AD 95-17-06

This amendment adopts a new airworthiness directive (AD) that applies to Mooney Aircraft Corporation (Mooney) Model M20K airplanes with a Continental TSIO-520-NB engine installed in accordance with Supplemental Type Certificate (STC) SA5691NM. This action requires repetitively inspecting the exhaust transition tube and turbo mount assembly for cracks, and replacing any part found cracked. A report of a cracked exhaust transition tube that connects the exhaust manifolds to the turbocharger inlet on one of the affected airplanes prompted this action. The actions specified by this AD are intended to prevent exhaust gases from entering the cabin heating system because of a cracked exhaust transition tube, which, if not detected and corrected, could result in hazardous levels of carbon monoxide in the airplane cabin.

Final rule; request for comments.

95-17-06 MOONEY AIRCRAFT CORPORATION: Amendment 39-9337; Docket No. 95-CE-57-AD.

Applicability: Model M20K airplanes (all serial numbers), certificated in any category, that have a Continental TSIO-520-NB engine installed in accordance with Supplemental Type Certificate (STC) SA5691NM, which is owned by the Rocket Engineering Corporation.

NOTE 1: This AD applies to each airplane identified in the preceding applicability revision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (f) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition hasnot been eliminated, the request should include specific proposed actions to address it.

Compliance: Required initially within the next 10 hours time-in-service (TIS) after the effective date of this AD, and thereafter as indicated in the body of this AD.

To prevent exhaust gases from entering the cabin heating system because of a cracked exhaust transition tube, which, if not detected and corrected, could result in hazardous levels of carbon monoxide in the airplane cabin, accomplish the following:

(a) Inspect the following parts of the exhaust system for cracks in accordance with Rocket Engineering Corporation Mandatory Service Bulletin MSB95-305-1, dated August 9, 1995:

(1) Exhaust Transition Tube, part number 305-01-507HS, 305-01-507HS-Rev A, or 305-01-507HS-Rev B.

(2) Left Hand Forward Mount Tube, part number 305-03-501, 305-03-501-Rev A, or 305-03-501-Rev B.

(3) Right Hand Forward Mount Tube, part number 305-03-502 or 305-03-502-Rev-A.

(b) If cracks are found in either the exhaust transition tube or the turbo mount tubes during any of the required inspections, prior to further flight, accomplish the following in accordance with Rocket Engineering Corporation Mandatory Service Bulletin MSB95-305-1, dated August 9, 1995.

(1) Replace any cracked exhaust transition tube with Exhaust Transition Tube, part number 305-01-507HS-Rev C, and reinspect this new exhaust transition tube at intervals not to exceed 50 hours TIS.

(2) Replace any cracked left hand forward mount tube with Left Hand Forward Mount Tube, part number 305-03-501-Rev C. The repetitive inspections of this part required by this AD may be terminated after this replacement.

(3) Replace any cracked right hand forward mount tube with Right Hand Forward Mount Tube, part number 305-03-502-Rev B. The repetitive inspections of this part required by this AD may be terminated after this replacement.

(c) If no cracks are found in either the exhaust transition tube or the turbo mount tubes during any of the inspections required by this AD, reinspect at intervals not to exceed 25 hours TIS provided the parts are crack-free.

(d) The replacements required by paragraphs (b)(1), (b)(2), and (b)(3) of this AD may be accomplished regardless of whether a part is found cracked in order to extend the repetitive inspection time of the exhaust transition tube or eliminate the repetitive inspection requirement of the left and right hand forward mount tube as is specified in the applicable paragraph of this AD.

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(f) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Northwest Mountain Region, 1601 Lind Avenue S.W., Renton, Washington 98055-4056. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(g) The inspections and replacements required by this AD shall be done in accordance with Rocket Engineering Corporation Mandatory Service Bulletin MSB95-305-1, dated August 9, 1995. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the Rocket Engineering Corporation, East 6247 Rutter Road, Felts Field, Spokane, Washington 99212. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., 7th Floor, suite 700, Washington, DC.

(h) This amendment becomes effective on September 25, 1995.

The FAA has received a report of a cracked exhaust transition tube that connects the exhaust manifolds to the turbocharger inlet on a Mooney Model M20K airplane. This airplane has a Continental TSIO-520-NB engine installed in accordance with Supplemental Type Certificate (STC) SA5691NM, which is owned by the Rocket Engineering Corporation. Included with this STC SA5691NM installation is an AiResearch THO8A67 turbocharger and intercooler.

In the above-referenced incident, a 4 to 5-inch crack had developed in the exhaust transition tube. In addition, the turbo mount brace was found cracked. These cracks were discovered following an incident where the pilot reported loss of engine power while in flight. A cracked exhaust transition tube that connects the engine manifolds and the turbocharger inlet could allow exhaust gases to enter the cabin heating system. In this instance, a hazardous level of carbon monoxide could enter the airplane cabin, resulting in pilot injury and subsequent loss of control of the airplane.

The Rocket Engineering Corporation has issued Mandatory Service Bulletin MSB95-305-1, dated August 9, 1995, which specifies procedures for inspecting the exhaust transition tube and turbo mount assembly on Mooney Model M20K airplanes with a Continental TSIO-520-NB engine installed in accordance with STC SA5691NM.

The FAA examined all available information related to the incident described above including the referenced service information and has determined that AD action should be taken to prevent exhaust gases from entering the cabin heating system because of a cracked exhaust transition tube, which, if not detected and corrected, could result in hazardous levels of carbon monoxide in the airplane cabin.

Since an unsafe condition has been identified that is likely to exist or develop on other Mooney Model M20K airplanes of the same type design that have a Continental TSIO-520-NB engine installed in accordance with STC SA5691NM, this AD requires repetitively inspecting the exhaust transition tube and turbo mount assembly for cracks, and replacing any part found cracked. Accomplishment of these actions will be in accordance with Rocket Engineering Corporation Mandatory Service Bulletin MSB95-305-1, dated August 9, 1995.

Since a situation exists (possible hazardous carbon monoxide levels in the airplane cabin) that requires the immediate adoption of this regulation, it is found that notice and opportunity for public prior 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 immediate flight safety and, thus, was not preceded by notice and opportunity to 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 above. 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 acknowledgereceipt of their comments submitted in response to this request must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 95-CE-57-AD." The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation and 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 (otherwise, an evaluation is not required). A copy of it, if filed, may be obtained from the Rules Docket.

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 USC 106(g), 40101, 40113, 44701.

Section 39.13 - [AMENDED]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: