DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0620; Project Identifier 2019-SW-074-AD; Amendment
39-21766; AD 2021-21-06]
Airworthiness Directives; Helicopteres Guimbal Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
Helicopteres Guimbal (HG) Model Cabri G2 helicopters with
certain part-numbered aluminum cooling fans (cooling fan) installed.
This AD was prompted by a report of an occurrence of an in-flight
shutdown due to a crack and subsequent failure of the cooling fan. This
AD requires removing certain part-numbered cooling fans from service,
or modifying certain part-numbered cooling fans before exceeding a
certain total hours time-in-service (TIS), and installing newly
designed cooling fans. This AD also prohibits installing any affected
cooling fan on any helicopter. The FAA is issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective December 17, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of December 17,
ADDRESSES: For service information identified in this final rule,
contact Helicopteres Guimbal, Basile Ginel, 1070, rue du
Lieutenant Parayre, Aerodrome d'Aix-en-Provence, 13290 Les
Milles, France; telephone 33-04-42-39-10-88; email
firstname.lastname@example.org; web https://www.guimbal.com. You may view the
referenced service information at the FAA, Office of the Regional
Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort
Worth, TX 76177. For information on the availability of this material
at the FAA, call (817) 222-5110. Service information that is
incorporated by reference is also available at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No.
FAA-2021-0620; 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 European Union Aviation Safety Agency
(EASA) AD, any comments received, and other information. The street
address for Docket Operations 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: Andrea Jimenez, Aerospace Engineer,
COS Program Management Section, Operational Safety Branch, Compliance
Airworthiness Division, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY
11590; telephone (516) 228-7330; email email@example.com.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to
Helicopteres Guimbal (HG) Model Cabri G2 helicopters with
a cooling fan part number P/N G52-00-000; or P/N G52-00-001 or P/N G52-
04-100, if it is or has previously been mounted on a 12-hole engine
pulley P/N G52-10-100 or P/N G52-10-101, installed. The NPRM published
in the Federal Register on August 9, 2021 (86 FR 43449). In the NPRM,
the FAA proposed to require removing from service any affected part-
numbered cooling fan. As an alternative for certain part-numbered
cooling fans, modifying the cooling fan before it exceeds a certain
total hours TIS was proposed.
The NPRM was prompted by a series of EASA ADs beginning with EASA
AD 2014-0038, dated February 14, 2014 (EASA AD 2014-0038), issued by
EASA, which is the Technical Agent for the Member States of the
European Union, to correct an unsafe condition for
Helicopteres Guimbal Model Cabri G2 helicopters. EASA
advised of a report of an in-flight engine shutdown caused by a failure
of the cooling fan. EASA further advised the failure of the cooling fan
was caused by a crack in the fan external ring. After EASA AD 2014-0038
was issued, an occurrence was reported of an in-flight failure caused
by failure of the cooling fan, which was determined to be caused by a
crack on the cooling fan front flange.
Accordingly, EASA issued EASA AD 2014-0196, dated September 2, 2014
(EASA AD 2014-0196), which retained the modification requirements of
EASA AD 2014-0038 and required repetitive inspections of the engine
cooling fan front flange and corrective actions depending on the
findings. After EASA issued EASA AD 2014-0196, further analysis
determined the crack propagation depends mainly on the engine start/
stop (ESS) cycles. Therefore, EASA superseded EASA AD 2014-0196 with
EASA AD 2016-0033, dated February 24, 2016 (EASA AD 2016-0033), which
retained the inspection and modification requirements of EASA AD 2014-
0196 and depending on the findings, required replacement of the
affected part pending approval of the newly designed part.
After EASA issued EASA AD 2016-0033, HG developed a newly designed
engine cooling fan P/N G52-04-101, which consists of composite
materials having improved structural strength. Accordingly, EASA
superseded EASA AD 2016-0033 with EASA AD 2017-0039, dated February 24,
2017 (EASA AD 2017-0039), which retained the requirements of EASA AD
2016-0033 and required replacing the affected cooling fans with the
newly designed cooling fan which terminated the repetitive inspections
from EASA AD 2016-0033.
Since EASA issued EASA AD 2017-0039, HG issued a revision to its
service bulletin requiring a life limit requirement for the replacement
of the affected cooling fans. Accordingly, EASA superseded EASA AD
2017-0039 with EASA AD 2019-0187, dated July 31, 2019, and corrected
August 2, 2019 (EASA AD 2019-0187). EASA AD 2019-0187 retains some of
the requirements in EASA AD 2017-0039 and requires a new compliance
time and life limit for the replacement of the affected part. EASA AD
2019-0187 also removes the modification and inspection requirements
which are covered by EASA AD 2019-0025, dated February 4, 2019.
The unsafe condition described in the EASA ADs, if not addressed,
could result in failure of the cooling fan and subsequent engine in-
flight shut-down and reduced control of the helicopter.
Discussion of Final Airworthiness Directive
The FAA received comments from one commenter. The following
presents the comment received on the NPRM and the FAA's response.
Request To Change the Summary Paragraph
Helicopteres Guimbal requested the FAA revise the
references made to the amount of in-flight shut-down occurrences; the
commenter stated that there were not two engine shutdowns due to fan
failure but one. The FAA agrees that there was only one occurrence of
an in-flight shut-down, and one occurrence of an in-flight failure.
Therefore, the FAA has revised this final rule accordingly.
The FAA reviewed the relevant data and determined that air safety
requires adopting this AD as proposed. Accordingly, the FAA is issuing
this AD to address the unsafe condition on these products. Except for
minor editorial changes, including the changes described above, this AD
is adopted as proposed in the NPRM. These changes do not increase the
scope of the AD.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Guimbal Service Bulletin SB 16-021 E, dated August
27, 2019. This service information specifies instructions for
retrofitting the cooling fan with the new front flange, aft ring, and
24-hole pulley. This service information also specifies that upon
completion of all the required actions, the cooling fan assembly P/N
G52-00-000, P/N G52-00-001, and P/N G52-04-100 become P/N G52-04-101.
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 the ADDRESSES section.
Other Related Service Information
The FAA also reviewed Guimbal Service Bulletin SB 16-021 D, dated
May 20, 2019, which specifies procedures for accessing the cooling fan
and removing it from service; modifying, applying adhesive and
torqueing the rear flange; installing the improved cooling fan, and
Differences Between This AD and EASA AD 2019-0187
EASA AD 2019-0187 allows certain cooling fans with certain total
hours TIS to be retrofitted before exceeding their life limit, whereas
this AD requires removing these cooling fans from service or as an
alternate to removing them from service, modifying the cooling fan
before exceeding the total hours TIS. EASA AD 2019-0187 allows a
compliance time in months TIS to replace certain part-numbered cooling
fans, whereas this AD only allow hours TIS.
EASA AD 2019-0187 retains the compliance time of March 10, 2017,
which is the effective date of EASA AD 2017-0039. This AD requires
compliance within the effective date of this AD. The FAA has determined
that these compliance times are adequate to address the identified
Costs of Compliance
The FAA estimates that this AD affects 32 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates the following costs to comply with
Removing the affected cooling fan from service and installing the
newly designed cooling fan takes about 16 work-hours and parts cost
about $4,600 for an estimated cost of $5,960 per replacement and
$190,720 for the U.S. fleet.
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 helicopters identified in this rulemaking action.
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
(2) Will not affect intrastate aviation in Alaska, and
(3) 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
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