[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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[[Page 16618]]

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