E8-5193. Airworthiness Directives; M7 Aerospace LP SA226 and SA227 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain M7 Aerospace LP SA226 and SA227 series airplanes. This proposed AD would require you to inspect electrical wires/components, hydraulic and bleed air tube assemblies at left-hand (LH) and right-hand (RH) inboard wing leading edge/battery box areas, LH/RH wing stations 51.167 to 81.174, and at all feed-through locations into the LH/RH inboard keelson. If chafing/arcing is found, this proposed AD would require you to reposition, repair, and/or replace all chafed electrical wires, components, and hydraulic and bleed air tube assemblies, as required. This proposed AD would also require you to reposition the battery lead cables, cover four-gauge wires leaving the battery box with firesleeving and secure with clamps, and protect the battery power cable. This proposed AD results from five reports of chafing between the bleed air tube and the electrical starter cables with one incident resulting in a fire. We are proposing this AD to detect and correct chafing/arcing of electrical wires, components, and bleed air lines. This condition could result in arcing of the exposed wires and burn a hole in the bleed air line or the nearby hydraulic line, and lead to a possible hydraulic fluid leak and fire in the engine nacelle compartment.

DATES:

We must receive comments on this proposed AD by May 13, 2008.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact M7 Aerospace Repair Station, P.O. Box 790490, San Antonio, Texas 78279-0490; telephone: [phone]; fax: [phone].

FOR FURTHER INFORMATION CONTACT:

Werner Koch, Aerospace Engineer, FAA, Airplane Certification Office, 2601 Meacham Blvd., Fort Worth, Texas 76137; telephone: [phone]; fax: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number, “FAA-2008-0313; Directorate Identifier 2007-CE-095-AD” at the beginning 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 we receive concerning this proposed AD.

Discussion

We have received five reports of chafing between the bleed air tube and the electrical starter cables on SA226 and SA227 series airplanes. One report also noted the chafing damage resulted in a fire on a Model SA226TC airplane. Subsequent review by the FAA of the service experience of SA226 and SA227 series airplanes indicates that inadequate clearance for electrical wires/components, hydraulic and bleed air tube assemblies at LH/RH inboard wing leading edge/battery box areas, LH/RH wing stations 51.167 to 81.174, and at all feed-through locations into the LH/RH inboard keelson caused the chafing/arcing.

This condition, if not corrected, could result in arcing of the exposed wires and burn a hole in the bleed air line or the nearby hydraulic line, and lead to a possible hydraulic fluid leak and fire in the engine nacelle compartment.

Relevant Service Information

We have reviewed the following service bulletins and procedures:

Service Bulletin	Applicable model(s) of airplane(s)	Procedures described
M7 Aerospace SA226 Series Service Bulletin No. 226-24-036, issued: September 19, 2007	SA226-AT, SA226-T, and SA226-TC	Inspecting electrical wires/components, hydraulic and bleed air tube assemblies at LH/RH inboard wing leading edge/battery box areas, LH/RH wing stations 51.167 to 81.174, and at all feed-through locations into the LH/RH inboard keelson.
M7 Aerospace SA227 Series Service Bulletin No. 227-24-019, issued: September 19, 2007	SA227-AC and SA227-AT
M7 Aerospace SA227 Series Commuter Category Service Bulletin No. CC7-24-010, issued: September 19, 2007	SA227-CC and SA227-DC
Swearingen Aviation Corporation SA226 Series Service Bulletin No. SB 24-001, revised: September 16, 1975	SA226-AT, SA226-T, and SA226-TC	Repositioning battery lead cables.
Fairchild Aircraft Corporation SA226 Series Service Bulletin No. SB24-019, revised: May 17, 1983	SA226-AT, SA226-T, and SA226-TC	Covering four-gauge wires leaving battery box with firesleeving and securing with clamp.
Fairchild Aircraft Corporation SA227 Series Service Bulletin No. SB24-001, revised: May 17, 1983	SA227-AC and SA227-AT
Fairchild Aircraft Corporation SA226 Series Service Bulletin No. SB24-020, revised: February 15, 1984	SA226-AT, and SA226-TC	Protect battery power cable.
Fairchild Aircraft Corporation SA227 Series Service Bulletin No. SB24-002, revised: February 15, 1984	SA227-AC and SA227-AT

FAA's Determination and Requirements of the Proposed AD

We are proposing this AD because we evaluated all information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design. This proposed AD would require you to inspect electrical wires/components, hydraulic and bleed air tube assemblies at LH and RH inboard wing leading edge/battery box areas, LH/RH wing stations 51.167 to 81.174, and at all feed-through locations into the LH/RH inboard keelson. If chafing/arcing is found, this proposed AD would require you to reposition, repair, and/or replace all chafed electrical wires, components, and hydraulic and bleed air tube assemblies, as required. This proposed AD would also require you to reposition the battery lead cables, cover four-gauge wires leaving battery box with firesleeving and secure with clamps, and protect the battery power cable.

Costs of Compliance

We estimate that this proposed AD would affect 330 airplanes in the U.S. registry.

We estimate the following costs for all Models SA226, SA227, SA227-CC, and SA227-DC airplanes to do the proposed inspection required by SA226 Series Service Bulletin No. 226-24-036, SA227 Series Service Bulletin No. 227-24-019, or SA227 Series Commuter Category Service Bulletin No. CC7-24-010:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
4 work-hours × $80 per hour = $320	Not Applicable	$320	$105,600

We estimate the following costs for certain Models SA226-AT, SA226-T, and SA226-TC airplanes for the proposed repositioning of battery lead cables following SA226 Series Service Bulletin No. SB 24-001:

Labor cost	Parts cost	Total cost per airplane	Number of airplanes affected	Total cost on U.S. operators
4 work-hours × $80 per hour = $320	$6.80	$326.80	2	$653.60

We estimate the following costs for certain Models SA226-AT, SA226-T, SA226-TC, SA227-AC, and SA227-AT airplanes following SA226 Series Service Bulletin No. SB24-019 or SA227 Series Service Bulletin No. SB24-001, for the proposed covering of four-gauge wires leaving battery box with firesleeving and securing with clamp:

Labor cost	Parts cost	Total cost per airplane	Number of airplanes affected	Total cost on U.S. operators
13 work-hours × $80 per hour = $1,040	$6.80	$1,046.80	70	$73,276

We estimate the following costs for certain Models SA226-AT, SA226-TC, SA227-AC, and SA227-AT airplanes following SA226 Series Service Bulletin No. SB24-020 or SA227 Series Service Bulletin No. SB24-002, for the proposed protection of the battery power cable:

Labor cost	Parts cost	Total cost per airplane	Number of airplanes affected	Total cost on U.S. operators
50 work-hours × $80 per hour = $4,000	$3,000	$7,000	60	$420,000

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. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

Examining the AD Docket

You may examine the AD docket that contains the proposed AD, the regulatory evaluation, any comments received, and other information on the Internet at http://www.regulations.gov;​; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

M7 Aerospace LP: Docket No. FAA-2008-0313; Directorate Identifier 2007-CE-095-AD.

Comments Due Date

(a) We must receive comments on this airworthiness directive (AD) action by May 13, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the following airplane models and serial numbers (S/N) that are certificated in any category:

(1) Group 1: Model SA226-AT Airplanes, All S/N.

(2) Group 2: Model SA226-T Airplanes, All S/N.

(3) Group 3: Model SA226-TC Airplanes, All S/N.

(4) Group 4: Model SA227-AC Airplanes, All S/N.

(5) Group 5: Model SA227-AT Airplanes, All S/N.

(6) Group 6: Model SA227-CC Airplanes, All S/N.

(7) Group 7: Model SA227-DC Airplanes, All S/N.

Unsafe Condition

(d) This AD results from five reports of chafing between the bleed air tube and the electrical starter cables with one incident resulting in a fire. We are proposing this AD to detect and correct chafing/arcing of electrical wires, components, and bleed air lines. This condition could result in arcing of the exposed wires and burn a hole in the bleed air line or the nearby hydraulic line, and lead to a possible hydraulic fluid leak and fire in the engine nacelle compartment.

Compliance

(e) To address this problem, you must do the following, unless already done:

Actions	Compliance	Procedures
(1) For Group 1, Group 2, and Group 3 Airplanes: (i) Inspect electrical wires/components, hydraulic and bleed air tube assemblies at left-hand (LH)/right-hand (RH) inboard wing leading edge/battery box areas, LH/RH wing stations 51.167 to 81.174, and at all feed-through locations into the LH/RH inboard keelson for any evidence of chafing/arcing. Clear, repair, and/or replace all chafed electrical wires and components, hydraulic, and bleed air tube assemblies, and all feed-through locations, as required.	Within 250 hours time-in-service (TIS) after the effective date of this AD. Repetitively thereafter inspect (paragraph (e)(1)(i) of this AD) at intervals not to exceed 12 months	Follow M7 Aerospace SA226 Series Service Bulletin No. 226-24-036, issued: September 19, 2007; Swearingen Aviation Corporation SA226 Series Service Bulletin No. SB 24-001, issued: May 18, 1971; revised: September 16, 1975; Fairchild Aircraft Corporation SA226 Series Service Bulletin No. SB 24-019, issued: June 2, 1982; revised: May 17, 1983; and Fairchild Aircraft Corporation SA226 Series Service Bulletin No. SB 24-020, issued: January 18, 1983; revised: February 15, 1984.
(ii) Reposition battery lead cables, protect the battery power cable, and cover four-gauge wires leaving battery box with firesleeving and secure with clamp
(2) For Group 4 and Group 5 Airplanes: (i) Inspect electrical wires/components, hydraulic and bleed air tube assemblies at LH/RH inboard wing leading edge/battery box areas, LH/RH wing stations 51.167 to 81.174, and at all feed-through locations into the LH/RH inboard keelson for any evidence of chafing/arcing. Clear, repair, and/or replace all chafed electrical wires and components, hydraulic, and bleed air tube assemblies, and all feed-through locations, as required.	Within 250 hours TIS after the effective date of this AD. Repetitively thereafter inspect (paragraph (e)(2)(i) of this AD) at intervals not to exceed 12 months	Follow M7 Aerospace SA227 Series Service Bulletin No. 227-24-019, issued: September 19, 2007; Fairchild Aircraft Corporation SA227 Series Service Bulletin No. SB24-001, issued: June 2, 1982; revised: May 17, 1983; and Fairchild Aircraft Corporation SA227 Series Service Bulletin No. SB24-002, issued: January 18, 1983; revised: February 15, 1984.
(ii) Protect the battery power cable and cover four-gauge wires leaving battery box with firesleeving and secure with clamp
(3) For Group 6 and Group 7 Airplanes: Inspect electrical wires/components, hydraulic and bleed air tube assemblies at LH/RH inboard wing leading edge/battery box areas, LH/RH wing stations 51.167 to 81.174, and at all feed-through locations into the LH/RH inboard keelson for any evidence of chafing/arcing. Clear, repair, and/or replace all chafed electrical wires and components, hydraulic, and bleed air tube assemblies, and all feed-through locations, as required	Within 250 hours TIS after the effective date of this AD. Repetitively thereafter inspect at intervals not to exceed 12 months	Follow M7 Aerospace SA227 Series Commuter Category Service Bulletin No. CC7-24-010, issued: September 19, 2007.

Note:

Although not a requirement of this AD, you may incorporate Swearingen Aviation Corporation SA226 Series Service Bulletin No. 57-010, Revised: December 5, 1975, on those airplanes that have not installed the access panel. Installation of the access panel will simplify the incorporation of the service bulletins referenced in this AD and future inspections of the areas of concern.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Fort Worth Airplane Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Werner Koch, Aerospace Engineer, 2601 Meacham Blvd., Fort Worth, Texas 76137; telephone: [phone]; fax: [phone]. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Related Information

(g) To get copies of the service information referenced in this AD, contact M7 Aerospace Repair Station, P.O. Box 790490, San Antonio, Texas 78279-0490; telephone: [phone]; fax: [phone]. To view the AD docket, go to U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, or on the Internet at http://www.regulations.gov. The docket number is Docket No. FAA-2008-0313; Directorate Identifier 2007-CE-095-AD.

Issued in Kansas City, Missouri, on March 7, 2008.

David R. Showers,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.