On March 7, 2002, the FAA issued emergency AD 2002-05-51, applicable to Hamilton Sundstrand Corporation (formerly Hamilton Standard Division) model 568F-1 propellers installed with blades, P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower. That AD requires:
Replacement of propeller blades, P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower, with serviceable propeller blades.
A prohibition against installing any propeller blades, P/N's R815505-2 and R815505-3, that have a SN of FR428 or lower, that were previously installed on an ATR-42-400 or an ATR-72 airplane, on any other airplane.
Ultrasonic shear wave inspection of the blade tulip on installed blades P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower, within 50 hours after receipt to that emergency AD.
Repetitive ultrasonic shear wave inspection of the blade tulip on installed blades, P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower, within 50 flight hours since-last-inspection.
That action was prompted by a report that a Hamilton Sundstrand propeller blade failed on an Aerospatiale ATR42-500 airplane. The failure occurred shortly after takeoff. The airplane was able to return safely to the point of departure. The position 5 blade failed outboard of the counterweight mounting flange. Additional damage to the propeller, engine, and nacelle was found. Root cause investigation has determined that the fracture began at an area of corrosion on the metallic portion of the blade just above and opposite the counterweight mounting flange. Engineering evaluation of the blade population that is susceptible to corrosion-induced fatigue has determined that the affected blades must be replaced to prevent blade failure. Subsequent investigation has determined that the suspect blade population must be inspected for fatigue cracks, due to corrosion pitting, using a repetitive ultrasonic shear wave inspection. This condition, if not corrected, could result in blade failure due to corrosion-induced fatigue, which could result in blade separation and possible loss of airplane control.
Manufacturer's Service Information
The FAA has reviewed and approved the technical contents of Hamilton Sundstrand Alert Service Bulletin No. 568F-61-A35, Revision 2, dated March 21, 2002, which provides procedures to perform the ultrasonic shear wave inspection of the blade tulip.
FAA's Determination of an Unsafe Condition and Required Actions
Since the unsafe condition described is likely to exist or develop on other propellers of the same type design, the FAA issued emergency AD 2002-05-51 to prevent blade failure due to corrosion-induced fatigue, which could result in blade separation and possible loss of airplane control. This AD requires:
Replacement of propeller blades, P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower, that are installed on ATR 42-400 and ATR 72 airplanes, with serviceable propeller blades before further flight.
A prohibition against installing any propeller blades, P/N's R815505-2 and R815505-3, that have a SN of FR428 or lower, that were previously installed on an ATR 42-400 or an ATR 72 airplane, on any other airplane after the effective date of this AD.
Ultrasonic shear wave inspection of the blade tulip on installed blades P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower, within 50 hours after the effective date of this AD.
Repetitive ultrasonic shear wave inspection of the blade tulip on installed blades, P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower, within 50 flight hours since-last-inspection.
The actions must be done in accordance with the service bulletin described previously.
Immediate Adoption of This AD
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 2002-NE-02-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 ofpower 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 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. 106(g), 40113, 44701.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: