Discussion
What Events Have Caused This AD?
The Japanese Civil Airworthiness Bureau (JCAB), which is the airworthiness authority for Japan, notified the FAA that an unsafe condition may exist on certain Mitsubishi MU-2B series airplanes. The JCAB reports that several Mitsubishi MU-2B series airplanes have had windshield or window separation during flight. Separation is defined as shattering glass. Further analysis shows that the separation is happening as a result of repeated cabin pressurization cycles.
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 Mitsubishi MU-2B series airplanes. This proposal was published in the Federal Register as a supplemental notice of proposed rulemaking (NPRM) on March 26, 2003 (68 FR 14558). The supplemental NPRM proposed to require you to:
--Repetitively inspect the cockpit windshield and cabin window surfaces for damage (damage would be defined as crazing, scratches, and cracks);
--Blend out the damage if the damage does not exceed certain limits; and
--Replace the windshield or window if damage exceeds certain limits.
What Is the Potential Impact if FAA Took No Action?
This condition, if not corrected, could result in shattering or separation of the cockpit windshield or cabin windows during flight, which could cause loss of control of the airplane.
Was the Public Invited To Comment?
The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment:
Comment Issue No. 1: Update the Contact Information for Mitsubishi Heavy Industries America, Inc. (MHIA)
What Is the Commenter's Concern?
MIHA has moved and the contact information should be changed to reflect the new address and telephone numbers.
WhatIs FAA's Response to the Concern?
We concur and have changed the final rule based on this comment.
Comment Issue No. 2: Remove the Contact Information for Mitsubishi Heavy Industries, Nagoya, Japan
What Is the Commenter's Concern?
MIHA is licensed by Mitsubishi Heavy Industries, Ltd. to maintain the type design for Model MU-2B series airplanes. Since MIHA manufactures replacement and modification parts for Model MU-2B series airplanes and is responsible for worldwide support the these airplanes, the reference to Mitsubishi Heavy Industries, Nagoya, Japan should be removed.
What Is FAA's Response to the Concern?
We concur and have changed the final rule based on this comment.
Comment Issue No. 3: Clarify Which Service Bulletin Is Applicable to the Affected Airplane Models and Serial Numbers
What Is the Commenter's Concern?
The commenter states that the final rule AD should clearly define which service bulletin is applicable to each airplane modeland serial number in order to facilitate the owners/operators in obtaining the correct service bulletin for their airplane.
What Is FAA's Response to the Concern?
We concur with the commenter. In paragraphs (a)(2)(i) and (a)(2)(ii) of the proposed AD, we specifically referenced the affected airplane models and serial numbers that are applicable to each service bulletin. We have added language in paragraph (d) to further clarify this issue.
We have changed the final rule based on this comment.
Comment Issue No. 4: Update the Cost for Parts and Add Configuration Information in the Cost Impact Section
What Is the Commenter's Concern?
Since the issuance of the proposed AD, the price for replacements parts has significantly increased. The cost impact section should be changed to reflect current pricing and should also include the number of windshields and cabin windows each airplane has in its configuration.
What Is FAA's Response to the Concern?
We concur and have changed the final rule based on this comment.
FAA's Determination
What Is FAA's Final Determination on this Issue?
After careful reviewed all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. We have determined that these minor corrections:
--Provide the intent that was proposed in the supplemental NPRM for correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already proposed in the supplemental NPRM.
How Does the Revision to 14 CFR Part 39 Affect This AD?
On July 10, 2002, FAA 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 special flight permits, alternative methods of compliance, and altered products. This material previously was includedin each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Cost Impact
How Many Airplanes Does This AD Impact?
We estimate that this AD affects 315 airplanes in the U.S. registry.
What Is the Cost Impact of This AD on Owners/Operators of the Affected Airplanes?
We estimate the following costs to accomplish the inspection:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
8 workhours x $60 = $480
No parts required
$480
$480 x 315 = $151,200
We estimate the following costs to accomplish any necessary replacements that will be required based on the results of the inspection. We have no way of determining the number of airplanes that may need such replacement:
Labor cost
Parts cost per part No. (P/N)
Number of parts per short body model
Number of parts per long body model
Total cost per windshield/
window
16 workhours x $60 = $960
010A-31450-1 = $6,8931
1
$7,853
010A-31450-2 = $6,893
1
1
7,853
010A-31451-1 = $5,024
1
1
5,984
010A-31451-2 = $5,029
1
1
5,989
010A-31874-1 = $4,838
1
1
5,798
010A-31874-2 = $4,838
1
1
5,798
010A-31870 = $3,279
2
5
4,239
010A-31870-11 = $3,279
2
2
4,239
030A-32402 = $2,308
0
1
3,268
Regulatory Impact
Does This AD Impact Various Entities?
The regulations adopted herein will 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.
Does This AD Involve a Significant Rule or Regulatory Action?
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, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under 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 U.S.C. 106(g), 40113, 44701.
39.13 [Amended]
2. FAA amends Sec. 39.13 by adding a new AD to read as follows: