[Federal Register Volume 59, Number 61 (Wednesday, March 30, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-7497]


[[Page Unknown]]

[Federal Register: March 30, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 91-CE-12-AD]

 

Airworthiness Directives: Fairchild Aircraft Models SA227-AC and 
SA227-AT Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to supersede Airworthiness Directive 
(AD) 83-12-01, which currently requires repetitively inspecting the 
lower wing skin panel for cracks on certain Fairchild Models SA227-AC 
and SA227-AT airplanes, and installing wing skin reinforcement doublers 
if any wing skin crack is found. The Federal Aviation Administration's 
policy on aging commuter-class aircraft is to eliminate or, in certain 
instances, reduce the number of certain repetitive short-interval 
inspections when improved parts or modifications are available. The 
proposed action would require installing wing skin reinforcement 
doublers or wing skin stringer ties as terminating action for the 
repetitive inspections that are currently required by AD 83-12-01. The 
actions specified in the proposed AD are intended to prevent fatigue 
failure of the lower wing skin panels, which could result in loss of 
control of the airplane.

DATES: Comments must be received on or before June 10, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 91-CE-12-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. Hung Viet Nguyen, Aerospace 
Engineer, FAA, Airplane Certification Office, 2601 Meacham Boulevard, 
Fort Worth, Texas 76137-0150; telephone (817) 222-5150; 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. 91-CE-12AD.'' 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. 91-CE-12-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA has determined that reliance on critical repetitive 
inspections on aging commuter-class airplanes carries an unnecessary 
safety risk when a design change exists that could eliminate or, in 
certain instances, reduce the number of those critical inspections. In 
determining what inspections are critical, the FAA considers (1) the 
safety consequences of the airplane if the known problem is not 
detected by the inspection; (2) the reliability of the inspection such 
as the probability of not detecting the known problem; (3) whether the 
inspection area is difficult to access; and (4) the possibility of 
damage to an adjacent structure as a result of the problem.
    These factors have led the FAA to establish an aging commuter-class 
aircraft policy that requires incorporating a known design change when 
it could replace a critical repetitive inspection. With this policy in 
mind, the FAA recently conducted a review of existing ADs that apply to 
Fairchild SA227 series airplanes. Assisting the FAA in this review were 
(1) Fairchild Aircraft; (2) the Regional Airlines Association (RAA); 
and (3) several operators of the affected airplanes.
     From this review, the FAA has identified AD 83-12-01, Amendment 
39-4693, as one that should be superseded with a new AD that would 
require a modification that could eliminate the need for short-interval 
and critical repetitive inspections. AD 83-12-01 currently requires 
repetitively inspecting the lower wing skin panel for cracks on certain 
Fairchild Models SA227-AC and SA227-AT airplanes, and installing wing 
skin reinforcement doublers if any wing skin crack is found.
     Fairchild has issued Service Bulletin (SB) No. 227-57-002, Issued: 
June 6, 1983, Revised: January 23, 1984, which specifies procedures for 
accomplishing the following on Models SA227-AC and SA227-AT airplanes: 
dye penetrant inspections of the wing skin panel, and installation of 
wing skin reinforcement doublers and wing skin stringer ties.
     Based on its aging commuter-class aircraft policy and after 
reviewing all available information, the FAA has determined that AD 
action should be taken to eliminate the repetitive short-interval 
inspections required by AD 83-12-01, and to prevent fatigue failure of 
the lower wing skin panels, which could result in loss of control of 
the airplane.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Fairchild Models SA227-AC and SA227-AT 
airplanes of the same type design, the proposed AD would supersede AD 
83-12-01 with a new AD that would (1) retain the requirement of 
repetitively inspecting the lower wing skin panel, and installing wing 
skin reinforcement doublers if any wing skin crack is found; and (2) 
require either installing wing skin reinforcement doublers or wing skin 
stringer ties as terminating action for the repetitive inspections. The 
proposed actions would be accomplished in accordance with Fairchild SB 
No. 227-57-002, Issued: June 6, 1983, Revised: January 23, 1984.
    The FAA estimates that 125 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 9 
workhours per airplane to accomplish the proposed action if 
reinforcement doublers were installed (1 workhour/inspection and 8 
workhours/modification) or 25 workhours per airplane to accomplish the 
proposed action if wing skin stringer ties were installed (1 workhour/
inspection and 24 workhours/modification), and that the average labor 
rate is approximately $55 an hour. Parts cost approximately $56 per 
airplane for the wing skin reinforcement doublers and $179 per airplane 
for the wing skin stringer ties. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be either 
$68,875 for those airplane operators incorporating the reinforcement 
doubler modification or $194,250 for those airplane operators utilizing 
the wing skin stringer ties modification. This cost figure is based on 
the assumption that no affected airplane owner/operator has 
accomplished one of the proposed inspection-terminating modifications. 
The figure does not include repetitive inspection costs. The FAA has no 
way of determining how many repetitive inspections each owner/operator 
may incur.
     The intent of the FAA's aging commuter airplane program is to 
ensure safe operation of commuter-class airplanes that are in 
commercial service without adversely impacting private operators. Of 
the approximately 125 airplanes in the U.S. registry that would be 
affected by the proposed AD, approximately 76 are operated in scheduled 
passenger service. A significant number of the remaining 49 airplanes 
are operated in other forms of air transportation such as air cargo and 
air taxi.
    The proposed AD allows 500 hours time-in-service (TIS) before 
mandatory accomplishment of the design modification. The average 
utilization of the fleet for those airplanes in commercial commuter 
service is approximately 25 to 50 hours TIS per week. Based on these 
figures, operators of commuter-class airplanes involved in commercial 
operation would have to accomplish the proposed modification within 2 
to 5 calendar months after the proposed AD would become effective. For 
private owners, who typically operate between 100 to 200 hours TIS per 
year, this would allow 2 to 5 calendar years before the proposed 
modification would be mandatory.
    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 14 
CFR part 39 of the Federal Aviation Regulations 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 removing AD 83-12-01, Amendment 39-
4693, and adding the following new AD to read as follows:

Fairchild Aircraft: Docket No. 91-CE-12-AD. Supersedes AD 83-12-01, 
Amendment 39-4693.

    Applicability: The following model and serial number airplanes, 
certificated in any category: 

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      Model                             Serial No.                      
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SA227-AC........  415, 416, and 420 through 554.                        
SA227-AT........  423 through 554.                                      
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    Compliance: Required as indicated, unless already accomplished.
    To prevent fatigue failure of the lower wing skin panels, which 
could result in loss of control of the airplane, accomplish the 
following:
    (a) Within the next 50 hours time-in-service (TIS) after the 
effective date of this AD, unless already accomplished (compliance 
with AD 83-12-01), dye penetrant inspect the lower wing skin panel 
in the area of Fuselage Station (FS) 187.0 in accordance with 
paragraph IIA of the ACCOMPLISHMENT INSTRUCTIONS section of 
Fairchild Service Bulletin (SB) 227-57-002, Issued: June 6, 1983, 
Revised: January 23, 1984.
    (1) If cracks are found, prior to further flight, install 
reinforcement doublers, part number 27K31013-001 LH and 27K31013-002 
RH, in accordance with paragraph IIB of the ACCOMPLISHMENT 
INSTRUCTIONS section of Fairchild SB 227-57-002, Issued: June 6, 
1983, Revised: January 23, 1984.
    (2) If no cracks are found, reinspect thereafter at intervals 
not to exceed 50 hours TIS until the modification specified in 
paragraph (b) of this AD is accomplished.
    (b) Within the next 500 hours TIS after the effective date of 
this AD, unless already accomplished as specified in either 
paragraph (a)(1) of this AD, accomplish one of the following:
    (1) Install reinforcement doublers, part number 27K31013-001 LH 
and 27K31013-002 RH, in accordance with paragraph IIB of the 
ACCOMPLISHMENT INSTRUCTIONS section of Fairchild SB 227-57-002, 
Issued: June 6, 1983, Revised: January 23, 1984; or
    (2) Install stringer ties, P/N 27-13869, in accordance with 
paragraph IIC of the ACCOMPLISHMENT INSTRUCTIONS section of 
Fairchild SB 227-57-002, Issued: June 6, 1983, Revised: January 23, 
1984.
    (c) Incorporating the modification specified in paragraphs 
(a)(1) and (b)(1) or (b)(2) of this AD terminates the repetitive 
inspection requirement of this AD.
    (d) Special flight permits may be issued in accordance with 14 
CFR 21.197 and 21.199 to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (e) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Airplane 
Certification Office (ACO), 2601 Meacham Boulevard, Fort Worth, 
Texas 76137-0150. 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: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Fort Worth ACO.

    (f) 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.
    (g) This amendment supersedes AD 83-12-01, Amendment 39-4693.

    Issued in Kansas City, Missouri, on March 24, 1994.
Bobby W. Sexton,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-7497 Filed 3-29-94; 8:45 am]
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