Source: https://www.federalregister.gov/documents/2002/09/13/02-23289/airworthiness-directives-mitsubishi-heavy-industries-ltd-mu-2b-series-airplanes
Timestamp: 2018-04-26 19:45:13
Document Index: 743901939

Matched Legal Cases: ['§\u200939', 'ART 1', 'ART 1', 'ART 2', 'ART 3', 'ART 2', 'ART 3']

67 FR 57989
57989-57991 (3 pages)
02-23289
What Has Happened Since AD 88-23-01 To Initiate This Action?
What Is the Difference Between the Cost Impact of This Proposed AD and the Cost Impact of AD 88-23-01?
https://www.federalregister.gov/d/02-23289 https://www.federalregister.gov/d/02-23289
This document proposes to supersede Airworthiness Directive (AD) 88-23-01, which currently requires repetitively inspecting torque tube joints for cracks, and, if cracks are found, replacing the joints on all Mitsubishi Heavy Industries, Ltd. (Mitsubishi) MU-2B Series airplanes. AD 88-23-01 resulted from field reports that fatigue cracks were found in the flap control system. A design change exists that could eliminate the need for the repetitive inspections. The proposed AD would require you to replace the existing joints with new improved-design joints as terminating action for the repetitive inspections. The actions specified by this proposed AD are intended to prevent failures of the flap control system due to the existing design torque tube joints. Such failure could lead to loss of control of the aircraft.
Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2002-CE-27-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may view any comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except Federal holidays. You may also send comments electronically to the following address: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain “Docket No. 2002-CE-27-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 text.
You may get service information that applies to this proposed AD from Mitsubishi Heavy Industries America, Inc., 4951 Airport Parkway, Suite 800, Addison, Texas 75001; telephone: (972) 934-5480; facsimile: (972) 934-5488.
You may also view this information at the Rules Docket at the address above.
—For the airplanes manufactured in Japan (Type Certificate A2PC): Carl Fountain, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, 3960 Paramount Boulevard, Lakewood, California 90712; telephone: (562) 627-5222; facsimile: (562) 627-5228; and
If you want FAA to acknowledge the receipt of your mailed comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2002-CE-27-AD.” We will date stamp and mail the postcard back to you.
Field reports indicating fatigue cracks were found in the joint of the torque tube assemblies that had been in service for more than 4,000 hours on Mitsubishi MU-2 Series airplanes caused us to issue AD 88-23-01, Amendment 39-6056. This AD requires the following on Mitsubishi MU-2B Series airplanes:
—Repetitively inspecting joints of the torque tube assembly for cracks; and
—Replacing joints if cracks are found.
A recent accident investigation revealed that the improper reinstallation (following an AD 88-23-01 required repetitive inspection) of two cotter pins in the torque tube resulted in a disconnect in the flap drive train. This disconnect resulted in an asymmetrical flap deployment during a landing approach. The pilot lost control of the aircraft, resulting in destruction of the aircraft and death of the pilot.
Mitsubishi has issued:
—Service Bulletin No. 067/27-008A, Revision A, dated March 29, 1995; andStart Printed Page 57990
—Service Bulletin No. 189C, Revision C, dated June 28, 1994.
These service bulletins include procedures for replacing the torque tube assemblies with the improved-design torque tube assemblies.
—The unsafe condition referenced in this document exists or could develop on other Mitsubishi MU-2B Series airplanes of the same type design;
This proposed AD would supersede AD 88-23-01 with a new AD that would eliminate the repetitive inspections by replacing the existing joints with new improved-design joints.
We estimate that this proposed AD affects 360 airplanes in the U.S. registry.
16 workhours × $60 = $960 $20,000 per airplane $20,960 per airplane $20,960 × 360 = $7,545,600
The cost impact of the proposed AD is a one-time cost as shown above. The cost impact of AD 88-23-01 is the cost impact of the repetitive inspections and the eventual replacement cost.
2. FAA amends § 39.13 by removing Airworthiness Directive (AD) 88-23-01, Amendment 39-6056, and by adding a new AD to read as follows:
Mitsubishi Heavy Industries, Ltd.: Docket No. 2002-CE-27-AD; Supersedes AD 88-23-01, Amendment 39-6056.
(a) What airplanes are affected by this AD? This AD affects all serial numbers of Models MU-2B, MU-2B-10, MU-2B-15, MU-2B-20, MU-2B-25, MU-2B-26, MU-2B-26A, MU-2B-30, MU-2B-35, MU-2B-36, MU-2B-36A, MU-2B-40, and MU-2B-60, that are certificated in any category.
(c) What problem does this AD address? The actions specified by this AD are intended to prevent failures of the flap control system due to the existing design of the torque tube joints. Such failure could lead to loss of control of the aircraft.
(1) On torque tube assembly part (P/N) 010A-61250, replace joint P/N 010A-61254 with improved-design joint P/N 010A-61254-3 and joint P/N 010-61255-3 with improved-design joint P/N 010A-61255-17 (or FAA-approved equivalent part number), unless already accomplished. Upon the accumulation of 4,000 hours time-in-service (TIS) on the torque tube assembly or within the next 100 hours TIS after the effective date of this AD, whichever occurs later, unless already accomplished In accordance with PART 1 of MU-2 Service Bulletin No. 067/27-008A, Revision A, dated March 29, 1995; or PART 1 of MU-2 Service Bulletin No. 189C, Revision C, dated June 28, 1994, as applicable.
(2) Replace joint with improved-design joint (or FAA-approved equivalent part number), unless already accomplished: Upon the accumulation of 4,000 hours of TIS on the torque tube assembly or within the next 200 hours TIS after the effective date of this AD, whichever occurs later, unless already accomplished In accordance with PART 2 and PART 3 of MU-2 Service Bulletin No. 067/27-008A, Revision A, dated March 29, 1995; or PART 2 and PART 3 of MU-2 Service Bulletin No. 189C, Revision C, dated June 28, 1994, as applicable.
Start Printed Page 57991
(i) on torque tube assembly P/N 010A-61251-11, replace joint P/N 010A-61255-3 with improved-design joint P/N 010A-61255-17 and joint P/N 010-61255-7 with improved-design joint P/N 010A-61255-19;
(ii) on torque tube assembly P/N 017A-61805, replace joint P/N 010A-61264-3 with improved-design joint P/N 010A-61264-7 and P/N 010-61264-5 with improved-design joint P/N 010A-61264-9;
(iii) on torque tube assembly P/N 017A-61805-11, replace joint P/N 010A-61264-3 with improved-design joint P/N 010A-61264-7 and P/N 010-61264-5 with improved-design joint P/N 010A-61264-9;
(iv) on torque tube assembly P/N 010A-61251-31, replace joint P/N 010A-61255-9 with improved-design joint P/N 010A-61255-17 and P/N 010-61255-15 with improved-design joint P/N 010A-61255-23;
(v) on torque tube assembly P/N 010A-61251, replace joint P/N 010A-61255-3 with improved-design joint P/N 010A-61255-17 and P/N 010-61255-5 with improved-design joint P/N 010A-61255-23;
(vi) on torque tube assembly P/N 010A-61260, replace joint P/N 010A-61264-3 with improved-design joint P/N 010A-61264-7 and P/N 010-61264-5 with improved-design joint P/N 010A-61264-9; and
(vii) on torque tube assembly P/N 010A-61260-21, replace joint P/N 010A-61264-3 with improved-design joint P/N 010A-61264-7 and P/N 010-61264-5 with improved-design joint P/N 010A-61264-9.
(3) Only install joints that are P/N 010A-61254-3, P/N 010A-61255-17, P/N 010A-61255-19, P/N 010A-61255-23, P/N 010A-61264-7, P/N 010A-61264-9, or FAA-approved equivalent P/Ns. Replace all joints at the same time. As of the effective date of this AD Not Applicable.
(ii) The Manager, Fort Worth Aircraft Certification Office, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager.
(2) Alternative methods of compliance approved in accordance with AD 88-23-01, which is superseded by this AD, are not approved as alternative methods of compliance with this AD.
(f) Where can I get information about any already-approved alternative methods of compliance? Contact:
—For the airplanes manufactured in Japan (Type Certificate A2PC): Carl Fountain, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, 3960 Paramount Boulevard., Lakewood, California, 90712; telephone: (562) 627-5222; facsimile: (562) 627-5228; and
(h) How do I get copies of the documents referenced in this AD? You may get copies of the documents referenced in this AD from Mitsubishi Heavy Industries America, Inc., 4951 Airport Parkway, suite 800, Addison, Texas 75001; telephone: (972) 934-5480; facsimile: (972) 934-5488.
(i) Does this AD action affect any existing AD actions? This amendment supersedes AD 88-23-01, Amendment 39-6056.
Issued in Kansas City, Missouri, on September 4, 2002.
[FR Doc. 02-23289 Filed 9-12-02; 8:45 am]