to this AD to provide credit for actions performed before the effective date of this AD using Boeing Alert Requirements Bulletin 747-53A2899 RB, dated April 5, 2019. The FAA has redesignated subsequent paragraphs accordingly.

### Conclusion

The FAA reviewed the relevant data, considered the comment 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 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.

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 Boeing Alert Requirements Bulletin 747-53A2899 RB, Revision 1, dated April 7, 2020. This service information describes procedures for repetitive detailed inspections and open hole HFEC inspections of the left and right upper splice fittings for cracks and applicable on-condition actions. On-condition actions include 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.

### Costs of Compliance

The FAA estimates that this AD affects 125 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

*Estimated Costs for Required Actions*

| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
| --- | --- | --- | --- | --- |
| Repetitive detailed inspections and open hole HFEC inspections | 5 work-hours × $85 per hour = $425 per inspection cycle | $0 | $425 per inspection cycle | $53,125 per inspection cycle. |

The FAA has received no definitive data that would enable the agency to provide cost estimates for the on-condition actions 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.

### Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H4SW](https://openairdocs.org/tcds/H4SW): Bell Textron Inc.; names 4 of 4 models: 412CF, 212, 412EP, 412
- [TCDS H1SW](https://openairdocs.org/tcds/H1SW): Bell Textron Inc.; names 3 of 5 models: 205A, 205B, 205A-1

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 206 (206 by airframe model, 0 by engine model)
- Makers: Bell 148, Bell Textron Canada 33, Bell Helicopter Textron Canada 17, Bell Helicopter Textron 6, Bell/Southwest Florida Aviatio 2

Models with the most aircraft:

- [Bell 205A-1](https://openairdocs.org/model/bell-205a-1): 56 aircraft (airframe model)
- [Bell 212](https://openairdocs.org/model/bell-212): 54 aircraft (airframe model)
- [Bell Textron Canada 412EP](https://openairdocs.org/model/bell-textron-canada-412ep): 33 aircraft (airframe model)
- [Bell 412EP](https://openairdocs.org/model/bell-412ep): 26 aircraft (airframe model)
- [Bell Helicopter Textron Canada 412EP](https://openairdocs.org/model/bell-helicopter-textron-canada-412ep): 17 aircraft (airframe model)
- [Bell 412](https://openairdocs.org/model/bell-412): 11 aircraft (airframe model)
- [Bell Helicopter Textron 212](https://openairdocs.org/model/bell-helicopter-textron-212): 5 aircraft (airframe model)
- [Bell/Southwest Florida Aviatio 205 A1](https://openairdocs.org/model/bell-southwest-florida-aviatio-205-a1): 2 aircraft (airframe model)
- [Bell 205B](https://openairdocs.org/model/bell-205b): 1 aircraft (airframe model)
- [Bell Helicopter Textron 205A-1](https://openairdocs.org/model/bell-helicopter-textron-205a-1): 1 aircraft (airframe model)

All 10 models: https://openairdocs.org/ad/2020-12-10/models.md
Every aircraft: https://openairdocs.org/ad/2020-12-10/aircraft.md

## Related documents

- [AD 2011-12-08](https://openairdocs.org/ad/2011-12-08) (historical): Tail rotor (T/R) blades · Bell Helicopter Textron 205A, 205A-1, 205B and 4 more. Effective Jul 5, 2011. Replaced by this AD
- [Proposed rule FAA-2018-0866](https://openairdocs.org/proposed/FAA-2018-0866): Notice of proposed rulemaking (NPRM), published Apr 11, 2019

Its text cites no advisory circulars or STCs.

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