[Federal Register Volume 59, Number 49 (Monday, March 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5704]
[[Page Unknown]]
[Federal Register: March 14, 1994]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-ANE-09; Amendment 39-8853; AD 94-06-05]
Airworthiness Directives; Hamilton Standard 14RF Series
Propellers
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to Hamilton Standard 14RF series propellers. This action
adopts new torquing procedures for the propeller hub retaining nuts,
requires initial and repetitive torque checks of propeller hub
retaining nuts using those new procedures. In addition, this AD
requires repetitive visual inspections for external propeller oil,
investigation, and removal from service of propellers hubs found
cracked or with undetermined leakage. This amendment is prompted by
reports of cracks in propeller hubs that initiate in hub dowel pin
holes at the connection of the hub to the engine flange. The actions
specified in this AD are intended to prevent propeller hub cracking and
loss of engine oil, and possible loss of a propeller blade or hub.
DATES: Effective March 29, 1994.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 29, 1994.
Comments for inclusion in the Rules Docket must be received on or
before May 13, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 94-ANE-09, 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.
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: Francis X. 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: The Federal Aviation Administration (FAA)
has received reports of cracks found in some Hamilton Standard Model
14RF-9, 14RF-19, and 14RF-21 propeller hubs. Through testing and field
investigation the FAA has determined that insufficient torque of the
propeller hub retaining nuts has resulted in damage by fretting within
the dowel holes and subsequent cracks initiating in the hub dowel pin
holes at the connection of the hub to the engine flange. The FAA has
also determined that the present torquing procedures for propeller hub
retaining nuts on this model propeller are insufficient to control
fretting during the conditions experienced in service. Therefore,
through engineering analysis, the FAA has determined that new, more
stringent torquing procedures must be applied to this propeller model
to mitigate this fretting condition. Cracks that may be caused by this
condition can be detected by oil leakage not explained by other
conditions such as leaks in the blade seal, the pressure relief valve,
or actuator assembly. Since undetermined oil leakage is a good
indication of cracks in the propeller hub, the FAA has also determined
that propellers hubs with unexplained oil leakage must be removed from
service and inspected for cracks prior to return to service. This
fretting condition, if not corrected, could result in propeller hub
cracking and loss of engine oil, and possible loss of a propeller blade
or hub.
The FAA has reviewed and approved the technical contents of
Temporary Revision (TR) No. 61-6, dated March 15, 1993, and TR No. 61-
7, dated July 27, 1993, to Hamilton Standard Maintenance Manual (MM)
P5186, applicable to Model 14RF-9 propellers; TR No. 61-6, dated April
8, 1993, and TR No. 61-7, dated July 27, 1993, to Hamilton Standard MM
P5199, applicable to Model 14RF-19 propellers; and TR No. 61-4, dated
March 15, 1993, and TR No. 61-5, dated July 27, 1993, to Hamilton
Standard MM P5189, applicable to Model 14RF-21 propellers. These TR's
describe the new torquing procedures for torque checks of propeller hub
retaining nuts, and procedures for inspecting propeller hubs for
cracks.
Since an unsafe condition has been identified that is likely to
exist or develop on other Hamilton Standard 14RF series propellers of
the same type design, this AD is being issued to prevent propeller hub
cracking and loss of engine oil, and possible loss of a propeller blade
or hub. This AD requires an initial torque check of the propeller hub
retaining nuts within 30 days after the effective date of this AD, the
implementation of a new, more stringent hub retaining nut tightening
procedure, and repetitive torque checks of the hub retaining nuts. If
the torque checks of the hub retaining nuts do not meet the acceptance
critieria of the applicable TR's during the initial or subsequent
repetitive checks, then the propeller hub must be removed from service
and inspected for cracks prior to return to service. Propeller hubs
with crack indications must be removed from service and replaced with a
serviceable propeller hub prior to further flight. The FAA's analysis
indicates that 30 days will be sufficient to schedule the torque checks
without adversely affecting flight safety.
Subsequent to an acceptable initial torque check and the
implementation of the new hub retaining nut tightening procedure, this
AD requires a one-time entry in the propeller maintenance records that
the new tightening procedure was incorporated. In addition, all future
propeller installations should follow the new installation and hub
retaining nut tightening procedure.
The AD will thereafter require repetitive torque checks at
intervals not to exceed 500 hours time in service since the last
inspection. In addition, this AD requires repetitive visual inspections
for external propeller oil, investigation, and removal from service of
propellers hubs found cracked or with undetermined leakage. These
inspections must be performed at intervals not to exceed 70 hours time
in service (TIS) since the last inspection, or at line checks,
whichever occurs first. If the leakage is found to be caused by other
than a leak in the blade seal, the pressure relief valve, or actuator
assembly, the leakage may be due to a propeller hub crack and the
propeller must be removed from service and replaced with a serviceable
propeller prior to further flight. The actions would be required to be
accomplished in accordance with the applicable TR's to the MM'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 94-ANE-09.'' 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 14 CFR part
39 of the Federal Aviation Regulations 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 adding the following new
airworthiness directive:
94-06-05 Hamilton Standard: Amendment 39-8853. Docket 94-ANE-09.
Applicability: Hamilton Standard Model 14RF-9, 14RF-19, and
14RF-21 propellers, installed on but not limited to Embraer EMB-120
series, Construcciones Aeronauticas, SA (CASA) CN-235 series, and
SAAB-SCANIA SF340 series aircraft.
Compliance: Required as indicated, unless accomplished
previously.
To prevent propeller hub cracking and loss of engine oil, and
possible loss of a propeller blade or hub, accomplish the following:
(a) Within 30 days after the effective date of this
airworthiness directive (AD), perform an initial torque check of the
propeller hub retaining nuts, as follows:
(1) For Hamilton Standard Model 14RF-9 propellers, in accordance
with Temporary Revision (TR) No. 61-6, dated March 15, 1993, to
Hamilton Standard Maintenance Manual (MM) P5186.
(2) For Hamilton Standard Model 14RF-19 propellers, in
accordance with TR No. 61-6, dated April 8, 1993, to Hamilton
Standard MM P5199.
(3) For Hamilton Standard Model 14RF-21 propellers, in
accordance with TR No. 61-4, dated March 15, 1993, to Hamilton
Standard MM P5189.
(b) If propeller hub retaining nuts are found not to meet the
acceptance criteria in accordance with the applicable TR to the
Hamilton Standard MM's during the initial torque check in accordance
with paragraph (a), and during the repetitive torque checks
performed in accordance with paragraph (e) of this AD, remove the
propeller hub from service and inspect for cracks in accordance with
the applicable TR's listed in paragraph (a) of this AD. Remove
propeller hubs with crack indications and replace with serviceable
propeller hubs prior to further flight.
(c) If the initial propeller hub retaining nut torque check is
acceptable in accordance with the applicable TR listed in paragraph
(a) of this AD, support the propeller with an appropriate lifting
fixture and loosen all the propeller hub retaining nuts. Tighten the
propeller hub retaining nuts as follows:
(1) For Hamilton Standard Model 14RF-9 propellers, in accordance
with TR No. 61-7, dated July 27, 1993, to Hamilton Standard MM
P5186.
(2) For Hamilton Standard Model 14RF-19 propellers, in
accordance with TR No. 61-7, dated July 27, 1993, to Hamilton
Standard MM P5199.
(3) For Hamilton Standard Model 14RF-21 propellers, in
accordance with TR No. 61-5, dated July 27, 1993, to Hamilton
Standard MM P5189.
(d) Make a one-time entry into propeller maintenance records to
record:
(1) That the initial torque check was performed;
(2) The propeller hub retaining nuts were loosened and tightened
in accordance with paragraph (c) of this AD; and
(3) The torque values.
(e) Thereafter, perform repetitive torque checks at intervals
not to exceed 500 hours time in service since the last inspection,
in accordance with the applicable TR to the Hamilton Standard MM's
listed in paragraph (a) of this AD.
(f) Install all propellers after the effective date of this AD
using the propeller hub retaining nut tightening procedure defined
in the applicable TR to the Hamilton Standard MM's listed in
paragraph (c) of this AD. Record the torque values in accordance
with paragraph (d) of this AD.
(g) Visually inspect and investigate all external propeller oil
leakage at the next line check, or within 70 hours TIS after the
effective date of this AD, whichever occurs first. If the leakage is
found to be caused by other than a leak in the blade seal, the
pressure relief valve, or actuator assembly, the propeller must be
removed from service and replaced with a serviceable propeller prior
to further flight.
(h) Thereafter, visually inspect and investigate all external
propeller oil leakage at intervals not to exceed 70 hours TIS since
the last inspection, or at the next line check, whichever occurs
first. If the leakage is found to be caused by other than a leak in
the blade seal, the pressure relief valve, or actuator assembly, the
propeller must be removed from service and replaced with a
serviceable propeller prior to further flight.
(i) 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.
(j) Special flight permits may be issued in accordance with FAR
21.197 and 21.199 to operate the aircraft to a location where the
requirements of this AD can be accomplished.
(k) The torque checks, retightening, and installation procedures
shall be done in accordance with the following service documents:
------------------------------------------------------------------------
Document No. Pages Date
------------------------------------------------------------------------
TR No. 61-6 to Hamilton Standard MM P5186.. 1-8 Mar. 15, 1993.
Total pages: 8.
TR No. 61-7 to Hamilton Standard MM P5186.. 1-9 July 27, 1993.
Total pages: 9.
TR No. 61-6 to Hamilton Standard MM P5199.. 1-6 Apr. 8, 1993.
Total pages: 6.
TR No. 61-7 to Hamilton Standard MM P5199.. 1-7 July 27, 1993.
Total pages: 7.
TR No. 61-4 to Hamilton Standard MM P5189.. 1-8 Mar. 15, 1993.
Total pages: 8.
TR No. 61-5 to Hamilton Standard MM P5189.. 1-7 July 27, 1993.
Total pages: 7.
------------------------------------------------------------------------
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. 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.
(l) This amendment becomes effective on March 29, 1994.
Issued in Burlington, Massachusetts, on March 7, 1994.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 94-5704 Filed 3-11-94; 8:45 am]
BILLING CODE 4910-13-P
