The FAA and Hartzell Propeller Inc. have been reviewing and investigating reports of current design propeller blade thrust bearings, P/N's C-2882-1, C-2882-2, and C-7075, found fractured during disassembly, one or more blades becoming jammed in position during operation, pitch change fork fractures causing loss of blade pitch control, and excessive vibration. The current design thrust bearings have demonstrated a tendency to have brittle fracture and reduced strength characteristics, for which the cause has yet to be determined. This action requires replacement of the current design propeller blade thrust bearings, P/N's C-2882-1, C-2882-2, and C-7075, with a new design propeller blade thrust bearing, P/N C-7438, and a 10X magnification-assisted visual inspection and ECI of propeller hubs for cracks. This amendment is prompted by reports of fractured thrust bearings observed during disassembly, one or more blades becoming jammed in position during operation,pitch change fork fractures causing loss of blade pitch control, and excessive vibration. This condition, if not corrected, could result in loss of aircraft control due to loss of blade pitch control, inability to fully feather the propeller, hub fracture, and blade release.
Manufacturer's Service Information
The FAA has reviewed and approved the technical contents of the following Hartzell Propeller Inc. Alert Service Bulletins (ASB's):
ASB HD-ASB-61-026, dated August 6, 2001, that describes the schedule and procedures for replacing P/N's C-2882-1, C-2882-2, and C- 7075 propeller thrust bearings with blade thrust bearing P/N C-7438.
ASB HD-ASB-61-023, Revision 1, dated May 23, 2001, that describes procedures for 10X magnification-assisted visual inspections of the O-ring groove and hub-half and parting surface areas and ECI inspections of propeller hubs, P/N D-5108-( ), for cracks in the bearing retention radius.
FAA's Determination of an Unsafe Condition andRequired Actions
Since an unsafe condition has been identified that is likely to exist or develop on other Hartzell Propeller Inc. model HD-E6C-3( ) propellers of the same type design, this AD is being issued to prevent loss of aircraft control due to loss of blade pitch control, inability to fully feather the propeller, hub fracture, and blade release. This AD requires within 50 hours time-in-service (TIS) after the effective date of this AD, or nine months after the effective date of this AD, or when the propeller is next disassembled after the effective date of this AD, whichever occurs earliest:
Replacement of the current design propeller blade thrust bearings P/N's C-2882-1, C-2882-2, and C-7075 with a new design propeller blade thrust bearing P/N C-7438.
10X Magnification-assisted visual inspections and ECI of propeller hubs for cracks.
The actions must be done in accordance with the service bulletins described previously.
Immediate Adoption of This ADSince 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 isextremely 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 action must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2001-NE-43-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Analysis
This final rule does not have federalism implications, as defined in Executive Order 13132, because it 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this final rule.
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 Docketat 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. 106(g), 40113, 44701.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: