DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0002; Directorate Identifier 2011-NE-42-AD]
RIN 2120-AA64

Airworthiness Directives; Continental Motors, Inc. Reciprocating
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of
comment period.

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SUMMARY: We are revising an earlier proposed airworthiness directive
(AD) for certain Airmotive Engineering Corp. (AEC) replacement parts
manufacturer approval (PMA) cylinder assemblies marketed by Engine
Components International Division (ECi). We subsequently issued an
initial supplemental NPRM (SNPRM) that proposed to modify the schedule
for removal of the affected cylinder assemblies, added that overhauled
affected cylinder assemblies be removed within 80 hours, eliminated a
reporting requirement, and removed a requirement for initial and
repetitive inspections. This second SNPRM reopens the comment period to
allow the public the chance to comment on additional information added
to the docket of this proposed rule. We are proposing this SNPRM to
prevent failure of the cylinder assemblies, which could lead to failure
of the engine, in-flight shutdown, and loss of control of the airplane.

DATES: We must receive comments on this SNPRM by September 28, 2015.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to http://www.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: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact
Engine Components International Division, 9503 Middlex Drive, San
Antonio, TX 78217; phone: 210-820-8101; Internet: http://www.eci.aero/
pages/tech_svcpubs.aspx. You may view this service information at the
FAA, Engine & Propeller Directorate, 12 New England Executive Park,
Burlington, MA. For information on the availability of this material at
the FAA, call 781-238-7125.

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-2012-
0002; or in person at the Docket Management Facility between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains this proposed AD, the regulatory evaluation, any comments
received, and other information. The street address for the Docket
Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Jurgen E. Priester, Aerospace
Engineer, Delegation Systems Certification Office, FAA, Rotorcraft
Directorate, 2601 Meacham Blvd., Fort Worth, TX 76137; phone: 817-222-
5190; fax: 817-222-5785; email: jurgen.e.priester@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include "Docket No. FAA-2012-0002;
Directorate Identifier 2011-NE-42-AD" at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.
regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.

Discussion

We issued an NPRM to amend 14 CFR part 39 by adding an AD that
would apply to certain AEC replacement PMA cylinder assemblies marketed
by ECi. These assemblies are used on Continental Motors, Inc. (CMI)
model 520 and 550 reciprocating engines, and all other CMI engine
models approved for the use of models 520 and 550 cylinder assemblies
such as the CMI model 470 when modified by STC. The NPRM published in
the Federal Register on August 12, 2013 (78 FR 48828). The NPRM
proposed to require initial and repetitive inspections, immediate
replacement of cracked cylinder assemblies, and replacement of cylinder
assemblies at reduced times-in-service (TIS) since new. The NPRM also
proposed to prohibit the installation of affected cylinder assemblies
into any engine.

We subsequently issued an SNPRM which published in the Federal
Register on January 8, 2015 (80 FR 1008). The SNPRM proposed a modified
schedule for removal of the affected cylinder assemblies, added that
overhauled affected cylinder assemblies be removed within 80 hours,
eliminated a reporting requirement, and removed the requirement for
initial and repetitive inspections.

Actions Since Previous SNPRM Was Issued

Since we issued the SNPRM (80 FR 1008, January 8, 2015), we
received numerous additional comments on the proposed rule. After
reviewing the comments, we decided to reopen the docket so that we
could provide additional information to explain the rationale for this
AD action. We also wanted to provide commenters with the opportunity to
comment on this additional information. We added the following
information to Docket No. FAA-2012-0002: (1) The risk analysis
conducted by the FAA's Chief Scientific and Technical Adviser, Aircraft
Safety Analysis; (2) a risk analysis using the Small Airplane Risk
Analysis methods; (3) a June 2011, presentation by Airmotive
Engineering to the FAA concerning its ECi cylinder assemblies; (4) a list
of ECi cylinder
assembly failure reports consisting of only those reports where both
cylinder serial number and Time in Service are included in the reports;
(5) a list of additional failures of ECi cylinder assemblies reported
by a maintenance organization; (6) copies of the slides discussed with
the NTSB on June 9, 2015 during the meeting with the NTSB to understand
its comments to 2011-NE-42-AD, and (7) Airmotive Engineering
Corporation Technical Report 1102-13, dated April 30, 2011.

In addition, we met with National Transportation Safety Board
(NTSB) representatives on June 9, 2015, to clarify the NTSB's basis for
its comments of FAA's actions in this proposed rule.

We are taking this opportunity to respond to a limited number of
comments. Specifically, we found that numerous commenters cited
differences between the FAA's proposed action and the NTSB's
recommendations in NTSB Safety Recommendation A-12-7. We will respond
to remaining comments to the initial SNPRM (80 FR 1008, January 8,
2015) and to this second SNPRM when we issue the final rule.

Comments to the Previous SNPRM

Request To Provide Supporting Information

Danbury Aerospace, Inc., and others in their comments to the SNPRM
(80 FR 1008, January 8, 2015), requested that we provide additional
information that supports this AD action.

We agree. We added our risk analyses and other technical
information, such as the list of cylinder failures noted above and ECi
Technical Report 1102-13 that supports this proposed rule, to Docket
No. FAA-2012-0002 to help commenters and the general public understand
the need for this proposed rule.

Request To Withdraw the SNPRM Because ECi Cylinder Assemblies Are Not
Unsafe

Several operators, maintenance organizations, and private citizens
asked that we withdraw the SNPRM (80 FR 1008, January 8, 2015) because
the affected ECi cylinder assemblies have an equivalent, or lower,
failure rate than that of cylinder assemblies manufactured by the
original equipment manufacturer (OEM).

We disagree. We found that the failure rate for ECi cylinder
assemblies is much higher than for OEM cylinder assemblies over the
same period. Accident data confirms, that engines and airplanes may not
always continue to operate safely with a separated cylinder and that
separated cylinders have been the precipitating event in at least two
fatal accidents. This accident data is included in the risk analyses
that we uploaded to the docket (see NTSB Accident Identifiers
NYC02FA178 and ERA11WA008, which are cited in these analyses). We did
not withdraw this proposed rule.

Request To Review Comparison of Failure Rate Between OEM and ECi
Cylinder Assemblies

The NTSB commented that the comparison between failure rates of OEM
and ECi cylinder assemblies was not valid because the cylinder heads
represented substantially different designs.

We disagree that the comparison between OEM and ECi cylinder
assemblies is not valid. The ECi PMA design was reverse engineered by
ECi from earlier vintage OEM cylinders, and uses the same time between
overhaul (TBO) as the OEM cylinders. Since these ECi cylinder
assemblies are approved to the same TBO as the OEM cylinders, the ECi
cylinders should have durability that is equivalent to the OEM
cylinders. Our comparison of ECi cylinder assembly service history with
the OEM cylinder assembly history showed that the rate of separation
for the affected ECi cylinder assemblies is at least 32 times greater
than that of OEM cylinder assemblies over the same period. We uploaded
this data for commenter review. It may be viewed in Docket No. FAA-
2012-0002. We did not change this proposed AD.

Request To Revise Applicability

The NTSB commented that it has not investigated any cases involving
engines with cylinder assemblies ranging from serial number (S/N) 1
through S/N 1043. The NTSB indicated that cylinder assemblies in this
S/N range should not be affected by the AD.

We disagree. Cylinder assemblies with S/N 1 through S/N 1043 have
the same design as noted in this SNPRM, exhibit the same unsafe
condition, and therefore must be included in the applicability. We did
not change this proposed AD.

The NTSB also commented that AD 2004-08-10, which was issued on May
5, 2004, requires replacement before further flight of ECi cylinder
assemblies ranging from S/N 1044 through S/N 7708 installed on CMI 520
and 550 series engines. According to AD 2004-08-10, ECi identified a
manufacturing discrepancy that occurred between September 2002 and May
2003 affecting cylinder assemblies S/N 1044 through S/N 7708, which
resulted in an over-hardened condition that would reduce the fatigue
strength of the aluminum cylinder head. The NTSB commented, therefore,
that cylinder assemblies S/N 1044 through S/N 7708 should not be
included in the proposed AD.
We disagree. AD 2004-08-10 does not apply to all cylinder
assemblies S/N 1044 through S/N 7708; it applies only to cylinder
assemblies having specific cast markings. Cylinder assemblies S/N 1004
through S/N 7708 have the same design as noted in this SNPRM, exhibit
the same unsafe condition, and therefore must be included in the
applicability. We did not change this proposed AD.

The NTSB also commented that, based on its review of the additional
seal band interference fit data provided by ECi, action is only
required for 165 cylinder assemblies S/N 36210 through S/N 61176.

We disagree. We have received reports of separations of cylinder
assemblies S/N 36210 through S/N 61176 that were not among the 165
cylinders that ECi claimed may be at risk for separation due to
insufficient head to barrel interference fit. We have uploaded
information in Docket No. FAA-2012-0002 that identifies S/Ns of failed
cylinder assemblies that were not among the 165 cylinder assemblies
identified by ECi. We did not change this proposed AD.

The NTSB commented that the applicability represented by the
SNPRM--S/N 1 through S/N 61176--represents a much larger number of
affected cylinder assemblies than is supported by its investigations.

We disagree. ECi's next increase in the design interference fit was
incorporated beginning with S/N 61177. Consequently, all cylinder
assemblies S/N 1 through S/N 61176 are at risk for separation in the
first thread due to insufficient interference fit. We, therefore, find
that based on service failure data, identified in the docket as "U.S.
DOT/FAA--04 ECi 520-550 Cylinder Separations," and ECI's
implementation of design improvements, this proposed AD must apply to
cylinder assemblies S/N 1 through S/N 61176. We did not change this
proposed AD.

Request To Include Repetitive Inspection Requirement

The NTSB commented that we should impose a repetitive inspection
requirement for certain ECi cylinder assemblies and their removal once
they reach the manufacturer's recommended TBO. This repetitive
inspection requirement was part of the NPRM (78
FR 48828, August 12, 2013), but we removed it from the SNPRM (80 FR
1008, January 8, 2015).

The NTSB observed that the FAA had published Special Airworthiness
Information Bulletin (SAIB) NE-07-09R1, dated March 21, 2007, and
approved ECi Mandatory Service Bulletin 06-2, Revision 2, dated October
26, 2006. Both of these documents emphasize the importance of
conducting periodic inspections of ECi cylinder assemblies.

We disagree. We have found, based on service experience since the
publication of SAIB NE-07-09R1, that the inspection and tests are not
reliable in detecting cracked cylinders and the cost associated with
such ongoing tests outweighs the safety benefit. In addition, the crack
propagation growth rate is unknown. As a result, we have received field
reports of separated cylinders that occurred within the repetitive 50-
hour compression test and leak check inspection intervals proposed by
the NPRM. We did not change this proposed AD.

The NTSB also noted that repetitive inspections are not perfect but
are still effective in detecting cracks that have propagated through
the cylinder wall. These inspections provide an added level of safety
from the time of the issuance of the final rule AD until the required
removal of the cylinder assembly.

We disagree. We find that repetitive inspections until TBO are
inconsistent with the serious hazard represented by cylinder assembly
failures. See the "U.S. DOT/FAA-01 Risk Analysis White Paper" for
2011-NE-42-AD that we uploaded to the AD docket on June 23, 2015.
Therefore, we are requiring removal of affected cylinder assemblies
from service prior to TBO. We did not change this proposed AD.

FAA's Determination

We are proposing this SNPRM to allow the public the opportunity to
comment on additional information we added to the docket of this
proposed rule.

Proposed Requirements of this SNPRM

As proposed in the first SNPRM published on January 8, 2015 (80 FR
1008), this second SNPRM would require removal of the affected cylinder
assemblies, including overhauled cylinder assemblies, according to a
phased removal schedule.

Costs of Compliance

We estimate that this proposed AD would affect about 5,000 CMI
models IO-520, TSIO-520, IO-550, and IOF-550 reciprocating engines and
all other CMI engine models approved for the use of CMI models 520 and
550 cylinder assemblies (such as the CMI model 470 when modified by
STC), installed on airplanes of U.S. registry. The average labor rate
is $85 per hour. We estimate that about 18 hours would be required to
replace all six cylinder assemblies during overhaul maintenance. We
estimate the pro-rated value of the cost of replacement of six cylinder
assemblies to be about $4,202 per engine. Based on these figures, we
estimate the total cost of this proposed AD to U.S. operators to change
all ECi cylinder assemblies to be $28,660,000. Our cost estimate is
exclusive of possible warranty coverage.

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 above, 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.

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):