Bell 505 Helicopter Airworthiness Directive - Ballast Box Hinge Assembly

Content

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (Bell) Model 505 helicopters.
The FAA previously sent this AD as an emergency AD to all known U.S. owners and operators of these helicopters. This AD was
prompted by a failure of the hinge assembly on the aft movable ballast box assembly, which could allow the ballast weights
to escape the ballast box and strike the tail rotor assembly. This AD requires revising the Limitations section of the existing
rotorcraft flight manual (RFM) for the helicopter to prohibit the use of ballast weights within the aft movable ballast box
assembly. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective April 16, 2026. Emergency AD 2026-05-51, issued on March 6, 2026, which contained the requirements of
this amendment, was effective with actual notice.

The FAA must receive comments on this AD by May 18, 2026.

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 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.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2026-3472; 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 mandatory continuing
airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is
listed above.

FOR FURTHER INFORMATION CONTACT:

Kurt Landendorf, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5254;
email: kurt.d.ladendorf@faa.gov.

SUPPLEMENTARY INFORMATION:

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 “Docket No. FAA-2026-3472; Project Identifier MCAI-2026-00217-R” 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 date and may amend this final rule 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 regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact
received about this final rule.

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
AD 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 AD, 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 AD. Submissions containing CBI should be sent to Kurt Landendorf, Aviation
  Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590. Any commentary that the FAA receives that is not
  specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The FAA issued Emergency AD 2026-05-51, dated March 6, 2026 (also referred to as the emergency AD), to address an unsafe condition
on Bell Model 505 helicopters, serial numbers 65011 and subsequent with ballast box assembly part number (P/N) SLS-706-201-207
or P/N SLS-706-201-207FM installed. The FAA sent the emergency AD to all known U.S. owners and operators of these helicopters.
The emergency AD requires revising the Limitations section of the existing RFM for the helicopter to prohibit the use of ballast
weights within the aft movable ballast box assembly P/N SLS-706-201-207 or P/N SLS-706-201-207FM.

The emergency AD was prompted by Transport Canada Emergency AD CF-2026-12, dated March 3, 2026 (Transport Canada Emergency
AD CF-2026-12) (also referred to as the MCAI), issued by Transport Canada, which is the aviation authority for Canada. The
MCAI states that Bell has discovered possible plastic deformation and improper pin engagement in the knuckles of the door
hinge on the aft movable ballast box assembly. Bell stated there was a failure of the current hinge assembly P/N SLS-706-201-169,
which was found during a post flight inspection. Ballast weights escaping the ballast box have a high potential of striking
the tail rotor assembly.

The FAA is issuing this AD to prevent damage to and/or departure of tail rotor blades, loss of tail rotor thrust, and severe
vibrations. Any of these conditions, if not addressed, will lead to loss of control of the helicopter.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-3472.

FAA's Determination

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

AD Requirements

This AD requires revising the Limitations section of the existing RFM for the helicopter to prohibit the use of the ballast
weights within the aft movable ballast box assembly P/N SLS-706-201-207 or SLS-706-201-207FM.

The owner/operator (pilot) holding at least a private pilot certificate may revise the existing RFM for the helicopter and
must enter compliance into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The pilot
may perform this action because it only involves revising the RFM, which could be performed equally well by a pilot or a mechanic.
This is an exception to the FAA's standard maintenance regulations.

Justification for Immediate Adoption and Determination of the Effective Date

Section 553(b) 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
553(d) 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 2026-05-51 issued on March 6, 2026, 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 ballast weights escaping the ballast box have a high potential of striking
the tail rotor assembly, which could result in damage to and/or departure of tail rotor blades, loss of tail rotor thrust,
and severe vibrations; these conditions will result in loss of control of the helicopter. In addition, this AD requires revising
the existing RFM for the helicopter before further flight. This compliance time is shorter than the time necessary for the
public to comment and for the publication of the final rule. These conditions still exist, therefore, notice and opportunity
for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b).

In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less
than 30 days, for the same reasons the FAA found good cause to forgo notice and comment.

Regulatory Flexibility Act

The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C.
553 to adopt a rule without prior notice and comment. Because the FAA has determined that it has good cause to adopt this
rule without prior notice and comment, RFA analysis is not required.

Interim Action

The FAA considers that this AD is an interim action. If final action is later identified, the FAA might consider additional
rulemaking.

Costs of Compliance

The FAA estimates that this AD affects 174 helicopters of U.S. registry. The FAA estimates the following costs to comply with
this AD:

| Action | Labor cost | Parts cost | Cost per
product | Cost on U.S. operators |
| --- | --- | --- | --- | --- |
| Revise the RFM | 1 work-hour × $85 per hour = $85 | $0 | $85 | $14,790 |

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, and

(2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

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

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

Authority:

49 U.S.C. 106(g), 40113, 44701.

§ 39.13 [Amended] Regulatory Text 2. The FAA amends § 39.13 by adding the following new airworthiness directive:

2026-05-51 Bell Textron Canada Limited:
Amendment 39-23306; Docket No. FAA-2026-3472; Project Identifier MCAI-2026-00217-R.

(a) Effective Date

The FAA issued emergency Airworthiness Directive (AD) 2026-05-51 on March 6, 2026 (also referred to as the emergency AD),
directly to affected owners and operators. As a result of such actual notice, the emergency AD was effective for those owners
and operators on the date it was received. This AD contains the same requirements as the emergency AD and, for those who did
not receive actual notice, is effective on April 16, 2026.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Bell Textron Canada Limited Model 505 helicopters, certificated in any category, serial numbers 65011 and
subsequent, with ballast box assembly part number (P/N) SLS-706-201-207 or P/N SLS-706-201-207FM installed.

(d) Subject

Joint Aircraft System Component (JASC) Code 2500, Equipment/furnishings.

(e) Unsafe Condition

This AD was prompted by a failure of the hinge assembly on the aft movable ballast box assembly, which could allow the ballast
weights to escape the ballast box and strike the tail rotor assembly. The FAA is issuing this AD to prevent damage to and/or
departure of tail rotor blades, loss of tail rotor thrust, and severe vibrations. The unsafe condition, if not addressed,
could result in loss of control of the helicopter.

(f) Compliance

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

(g) Requirements

Before further flight, revise the Limitations section of the existing rotorcraft flight manual (RFM) for the helicopter by
inserting the following text: “the use of the ballast weights within the aft movable ballast box assembly P/N SLS-706-201-207
or SLS-706-201-207FM, is prohibited.”

(1) Inserting a copy of this AD into the Limitations section of the RFM satisfies the requirements of paragraph (g) of this
AD.

(2) For this AD, the owner/operator (pilot) holding at least a private pilot certificate may revise the existing RFM for the
helicopter and must enter compliance into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v).
The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439.

(h) Special Flight Permits

Special flight permits, as described in 14 CFR 21.197 and 21.199, are not allowed.

(i) Alternative Methods of Compliance (AMOCs)

(1) The Manager, 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 International Validation
Branch, send it to the attention of the person identified in paragraph (j) of this AD and email to: 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.

(j) Additional Information

For more information about this AD, contact Kurt Landendorf, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (817) 222-5254; email: kurt.d.ladendorf@faa.gov.

(k) Material Incorporated by Reference

None.

Issued on March 30, 2026. Christopher R. Parker, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2026-06369 Filed 3-31-26; 8:45 am] BILLING CODE 4910-13-P

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