Federal Aviation Administration (FAA), Department of Transportation (DOT).
Notice of proposed rulemaking (NPRM).
The FAA proposes to adopt a new airworthiness directive (AD) for certain TCM IO-520, TSIO-520, and IO-550 reciprocating engines with certain SAP cylinder assemblies installed. This proposed AD would require initial and repetitive inspections and compression tests to detect cracks in those cylinders with more than 750 flight hours time-in-service (TIS). This proposed AD results from reports of cracks in the area of the exhaust valve and separation of cylinder heads from the barrels of SAP cylinder assemblies with certain part numbers. We are proposing this AD to prevent separation of the cylinder head, which could result in immediate loss of engine power, possible structural damage to the engine, and possible fire in the engine compartment.
We must receive any comments on this proposed AD by June 10, 2008.
Use one of the following addresses to comment on this proposed AD.
- Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
- Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
- Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
- Fax: (202) 493-2251.
FOR FURTHER INFORMATION CONTACT:
Tausif Butt, Aerospace Engineer, Special Certification Office, FAA, Rotorcraft Directorate, 2601 Meacham Blvd, Fort Worth, TX 76137-4298; e-mail: firstname.lastname@example.org; telephone (817) 222-5195; fax (817) 222-5785.End Further Info End Preamble Start Supplemental Information
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-2007-0051; Directorate Identifier 2007-NE-37-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://www.regulations.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. Start Printed Page 19773Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, 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).
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
Superior Air Parts and operators in the field have reported 24 SAP cylinder assemblies with cracks or separation in the area of the exhaust valves. Some instances resulted in forced landings of the airplanes. The reported failures were cylinder assemblies in the naturally-aspirated and turbocharged engines. Most of the failures were on airplanes that have a high ratio of takeoffs and landings per flight hour. Most of the failures also occurred on airplanes that are operated predominantly at low altitude. SAP first informed us on July 12, 2006, that at least 14 SAP investment cast cylinder assemblies, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, SA55000-A20P, had cracked in the area of the exhaust valve of the cylinder head since the year 2000. We received reports of 10 additional failures since that time, and the total number of reported failures is currently 24. We determined that the minimum wall thickness of the SAP cylinder assemblies, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, SA55000-A20P, is significantly thinner in the failure location than the original equipment manufacturer (OEM) cylinders. We certified the SAP cylinders as equivalent replacement Parts Manufacturer Approval (PMA) parts for TCM 520 and 550 series engines, however, this design discrepancy results in stresses in the cylinder wall that are much higher in the SAP cylinder assemblies than in the OEM cylinder assemblies when subjected to identical loading. These higher stresses result in a lower fatigue life for the SAP cylinder assemblies relative to that of the OEM parts. The time-to-cracking or separation for this failure mode ranges between 823 hours time-since-new (TSN) and 1,985 TSN. The thin-wall thickness condition in the area of the exhaust valve seat of the cylinder head has been present since the initial SAP design, and it is present in all SAP cylinders of that design that have been manufactured to date. This condition, if not corrected, could result in immediate loss of engine power, possible structural damage to the engine, and possible fire in the engine compartment.
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 inspecting or replacing, or both, certain SAP cylinder assemblies within 25 flight hours TIS after the effective date of the proposed AD for cylinders that are at their respective time-before-overhaul (TBO) TIS flight hours or have exceeded their respective TBO TIS flight hours.
Costs of Compliance
We estimate that this proposed AD could affect 8,000 engines installed on airplanes of U.S. registry. We also estimate that it would take about 5 work-hours per cylinder to perform the proposed actions, and that the average labor rate is $80 per work-hour. Required parts would cost about $1,150 per cylinder. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $12,400,000.
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.
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 AD:
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 regulatory evaluation of the estimated costs to comply with this proposed AD. You may get a copy of this summary at the address listed under ADDRESSES.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
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:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The FAA amends § 39.13 by adding the following new airworthiness directive:
Superior Air Parts, Inc. (SAP): Docket No. FAA-2007-0051; Directorate Identifier 2007-NE-37-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by June 10, 2008.
(c) This AD applies to Teledyne Continental Motors (TCM) IO-520, TSIO-Start Printed Page 19774520, and IO-550 series engines with SAP cylinder assemblies, part numbers (P/Ns) SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P, installed. These engines are installed on, but not limited to, the airplanes listed in Table 1 of this AD.
|Engine model||Aircraft manufacturer||Aircraft model designation|
|IO-520-A||Cessna||210 D, E, F, G, & H|
|IO-520-BA||Beechcraft||S & V35, V35A, V35B|
|IO-520-BA||Beechcraft||E33 A & C|
|IO-520-BA||Beechcraft||F33 A & C|
|IO-520-C & CB||Beechcraft||C55—E55 Baron|
|IO-520-D||Cessna||A188-300 AG Truck|
|IO-520-E||(Cessna 310)||Exec 600|
|IO-520-E||(Beech Baron)||Pres 600|
|IO-520-L||Cessna||210 K, L, M, N & R|
(d) This AD results from reports of cracks in the area of the exhaust valve and separation of cylinder heads from the barrels of SAP cylinder assemblies with certain part numbers. We are issuing this AD to prevent separation of the cylinder head, which could result in immediate loss of engine power, possible structural damage to the engine, and possible fire in the engine compartment.
(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
Inspecting SAP Cylinder Assemblies
(f) For TCM IO-520, TSIO-520, and IO-550 series engines with SAP cylinder assemblies, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P, installed, with over 750 flight hours time-in-service (TIS), do the following within 25 flight hours TIS after the effective date of this AD:
(1) Inspect each cylinder head around the exhaust valve side for visual cracks or any signs of black combustion leakage.
(2) Replace any cracked or leaking cylinders.
(3) Perform a standard cylinder compression test using paragraph 8-14., Compression Testing of Aircraft Engine Cylinders, in Advisory Circular 43.13-1B, Change 1, dated September 27, 2001. Also, SAP Service Bulletin B08-01, dated January 10, 2008, contains information on cylinder differential pressure tests.
(i) If the cylinder pressure gage reads below 60 pounds per-square inch, apply a 2 percent soapy solution to the side of the leaking cylinder.
(ii) If you see air leakage and bubbles on the side of the cylinder, near the head-to-cylinder interface, replace the cylinder assembly.
(g) Thereafter, repeat the cylinder visual inspections and compression tests within 50 flight hours time-since-last inspection (TSLI) until the cylinders reach their time-before-overhaul (TBO) limits.
Replacing SAP Cylinder Assemblies
(h) For TCM IO-520, TSIO-520, and IO-550 series engines with SAP cylinder assemblies, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P, installed, that have accumulated or exceeded their respective TBO hours, replace the cylinder assembly within 25 flight hours TIS after the effective date of this AD.
Prohibition Against Installing Certain P/N SAP Cylinder Assemblies
(i) After the effective date of this AD, do not install any SAP cylinder assembly, P/Ns SA52000-A1, SA52000-A20P, SA52000-A21P, SA52000-A22P, SA52000-A23P, SA55000-A1, or SA55000-A20P, in any engine.
Alternative Methods of Compliance
(j) The Manager, Special Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. Start Printed Page 19775
(k) FAA Advisory Circular 43.13-1B, Change 1, dated September 27, 2001, and SAP service bulletin B08-01, dated January 10, 2008, contain information on cylinder differential pressure tests.
(l) Contact Tausif Butt, Aerospace Engineer, Special Certification Office, FAA, Rotorcraft Directorate, 2601 Meacham Blvd., Fort Worth, TX 76137-4298; e-mail: email@example.com; telephone (817) 222-5195; fax (817) 222-5785, for more information about this AD.
Issued in Burlington, Massachusetts, on April 4, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.
[FR Doc. E8-7711 Filed 4-10-08; 8:45 am]
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