
[Federal Register: July 28, 2008 (Volume 73, Number 145)]
[Proposed Rules]               
[Page 43646-43648]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28jy08-12]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0772; Directorate Identifier 2008-SW-30-AD]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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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

[[Page 43647]]

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: 202-493-2251.
     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 1-
800-388-3378, fax 480-346-6813, 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 (562) 627-
5369, fax (562) 627-5210.

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 (800) 647-5527) 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[deg] to 135[deg] 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

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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.


Sec.  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 (562) 
627-5369, fax (562) 627-5210, 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.
 [FR Doc. E8-17262 Filed 7-25-08; 8:45 am]

BILLING CODE 4910-13-P
