DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0947; Product Identifier 2017-SW-059-AD]
RIN 2120-AA64

Airworthiness Directives; Robinson Helicopter Company Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
Robinson Helicopter Company (Robinson) Model R44 and R44 II
helicopters. This proposed AD would require visually checking each tail
rotor blade for a crack. This proposed AD is prompted by a report of
cracking in certain tail rotor blades. The actions of this proposed AD
are intended to address an unsafe condition on these products.

DATES: We must receive comments on this proposed AD by July 23, 2018.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the
online instructions for sending your comments electronically.

Fax: 202-493-2251.

Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.

Hand Delivery: Deliver to the "Mail" address between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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-2017-0947;
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 proposed AD, the economic evaluation, any comments received, and
other information. The street address for Docket Operations (telephone
800-647-5527) is in the ADDRESSES section. Comments will be available
in the AD docket shortly after receipt.

For service information identified in this proposed rule, contact
Robinson Helicopter Company, 2901 Airport Drive, Torrance, CA 90505;
telephone (310) 539-0508; fax (310) 539-5198; or at http://www.
robinsonheli.com/servelib.htm. You may review 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 FURTHER INFORMATION CONTACT: James Guo, Aerospace Engineer, Los
Angeles ACO Branch, Compliance & Airworthiness Division, FAA, 3960
Paramount Blvd., Lakewood, California 90712; telephone (562) 627-5357;
email james.guo@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to participate in this rulemaking by submitting
written comments, data, or views. We also invite comments relating to
the economic, environmental, energy, or federalism impacts that might
result from adopting the proposals in this document. The most helpful
comments reference a specific portion of the proposal, explain the reason
for any recommended change, and include supporting data. To ensure the
docket does not contain duplicate comments, commenters should send only
one copy of written comments, or if comments are filed electronically,
commenters should submit only one time.

We will file in the docket all comments that we receive, as well as
a report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking. Before acting on this proposal, we
will consider all comments we receive on or before the closing date for
comments. We will consider comments filed after the comment period has
closed if it is possible to do so without incurring expense or delay.
We may change this proposal in light of the comments we receive.

Discussion

We propose to adopt a new AD for Robinson R44 and R44 II
helicopters with a tail rotor blade part number (P/N) C029-1 or P/N
C029-2 installed. This proposed AD would require checking the tail
rotor blades for cracks within 50 hours time-in-service (TIS) and
thereafter before each flight.

This proposed AD is prompted by reports of P/N C029-1 and P/N C029-2
tail rotor blades with fatigue cracks at the leading edge. The cracks
were caused by high fatigue stresses due to resonance when the blades
were at high pitch angles from large left pedal inputs. Robinson
consequently issued R44 Service Bulletin SB-83, dated May 30, 2012 (SB-
83). At the time SB-83 was issued, the reports of cracking on the tail
rotor blade were isolated and infrequent. Since 2015, five events have
been reported of helicopters with cracking on tail rotor blades.
Therefore, we are proposing actions that are intended to detect a
cracked tail rotor blade and prevent loss of the blade and subsequent
loss of directional control.

FAA's Determination

We are proposing this AD because we evaluated all known relevant
information and determined that an unsafe condition exists and is
likely to exist or develop on other products of these same type
designs.

Related Service Information

We have reviewed Robinson SB-83 which specifies, within 10 flight
hours or by June 30, 2012, whichever occurs first, inserting a caution
page into the Pilot's Operating Handbook. The caution page specifies
inspecting the leading edges of each tail rotor blade for a crack
before each flight. The caution page also advises that to reduce
fatigue stress damage to the tail rotor blades, pilots should avoid
maneuvers that require large left pedal inputs. SB-83 specifies that
the caution page may be removed when the tail rotor blades are replaced
with tail rotor blade P/N C029-3.

Proposed AD Requirements

This proposed AD would require within 50 hours TIS and thereafter
before each flight, visually checking each tail rotor blade for a crack
in the tail leading edge, paying particular attention to the most
inboard white paint stripe. An owner/operator (pilot) may perform the
required visual check and must enter compliance with the applicable
paragraph of the AD into the helicopter maintenance records in
accordance with 14 CFR 43.9(a)(1) through (4) and 91.417(a)(2)(v). A
pilot may perform this check because it involves only a visual check
and can be performed equally well by a pilot or a mechanic. This check
is an exception to our standard maintenance regulations.

This proposed AD also would require before further flight,
replacing any cracked tail rotor blade.

Differences Between This Proposed AD and the Service Information

Robinson SB SB-83 requires compliance within 10 flight hours or by
June 30, 2012, whichever occurs first. This proposed AD would require
compliance within 50 hours TIS. Given the helicopter's history and the
type of operations conducted by the current fleet, we determined that
this compliance time is adequate to reduce the risk of a crack on the
tail rotor blade to an acceptable level.

Costs of Compliance

We estimate that this proposed AD would affect 1,631 helicopters of
U.S. Registry and that labor costs average $85 per work-hour. Visually
checking the tail rotor blades for a crack would require 0.2 hour for a
cost of $17 per helicopter and $27,727 for the U.S. fleet per check
cycle. Replacing a tail rotor blade, if required, would require 2 work-
hours and parts would cost $3,080 for a cost of $3,250 per blade.

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

We 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, I certify this proposed regulation:

1. Is not a "significant regulatory action" under Executive Order
12866;

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 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 proposed 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.

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
directive (AD):