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Federal Register / Vol. 86, No. 150 / Monday, August 9, 2021 / Rules and Regulations
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Background On July 6, 2021, the FAA issued Emergency AD 20211551 Emergency AD 20211551, which requires, before further flight, removing from service all part number P/N 204012104005
pins with a serial number S/N prefix FNFS. Emergency AD 20211551
also prohibits installing the pin on any helicopter as of the emergency ADs effective date. The FAA sent Emergency AD 20211551 to all known U.S.
owners and operators of these helicopters.
Emergency AD 20211551 was prompted by a fatal accident on a Bell Textron Inc. Model 212 helicopter in which a pin P/N 204012104005 with an S/N prefix FNFS sheared off during flight, which resulted in the main rotor blade and the main rotor head detaching from the helicopter. The pin had accumulated only 20 total hours time-in-service TIS. An inspection of a different Model 212 helicopter revealed that another pin installed, and made by the same manufacturer and with the same S/N prefix, was deformed; this pin had accumulated only 29 total hours TIS. Failure of the pin could result in the main rotor blade detaching from the helicopter and subsequent loss of control of the helicopter.
Prior to the FAA issuing Emergency AD 20211551, Transport Canada, which is the aviation authority for Canada, issued Canadian Emergency AD
CF202123, dated July 5, 2021
Transport Canada Emergency AD CF
202123, to correct an unsafe condition for the following Bell Helicopter Textron Inc., helicopters:
Model 204B helicopters, S/Ns 2001
through 2070 and 2196 through 2199;
Model 205A1 helicopters, S/Ns 30001 through 30065, 30067 through 30165, 30167 through 30187, 30189
through 30296, and 30298 through 30332;
Model 205B helicopters, S/Ns 30066, 30166, 30188, and 30297; and Model 212 helicopters, S/Ns 30501
through 30999, 31101 through 31311, 32101 through 32142, and 35001
through 35103.
Transport Canada advises that during an investigation of a Bell Textron Inc., Model 212 fatal accident in Canada, it was discovered that a pin P/N 204012
104005 with an S/N prefix FNFS, sheared off during flight, leading to detachment of the main rotor blade and the main rotor head. The pin had accumulated only 20 hours of service, and inspection of another Canadian Bell Textron Inc., Model 212 helicopter found a pin of the same P/N, made by the same manufacturer, with the same
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S/N prefix FNFS, to be deformed after only approximately 29 hours in service.
According to Transport Canada, failure of a main rotor hub strap pin will result in detachment of the main rotor blade and loss of control of the helicopter.
Transport Canada also advises that, although the defective pins were only reported on Bell Textron Inc., Model 212 helicopters, pins of the same P/N
can also be installed on Bell Textron Inc., Model 204B, 205A1, and 205B
helicopters. While the cause of failure has not been determined, as a precautionary measure and to address the risk of detachment of main rotor hub strap pins in flight, Bell has issued Alert Service Bulletins to require replacing all pins with P/N 204012104005 that have S/N prefix FNFS. Accordingly, Transport Canada Emergency AD CF
202123 mandates replacement of affected pins. Transport Canada considers its emergency AD an interim action and states that further AD action may follow.
FAAs Determination The FAA is issuing this AD after evaluating all the relevant information and determining that the unsafe condition described previously is likely to exist or develop in other products of these same type designs.
Related Service Information The FAA reviewed the following Bell Alert Service Bulletins ASBs, each dated July 5, 2021:
ASB 204B2174 for Bell Textron Inc., Model 204B helicopters, S/Ns 2001
through 2070 and 2196 through 2199;
ASB 20521117 for Bell Textron Inc., Model 205A and 205A1
helicopters, S/Ns 30001 through 30065, 30067 through 30165, 30167 through 30187, 30189 through 30296, and 30298
through 30332;
ASB 205B2171 for Bell Textron Inc., Model 205B helicopters, S/
Ns30066, 30166, 30188 and 30297; and ASB 21221165 for Bell Textron Inc., Model 212 helicopters, S/Ns 30501
through 30999, 31101 through 31311, 32101 through 32142, and 35001
through 35103.
The ASBs specify removing all P/N
204012104005 pins with an S/N
prefix FNFS before further flight. The ASBs also specify that, although the investigation is still in progress, removing these pins from service is required. The ASBs state that these pins may not have been manufactured in accordance with the engineering design requirements and may therefore shear as a result of this nonconformance.

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AD Requirements This AD requires removing from service all P/N 204012104005 pins with an S/N prefix FNFS before further flight. This AD also prohibits installing this pin on any helicopter as of the effective date of this AD.
Interim Action The FAA considers this AD to be an interim action. If final action is later identified, the FAA might consider further rulemaking.
Justification for Immediate Adoption and Determination of the Effective Date Section 553b3B of the Administrative Procedure Act APA 5
U.S.C. 551 et seq. authorizes agencies to dispense with notice and comment procedures for rules when the agency, for good cause, finds that those procedures are impracticable, unnecessary, or contrary to the public interest. Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance.
Further, section 553d of the APA
authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.
An unsafe condition exists that required the immediate adoption of Emergency AD 20211551, issued on July 6, 2021, to all known U.S. owners and operators of these helicopters. The FAA found that the risk to the flying public justified waiving notice and comment prior to adoption of this rule because an urgent unsafe condition existed and corrective action was required before further flight. This condition still exists, therefore, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5
U.S.C. 553b3B.
In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553d for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forego notice and comment.
Comments Invited The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under ADDRESSES.
Include the docket number FAA 2021
0619 and Project Identifier AD2021
00789R at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing
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