[Federal Register Volume 61, Number 74 (Tuesday, April 16, 1996)]
[Rules and Regulations]
[Pages 16617-16620]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-8950]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-ANE-04; Amendment 39-9567, AD 96-08-01]
Airworthiness Directives; Hamilton Standard Model 14RF-9
Propellers
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to Hamilton Standard Model 14RF-9 propellers. This action
supersedes priority letter AD 95-24-09 that currently requires a one-
time ultrasonic shear wave inspection of the propeller blade shank for
cracks or surface indications. This action continues to require an
ultrasonic shear wave inspection, but adds a one-time visual and
fluorescent penetrant inspection and repair of the propeller blade
shank for mechanical damage. This amendment is prompted by propeller
blade shank visual inspection results on blades that were removed from
service as a result of the one-time ultrasonic shear wave inspections.
The inspection results showed that minor damage could exist that is not
detected by the ultrasonic shear wave inspection. This amendment is
also prompted by the development of a method to remove the fiberglass
on the blade shank permitting shank inspection and repair procedures.
The actions specified by this AD are intended to prevent propeller
blade separation due to propeller blade shank cracking, which could
result in loss of control of the aircraft.
DATES: Effective May 1, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of May 1, 1996.
Comments for inclusion in the Rules Docket must be received on or
before June 17, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 96-ANE-04, 12 New England
Executive Park, Burlington, MA 01803-5299.
The service information referenced in this AD may be obtained from
Hamilton Standard, One Hamilton Road, Windsor Locks, CT 06096-1010;
telephone (203) 654-6876. This information may be examined at the FAA,
New England Region, Office of the Assistant Chief Counsel, 12 New
England Executive Park, Burlington, MA; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Frank Walsh, Aerospace Engineer,
Boston Aircraft Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299;
telephone (617) 238-7158, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION:
On November 16, 1995, the Federal Aviation Administration (FAA)
issued priority letter airworthiness directive (AD) 95-24-09,
applicable to Hamilton Standard Model 14RF-9 propellers, which requires
a one-time ultrasonic shear wave inspection of the propeller blade
shank for cracks or surface indications within the next 150 cycles in
service, or 20 days after the effective date of that AD, whichever
occurs first. Propeller blades with ultrasonic shear wave readings that
exceed the acceptable limits described in the applicable SB or ASB must
be replaced with serviceable propeller blades prior to further flight.
That action was prompted by a report of an inflight loss of a Hamilton
Standard Model 14RF-9 propeller blade installed on an Embraer EMB-120
aircraft. The loss of the propeller blade resulted in the subsequent
loss of the propeller and portions of the gearbox. The propeller blade
separated due to a crack approximately 9 inches from the butt end of
the blade. The FAA determined that the crack initiated on the outer
surface of the blade shank in an area of mechanical damage induced as a
result of a localized interference condition between the blade spar and
the foam mold which occurred during blade manufacture. That condition,
if not corrected, could result in propeller blade separation due to
propeller blade shank cracking, which could result in loss of control
of the aircraft.
Since the issuance of that priority letter AD, the manufacturer has
developed improved inspection and repair procedures. The new inspection
procedure can find damage in areas of the propeller blade shank that
might have been damaged by interference with the propeller blade foam
mold during manufacture. The damage will be visible when the overlying
fiberglass and adhesive layers are removed. Propeller blades with
damage that is beyond repair limits can not be returned to service. For
propeller blades with repairable damage, the damage is blended. The
surface is then shotpeened and the fiberglass airfoil is restored.
The FAA has reviewed and approved the technical contents of
Hamilton Standard Service Bulletin (SB) No. 14RF-9-61-86, Revision 4,
and Alert Service Bulletin (ASB) No. 14RF-9-61-A90, both dated November
9, 1995, that describe procedures for an ultrasonic shear wave
inspection of propeller blade shanks for cracks or surface indications.
In addition, the FAA has reviewed and approved the technical contents
of Hamilton Standard ASB No. 14RF-9-61-A92, Revision 2, dated March 6,
1996, that describes procedures for an inspection and repair for
mechanical damage.
Since an unsafe condition has been identified that is likely to
exist or develop on other propellers of this same type design, this AD
supersedes priority letter AD 95-24-09. All propeller blades with
serial numbers (S/N's) less than 885751 that are currently installed on
aircraft must have been inspected in accordance with priority letter AD
95-24-09 as of the effective date of this AD. Propeller blades that
have not been inspected in accordance with priority letter AD 95-24-09
must be ultrasonically shear wave inspected for cracks or surface
indications, or inspected for mechanical shank damage, in accordance
with applicable SB's or ASB's prior to further flight. Propeller blades
with ultrasonic shear wave readings that exceed the acceptable limits
described in the applicable SB's or ASB's must be replaced with
serviceable propeller blades prior to further flight. In addition, this
AD adds a new requirement of a one-time inspection and repair of
mechanical damage of all applicable propeller blades by August 31,
1996, in accordance with Hamilton Standard ASB No. 14RF-9-61-A92,
Revision 2, dated March 6, 1996. Propeller blades with mechanical
damage that exceed repair limits specified in Hamilton Standard ASB No.
14RF-9-61-A92, Revision 2, dated March 6, 1996, must be replaced with
serviceable propeller blades prior to further flight. The calendar end-
date was determined based upon fracture mechanics and engineering
analysis that supports the specified calendar end-date. The actions are
required to be accomplished in accordance with the service documents
described previously.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
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Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this rule by
submitting such written data, views, or arguments as they may desire.
Communications should identify the Rules Docket number and be submitted
in triplicate to the address specified under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments submitted will be
available, both before and after the closing date for comments, in the
Rules Docket for examination by interested persons. A report that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 96-ANE-04.'' The postcard will be date stamped and
returned to the commenter.
The regulations adopted herein will not have substantial direct
effects 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. Therefore, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a ``significant regulatory action''
under Executive Order 12866. It has been determined further that this
action involves an emergency regulation under DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979). If it is determined
that this emergency regulation otherwise would be significant under DOT
Regulatory Policies and Procedures, a final regulatory evaluation will
be prepared and placed in the Rules Docket. A copy of it, if filed, may
be obtained from the Rules Docket at the location provided under the
caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
96-08-01 Hamilton Standard: Amendment 39-9567. Docket No. 96-ANE-04.
Supersedes AD 95-24-09.
Applicability: Hamilton Standard Model 14RF-9 propellers,
installed on but not limited to Embraer EMB-120 series aircraft.
Note: This airworthiness directive (AD) applies to each
propeller identified in the preceding applicability provision,
regardless of whether it has been modified, altered, or repaired in
the area subject to the requirements of this AD. For propellers that
have been modified, altered, or repaired so that the performance of
the requirements of this AD is affected, the owner/operator must use
the authority provided in paragraph (d) to request approval from the
Federal Aviation Administration (FAA). This approval may address
either no action, if the current configuration eliminates the unsafe
condition, or different actions necessary to address the unsafe
condition described in this AD. Such a request should include an
assessment of the effect of the changed configuration on the unsafe
condition addressed by this AD. In no case does the presence of any
modification, alteration, or repair remove any propeller from the
applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent propeller blade separation due to propeller blade
shank cracking, which could result in loss of control of the
aircraft, accomplish the following:
(a) Propeller blades that have been ultrasonically shear wave
inspected in accordance with the requirements of priority letter AD
95-24-09 need not undergo another ultrasonic shear wave inspection
in accordance with paragraph (b) of this AD. All affected propeller
blades with S/N's less than 885751, however, must be inspected for
mechanical damage in accordance with paragraph (c) of this AD by
August 31, 1996. Propeller blades with S/N's less than 885751 that
have not been ultrasonically shear wave inspected in accordance with
priority letter AD 95-24-09 must undergo ultrasonic shear wave
inspection in accordance with paragraph (b) of this AD prior to
further flight, and must be inspected for mechanical damage in
accordance with paragraph (c) of this AD by August 31, 1996; or must
be inspected for mechanical damage in accordance with paragraph (c)
of this AD prior to further flight.
(b) Prior to further flight, perform an ultrasonic shear wave
inspection for cracks or surface indications in accordance with the
applicable Hamilton Standard Service Bulletin (SB) or Alert Service
Bulletin (ASB) described in paragraphs (b)(1) and (b)(2) of this AD
unless accomplished previously in accordance with AD 95-24-09. Prior
to further flight, remove from service propeller blades with
ultrasonic shear wave readings that exceed the acceptable limits
described in the applicable SB or ASB, and replace with serviceable
propeller blades:
(1) Inspect, and if necessary, remove and replace with a
serviceable propeller blade, in accordance with the Accomplishment
Instructions of Hamilton Standard SB No. 14RF-9-61-86, Revision 4,
dated November 9, 1995, propeller blade shanks with propeller blade
spars, Part Number (P/N) 792231-1. These propeller blades may be
identified by, but not limited to, Serial Numbers (S/N's) 853445 and
higher except for the S/N's listed in Table 1 of this SB. Propeller
blades inspected in accordance with the original, Revision 1,
Revision 2, or Revision 3 of Hamilton Standard SB No. 14RF-9-61-86,
and which passed inspection, need not be ultrasonically shear wave
inspected again.
(2) Remove propeller blade for off-wing inspection, inspect, and
if necessary, replace with a serviceable propeller blade, in
accordance with the Accomplishment Instructions of Hamilton Standard
ASB No. 14RF-9-61-A90, dated November 9, 1995, propeller blade
shanks with propeller blade spars, P/N 782683-1. These propeller
blades may be identified by, but not limited to, S/N's less than
853445, and propeller blades with S/N's greater than 853445 that are
listed in Table 1 of this ASB.
(c) Perform a one-time visual and fluorescent penetrant
inspection of the propeller blade shank for mechanical damage by
August 31, 1996, in accordance with the Accomplishment Instructions
of Hamilton Standard ASB No. 14RF-9-61-A92, Revision 2, dated March
6, 1996, on all propeller blade shanks with S/N's before 885751.
Propeller blades inspected in accordance with the original or
Revision 1 of Hamilton Standard ASB No. 14RF-9-61-A92, and which
passed inspection or were repaired, need not be inspected again.
(1) Prior to further flight, remove from service propeller
blades with mechanical
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damage that exceed repair limits specified in that ASB, and replace
with serviceable parts.
(2) Prior to further flight, repair propeller blades with
repairable damage in accordance with the procedures described in
that ASB.
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Boston Aircraft Certification
Office. The request should be forwarded through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, Boston Aircraft Certification Office.
Note: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Boston Aircraft Certification
Office.
(e) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the aircraft to a location where
the requirements of this AD can be accomplished.
(f) The actions required by this AD shall be performed in
accordance with the following Hamilton Standard service documents:
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Document No. Page Revision Date
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SB No. 14RF-9-61-86............. 1-34 4 November 9, 1995.
Total pages: 34.
ASB No. 14RF-9-61-A90........... 1-39 Original November 9, 1995.
Total pages: 39.
ASB No. 14RF-9-61-A92........... 1-44 2 March 6, 1996.
Total Pages: 44.
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This incorporation by reference was approved by the Director of
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. Copies may be obtained from Hamilton Standard, One Hamilton
Road, Windsor Locks, CT 06096-1010; telephone (203) 654-6876. Copies
may be inspected at the FAA, New England Region, Office of the
Assistant Chief Counsel, 12 New England Executive Park, Burlington,
MA; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
(g) This amendment supersedes priority letter AD 95-24-09,
issued November 16, 1995.
(h) This amendment becomes effective on May 1, 1996.
Issued in Burlington, Massachusetts, on April 1, 1996.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 96-8950 Filed 4-15-96; 8:45 am]
BILLING CODE 4910-13-U
