Airworthiness Directives; Hartzell Propeller Inc. Propellers

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Hartzell Propeller Inc. propellers. This proposed AD would require inspecting the propeller blades and other critical propeller parts for corrosion and mechanical damage. This proposed AD results from two events where a “Z-shank” blade failed and separated and the results of teardown inspections that detected corrosion in the blade bore. We are proposing this AD to detect corrosion and mechanical damage that can cause failure of a propeller, which could result in loss of control of the airplane.

DATES:

We must receive any comments on this proposed AD by February 28, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-001.
• Fax: (202) 493-2251.
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You can get the service information identified in this proposed AD from Hartzell Propeller Inc. Technical Publications Department, One Propeller Place, Piqua, OH 45356; telephone (937) 778-4200; fax (937) 778-4391.

You may examine the comments on this proposed AD in the AD docket on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT:

Tomaso DiPaolo, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, Small Airplane Directorate, 2300 East Devon Avenue, Des Plaines, IL 60018-4696; telephone (847) 294-7031; fax (847) 294-7834.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-19955; Directorate Identifier 2004-NE-17-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the DMS Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

Examining the AD Docket

You may examine the docket that contains the proposal, any comments received, and any final disposition in person at the DMS Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647-5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

On January 25, 2003, a Beech 95 airplane lost control after takeoff when a 2.5-foot section of a Hartzell HC-92ZK-2/8447 propeller blade separated. Examination of the fracture surfaces revealed the blade failed because of fatigue cracking. The cracking began at corrosion pits on the internal surface of the blade bore. On July 23, 2001, a Beech 95A airplane suffered severe engine damage after a Hartzell HC-92ZK-2B/8447 blade separated. Examination of the fracture surfaces revealed the blade failed from fatigue cracks that started in an area that had scratches and a gouge on the internal surface of the blade bore.

The “Z” shank design propellers are often installed on airplanes that do not have a mandatory periodic propeller maintenance program and as a result, some propellers have not been maintained as specified in the manufacturers instructions. Many of the propeller models have been in service for more than 40 years. If they are not serviced to a recent maintenance document, like that required by Hartzell Service Bulletin 136, revisions G, H, or I, those propellers are likely to contain corrosion or mechanical damage in the blade bore.

After the event on January 24, 2003, the National Transportation Safety Board (NTSB) issued a recommendation to require repetitive inspections on all “Z” shank propellers at the time-between-overhaul interval recommended by Hartzell Propeller Inc. Because most “Z” shank propellers are installed on airplanes that do not have mandatory periodic maintenance, we are proposing a onetime inspection of “Z” shank propellers. We are also proposing a onetime inspection of “P,” “R,” and “W” shank propellers because of their similarities to the “Z” shank propellers. This condition, if not corrected, could result in failure and separation of a propeller blade, which could result in loss of control of the airplane. In addition, while the propeller is disassembled for the blade bore inspection, we are taking this significant opportunity to also inspect and remove corrosion and damaged areas in other critical propeller parts.

We are also proposing requirement to report the inspection findings. The affected propellers are aging and there is no regulatory requirement for any type of repetitive safety inspections. We have been reviewing service difficulty information gathered over the past ten years and have received reports of “old” propellers (some over forty years of age), which have not had an overhaul, that are corroded, cracked, or beyond airworthy limits.

Relevant Service Information

We have reviewed and approved the technical contents of Hartzell Propeller Inc. Service Bulletin (SB) 136, Revision G, dated November 15, 1991; Revision H, dated March 12, 1993; and Revision I, dated April 25, 2003. Those SBs describe procedures for disassembling, cleaning, inspecting, and reworking the propeller blades. We have also reviewed the applicable Hartzell overhaul manuals that we reference for the various additional inspections.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require a onetime inspection of the bore of the propeller blade and other critical propeller parts, and if necessary, removing any corrosion or mechanical damage:

• Within 12 months after the effective date of the proposed AD, if the propeller was not overhauled within the past 25 years.
• Within 18 months after the effective date of the proposed AD, if the propeller was not overhauled within the past 20 years.
• Within 24 months after the effective date of the proposed AD, if the propeller was not overhauled within the past 15 years.
• Within 36 months after the effective date of the proposed AD, if the propeller was not overhauled within the past 10 years.

The proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

There are about 1,700 Hartzell propeller assemblies of the affected design in the worldwide fleet. We estimate that 1,200 propeller assemblies installed on airplanes of U.S. registry would be affected by this proposed AD. We also estimate that it would take about 20 work hours per propeller assembly to perform the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost about $450 per propeller assembly. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $2,100,000.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a summary of the costs to comply with this proposal and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.