EMERGENCY
FAA AIRWORTHINESS DIRECTIVE
Aviation Safety www.faa.gov/aircraft/safety/alerts/
DATE: March 21, 2025
AD #: 2025-06-51
Emergency Airworthiness Directive (AD) 2025-06-51 is sent to owners and operators of Bell
Textron Canada Limited (Bell) Model 505 helicopters.
Background
Transport Canada, which is the aviation authority for Canada, has issued Transport Canada
Emergency AD CF-2025-17, dated March 19, 2025 (Transport Canada Emergency AD CF-2025-17)
(referred to after this as “the MCAI”), to correct an unsafe condition on Bell Model 505 helicopters,
serial numbers 65011 and subsequent, with ballast kit part number (P/N) SLS-706-201-007 installed.
The MCAI states that Bell has discovered possible plastic deformation and/or improper pin
engagement in the knuckles of the door hinge on the aft movable ballast box assembly, P/N
SLS-706-201-007. Ballast weights escaping the ballast box have a high potential of striking the tail
rotor assembly. This emergency AD is intended to prevent damage to and 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.
Related Material
Transport Canada Emergency AD CF-2025-17 specifies procedures for removing all ballast
weights from the aft movable ballast box assembly, P/N SLS-706-201-007, and prohibits the use of
ballast weights within the aft movable ballast box assembly.
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 described
above. The FAA is issuing this AD after determining that the unsafe condition described previously
is likely to exist or develop in other products of the same type design.
Emergency AD Requirements
This emergency AD requires accomplishing the actions specified in the MCAI, except for any
differences identified as exceptions in the regulatory text of this AD.
Interim Action
The FAA considers that this emergency AD is an interim action. Bell is developing inspection
procedures intended to address the unsafe condition. Once this inspection is developed, approved,
and available, the FAA might consider additional rulemaking.
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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 requires the immediate adoption of this emergency AD to all
known U.S. owners and operators of these airplanes. The FAA has found that the risk to the flying
public justifies forgoing 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 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 removal of the
ballast weights from the aft movable ballast box assembly before further flight. Accordingly, 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.
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.
Presentation of the Actual Emergency Airworthiness Directive
The FAA is issuing this emergency airworthiness directive under 49 U.S.C. 106(f), 40113,
and 44701 according to the authority delegated to me by the Administrator.
2025-06-51 Bell Textron Canada Limited: Project Identifier MCAI-2025-00348-R.
(a) Effective Date
This emergency airworthiness directive (AD) is effective upon receipt.
(b) Affected ADs
None.
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(c) Applicability
This emergency AD applies to Bell Textron Canada Limited Model 505 helicopters,
certificated in any category, as identified in Transport Canada Emergency AD CF-2025-17, dated
March 19, 2025 (Transport Canada Emergency AD CF-2025-17).
(d) Subject
Joint Aircraft System Component (JASC) Code 2500, Equipment/furnishings.
(e) Unsafe Condition
This emergency AD was prompted by deformation and/or improper pin engagement in the
knuckles of the door hinge 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
emergency AD to prevent damage 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 emergency AD within the compliance times specified, unless already done.
(g) Requirements
Except as specified in paragraph (h) of this AD: Comply with all required actions and
compliance times specified in, and in accordance with, Transport Canada Emergency AD
CF-2025-17.
(h) Exception to Transport Canada Emergency AD CF-2025-17
Where Transport Canada Emergency AD CF-2025-17 refers to its effective date, this AD
requires using the effective date of this AD.
(i) Special Flight Permits
Special flight permits are prohibited.
(j) Additional Emergency AD Provisions
The following provisions also apply to this emergency AD:
(1) Alternative Methods of Compliance (AMOCs): 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 responsible Flight Standards 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 (k)(1) of this AD and email to AMOC@faa.gov. Before using any approved AMOC,
notify your appropriate principal inspector, or lacking a principal inspector, the manager of the
responsible Flight Standards Office.
(2) Contacting the Manufacturer: For any requirement in this emergency AD to obtain
instructions from a manufacturer, those instructions must be accomplished using a method approved
by the Manager, International Validation Branch, FAA; or Transport Canada; or Bell Textron Canada
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Limited’s Transport Canada Design Approval Organization (DAO). If approved by the DAO, the
approval must include the DAO-authorized signature.
(k) Additional Information
(1) For more information about this emergency AD, contact Dan McCully, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (404) 474-5548;
email: William.McCully@faa.gov.
(2) For Transport Canada material identified in this emergency AD, contact Transport
Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario
K1A 0N5, Canada; telephone 888-663-3639; email TC.AirworthinessDirectives-
Consignesdenavigabilite.TC@tc.gc.ca; website tc.canada.ca/en/aviation. You may view this material
at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room
6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call
(817) 222-5110.
Issued on March 21, 2025.
Paul R. Bernado,
Acting Director, Compliance & Airworthiness Division,
Aircraft Certification Service.
