E8-17262. Airworthiness Directives; MD Helicopters, Inc. Model MD900 (including the MD902 Configuration) Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes adopting a new airworthiness directive (AD) for the specified MD Helicopters, Inc. (MDHI) model helicopters that would require, within 30 days, reducing the current gross weight limit to a maximum gross weight limit of 5,400 pounds and inserting a copy of this AD into the Limitations section of the Rotorcraft Flight Manual (RFM) or making certain optional modifications that constitute terminating actions. This proposal is prompted by flight tests that show that the information currently listed in the Limitations section of the RFM is inconsistent with the actual performance of the helicopter. The actions specified by the proposed AD are intended to prevent loss of directional control of the helicopter.

DATES:

Comments must be received on or before September 26, 2008.

ADDRESSES:

Use one of the following addresses to submit comments 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.

You may get the service information identified in this proposed AD from MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, Arizona 85215-9734, telephone [phone], fax [phone], or on the Web at http://www.mdhelicopters.com.

FOR FURTHER INFORMATION CONTACT:

Chip Adam, Flight Test Pilot, FAA, Los Angeles Aircraft Certification Office, Flight Test Branch, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any written data, views, or arguments regarding this proposed AD. Send your comments to the address listed under the caption ADDRESSES. Include the docket number “FAA-2008-0772, Directorate Identifier 2008-SW-30-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 with FAA personnel concerning this proposed rulemaking. Using the search function of our docket web site, you can find and read the comments to any of our dockets, including the name of the individual who sent or signed the comment. You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000.

Examining the Docket

You may examine the docket that contains the proposed AD, any comments, and other information in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone [phone]) is located in Room W12-140 on the ground floor of the West Building at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

This proposed amendment would apply to MDHI Model MD900 (including the MD902 Configuration) helicopters. This proposed amendment is prompted by flight tests related to a proposed type design change that showed that the critical wind azimuth in hover calculated during original certification as depicted in the Limitations section of the RFM is in error. RFM Figure 2-2, “Controllability Envelope and Critical Azimuth for Crosswind Operation,” which shows an envelope of adequate control capability for weights up to the maximum weight in winds of 17 knots or less from any azimuth and in winds of 15 knots or less from the 120° to 135° azimuth region, is inconsistent with the actual performance of the helicopter as demonstrated in recent flight tests. Use of this incorrect information could lead a pilot to believe that, at gross weights and altitudes at or near the upper boundary of the envelope, the helicopter is fully controllable with sustained crosswinds or winds within the critical wind azimuth area; the recent flight tests have shown otherwise. This condition, if not corrected, could result in loss of directional control of the helicopter.

We have reviewed MDHI SB900-099 R1, dated December 27, 2006, which describes procedures for adjusting the directional control system rigging, installing a thruster extension kit, and verifying that a NOTAR fan felt seal, part number (P/N) 900F3441025-103 is installed. The SB specifies that failure to comply with the procedures may result in reduced anti-torque control during certain combinations of high gross weight, density altitude, and wind critical conditions. The SB also indicates that the maximum gross weight of the helicopter will be lowered if the SB is not complied with.

This unsafe condition is likely to exist or develop on other helicopters of the same type designs. Therefore, the proposed AD would require, for helicopters that have not complied with MDHI SB900-099 R1, reducing the gross weight limit to a maximum gross weight limit of 5,400 pounds and inserting a copy of the AD into the Limitations section of the RFM. These actions would be required within 30 days. The proposed AD would also include optional terminating actions for the weight reduction. Those terminating actions would be to:

• Determine if a NOTAR fan felt seal part number (P/N) 900F3441025-103 is installed. If a NOTAR fan felt seal, P/N 900F3441025-103, is not installed, replace the installed seal with an airworthy NOTAR fan felt seal, P/N 900F3441025-103, before further flight; and
• Install a thruster extension kit in accordance with specified portions of the service bulletin described previously.

We estimate that this proposed AD would affect 31 helicopters of U.S. registry. The estimated lost revenue attributable to the gross weight reduction would be $1,750,000 per helicopter over the life of the helicopter. It would take approximately 1/2 work hour per helicopter to insert the proposed AD into the Limitations section of the RFM; 8 work hours to adjust the directional control system rigging; 8 work hours to install a NOTAR fan felt seal; and 24 work hours to install a thruster extension kit at an average labor rate of $80 per work hour. The NOTAR fan felt seal and thruster extension kit would cost approximately $16,000. However, the manufacturer has stated that they would provide the fan felt seal and the thruster extension kit to all operators at no cost to them and that they will also provide each affected operator a credit for the labor costs for a total of 32 work hours for those work hours required to perform the directional control rigging adjustment (8 work hours) and installation of the thruster extension kit (24 work hours). Based on these figures, the total estimated cost impact of this proposed AD on U.S. operators would be $1,920, assuming (1) the entire fleet chooses to modify their affected helicopter in accordance with the optional terminating action provision of this proposal and there is no reduction in gross weight necessary, (2) the manufacturer covers all the costs of the parts and the labor costs associated with the rigging adjustment and installation of the thruster extension kit and (3) only 3 helicopters need to have a new fan felt seal installed.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. Additionally, 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 draft economic evaluation of the estimated costs to comply with this proposed AD. See the AD docket to examine the draft economic evaluation.

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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

MD Helicopters, Inc.: Docket No. FAA-2008-0772; Directorate Identifier 2008-SW-30-AD.

Applicability: Model MD900 (including MD902 Configuration) helicopters that have not complied with MD Helicopters, Inc. (MDHI) Service Bulletin SB900-099 R1, dated December 27, 2006, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent loss of directional control of the helicopter, accomplish the following:

(a) Within 30 days, reduce the gross weight limit to a maximum gross weight limit of 5,400 pounds by inserting a copy of this AD into the Limitations section of the RFM.

(b) As an optional terminating action for the weight reduction mandated by paragraph (a) of this AD, accomplish the following:

(1) Determine if a NOTAR fan felt seal part number (P/N) 900F3441025-103 is installed. If a NOTAR fan felt seal, P/N 900F3441025-103, is not installed, replace the installed seal with an airworthy NOTAR fan felt seal, P/N 900F3441025-103, before further flight.

(2) Install a thruster extension kit in accordance with the Accomplishment Instructions, paragraph B. (3). through (17). of MDHI SB900-099 R1, dated December 27, 2006 (SB), before further flight. Contacting the manufacturer is not required by this AD.

(c) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Manager, Los Angeles Aircraft Certification Office, Attn: Chip Adam, Flight Test Pilot, FAA, Flight Test Branch, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone [phone], fax [phone], for information about previously approved alternative methods of compliance.

(d) Special flight permits will not be issued.

Issued in Fort Worth, Texas, on July 8, 2008.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.