[Federal Register Volume 60, Number 45 (Wednesday, March 8, 1995)]
[Rules and Regulations]
[Pages 12663-12666]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-5483]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-02; Amendment 39-9170; AD 95-05-03]


Airworthiness Directives; Hamilton Standard 14RF Series, 14SF 
Series, and Hamilton Standard/British Aerospace Model 6/5500/F 
Propellers

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Hamilton Standard 14RF series, 14SF series, and 
Hamilton Standard/British Aerospace 6/5500/F series propellers, that 
currently requires a one-time ultrasonic shear wave inspection for 
cracks in the propeller blade taper bore. This amendment requires 
initial and repetitive ultrasonic shear wave inspections, and a one-
time visual and borescope inspection of the taper bore for corrosion as 
a terminating action to the ultrasonic shear wave inspections. This 
amendment is prompted by reports of two incidents where a portion of 
the propeller blade was lost in flight. The actions specified by this 
AD are intended to prevent loss of a propeller blade due to cracks 
initiating in the blade taper bore, that can result in possible 
aircraft damage, and possible loss of aircraft control.

DATES: Effective March 23, 1995.
    The incorporation by reference of the following Hamilton Standard 
Alert Service Bulletins (ASB) was approved by the Director of the 
Federal Register as of May 2, 1994: ASB's No. 14RF-9-61-A66, No. 14RF-
19-61-A34, No. 14RF-21-61-A53, No. 14SF-61-A73, and No. 6/5500/F-61-
A27, all dated April 18, 1994.
    The incorporation by reference of all other Hamilton Standard ASB's 
and Service Bulletins listed in this AD is approved by the Director of 
the Federal Register as of March 23, 1995.
    Comments for inclusion in the Rules Docket must be received on or 
before May 8, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 95-ANE-02, 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) 654-3610. This information may be examined at the FAA, 
New England Region, Office of the Assistant Chief Counsel, 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 April 18, 1994, the Federal Aviation 
Administration (FAA) issued airworthiness directive (AD) 94-09-06, 
Amendment 39-8894 (59 FR 19127, April 22, 1994), applicable to Hamilton 
Standard 14RF series, 14SF series, and Hamilton Standard/British 
Aerospace 6/5500/F series propellers, to require an ultrasonic shear 
wave inspection of the blade taper bore for cracks, and replacement, if 
necessary, with a serviceable propeller blade. That action was prompted 
by reports of two incidents where a portion of the propeller blade was 
lost in flight. On March 13, 1994, an ATR-42 commuter aircraft 
experienced an inflight loss of the right propeller and a portion of 
the associated engine gearbox. Later that month, on March 30, 1994, an 
Embraer EMB-120 commuter aircraft also experienced an inflight loss of 
a portion of a propeller blade. This blade fractured at approximately 
the 19-inch station and the remainder of the propeller blade, 
propeller, and gearbox remained intact.
    Subsequent metallurgical examination of these fractured blades 
revealed that the fracture initiated in a small cavity or pit that 
formed on the inner surface of the taper bore inside the aluminum blade 
spar. Further laboratory investigations revealed these corrosion pits 
may develop occasionally when chlorine residue present in the cork used 
to seal the inner taper bore combines with water in the presence of 
oxygen. That condition, if not corrected, could result in loss of a 
propeller blade due to cracks initiating in the blade taper bore, that 
can result in possible aircraft damage, and possible loss of aircraft 
control.
    Since the issuance of that AD, the FAA has conducted engineering 
and laboratory investigation and analysis of world-wide inspection 
results received from AD 94-09-06. This data indicates that either 
periodic ultrasonic shear wave inspection of the propeller taper bore 
should be conducted every 1,250 flight cycles in service (CIS) in order 
to discover cracks that may initiate in pits, or a one-time visual and 
borescope inspection of the taper bore should be conducted after 
removing the propeller inner taper bore cork seal to insure that no 
corrosion has occurred.
    The FAA has reviewed and approved the technical contents of the 
following Hamilton Standard Service Bulletins (SB's) and Alert Service 
Bulletins (ASB's):
    ASB's No. 14RF-9-61-A66, No. 14RF-19-61-A34, No. 14RF-21-61-A53, 
No. 14SF-61-A73, and No. 6/5500/F-61-A27, all dated April 18, 1994, 
that describe procedures for ultrasonic shear wave inspections of the 
[[Page 12664]] blade taper bores for cracks. These ASB's are the same 
as those referenced in AD 94-09-06.
    SB's No. 14RF-9-61-70, dated August 26, 1994; No. 14RF-19-61-37, 
dated August 29, 1994; No. 14RF-21-61-56, dated August 29, 1994; No. 
14SF-61-75, dated August 29, 1994; and No. 6/5500/F-61-30, dated August 
29, 1994. These SB's describe procedures to remove the propeller inner 
taper bore cork seal and inspect the inside surface of the taper bore 
for corrosion pits visually and by borescope. Blades found to be free 
of pits are marked and reidentified. Propeller blade maintenance logs 
shall also be annotated to show compliance with this AD. Blades found 
to have any corrosion pits during these inspections shall be removed 
from service prior to further flight and sent to an FAA-approved repair 
facility for disposition in accordance with the instructions of the 
appropriate SB.
    ASB's No. 14SF-61-A74, Revision 1, dated October 5, 1994; No. 14RF-
9-61-A69, Revision 1, dated October 5, 1994; No. 14RF-19-61-A36, 
Revision 1, dated October 5, 1994; No. 14RF-21-61-A55, Revision 1, 
dated October 5, 1994; and No. 6/5500/F-61-A29, dated August 29, 1994. 
These ASB's list the serial numbers of all blades with unpeened taper 
bores by model that require inspection. These ASB's present several 
options as to how to inspect the blade taper bores, and also give 
instructions to operators and repair facilities on how to report 
inspection data in order to show compliance with the AD.
    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 AD 94-09-06 to require initial and repetitive ultrasonic 
shear wave inspections and a one-time visual and borescope inspection 
of the taper bore for corrosion. Accomplishment of the visual and 
borescope inspection constitutes terminating action to the repetitive 
ultrasonic shear wave inspections. The actions are required to be 
accomplished in accordance with the SB's and ASB's 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.

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 95-ANE-02.'' 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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-8894, (59 FR 
19127, April 22, 1994), and by adding a new airworthiness directive, 
Amendment 39-9170, to read as follows:

95-05-03  Hamilton Standard: Amendment 39-9170. Docket 95-ANE-02. 
Supersedes AD 94-09-06, Amendment 39-8894.

    Applicability: Hamilton Standard Models 14RF-9, 14RF-19, 14RF-
21, and 14SF-5, 14SF-7, 14SF-11, 14SFL11, 14SF-15, 14SF-17, 14SF-19, 
and 14SF-23; and Hamilton Standard/British Aerospace 6/5500/F 
propellers installed on but not limited to Embraer EMB-120 and EMB 
120-RT; SAAB-SCANIA SF 340B; Aerospatiale ATR42-100, ATR42-300, 
ATR42-320, ATR72; DeHavilland DHC-8-100 series, DHC-8-300 Series; 
Construcciones Aeronauticas SA (CASA) CN-235 series and CN-235-100; 
Canadair CL-215T and CL-415; and British Aerospace ATP airplanes.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent loss of a propeller blade due to cracks initiating in 
the blade taper bore, that can result in possible aircraft damage, 
and possible loss of aircraft control, accomplish the following:
    (a) For propeller blades that have accumulated 1,750 or more 
flight cycles since ultrasonic shear wave inspection in accordance 
with AD 94-09-06, perform either paragraph (a) or (d) of this AD 
within 100 flight cycles of the effective date of this AD:
    (1) Perform an ultrasonic shear wave inspection for cracks in 
the blade taper bore, in accordance with the procedures described in 
the following Hamilton Standard Alert Service Bulletins (ASB's), as 
applicable: No. 14RF-21-61-A53, dated April 18, 1994, and No. 14RF-
21-61-A55, Revision 1, dated October 5, 1994; No. 14SF-61-A73, dated 
April 18, 1994, and No. 14SF-61-A74, [[Page 12665]] Revision 1, 
dated October 5, 1994; No. 14RF-19-61-A34, dated April 18, 1994, and 
No. 14RF-19-61-A36, Revision 1, dated October 5, 1994; No. 14RF-9-
61-A66, dated April 18, 1994, and No. 14RF-9-61-A69, Revision 1, 
dated October 5, 1994; No. 6/5500/F-61-A27, dated April 18, 1994, 
and No. 6/5500/F-61-A29, dated August 29, 1994. Remove cracked 
propeller blades and replace with a serviceable blade prior to 
further flight.
    (2) Thereafter, perform repetitive ultrasonic shear wave 
inspections at intervals not to exceed 1,250 CIS since last 
inspection in accordance with the applicable Hamilton Standard ASB's 
listed in paragraph (a)(1) of this airworthiness directive (AD). 
Remove cracked propeller blades and replace with a serviceable blade 
prior to further flight.
    (3) No later than December 31, 1997, perform the visual and 
borescope inspection required by paragraph (d) of this AD.
    (b) For propeller blades that have accumulated less than 1,750 
flight cycles since ultrasonic shear wave inspection in accordance 
with AD 94-09-06, perform either paragraph (a) or (d) of this AD 
before accumulating 1,850 flight cycles since ultrasonic shear wave 
inspection in accordance with AD 94-09-06.
    (c) For propeller blades that have not been inspected in 
accordance with AD 94-09-06, perform paragraphs (a)(1) or (d) of 
this AD prior to installing the blade in service and thereafter 
perform paragraph (a)(2) of this AD if applicable.
    (d) Prior to December 31, 1997, remove and scrap the propeller 
inner taper bore cork seal and visually inspect the inside surface 
of the taper bore for corrosion pits in accordance with the 
applicable Hamilton Standard Service Bulletins (SB's): No. 14RF-9-
61-70, dated August 26, 1994; No. 14RF-19-61-37, dated August 29, 
1994; No. 14RF-21-61-56, dated August 29, 1994; No. 14SF-61-75, 
dated August 29, 1994; and No. 6/5500/F-61-30, dated August 29, 
1994.
    (1) For propeller blades found with any corrosion pits, remove 
from service prior to further flight and send the propeller blades 
to an FAA-approved repair facility for disposition in accordance 
with Hamilton Standard ASB's No. 14SF-61-A74, Revision 1, dated 
October 5, 1994; No. 14RF-9-61-A69, Revision 1, dated October 5, 
1994; No. 14RF-19-61-A36, Revision 1, dated October 5, 1994; No. 
14RF-21-61-A55, Revision 1, dated October 5, 1994; and No. 6/5500/F-
61-A29, dated August 29, 1994; as applicable.
    (2) For propeller blades found with no corrosion pits, mark the 
blade and return it to service in accordance with the Hamilton 
Standard SB's listed in paragraph (d) of this AD.
    (3) Returning propeller blades to service in accordance with 
paragraph (d) of this AD constitutes terminating action to the 
repetitive ultrasonic shear wave inspections required by paragraph 
(a)(2) of this AD.
    (e) For the purpose of this AD, a flight cycle is defined as one 
takeoff and the next landing of an aircraft.
    (f) 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.

    (g) 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.
    (h) The requirements of this AD shall be done in accordance with 
the following Hamilton Standard ASB's and SB's:

------------------------------------------------------------------------
   Document No.        Pages         Revision               Date        
------------------------------------------------------------------------
ASB No. 14SF-61-            1-7  1...............  October 5, 1994.     
 A74.                                                                   
    Total pages:                                                        
     7.                                                                 
ASB No. 14SF-61-           1-19  Original........  April 18, 1994.      
 A73.                                                                   
    Total pages:                                                        
     19.                                                                
SB No. 14SF-61-75.         1-17  Original........  August 29, 1994.     
    Total pages:                                                        
     17.                                                                
ASB No. 14RF-9-61-          1-6  1...............  October 5, 1994.     
 A69.                                                                   
    Total pages:                                                        
     6.                                                                 
ASB No. 14RF-9-61-         1-19  Original........  April 18, 1994.      
 A66.                                                                   
    Total pages:                                                        
     19.                                                                
SB No. 14RF-9-61-          1-17  Original........  August 29, 1994.     
 70.                                                                    
    Total pages:                                                        
     17.                                                                
ASB No. 14RF-19-61-         1-6  1...............  October 5, 1994.     
 A36.                                                                   
    Total pages:                                                        
     6.                                                                 
ASB No. 14RF-19-61-        1-19  Original........  April 18, 1994.      
 A34.                                                                   
    Total pages:                                                        
     19.                                                                
SB No. 14RF-19-61-         1-17  Original........  August 29, 1994.     
 37.                                                                    
    Total pages:                                                        
     17.                                                                
ASB No. 14RF-21-61-         1-6  1...............  October 5, 1994.     
 A55.                                                                   
    Total pages:                                                        
     6.                                                                 
ASB No. 14RF-21-61-        1-19  Original........  April 18, 1994.      
 A53.                                                                   
    Total pages:                                                        
     19.                                                                
SB No. 14RF-21-61-         1-17  Original........  August 29, 1994.     
 56.                                                                    
    Total pages:                                                        
     17.                                                                
ASB No. 6/5500/F-           1-5  Original........  August 29, 1994.     
 61-A29.                                                                
    Total pages:                                                        
     5.                                                                 
ASB No. 6/5500/F-          1-19  Original........  April 18, 1994.      
 61-A27.                                                                
    Total pages:                                                        
     19.                                                                
SB No. 6/5500/F-61-        1-17  Original........  August 29, 1994.     
 30.                                                                    
    Total pages:                                                        
     17.                                                                
------------------------------------------------------------------------

    The incorporation by reference of the following Hamilton 
Standard ASB's was approved by the Director of the Federal Register 
as of May 2, 1994: ASB's No. 14RF-9-61-A66, No. 14RF-19-61-A34, No. 
14RF-21-61-A53, No. 14SF-61-A73, and No.P6/5500/F-61-A27, all dated 
April 18, 1994. The incorporation by reference of all other Hamilton 
Standard ASB's and SB's listed in this AD 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) 
654-3610. 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.
    (i) This amendment becomes effective on March 23, 1995.

    [[Page 12666]] Issued in Burlington, Massachusetts, on February 
28, 1995.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 95-5483 Filed 3-7-95; 8:45 am]
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