[Federal Register Volume 60, Number 51 (Thursday, March 16, 1995)]
[Proposed Rules]
[Pages 14235-14236]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-6471]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-CE-13-AD]


Airworthiness Directives; Fairchild Aircraft SA226 and SA227 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to certain Fairchild Aircraft SA226 and SA227 
series airplanes that utilize a direct current (DC) generator. The 
proposed action would require relocating the left-hand (LH) and right-
hand (RH) essential bus current limiters (225 amp) to the battery bus 
(main bus tie). A safety recommendation received by the Federal 
Aviation Administration (FAA) that details potential electrical failure 
problems on Fairchild SA226 and SA227 series airplanes prompted the 
proposed action. The actions specified by the proposed AD are intended 
to prevent failure of the LH or RH essential bus when engine failure 
results in a blown generator current limiter, which could result in 
loss of airplane electrical power.

DATES: Comments must be received on or before June 2, 1995.

ADDRESSES: Submit comments in triplicate to the FAA, Central Region, 
Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-
CE-13-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. 
Comments may be inspected at this location between 8 a.m. and 4 p.m., 
Monday through Friday, holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279-
0490; telephone (210) 824-9421. This information also may be examined 
at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. George R. Hash, Aerospace 
Engineer, FAA, Airplane Certification Office, 2601 Meacham Boulevard, 
Fort Worth, Texas 76193-0150; telephone (817) 222-5134; facsimile (817) 
222-5959.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report that summarizes each FAA-public contact concerned 
with the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 95-CE-13-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 95-CE-13-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA has received a safety recommendation that details potential 
electrical failure problems on Fairchild SA226 and SA227 series 
airplanes. Flight simulation revealed that electrical power loss could 
occur on the affected airplanes because of failure of the LH essential 
bus. Switching delays between the left and right side electrical 
systems result in left generator motor action, which could then cause 
the left side current limiter to open. This would result in failure of 
the left essential bus, which will result in loss of alternating 
current (AC) power to the primary attitude indicator and the lighting 
for the standby attitude indicator.
    Failure of either engine will result in the loss of the essential 
bus for that side if the motoring action of the generator causes the 
current limiter to open. This condition, if not detected and corrected, 
could result in loss of airplane electrical power including loss of 
attitude and landing gear power.
    Fairchild has issued Service Bulletin (SB) 226-24-034, SB 227-24-
015, and SB CC7-24-002, all Issued: September 29, 1994. These service 
bulletins reference a modification that relocates the RH and LH 
essential bus current limiters (225 amp) to the battery bus (main bus 
tie). Fairchild Aircraft Engineering Kit Drawing 27K82376, ``Current 
Limiter Rebussing Kit,'' contains the specific procedures for 
incorporating this modification on the affected airplanes.
    After examining the circumstances and reviewing all available 
information related to the incidents described above, the FAA has 
determined that AD action should be taken to prevent the situation 
described above from occurring. [[Page 14236]] 
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Fairchild Aircraft SA226 and SA227 series 
airplanes of the same type design that utilize a direct current (DC) 
generator, the proposed AD would require relocating the LH and RH 
essential bus current limiters (225 amp) to the battery bus (main bus 
tie). Accomplishment of the proposed modification would be in 
accordance with Fairchild Aircraft Engineering Kit Drawing 27K82376, 
``Current Limiter Rebussing Kit,'' as referenced in Fairchild SB 226-
24-034, SB 227-24-015, and SB CC7-24-002, all Issued: September 29, 
1994.
    The FAA estimates that 622 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 4 
workhours per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. Parts cost 
approximately $98 per airplane. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be $210,236 
($338 per airplane). This figure is based on the assumption that no 
affected airplane owner/operator has incorporated the proposed 
modification. Fairchild Aircraft has informed the FAA that parts have 
not been distributed to any owner/operator of the affected airplanes.
    The regulations proposed herein would not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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) if promulgated, 
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 draft regulatory evaluation 
prepared for this action has been placed 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, 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new AD to read as follows:

Fairchild Aircraft: Docket No. 95-CE-13-AD.

    Applicability: The following model and serial number airplanes 
that utilize a direct current (DC) generator, certificated in any 
category.

------------------------------------------------------------------------
                      Models                             Serial Nos.    
------------------------------------------------------------------------
SA226-T, SA226-AT, SA226-TC, and SA226-T(B).......  All.                
SA227-AC, SA227-AT, SA227-BC, and SA227-TT........  1 through 733.      
SA227-CC and SA227-DC.............................  784, and 790 through
                                                     883.               
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    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (c) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition, or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any aircraft from the applicability of this AD.

    Compliance: Required within the next 2,000 hours time-in-service 
after the effective date of this AD, unless already accomplished.
    To prevent failure of the left hand (LH) and right hand (RH) 
essential bus when engine failure results in a blown generator 
current limiter, which could result in loss of airplane electrical 
power, accomplish the following:
    (a) Relocate the LH and RH essential bus current limiters (225 
amp) to the battery bus (main bus tie) in accordance with Fairchild 
Aircraft Engineering Kit Drawing 27K82376, ``Current Limiter 
Rebussing Kit,'' as referenced in the following service bulletins 
(SB):

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         SB                    Date                                     Models affected                         
----------------------------------------------------------------------------------------------------------------
226-24-034.........  September 29, 1994.....  All affected SA226 models.                                        
227-24-05..........  September 29, 1994.....  SA227-AD, SA227-AT, SA227-BC, and SA227-TT.                       
CC7-24-002.........  September 29, 1994.....  SA227-CC and SA227-DC.                                            
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    (b) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Fort Worth Airplane Certification Office 
(ACO), FAA, 2601 Meacham Boulevard, Fort Worth, Texas 76193-0150. 
The request shall be forwarded through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Fort Worth ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Fort Worth ACO.

    (d) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Fairchild Aircraft, 
P.O. Box 790490, San Antonio, Texas 78279-0490; or may examine this 
document at the FAA, Central Region, Office of the Assistant Chief 
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on March 10, 1995.
Barry D. Clements,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 95-6471 Filed 3-15-95; 8:45 am]
BILLING CODE 4910-13-U