AD 2012-21-01
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | MD Helicopters, Inc. | MD900 | Airworthiness Directives; MD Helicopters, Inc. |
Unsafe Condition
A crack in the main rotor lower hub assembly could lead to failure of the lower hub and subsequent loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Visually inspect and, if necessary, perform an eddy current inspection of the main rotor lower hub assembly for cracks. Replace the lower hub with an airworthy one if a crack is found.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
before further flight if a crack is found; otherwise, inspections must be conducted at 100-hour intervals initially and 300-hour intervals recurring, or during the next annual inspection whichever occurs first, with replacement required within three years.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
MD Helicopters, Inc. Model MD900 helicopters.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Equipment/furnishing system wiring
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - 2012-21-01.pdf Copy URL Document Versions Feedback DetailsAttachments/Public Comments AD Number: 2012-21-01 Document Type: AD Final Rules Docket Number: FAA-2012-0342 Subject Heading: Airworthiness Directives; MD Helicopters, Inc. Subject: Equipment/furnishing system wiring Status: Current Citation: Federal Register Volume 77, Number 205 (Tuesday, October 23, 2012) Citation Publish Date: 10/23/2012 Effective Date: 11/27/2012 Make: MD Helicopters, Inc. Model: MD900 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: 2011-14-05 Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Automatic Zoom Actual Size Page Fit Page Width 50% 75% 100% 125% 150% 200% 300% 400% 125% of 5 1 [Federal Register Volume 77, Number 205 (Tuesday, October 23, 2012)] [Rules and Regulations] [Pages 64709-64711] From the Federal Register Online via the Government Printing Office [www.gpo.gov] [FR Doc No: 2012-25387] –––––––––––––––––––––––––––––––––– DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2012-0342; Directorate Identifier 2011-SW-028-AD; Amendment 39-17216; AD 2012-21-01] RIN 2120-AA64 Airworthiness Directives; MD Helicopters, Inc. AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. –––––––––––––––––––––––––––––––––– SUMMARY: We are adopting a new airworthiness directive (AD) to supersede an existing airworthiness directive for MD Helicopters, Inc. (MDHI), Model MD900 helicopters. The existing AD requires a visual inspection, and if necessary, an eddy current inspection of the main rotor lower hub assembly (lower hub) for a crack. If a crack exists, the AD requires replacing the lower hub with an airworthy lower hub before further flight. Because that AD was immediately effective, we declined to require certain long-term actions prior to public comment. This superseding AD will require the same inspections as the existing AD but will also require long-term recurring inspections and replacing the lower hub with an airworthy lower hub. We are issuing this AD to detect a crack in the lower hub and prevent failure of the lower hub and subsequent loss of control of the helicopter. DATES: This AD is effective November 27, 2012. The Director of the Federal Register approved the incorporation by reference of certain documents listed in this AD as of November 27, 2012. ADDRESSES: For service information identified in this AD, contact MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, AZ 85215-9734, telephone 1-800-388-3378, fax 480-346-6813, or at http://www.mdhelicopters.com. You may review a copy of the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth Texas 76137. Examining the AD Docket: You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the Docket Operations Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, any incorporated- by-reference service information, the economic evaluation, any comments received, and other information. The street address for the Docket Operations Office (phone: 800-647-5527) is U.S. 2 Department of Transportation, Docket Operations Office, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Eric Schrieber, Aviation Safety Engineer, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA, 3960 Paramount Blvd., Lakewood, CA 90712; telephone (562) 627-5348; email eric.schrieber@faa.gov. SUPPLEMENTARY INFORMATION: Discussion On March 29, 2012, at 77 FR 18963, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 to include an AD that would apply to MDHI Model MD900 helicopters. That NPRM proposed to supersede an existing AD to require the same inspections as the existing AD but also require recurring inspections and replacing the lower hub with an airworthy lower hub. The proposed requirements were intended to detect a crack in the lower hub and prevent failure of the lower hub and subsequent loss of control of the helicopter. Comments We gave the public the opportunity to participate in developing this AD, but we received no comments on the NPRM. FAA's Determination We have reviewed the relevant information and determined that an unsafe condition exists and is likely to exist or develop on other products of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed. Related Service Information We reviewed MDHI Service Bulletin SB900-117, dated January 14, 2011 (SB). The SB specifies an initial 100-hour and recurring 300-hour visual and eddy current inspections of the lower hub for a crack and, if a crack exists, replacement of the lower hub with an airworthy lower hub. The SB requires the inspections at the stated intervals or during the next annual inspection, whichever occurs first. The SB also specifies replacing the lower hub within three years. Costs of Compliance We estimate that this AD will affect 12 helicopters of U.S. registry. We estimate the following costs to comply with this AD: • Visually inspecting the hub. We estimate that will take one work-hour at $85 an hour, for a total cost per helicopter of $85 and a total cost of $1,020 for the fleet. • Eddy current inspecting the lower hub. We estimate that will take one work-hour at $85 an hour, for a total cost per helicopter of $85 and a total cost of $1,020 for the fleet. • Replacing the lower hub. We estimate that will take 11 work-hours at $85 an hour for a total labor cost of $935, and that parts will cost $12,480 per hub, for a total cost of $13,415 per helicopter and a total cost of $160,980 for the fleet. • The costs for U.S. operators will total $163,020, assuming that the lower hubs for the entire fleet get replaced.
Document Text
Show stored source text (verify against official source)
AD Final Rules - 2012-21-01.pdf Copy URL Document Versions Feedback DetailsAttachments/Public Comments AD Number: 2012-21-01 Document Type: AD Final Rules Docket Number: FAA-2012-0342 Subject Heading: Airworthiness Directives; MD Helicopters, Inc. Subject: Equipment/furnishing system wiring Status: Current Citation: Federal Register Volume 77, Number 205 (Tuesday, October 23, 2012) Citation Publish Date: 10/23/2012 Effective Date: 11/27/2012 Make: MD Helicopters, Inc. Model: MD900 Product Type: Aircraft Product Subtype: Rotorcraft Affected AD: Superseded AD: 2011-14-05 Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Automatic Zoom Actual Size Page Fit Page Width 50% 75% 100% 125% 150% 200% 300% 400% 125% of 5 1 [Federal Register Volume 77, Number 205 (Tuesday, October 23, 2012)] [Rules and Regulations] [Pages 64709-64711] From the Federal Register Online via the Government Printing Office [www.gpo.gov] [FR Doc No: 2012-25387] –––––––––––––––––––––––––––––––––– DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2012-0342; Directorate Identifier 2011-SW-028-AD; Amendment 39-17216; AD 2012-21-01] RIN 2120-AA64 Airworthiness Directives; MD Helicopters, Inc. AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. –––––––––––––––––––––––––––––––––– SUMMARY: We are adopting a new airworthiness directive (AD) to supersede an existing airworthiness directive for MD Helicopters, Inc. (MDHI), Model MD900 helicopters. The existing AD requires a visual inspection, and if necessary, an eddy current inspection of the main rotor lower hub assembly (lower hub) for a crack. If a crack exists, the AD requires replacing the lower hub with an airworthy lower hub before further flight. Because that AD was immediately effective, we declined to require certain long-term actions prior to public comment. This superseding AD will require the same inspections as the existing AD but will also require long-term recurring inspections and replacing the lower hub with an airworthy lower hub. We are issuing this AD to detect a crack in the lower hub and prevent failure of the lower hub and subsequent loss of control of the helicopter. DATES: This AD is effective November 27, 2012. The Director of the Federal Register approved the incorporation by reference of certain documents listed in this AD as of November 27, 2012. ADDRESSES: For service information identified in this AD, contact MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, AZ 85215-9734, telephone 1-800-388-3378, fax 480-346-6813, or at http://www.mdhelicopters.com. You may review a copy of the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth Texas 76137. Examining the AD Docket: You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the Docket Operations Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, any incorporated- by-reference service information, the economic evaluation, any comments received, and other information. The street address for the Docket Operations Office (phone: 800-647-5527) is U.S. 2 Department of Transportation, Docket Operations Office, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Eric Schrieber, Aviation Safety Engineer, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA, 3960 Paramount Blvd., Lakewood, CA 90712; telephone (562) 627-5348; email eric.schrieber@faa.gov. SUPPLEMENTARY INFORMATION: Discussion On March 29, 2012, at 77 FR 18963, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 to include an AD that would apply to MDHI Model MD900 helicopters. That NPRM proposed to supersede an existing AD to require the same inspections as the existing AD but also require recurring inspections and replacing the lower hub with an airworthy lower hub. The proposed requirements were intended to detect a crack in the lower hub and prevent failure of the lower hub and subsequent loss of control of the helicopter. Comments We gave the public the opportunity to participate in developing this AD, but we received no comments on the NPRM. FAA's Determination We have reviewed the relevant information and determined that an unsafe condition exists and is likely to exist or develop on other products of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed. Related Service Information We reviewed MDHI Service Bulletin SB900-117, dated January 14, 2011 (SB). The SB specifies an initial 100-hour and recurring 300-hour visual and eddy current inspections of the lower hub for a crack and, if a crack exists, replacement of the lower hub with an airworthy lower hub. The SB requires the inspections at the stated intervals or during the next annual inspection, whichever occurs first. The SB also specifies replacing the lower hub within three years. Costs of Compliance We estimate that this AD will affect 12 helicopters of U.S. registry. We estimate the following costs to comply with this AD: • Visually inspecting the hub. We estimate that will take one work-hour at $85 an hour, for a total cost per helicopter of $85 and a total cost of $1,020 for the fleet. • Eddy current inspecting the lower hub. We estimate that will take one work-hour at $85 an hour, for a total cost per helicopter of $85 and a total cost of $1,020 for the fleet. • Replacing the lower hub. We estimate that will take 11 work-hours at $85 an hour for a total labor cost of $935, and that parts will cost $12,480 per hub, for a total cost of $13,415 per helicopter and a total cost of $160,980 for the fleet. • The costs for U.S. operators will total $163,020, assuming that the lower hubs for the entire fleet get replaced.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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