AD 95-26-13

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to Piper Model PA28-140 airplanes was published in the Federal Register on March 8, 1995 (60 FR 12714). The action proposed to supersede AD 76-25-06, Amendment 39-2788, with a new AD that would retain the clearance inspection and oil cooler hose replacement for the Piper Model PA28-140 airplanes, and make the inspection and replacement repetitive for these airplanes as well as other PA28 series and the PA32 series airplanes. It would also provide the option of installing approved TSO-C53a, Type D oil cooler hose assemblies as terminating action for the repetitive inspection requirement.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

One commenter states that the proposal should take into account that the affected airplanescould have oil cooler hose assemblies installed other than those manufactured from Piper. The FAA concurs and has changed the AD to reflect that the AD applies to airplanes with oil cooler hose assemblies that do not meet TSO-C53a, Type D requirements.

This same commenter points out that paragraph (b)(2) of the proposed AD contains the words "oil cooler assembly" when it should contain the words "oil cooler hose assembly". The FAA concurs and has changed paragraph (b)(2) of the AD to reflect the above-referenced language.

This commenter also believes that the cost of the oil cooler hoses is too low and that the FAA did not take into account that each airplane has two oil cooler hoses installed. The commenter states that the price of an oil cooler hose is between $122 and $279, and the FAA estimates $110. The FAA will change the economic paragraph of the final rule to incorporate the upper end of the price range for oil cooler hoses of $279 per hose with two oil cooler hosesper airplane ($558 per airplane for parts).

A commenter proposes that the FAA clarify whether the date used to determine the eight-year replacement interval is the installation date, rubber cure date, or the pressure test date. The FAA will specify in the AD that the date used to determine the eight-year replacement interval is the installation date.

One commenter believes that the FAA should withdraw the notice of proposed rulemaking (NPRM) because a pilot can inspect these oil cooler hoses and, therefore, the action does not warrant the expense and record keeping required by AD action. Another commenter does not request that the AD be withdrawn, but requests that the FAA include the provision of allowing the pilot to inspect the oil cooler hoses. The FAA does not concur with either of these comments. Sections 43.3(g) and 43.7(f) of the Federal Aviation Regulations (14 CFR 43.3 and 14 CFR 43.7) contain the provision to allow a pilot to perform preventive maintenance and return the airplane to service. Part 43, Appendix A of the Federal Aviation Regulations (14 CFR, part 43, Appendix A) outlines what is considered preventive maintenance. Inspections of oil cooler hose assemblies are not authorized as preventive maintenance actions as detailed in the above-referenced portion of the regulations. The AD is unchanged as a result of these comments.

A commenter believes the NPRM should be withdrawn because the 20 reported incidents over a 19-year period with no damage reported do not justify repetitive 100-hour time-in-service (TIS) inspections and 8-year (or 1,000 hours TIS) repetitive oil cooler hose assembly replacements. The FAA does not concur. The FAA has received 26 incident/accident occurrences relating to oil cooler hose failure since 1985. In addition, 24 service difficulty reports (SDR) have been filed on this subject since 1987. The FAA has determined that oil cooler hoses that fail or rupture could result in engine stoppage and subsequent loss of control of the airplane. The AD is unchanged as a result of this comment.

Another commenter requests that the FAA withdraw the NPRM because the actions are the same as what is listed in the Piper service manuals. The commenter quotes the following from the FAA Airworthiness Directive Manual, FAA-AIR-M-8040.1:

"An AD should not be issued to assure the use of normal maintenance practices on a product where individual cases of improper maintenance or lack of maintenance have contributed to an unsafe condition. Corrective action in those instances should be taken through normal Flight Standards maintenance communication channels, such as General Alerts, Maintenance Bulletins, and Notices."

The FAA does not consider inspecting oil cooler hoses on the affected Piper PA28 and PA32 series airplanes a general maintenance action. The close proximity of the oil cooler hose assemblies to the exhaust stack causes the oil cooler hoses to rupture instead of developing leaksover time. A general maintenance action on oil cooler hoses would be to check for leaks; however, the service history of the affected airplanes is indicating ruptured oil cooler hoses. For this reason, the FAA has determined that the close proximity of the oil cooler hose assemblies to the exhaust stack require special inspections for the oil cooler hoses through AD action to prevent these hoses from failing or rupturing. The AD is unchanged as a result of this comment.

One other commenter (an owner of a Piper Model PA28R-201T airplane) recommends that the NPRM be withdrawn because no corrosion was found on this commenter's airplane oil cooler hoses when the tanks were removed and the hoses replaced. In addition, this owner operates the airplane away from seashores in a dry climate. For these reasons, this commenter believes the NPRM should be withdrawn. The FAA does not concur. AD's are issued based on a known "unsafe condition that could exist or develop on airplanes of the same type design." In this instance, the owner operates a Piper Model PA28R-201T airplane, which is not affected by this AD because this particular model does not have external oil cooler hose assemblies. The AD is unchanged as a result of this comment.

One commenter feels that the FAA is inferring that Piper airplane operators are less competent than other operators by only writing the AD against certain Piper PA28 and PA32 series airplanes. The commenter states that every reciprocating engine-powered aircraft has oil lines and hoses and that the AD should be written against all such aircraft. The FAA does not concur. As stated in the NPRM, "other airplane models have shown a history of oil cooler hose problems; however, most of these have been attributed to leaking oil cooler hoses instead of ruptured hoses or broken hoses as are detailed in the incident/accident reports of the affected PA28 and PA32 series airplanes. The close proximity of the oil cooler hose assembliesto the exhaust stacks in some of the affected airplanes contributes to the hazardous nature of these oil cooler hose failures." The AD is unchanged as a result of this comment.

A commenter states that Type D oil cooler hoses are less flexible than other hoses and, therefore, cannot always be interchanged. This commenter further explains that this less-flexible hose could kink during oil cooler hose installation or during flight because of in-service vibration. This could prevent oil passage and result in engine stoppage. The FAA concurs that these Type D oil cooler hoses are less flexible and could kink. The FAA is changing the AD to require a minimum bend radius of 6.5 inches on oil cooler hose assemblies incorporating 0.75-inch outer diameter hoses.

Another commenter requests that the FAA either delete the repetitive replacement requirement or have the replacement intervals coincide with every 10th annual inspection. The FAA does not concur. The close proximity of theoil cooler hose assemblies to the exhaust stacks causes the heat from the exhaust stacks to affect the life of the hoses. This also causes the hoses to rupture instead of leak. With this in mind, the FAA believes that repetitively inspecting the oil cooler hoses every 100 hours TIS and replacing all hoses every 8 years will accomplish the intent of eliminating the unsafe condition addressed in this action. The AD is unchanged as a result of this comment.

After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for the wording change to limit the applicability to oil cooler hose assemblies that do not meet TSO-C53a, Type D requirements; the rewording of "oil cooler assembly" to "oil cooler hose assembly" in paragraph (b)(2) of the AD; the change in the economic paragraph to reflect more accurate oil cooler hose price information; theclarification that the replacement interval is based on the installation date; the addition of requiring a minimum bend radius of 6.5 inches on oil cooler hose assemblies requiring a 0.75-inch outer diameter hose; and minor editorial corrections. The FAA has determined that the minor addition, changes, corrections, and clarification will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

The replacement compliance time for this AD is presented in both hours TIS and calendar time with the prevalent compliance time being that which occurs first. Deterioration or failure of the oil cooler hose assemblies could occur as a result of normal flight operation or as a result of time. Therefore, the FAA has determined that this dual replacement compliance time is needed to assure that the oil cooler hose assemblies are replaced before they deteriorate and rupture or fail.

The FAA estimates that 25,000 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 2 workhours (1 workhour per inspection and 1 workhour per replacement) per airplane to accomplish the required action, and that the average labor rate is approximately $60 an hour. Parts cost approximately $558 per airplane ($279 per oil cooler hose with two hoses per airplane). Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $16,950,000 or $678 per airplane. This figure does not take into the account the cost of repetitive inspections or repetitive replacements. The FAA has no way of determining the number of repetitive inspections or replacements each owner/operator would incur over the life of the airplane.

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.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption "ADDRESSES".

List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, 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 USC 106(g), 40101, 40113, 44701.

Section 39.13 - (AMENDED) 2. Section 39.13 is amended by removing Airworthiness Directive (AD) 76-25-06, Amendment 39-2788, and by adding a new AD to read as follows: