[Federal Register Volume 63, Number 147 (Friday, July 31, 1998)]
[Proposed Rules]
[Pages 40846-40849]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20440]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-65-AD]
RIN 2120-AA64


Airworthiness Directives; Fairchild Aircraft, Inc. 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, Inc. (Fairchild) 
SA226 and SA227 series airplanes. The proposed AD would require 
repetitively inspecting the wing spar center web cutout on both wings 
for cracks between Wing Station (WS) 8 and WS 17.5, and immediately 
repairing any area found cracked. This repair would eliminate the need 
for the repetitive inspections on that particular wing spar. The 
proposed AD is the result of reports of cracks in the wing spar center 
web cutout caused by fatigue due to airplane maneuvering and wind 
gusts. The

[[Page 40847]]

actions specified by the proposed AD are intended to detect and correct 
fatigue cracking of the wing spar center web cutout area, which could 
result in structural failure of the wing spar to the point of failure 
with consequent loss of control of the airplane.

DATES: Comments must be received on or before September 30, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 98-CE-65-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 Field Support Engineering, Fairchild Aircraft, Inc., P.O. Box 
790490, San Antonio, Texas 78279-0490; telephone: (210) 824-9421; 
facsimile: (210) 820-8609. This information also may be examined at the 
Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Hung Viet Nguyen, FAA, Airplane 
Certification Office, 2601 Meacham Boulevard, Fort Worth, Texas 76193-
0150; telephone: (817) 222-5155; facsimile: (817) 222-5960.

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. 98-CE-65-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 Regional Counsel, Attention: 
Rules Docket No. 98-CE-65-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    The FAA has received several reports of cracks in the center web of 
the wing main spar on Fairchild SA226 and SA227 series airplanes. In a 
recent occurrence, cracks were found during a regular maintenance 
inspection in the area between Wing Station (WS) 8 and WS 17.5. The 
cracks initiated from the corners of the String #13 cutout with one 
crack running towards the upper spar cap, and another heading in the 
opposite direction.
    Analysis of the areas that are cracking on the referenced airplanes 
indicates that gust loads and normal airplane maneuvering are the cause 
of the cracks.
    This condition, if not detected and corrected in a timely manner, 
could result in structural failure of the wing spar to the point of 
failure with consequent loss of control of the airplane.

Relevant Service Information

    Fairchild Aircraft has issued the following documents:
--Airframe Airworthiness Limitations Manual ST-UN-M001, Rev. No. C-6, 
dated April 7, 1998, which specifies, among other things, procedures 
for inspecting the wing spar center web cutout for cracks between WS 8 
and WS 17.5 in the area of Stringer 13 on Models SA227-TT, SA227-AT, 
SAA227-AC, and SA227-BC airplanes;
--Airframe Inspection Manual ST-UN-M002, Rev. No. A-6, dated December 
8, 1997, which specifies, among other things, procedures for inspecting 
the wing spar center web cutout for cracks between WS 8 and WS 17.5 in 
the area of Stringer 13 on Models SA226-T, SA226-T(B), SA226-AT, and 
SA226-TC airplanes;
--Airframe Airworthiness Limitations Manual ST-UN-M003, Rev. No. 5, 
dated April 7, 1998, which specifies, among other things, procedures 
for inspecting the wing spar center web cutout for cracks between WS 8 
and WS 17.5 in the area of Stringer 13 on Models SA227-CC and SA227-DC 
airplanes;
--SA226/227 Series Structural Repair Manual, part number (P/N) 27-
10054-079, pages 57 through 90; Initial Issue: March 1, 1983; Revision 
28, dated June 24, 1998. This document specifies procedures for 
repairing cracks at the wing spar center web cutout between WS 8 and WS 
17.5 in the area of Stringer 13 on Models SA226-T, SA226-T(B), SA226-
AT, SA226-TC, SA227-TT, SA227-AT, SA227-AC, and SA227-BC airplanes; and
--SA227 Series Structural Repair Manual, P/N 27-10054-127, pages 47 
through 60; Initial Issue: December 1, 1991; Revision 7, dated June 24, 
1998. This document specifies procedures for repairing cracks at the 
wing spar center web cutout between WS 8 and WS 17.5 in the area of 
Stringer 13 on Models SA227-CC and SA227-DC airplanes.

The FAA's Determination

    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 detect and correct fatigue 
cracking of the wing spar center web cutout area. A cracked wing spar 
center web cutout area could result in structural failure of the wing 
spar to the point of failure with consequent loss of control of the 
airplane.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Fairchild SA226 and SA227 series airplanes of 
the same type design, the FAA is proposing AD action. The proposed AD 
would require repetitively inspecting the wing spar center web cutout 
on both wings for cracks between WS 8 and WS 17.5, and immediately 
repairing any area found cracked. This repair would eliminate the need 
for the repetitive inspections on that particular wing spar. 
Accomplishment of the proposed actions would be required in accordance 
with the service information previously referenced.

Cost Impact

    The FAA estimates that 490 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 5 
workhours per airplane to accomplish the proposed initial inspection, 
and that the average labor rate is approximately $60 an hour. Based on 
these figures, the total cost impact of the initial inspection 
specified

[[Page 40848]]

in the proposed AD on U.S. operators is estimated to be $147,000, or 
$300 per airplane.
    These figures only take into account the costs of the proposed 
initial inspection and do not take into account the costs of repetitive 
inspections and the costs associated with any repair that would be 
necessary if corrosion or delamination damage is found. The FAA has no 
way of determining the number of repetitive inspections an owner/
operator will incur over the life of the airplane, or the number of 
airplanes that will need repairs.
    If an affected airplane would have cracks in both wing spar center 
webs, the repair would take 400 workhours to accomplish at an average 
labor rate of $60 per hour. Parts to accomplish this repair cost 
approximately $400 per airplane. Based on these figures, the cost to 
repair cracked wing spar center webs on both sides of the airplane 
would be approximately $24,400 per airplane.

Regulatory Impact

    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. 106(g), 40113, 44701.

Sec. 39.13  [Amended]

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

Fairchild Aircraft, Inc.: Docket No. 98-CE-65-AD.
    Applicability: The following model airplanes and serial numbers, 
certificated in any category:

------------------------------------------------------------------------
                 Model                             Serial No.           
------------------------------------------------------------------------
SA226-AT..............................  AT001 through AT074.            
SA226-TC..............................  TC201 through TC419.            
SA226-T...............................  T201 through T291.              
SA226-T(B)............................  T(B)276 and T(B)292 through     
                                         T(B)417.                       
SA227-TT..............................  TT421 through TT541.            
SA227-TT(300).........................  TT(300)447, TT(300)465,         
                                         TT(300)471, TT(300)483,        
                                         TT(300)512, TT(300)518,        
                                         TT(300)521, TT(300)527,        
                                         TT(300)529, and TT(300)536.    
SA227-AC..............................   AC406, AC415, AC416, and AC420 
                                         through AC785.                 
SA227-AT..............................  AT423 through AT631 and AT695.  
SA227-BC..............................  BC762, BC764, BC766, and BC770  
                                         through BC789.                 
SA227-CC/DC...........................  CC/DC784 and CC/DC790 through CC/
                                         DC878.                         
------------------------------------------------------------------------

    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 request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated in the body of this AD, unless 
already accomplished.
    To detect and correct fatigue cracking of the wing spar center 
web cutout area, which could result in structural failure of the 
wing spar to the point of failure with consequent loss of control of 
the airplane, accomplish the following:
    (a) Upon accumulating 6,500 hours time-in-service (TIS) on each 
wing spar or within the next 500 hours TIS after the effective date 
of this AD, whichever occurs later, unless already accomplished, and 
thereafter at intervals not to exceed 2,000 hours TIS, inspect each 
wing spar center web cutout for cracks between Wing Station (WS) 8 
and WS 17.5. Accomplish this inspection in accordance with one of 
the following, as applicable:
    (1) For Models SA227-TT, SA227-AT, SAA227-AC, and SA227-BC 
airplanes: In accordance with Fairchild Airframe Airworthiness 
Limitations Manual ST-UN-M001, Rev. No. C-6, dated April 7, 1998;
    (2) For Models SA226-T, SA226-T(B), SA226-AT, and SA226-TC 
airplanes: In accordance with Fairchild Airframe Inspection Manual 
ST-UN-M002, Rev. No. A-6, dated December 8, 1997; or
    (3) For Models SA227-CC and SA227-DC airplanes: In accordance 
with Fairchild Airframe Airworthiness Limitations Manual ST-UN-M003, 
Rev. No. 5, dated April 7, 1998.
    (b) If any crack(s) is/are found during any inspection required 
by paragraph (a) of this AD, prior to further flight, repair the 
crack(s) in accordance with one of the following, as applicable. 
This repair eliminates the repetitive inspections (2,000 hours TIS 
intervals) required in paragraph (a) of this AD for that particular 
wing spar.
    (1) For Models SA226-T, SA226-T(B), SA226-AT, SA226-TC, SA227-
TT, SA227-AT, SA227-AC, and SA227-BC airplanes: In accordance with 
Fairchild SA226/227 Series Structural Repair Manual, part number (P/
N) 27-10054-079, pages 57 through 90; Initial Issue: March 1, 1983; 
Revision 28, dated June 24, 1998; or
    (2) For Models SA227-CC and SA227-DC airplanes: In accordance 
with Fairchild SA227 Series Structural Repair Manual, P/N 27-10054-
127, pages 47 through 60; Initial Issue: December 1, 1991; Revision 
7, dated June 24, 1998.
    (c) The repetitive inspections required by paragraph (a) of this 
AD may be terminated if the wing spar center web repair specified in 
paragraph (b) of this AD has been accomplished on both the left and 
right wing spar. If one wing spar center web has been repaired, then 
repetitive inspections are still required on the other one if the 
repair has not been incorporated.
    (d) 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.
    (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, FAA, Airplane 
Certification Office (ACO), 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, Forth 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.


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

    Issued in Kansas City, Missouri, on July 23, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-20440 Filed 7-30-98; 8:45 am]
BILLING CODE 4910-13-U