03-28737. Airworthiness Directives; Raytheon Aircraft Company Model 1900, 1900C, 1900C (C-12J), and 1900D Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of the comment period.

SUMMARY:

The FAA proposes to revise an earlier proposed airworthiness directive (AD) that applies to certain Raytheon Aircraft Company (Raytheon) Model 1900, 1900C, 1900C (C-12J), and 1900D airplanes that do not have canted bulkhead Kit No. 129-4005-1 S incorporated. The earlier NPRM would have required you to repetitively inspect the canted bulkhead located at Fuselage Station (FS) 588.10 for cracks. If cracks are found that exceed certain limits, the NPRM would have required you to incorporate canted bulkhead Kit No. 129-4005-1 S as terminating action for the proposed AD repetitive inspection requirement. When Kit No. 129-4005-1 S is incorporated, no further action is required. The earlier NPRM resulted from numerous reports of multi-site cracks occurring in the canted bulkhead at Fuselage Station 588.10. The NPRM contradicts the FAA's policy to disallow airplane operation when known cracks exist in primary structure. You should have the kit incorporated anytime a crack is found and we are revising the NPRM accordingly. Since this action imposes an additional burden over that proposed in the earlier NPRM, we are reopening the comment period to allow the public the chance to comment on these revised actions.

DATES:

We must receive any comments on this proposed AD by January 16, 2004.

ADDRESSES:

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

• By mail: FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 95-CE-46-AD, 901 Locust, Room 506, Kansas City, Missouri 64106.
• By fax: [phone].
• By e-mail: [e-mail]. Comments sent electronically must contain “Docket No. 95-CE-46-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII.

You may get the service information identified in this proposed AD from Raytheon Aircraft Company, 9709 E. Central, Wichita, Kansas 67201-0085; telephone: [phone] or [phone].

You may view the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 95-CE-46-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. to 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Steven E. Potter, Aerospace Engineer, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Wichita, Kansas 67209; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This Proposed AD?

We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 95-CE-46-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it. We will date-stamp your postcard and mail it back to you.

Are There Any Specific Portions of This Proposed AD I Should Pay Attention To?

We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. If you contact us through a nonwritten communication and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments and contacts.

Discussion

What Events Have Caused the Earlier Proposed AD?

The FAA has received numerous reports of multi-site cracks in the canted bulkhead at Fuselage Station (FS) 558.10 on 3 Raytheon Model 1900, 1900C, and 1900D airplanes. These cracks were found at the outer flange radius and outer flange stringer cutouts of the canted bulkhead.

Has FAA Taken Any Action to This Point?

We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Raytheon Model 1900, 1900C, 1900C (C-12J), and 1900D airplanes that do not have canted bulkhead Kit No. 129-4005-1 S incorporated. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 4, 1995 (60 FR 51944). The earlier NPRM proposed to require you to:

—repetitively inspect the canted bulkhead located at FS 588.10 for cracks; and

—incorporate canted bulkhead Repair Kit No. 129-4005-1 S if cracks exceed certain limits and as a terminating action for the repetitive inspection requirement.

Was the Public Invited To Comment?

The FAA encouraged interested persons to participate in the making of this amendment. We received two comments in support of the proposed rule.

What Has Happened To Initiate This Supplemental NPRM?

As currently written, the existing NPRM allows continued flight if cracks are found in the canted bulkhead located at FS 588.10 that do not exceed certain limits. The NPRM contradicts the FAA's policy to disallow airplane operation when known cracks exist in primary structure, unless the ability to sustain ultimate load with these cracks is proven. The canted bulkhead located at FS 588.10 is considered primary structure, and the FAA has not received any analysis to prove that ultimate load can be sustained with cracks in this area. For this reason, the FAA has determined that the crack limits contained in the NPRM should be eliminated and that AD action should be taken to require immediate incorporation of canted bulkhead Repair Kit No. 129-4005-1 S anytime a crack is found.

Raytheon has revised Service Bulletin SB 53-2564, Revision 2, Revised: July 2003, to remove flight with allowable crack limits.

What Are the Consequences if the Condition Is Not Corrected?

This condition, if not detected and corrected, could prevent the bulkhead from carrying its ultimate design load because of cracks in the canted bulkhead. Failure of the bulkhead could affect the rudder cable tension and result in loss of rudder control.

FAA's Determination and Requirements of This Proposed AD

What Has FAA Decided?

After examining the circumstances and reviewing all available information related to the incidents described above, we have determined that:

—The unsafe condition referenced in this document exists or could develop on other Raytheon Model 1900, 1900C, 1900C (C-12J), and 1900D airplanes of the same type design that do not have canted bulkhead Repair Kit No. 129-4005-1 S incorporated airplanes:

—The NPRM should be changed to disallow airplane operation when known cracks exist in primary structure; and

—AD action should be taken in order to correct this unsafe condition.

The Supplemental NPRM

How Will the Changes to the NPRM Impact the Public?

Proposing that the NPRM disallow flight with cracks imposes an additional burden over that proposed in the earlier NPRM. Therefore, we are reopening the comment period to allow the public the chance to comment on these revised actions.

What Are the Provisions of the Supplemental NPRM?

The proposed AD would require you to:

—Repetitively inspect the canted bulkhead located at FS 588.10 for cracks; and

—Incorporate canted bulkhead Repair Kit No. 129-4005-1 S if any cracks are found and as a terminating action for the repetitive inspection requirement. When Kit No. 129-4005-1 S is incorporated, no further action is required.

How Does the Revision to 14 CFR Part 39 Affect This Proposed AD?

On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Costs of Compliance

How Many Airplanes Would This Proposed AD Impact?

We estimate that this proposed AD affects 364 airplanes in the U.S. registry.

What Would Be the Cost Impact of This Proposed AD on Owners/Operators of the Affected Airplanes?

We estimate the following costs to accomplish this proposed inspection:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
2 workhours × $65 per hour = $130	Not applicable	$130	$130 × 364 = $47,320.

We estimate the following costs to accomplish this proposed modification:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
80 workhours × $65 per hour = $5,200	$718	$5,918	$5,918 × 364 = $2,154,152.

Regulatory Findings

Would This Proposed AD Impact Various Entities?

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.

Would This Proposed AD Involve a Significant Rule or Regulatory Action?

For the reasons discussed above, I certify that this 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. 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 summary of the costs to comply with this proposed AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 95-CE-46-AD” in your request.

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 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Raytheon Aircraft Company: Docket No. 95-CE-46-AD.

When Is the Last Date I Can Submit Comments on This Proposed AD?

(a) We must receive comments on this proposed airworthiness directive (AD) by January 16, 2004.

What Other ADs Are Affected by This Action?

(b) None.

What Airplanes Are Affected by This AD?

(c) This AD affects the following airplane models and serial numbers that:

(1) Do not have canted bulkhead Kit No. 129-4005-1 S incorporated; and

(2) Are certificated in any category:

Model	Serial Nos.
1900	UA-1 through UA-3.
1900C	UB-1 through UB-74 and UC-1 through UC-174.
1900C (C12J)	UD-1 through UD-6.
1900D	UE-1 through UE-113.

(d) This AD is the result of FAA establishing a policy to disallow airplane operation when known cracks exist in primary structure. The actions specified in this AD are intended to detect and correct cracks in the canted bulkhead, which could result in failure of the bulkhead. Such failure could lead to loss of rudder control.

What Must I Do To Address This Problem?

(e) To address this problem, you must accomplish the following:

Actions	Compliance	Procedures
(1) Inspect the canted bulkhead at Fuselage Station 588.10 for any signs of cracks	Initially inspect at whichever occurs later, unless already accomplished: Upon the accumulation of 5,000 hours time-in-service (TIS) or within the next 600 hours TIS after the effective date of this AD. If no cracks are found, repetitively inspect thereafter at intervals not to exceed 600 hours TIS until Kit No. 129-4005-1 S is incorporated. When Kit No. 129-4005-1 S is incorporated, no further action is required	Per Raytheon Aircraft Company Mandatory Service Bulletin SB 53-2564, Revision 2, Revised: July 2003.
(2) If cracks exist or are found during any inspection required in paragraph (e)(1) of this AD, incorporate Kit No. 129-4005-1 S	Prior to further flight after the inspection in which the cracks are found or known to exist	Per Raytheon Aircraft Company Mandatory Service Bulletin SB 53-2564, Revision 2, Revised: July 2003.
(3) Incorporating Kit No. 129-4005-1 S is the terminating action for the repetitive inspection requirements specified in paragraph (e)(1) of this AD	Kit No. 129-4005-1 S can be incorporated at any time. When incorporated, no further action is required	Per Raytheon Aircraft Company Mandatory Service Bulletin SB 53-2564, Revision 2, Revised: July 2003.

What About Alternative Methods of Compliance?

(f) You may request a different method of compliance or a different compliance time for this AD by following the procedures in 14 CFR 39.13. Send your request to the Manager, Wichita Aircraft Certification Office (ACO), FAA. For information on any already approved alternative methods of compliance, contact Steven E. Potter, Aerospace Engineer, Wichita ACO, FAA, 1801 Airport Road, Wichita, Kansas 67209; telephone: [phone]; facsimile: [phone].

How Do I Get Copies of the Documents Referenced in This AD?

(g) You may get copies of the documents referenced in this AD from Raytheon Aircraft Company, 9709 E. Central, Wichita, Kansas 67201-0085; telephone: [phone] or [phone]. You may view these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Issued in Kansas City, Missouri, on November 10, 2003.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.