DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-1093; Directorate Identifier 2011-SW-020-AD;
Amendment 39-17989; AD 2014-20-16]
RIN 2120-AA64

Airworthiness Directives; Brantly International, Inc. Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for Brantly
International, Inc. (Brantly) Model B-2, Model B-2A, and Model B-2B
helicopters with certain main rotor blades. This AD requires inspecting
each main rotor (M/R) blade for a crack or delamination and removing
the blade if a crack exists or if the delamination exceeds certain
thresholds. This AD was prompted by multiple reports of M/R blade
cracks and an incident in which a crack that originated near the M/R
blade trailing edge resulted in the loss of a large section of the M/R
blade. The actions of this AD are intended to prevent loss of the M/R
blade and subsequent loss of control of the helicopter.

DATES: This AD is effective November 12, 2014.
The Director of the Federal Register approved the incorporation by
reference of certain documents listed in this AD as of November 12,
2014.

ADDRESSES: For service information identified in this AD, contact
Brantly International, Inc, 621 South Royal Lane, Suite 100, Coppell,
Texas 75019, telephone (972) 829-4638, email
tarcher@superiorairparts.com. You may review a copy of the referenced
service information at the FAA, Office of the Regional Counsel,
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas
76137.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.
gov or in person at the Docket Operations Office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, any incorporated-by-reference
service information, the economic evaluation, any comments received,
and other information. The street address for the Docket Operations
Office (phone: 800-647-5527) is U.S. Department of Transportation,
Docket Operations Office, M-30, West Building Ground Floor, Room W12-
140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Marc Belhumeur, Senior Project
Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA,
2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5170;
email 7-AVS-ASW-170@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

On October 16, 2012, at 77 FR 63285, the Federal Register published
our notice of proposed rulemaking (NPRM), which proposed to amend 14
CFR part 39 by adding an AD that would apply to Brantly Model B-2,
Model B-2A, and Model B-2B helicopters, with an M/R blade, part number
(P/N) 248-101, 248-202, or 248-404, installed. The proposed
requirements were intended to prevent loss of the M/R blade and
subsequent loss of control of the helicopter.
The NPRM was prompted by a 2007 incident in New Zealand in which a
large inboard section of the M/R blade of a Brantly B-2B helicopter
separated from the helicopter during flight. The pilot was able to land
the helicopter without further damage. Laboratory analysis concluded
that the M/R blade failure was caused by hydrocarbon contaminants
inside the blade's skin-to-foam bond and that the fracture originated
near the blade's trailing edge. There were three other reports of
portions of M/R blades separating during flight and another five
reports of M/R blades having cracks or other defects found during
inspections.

Comments

After our NPRM (77 FR 63285, October 16, 2012), was published, we
received comments from 10 commenters.

Request

Allow Some Cracking, Delamination, and Imperfections

Two commenters requested that the AD allow cracks in accordance
with approved maintenance inspection procedures and criteria. Three
commenters requested that the AD allow some delamination as provided
for in Brantly's service information, which is up to 10 square inches
of delamination outside of the inboard 12 inches of the M/R blade. Four
commenters requested that some imperfections be allowed in the blades
as listed in the approved factory maintenance inspection procedures.
Some of these commenters stated that a small dent, nick, crease,
wrinkle, or bend in the skin of the blade, especially in the middle or
trailing edge, does not cause the blade to crack and is not necessarily
a safety issue. These commenters expressed concern that many Brantly
helicopters will be grounded because of slight imperfections in the
main rotor blades that are not a safety issue.
We disagree with allowing any crack in a blade, but we agree the AD
should allow some delamination and imperfections. A crack in a blade
renders it unairworthy, and no data supports that any crack in these
blades is a safe condition. Also, no supporting data justifies allowing
10 square inches of delamination to address the unsafe condition, and
such a large area is not supported by any known industry standards. We
are changing the AD, however, to allow up to 2 square inches of
delamination outside of the inboard 12 inches. We are also removing the
dent, nick, crease, wrinkle, bends, extra hole, and inadequate rivet
spacing requirements from the AD. Although eliminating these conditions
is good design practice, the data we have does not support that a crack
in the Brantly rotor blade skins was caused by small dents, nicks,
creases, wrinkles, bends, extra hole, or inadequate rivet spacing.

Remove Certain Blades From the Applicability

Two commenters requested that we remove blade P/Ns 248-101 and 248-
202 from the applicability of the AD. These commenters did not believe
the unsafe condition applies to these blades because they are
significantly different in composition and bonding agent than the P/N
248-404 blade. The commenters stated the -101 and -202 blades develop
cracks from improper maintenance, rigging, and operation.
We disagree. Failures and fractures have occurred in the field in
the P/N 248-202 blades, and we have been provided with no supporting
data that shows they occurred because of improper rigging, maintenance,
or operation of the aircraft. Brantly, with help from a laboratory
report written by a metallurgical engineering company, concluded that
the M/R blade failure was caused by hydrocarbons contamination inside
the blades' skin-to-foam bond and that the fractures originated near
the trailing edge. The P/N 248-101 and P/N 248-404 blades are similar
in construction to the P/N 248-202 blades, and thus are included and
addressed in this AD. The AD does, however, address the blades
separately by not requiring inspecting the P/N 248-404 blades until after
10 years or 1,000 hours time-in-service (TIS), instead of within 8 hours
TIS like the other blades.

Eliminate or Change the Eddy Current Inspection Requirements

Eight commenters requested that we eliminate the eddy current
inspection from the AD. Five commenters requested replacing the eddy
current inspection with other types (visual, tap test, fluorescent or
dye penetrant) of inspection. Some commenters said eddy current testing
was impractical because it could not be done successfully at certain
locations. Many commenters believed an eddy current inspection would
not successfully detect a crack or would provide false readings. One
commenter stated that the eddy current inspection would destroy the
blade.
We disagree. An eddy current inspection is needed to detect a
potential unsafe condition, and it is a reasonable, widely used, and
cost-effective procedure. No alternate procedure has been provided that
can address the unsafe condition as reliably. Visual or magnifying
glass inspections are not as effective as eddy current inspections. The
eddy current inspection procedure has been validated and is similar to
other blade crack inspections. While there may be some false
indication, these should be false positives, which can be re-evaluated.
The procedure is a nondestructive inspection and if done correctly,
will not destroy any blade. The procedure can be done in the field by a
qualified inspector if the inspection area is clean, has proper
lighting, and has the proper equipment. We have not been provided with
any supporting data that justifies eliminating the eddy current
inspection from the AD.
We do agree with one commenter who requested a visual inspection
before the first flight of each day being performed by the helicopter
owner or operator, since this is best accomplished as part of the other
daily inspections and does not require tools. We also agree with
reducing the scope of the eddy current inspection area to just the
first inboard 12 inches because this is where the fractures have
occurred. Eddy current inspecting the outboard area would not be
effective in finding the unsafe condition. The AD reflects these
changes.

Replace the Inspection Requirements

Two commenters suggested replacing the AD requirements with
different requirements. One commenter requested a mandatory inspection
to identify those main rotor blades not produced or repaired using an
FAA approved quality system or materials or processes. The commenter
believed such blades alone may contain the unsafe condition due to
unapproved blade spars and hinge blocks. Another commenter proposed a
check of all used blades because the unsafe condition is caused by
incorrect installation of the blade damper units.
We disagree. The lab report concluded that the M/R blade failure
was caused by hydrocarbons contamination inside the blades' skin-to-
foam bond and that the fracture originated near the trailing edge. No
data supports a conclusion that the spar or hinge block were unapproved
or that the rivet hole edge distance or pattern caused the unsafe
condition. Also, no data shows that the damper caused the unsafe
condition and thus an initial check for improper damper installation is
not merited. There is history that the incident helicopter may have had
quick starts and that the dampers had to be replaced, but the quick
starts and damper issues have not been substantiated to be the root
cause.

Allow Routine Maintenance To Correct The Unsafe Condition

Five commenters stated that routine maintenance inspections are
sufficient to detect a crack in the blades. One commenter requested
that a revision to the Brantly Service Bulletin would correct the blade
problem and provided suggested content.
We disagree. The failures that have occurred in the field show that
the blades have an unsafe condition and that the current routine
maintenance and inspection procedures do not have adequate methods to
address it. The procedures in the commenter's suggested revision of the
service bulletin are also inadequate to address the unsafe condition
because those procedures do not include a necessary eddy current
inspection and allow too much duration between magnifying glass
inspections. Additionally, the FAA does not have the authority to
require Brantly to revise its service information with a specific
maintenance procedure. Rather, we correct an unsafe condition by
mandating certain actions through an AD.

Withdraw the NPRM Because There Is No Unsafe Condition

One commenter requested we withdraw the AD for more analysis and
testing of the blades. The commenter questioned the data and analyses
relied upon to conclude an unsafe condition exists on these blades and
suggested the FAA has insufficient information upon which to make its
determination. The commenter stated the FAA should determine the
precise root cause and the exact serial number series of affected
blades before issuing an AD. Another commenter requested that we
perform ``a verification and validation on actual Brantly helicopter
blades'' before issuing the AD. Four commenters stated that no blade
failures have caused an accident or loss of life and that the blade
problem that prompted this AD resulted from the aircraft owner's
improper maintenance.
We disagree. Improper maintenance and operation has not been shown
to be the root cause of the blade failures. The root cause of the
failures has been demonstrated by Brantly with help from a laboratory
report written by a metallurgical engineering company. The report took
into account stresses and loading and determined that skin fracture was
propagated by corrosion fatigue and mechanical fatigue. The report
concluded that the M/R blades failure was caused by hydrocarbons
contamination inside the blades' skin-to-foam bond and that the
fracture originated near the trailing edge.
Additional information about the data and analyses we relied upon
in issuing this AD includes the following. The original blades were
certificated using a crack initiation methodology (e.g., using the S-N
curves and Miner's Rule). Shortly after certification, a fatigue test
was accomplished on the mid-span of the spar and skin.
Stereomicroscopy, wavelength dispersive X-ray spectroscopy, combustion
testing, tensile testing, peel testing, scanning electron microscopy,
micro Fourier infrared spectroscopy, and hardness testing were all
performed to determine the causes of the delamination and crack
propagation. An M/R blade failure analysis, risk analysis, cost
analysis, and economic analysis were performed before we issued the
NPRM. The failures were found in the skin-to-foam bond and in the skin
and rivets at the rivet joints attaching the skin to the hinge block
and/or spar. The cracks originated near the skins' trailing edge and
propagated between rivet holes and into the leading edge rivet holes.
These rivets carry shear between the hinge block and skin and the spar
and skin. Per the laboratory report, the bonding material between the
skin to foam was 3M 1239 & 3M 11239A, the foam core was Stafoam AA604,
the type of rivets were AA1100, and the blade was P/N 248-202. No
serial number sequence has been determined or is needed since only the
part numbers are necessary to identify the applicable blades.
We also disagree that loss of life or significant damage to an
aircraft must occur for us to determine that there is an unsafe condition.
Because it is a critical component, failure of an M/R blade could have
catastrophic consequences. However, the commenters are correct that the
event in New Zealand was classified as an incident instead of an
accident because the helicopter landed without further damage. We have
revised the preamble of this AD to reflect this change.

Blade Repairs

One commenter requested the FAA license a certified repair center
to rebuild the blades if they crack before the spar and hinge-block
have reached their life limit. Another commenter asked us to approve a
blade re-skinning or repair process instead of the blade replacement
requirement in the AD. Three commenters stated that no replacement
blades exist, and therefore if the AD is adopted as proposed, it will
ground all flying Brantly helicopters until a source for new blades is
found or a facility is certified to re-build the blades.
We disagree. We are unaware of any approved process specification
or data to rebuild or re-skin blades to an airworthy condition.
Assuming such a process does exist, requiring a repair center to
rebuild or re-skin the blades is beyond the authority of the FAA. To
the extent spare blades may not exist to replace blades that fail the
inspection requirements of this AD, the FAA cannot base its AD action
on whether spare parts are available or can be produced. While every
effort is made to avoid grounding aircraft, we must address the unsafe
condition.

Issue an SAIB

One commenter requested that we issue a special airworthiness
information bulletin (SAIB) with certain visual inspection and
maintenance procedures and provided proposed contents.
We disagree. An SAIB contains non-mandatory information and
guidance for certain safety issues. The SAIB is an information tool to
alert, educate, and make recommendations to the aviation community
about ways to improve the safety of a product. An SAIB may not be
issued where there is an unsafe condition. The FAA has data supporting
its determination that an unsafe condition exists with the specified
Brantly main rotor blades.
We also disagree with the proposed SAIB contents. No supporting
data has been provided demonstrating how the proposed inspection and
maintenance practices would stop the blade skins from cracking or
delaminating from the foam core because of random overload events and
improper operation. Also, no supporting data has been provided that
shows that an improperly manufactured or installed hinge block caused
the unsafe condition. The proposed SAIB content also eliminates the
necessary eddy current inspection and reduces the 10x magnifying glass
inspection, which we have determined are necessary to correct the
unsafe condition.

Training Programs

One commenter requested education and training for maintenance
providers, operators, and owners with respect to the blades.
Specifically, the commenter wanted the training to include the
significance of the placards, type certificate data sheet (TCDS)
instructions, and operating limitations. The commenter stated that
Brantly helicopters are safe and attributed the blade failures to lack
of education and proper maintenance and operation of the aircraft and
its components.
We disagree. Individuals responsible for maintaining and operating
an airworthy helicopter are required to know the significance of
placards, TCDS instructions, and operating limitations. While
additional training may be beneficial, we have no information to
suggest that it would correct the unsafe condition.

FAA's Determination

We have reviewed the relevant information, considered the comments
received, and determined that an unsafe condition exists and is likely
to exist or develop on other products of these same type designs and
that air safety and the public interest require adopting the AD
requirements as proposed with the changes described previously. We have
also made minor editorial changes in referencing the service
information to meet current publishing requirements. These changes are
consistent with the intent of the proposals in the NPRM (77 FR 63285,
October 16, 2012) and will not increase the economic burden on any
operator nor increase the scope of the AD.

Related Service Information

We reviewed Brantly International Inc. Service Bulletin No. 111,
dated February 10, 2011 (SB 111). The bulletin describes procedures for
inspecting the M/R blades at intervals not to exceed 300 hours TIS
using Eddy Current Procedure ET002, performing a visual inspection
using a 10X power magnifying glass, and conducting a tap test every 25
hours TIS and a visual inspection of the M/R blades before the first
flight of the day.

Differences Between This AD and the Service Information

SB-111 requires accomplishment of sections 1 and 2 before further
flight. The AD requires them to be completed within 8 hours TIS. SB-111
allows up to 10 square inches of delamination outside of the inboard 12
inches of the M/R blade. The AD only allows up to 2 square inches of
delamination outside of the inboard 12 inches of the M/R blade. SB-111
requires inspecting for nicks, creases, wrinkles, bends, additional
holes, extra rivets, and inadequate rivet spacing and replacing the
blade if any of these conditions are found. The AD only requires
inspecting for a crack and delamination and replacing the blade if
there is a crack or if there is delamination in certain areas or
exceeding a certain amount. SB-111 calls for eddy current inspections
of the entire blade. The AD requires eddy current inspections for
cracks only within the inboard 12 inches. Lastly, SB-111 specifies a
daily inspection of the M/R blade. We are making a change from the NPRM
to allow an owner/operator (pilot) holding at least a private pilot
certificate to perform a daily check of the M/R blade. The performance
of the check is required to be entered into the aircraft's maintenance
records showing compliance with this AD in accordance with applicable
regulations. This authorization marks an exception to our standard
maintenance regulations.

Costs of Compliance

We estimate that this AD affects 76 helicopters of U.S. registry.
We estimate the following costs to comply with this AD, using an
average of $85 per work-hour:
For the visual check before the first flight of each day,
we estimate that it requires about one half work-hour for a labor cost
of about $43 per inspection cycle. No parts are needed, so the total
cost for the U.S. fleet is $3,268.
For the eddy current inspection, we estimate that it
requires about three work-hours for a labor cost of $255 per inspection
cycle. No parts are needed, so the total cost for the 76-helicopter
U.S. fleet is $19,380 per inspection cycle.
For the visual inspection with the magnifying glass and
the tap inspection, we estimate that it requires about three work-hours
for a labor cost of $255 per inspection cycle. No parts are needed, so
the total cost for the U.S. fleet is $19,380 per inspection cycle.
Replacing an M/R blade, if needed, requires about two
work-hours for a labor cost of $170. An M/R blade costs
$7,500 for a total cost of $7,670 per helicopter, assuming one M/R
blade is replaced.

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
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;
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979);
(3) Will not affect intrastate aviation in Alaska to the extent
that it justifies making a regulatory distinction; 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.
We prepared an economic evaluation of the estimated costs to comply
with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

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

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
directive (AD):