DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1820; Project Identifier AD-2023-00510-P]
Airworthiness Directives; Hamilton Sundstrand Corporation
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for all Hamilton Sundstrand Corporation (Hamilton Sundstrand) Model
14SF-7, 14SF-15, and 14SF-23 propellers. This proposed AD was prompted
by a report of an auxiliary motor and pump failing to feather a
propeller in flight. This proposed AD would require replacement of a
certain auxiliary motor and pump. This proposed AD would also prohibit
installation of a certain auxiliary motor and pump on any propeller.
The FAA is proposing this AD to address the unsafe condition on these
DATES: The FAA must receive comments on this proposed AD by October
ADDRESSES: You may send comments, using the procedures found in
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 by
searching for and locating Docket No. FAA-2023-1820; 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, any comments
received, and other information. The street address for Docket
Operations is listed above.
Material Incorporated by Reference:
For service information identified in this NPRM, contact
Hamilton Sundstrand, One Hamilton Road, Windsor Locks, CT 06096-1010,
phone: (877) 808-7575; email: CRC@collins.com.
You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 1200
District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call (817) 222-5110.
FOR FURTHER INFORMATION CONTACT: Isabel Saltzman, Aviation Safety
Engineer, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone:
(781) 238-7649; email: 9-AVS-AIR-BACO-COS@faa.gov.
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2023-1820; Project Identifier
AD-2023-00510-P'' 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
this 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
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.
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
Isabel Saltzman, Aviation Safety Engineer, FAA, 1701 Columbia Avenue,
College Park, GA 30337. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.
The FAA received a report of an auxiliary motor and pump installed
on a non-Hamilton Sundstrand propeller failing to feather the propeller
in flight through either the primary or the backup means. The failure
was caused by motor magnets in the auxiliary motor and pump that were
de-bonded due to corrosion at the magnet and housing interface. The de-
bonded motor magnets prevented motor rotation. Hamilton Sundstrand
Model 14SF-7, 14SF-15, and 14SF-23 propellers use the same auxiliary
motor and pump. These propellers are installed on, but not limited to,
De Havilland Aircraft of Canada Limited (Type Certificate previously
held by Bombardier Inc.) Model DHC-8-100 series, DHC-8-200 series, and
DHC-8-300 series airplanes. This condition, if not addressed, could
result in reduced controllability of the aircraft and consequent loss
of control of the aircraft.
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Hamilton Sundstrand Service Bulletin (SB) 14SF-61-
168, Revision 1, dated December 21, 2016. This service information
specifies instructions for replacing the auxiliary motor and pump.
Hamilton Sundstrand Corporation is a UTC Aerospace Systems Company.
This service information is identified as both Hamilton Sundstrand
Corporation and UTC Aerospace Systems. 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
Proposed AD Requirements in This NPRM
This proposed AD would require the removal from service of an
auxiliary motor and pump having part number (P/N) 782655-3
(Aerocontrolex P/N 4122-006009) and replacement with an auxiliary motor
and pump having P/N 782655-4 (Aerocontrolex P/N 4122-056000). This
proposed AD would also prohibit installation of an auxiliary motor and
pump having P/N 782655-3 (Aerocontrolex P/N 4122-006009) on any
Differences Between This Proposed AD and the Service Information
Where the service information specifies returning certain parts to
Hamilton Sundstrand, this proposed AD does not contain that
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 180 propellers installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
||Cost per product
||Cost on U.S. operators
|Replace auxiliary motor and pump
||2 work-hours x $85 per hour =
|Perform post-installation system
||1 work-hour x $85 per hour =
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.
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
(1) Is not a ``significant regulatory action'' under Executive
(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
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.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness