[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]
-----------------------------------------------------------------------
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).
-----------------------------------------------------------------------
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.
------------------------------------------------------------------------
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):
----------------------------------------------------------------------------------------------------------------
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.
----------------------------------------------------------------------------------------------------------------
(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