DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2018-0281; Product Identifier 2018-NE-06-AD; Amendment
39-19437; AD 2018-20-03]
Airworthiness Directives; Hoffmann GmbH & Co. KG Propellers
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: We are adopting a new airworthiness directive (AD) for
Hoffmann GmbH & Co. KG model HO-V 62 propellers. This AD was prompted
by the failure of the propeller blade lag screws. This AD requires
removal of the affected propeller blades and installation of modified
propeller blades marked with change letter ``A'' or ``B.'' We are
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective November 14, 2018.
ADDRESSES: For service information identified in this final rule,
contact Hoffmann Propeller GmbH & Co. KG, Sales and Service,
Kupferlingstrasse 9, 83022 Rosenheim, Germany; phone: +49 (0) 8031
1878 0; fax: +49 (0) 8031 1878 78; email: email@example.com. You
may view this service information at the FAA, Engine & Propeller
Standards Branch, 1200 District Avenue, Burlington, MA 01803. For
information on the availability of this material at the FAA, call 781-
238-7759. It is also available on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-0281.
Examining the AD Docket
You may examine the AD docket on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-
0281; 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), the regulatory evaluation, any comments received, and other
information. The address for Docket Operations (phone: 800-647-5527) is
U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Maureen Maisttison, Aerospace
Engineer, Boston ACO Branch, FAA, 1200 District Ave, Burlington, MA
01803; phone: 781-238-7076; fax: 781-238-7151; email:
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to certain Hoffmann GmbH & Co.
KG model HO-V 62 propellers. The NPRM published in the Federal Register
on July 12, 2018 (83 FR 32219). The NPRM was prompted by the failure of
the propeller blade lag screws. The NPRM proposed to require removal of
the affected propeller blades and installation of modified propeller
blades marked with change letter ``A'' or ``B.'' We are issuing this AD
to address the unsafe condition on these products.
The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued EASA
AD 2017-0220, dated November 10, 2017 (referred to after this as ``the
MCAI''), to address the unsafe condition on these products. The MCAI
In 1983, occurrences were reported of fatigue failure of
propeller blade lag screws, at rotation speeds between 2950 and 3250
revolutions per minute (RPM) in flight.
This condition, if not detected and corrected, could lead to in-
flight propeller blade detachment, possibly resulting in damage to
the powered sailplane and/or injury to persons on the ground.
To address this potential unsafe condition, Hoffmann issued
Service Bulletin (SB) 4, providing the necessary instructions.
Consequently, LBA Germany issued AD 83-150 (later revised), which
applied only to HO-V 62 propellers with R/L 160T blades, when in
combination with a Limbach L 2000 engine, to require a limitation of
continuous operation to 2 900 RPM, to prohibit aerobatic flights,
calibrate the tachometer, install a placard, and inspection of the
propeller blades. LBA AD 83-150/4 also required overhaul and
replacement of the affected propeller blades with modified blades,
either having 5 lag screws with 12 mm diameter, or 6 screws, and
required implementing a time between overhaul (TBO) of 600 flight
Since that [LBA] AD was issued, based on a stress analysis of
lag screws on blades with continuous operating speed above 2 900
RPM, it was determined that the 6-screws configuration or the 5
screws configuration with increased strength is necessary to ensure
safe propeller operation. In addition, since the LBA AD applied only
to a limited population (Limbach engine only), many propellers have
not been modified as described in Hoffmann SB 4C. Consequently,
Hoffmann issued SB E34 Revision B, to provide blade replacement
You may obtain further information by examining the MCAI in the AD
docket on the internet at http://www.regulations.gov by searching for
and locating Docket No. FAA-2018-0281.
We gave the public the opportunity to participate in developing
this final rule. We received no comments on the NPRM or on the
determination of the cost to the public.
Revised the Name of the Type Certificate Holder
We determined that the name of the type certificate (TC) design
holder that we used in the NPRM does not match the name used in the
type certificate data sheet. We have revised references in this AD from
``Hoffmann Propeller GmbH & Co. KG'' to ``Hoffmann GmbH & Co. KG'' when
we are referring to the name of the TC design holder.
We reviewed the relevant data and determined that air safety and
the public interest require adopting this final rule as proposed except
for minor editorial changes. We have determined that these minor
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.
Related Service Information
We reviewed Hoffmann Propeller GmbH & Co. KG Service Bulletin (SB)
E34 Rev. B, dated September 18, 2017. The SB describes the instructions
for the removal and installation of the propeller blades.
Costs of Compliance
We estimate that this AD affects 50 propellers installed on
airplanes of U.S. registry.
We estimate the following costs to comply with this AD:
||Cost per product
||Cost on U.S. operators
|Replace blades between overhaul
||3 work-hours x $85 per
hour = $255
|Replace blades at overhaul
||0 work-hours 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.
We are 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
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to engines, propellers, and
associated appliances to the Manager, Engine and Propeller Standards
Branch, Policy and Innovation Division.
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 this AD:
(1) Is not a ``significant regulatory action'' under Executive
(2) Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
Adoption of 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
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