[Federal Register Volume 59, Number 63 (Friday, April 1, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-7616]


[[Page Unknown]]

[Federal Register: April 1, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-CE-21-AD; Amendment 39-8868; AD 94-07-10]

 

Airworthiness Directives: Fairchild Aircraft SA226 and SA227 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to certain Fairchild Aircraft SA226 and SA227 series airplanes. 
This action requires repetitively inspecting (visually) the wing skin 
for cracks; dye penetrant inspecting the spar straps if the wing skin 
is found cracked; and, if any crack is found in the spar straps, 
repairing the spar straps and modifying the wing skin. This action also 
provides the option of modifying the wing skin as terminating action 
for the repetitive inspections. Reports of wing skin cracking because 
of repeated bending of the wing during service on several of the 
affected airplanes prompted this action. The actions specified by this 
AD are intended to prevent failure of the wing skin at the top aft 
outboard corner of the battery box, which could result in structural 
damage to the wing.

DATES: Effective May 27, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 27, 1994.

ADDRESSES: Service information that applies to this AD may be obtained 
from Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279-
0490; telephone (512) 824-9421. This information may also be examined 
at the Federal Aviation Administration (FAA), Central Region, Office of 
the Assistant Chief Counsel, room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an AD that would apply to certain 
Fairchild Aircraft SA226 and SA227 series airplanes was published in 
the Federal Register on October 4, 1993 (58 FR 51583). The action 
proposed to require repetitively inspecting (visually) the wing skin 
for cracks; dye penetrant inspecting the spar straps if the wing skin 
is found cracked; and, if any crack is found in the spar straps, 
repairing the spar straps and modifying the wing skin. This action also 
proposed providing the option of modifying the wing skin as terminating 
action for the repetitive inspections. The proposal would require 
accomplishing the actions in accordance with the following service 
bulletins (SB), as applicable:
     Fairchild SB 226-57-018, Issued: January 28, 1993, 
Revised: June 3, 1993 (pages 2 through 11 and 13 through 15), and 
Revised: July 1, 1993 (pages 1 and 12);
     Fairchild SB 227-57-005, Issued: December 21, 1992, 
Revised: June 3, 1993 (pages 2 through 11 and 13 through 15), and 
Revised: July 1, 1993 (pages 1 and 12); or
     Fairchild Aircraft SB CC7-57-002, Issued: January 28, 
1993, Revised: June 3, 1993 (pages 2 through 11 and 13 through 15), and 
Revised: July 1, 1993 (pages 1 and 12).
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the three comments received.
    One commenter, Ameriflight, states that the liquid penetrant 
inspection required on the part number (P/N) 2731130 straps when there 
is a crack in the wing skin is unjustified. Ameriflight conducted a 
survey of a number of SA226 and SA227 series airplane owners (a total 
of 101 airplanes). From this survey, Ameriflight found that 57 
airplanes had at least one wing with a skin crack evident. None of 
these 57 have any cracks in the strap, with many of the airplanes 
having in excess of 20,000 hours time-in-service (TIS), and no incident 
of cracking in these straps has ever occurred according to information 
provided by the Fort Worth Airplane Certification Office. Ameriflight 
believes that the FAA has not conclusively demonstrated the unsafe 
condition--the cracking of the straps; and, even if there is 
justification, the 50-hour TIS repetitive inspection interval is too 
stringent. The FAA does not concur that the strap inspection is 
unjustified. Based on FAA and Fairchild analysis, loads are shifted to 
other structures such as the straps when the upper wing skin cracks. 
Even though the strap carries more load, a crack will not necessarily 
immediately develop, but may initiate and then propagate slowly 
(fatigue) because of the additional load in this structural area. For 
these reasons, the FAA has determined that the strap inspection is 
needed, but at intervals of 150 hours TIS instead of 50 hours TIS. The 
proposal has been changed accordingly.
    Another commenter, Fairchild Aircraft, recommends the following 
changes to the proposal:
     Change the report of ``repeated bending of the wing during 
service'' that is contained in the preamble to ``reports of wing skin 
cracking because of repeated bending of the wing during service''. The 
FAA concurs, and has changed the proposal accordingly;
     Change the reference of the inspection area for cracks in 
the proposal from ``the lower edge of the nacelle and battery box'' to 
``the top aft outboard corner of the battery box''. The FAA concurs and 
has revised paragraphs (a) and (b)(1) of the proposal accordingly;
     Incorporate Fairchild SB 226-57-018, Issued: January 28, 
1993, Revised: October 25, 1993 (pages 1 through 3) into the proposal. 
The FAA concurs and has revised the AD accordingly. This service 
information revision only includes editorial corrections and does not 
impose any additional burden of U.S. operators of the affected 
airplanes; and
     Include additional Approved Repair Procedure (ARP) and 
Limited Approved Repair (LAR) documents and make provisions for the 
inclusion of future LAR's and ARP's that may be issued. The FAA concurs 
and has revised NOTE 2 of the proposal as follows: ``Certain Limited 
Approve Repair (LAR) and Approved Repair Procedure (ARP) documents 
issued by Fairchild Aircraft specify procedures for accomplishing the 
same modification referenced in paragraphs (b)(2), (c)(1)(ii), and 
(c)(2)(ii). Check with the Fort Worth Airplane Certification Office at 
the address presented in paragraph (e) of this AD to find out which 
LAR's and ARP's are considered ``unless already accomplished'' as they 
relate to this AD.''
    A third commenter states that the FAA incorrectly estimates the 
cost impact that the proposed AD would have on U.S. operators of the 
affected airplanes. This commenter explains that the FAA's cost 
analysis figure of $42,680 for the entire fleet does not take into 
account (1) the cost of repetitive inspections; (2) the cost of dye 
penetrant inspections when the wing skin is found cracked; nor (3) the 
cost of incorporating the inspection-terminating modification. The FAA 
concurs that this figure is based only on a one-time visual inspection 
of the wing skin, as was explained in the cost analysis section of the 
proposal. The FAA has no way of determining how many airplanes would 
have cracked wing skins, or how many repetitive inspections each 
affected airplane would incur. The cost of the modification is 
extremely labor intensive (100 workhours), a reason why the FAA 
determined to make it optional until a crack is found in the spar 
straps. The proposal is unchanged as a result of this comment.
    This same commenter states that the modification referenced in the 
service bulletins is ``extreme overkill'' because the amount and 
locations of rivets that require removal creates a potential for 
additional damage and weakening of the area. The FAA does not concur. 
Fairchild Aircraft and many operators have already accomplished this 
modification and the FAA has received no reports of weakening or damage 
occurring in the affected area. The proposed AD is unchanged as a 
result of this comment.
    After careful review of all available information including the 
comments referenced above, the FAA has determined that air safety and 
the public interest require the adoption of the rule as proposed except 
for the wording changes described above, the incorporation of the 
revised service information, and minor editorial corrections. The FAA 
has determined that these minor changes and corrections will not change 
the meaning of the AD nor add any additional burden upon the public 
than was already proposed.
    The FAA estimates that 776 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 1 workhour per 
airplane to accomplish the required visual inspection of the wing skin 
on both wings, and that the average labor rate is approximately $55 an 
hour. Based on these figures, the total cost impact of the AD on U.S. 
operators is estimated to be $42,680. This figure does not include the 
cost of any dye penetrant inspections of the spar strap that could be 
required if the wing skin is found cracked, nor does it include the 
cost of the wing skin modification or the repetitive inspections. The 
optional modification would terminate the need for the repetitive 
inspection requirement. The figure above is based upon the assumption 
that no affected airplane owner/operator has accomplished this 
inspection-terminating modification.
    The regulations adopted herein will 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 final 
rule does 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) 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 final evaluation prepared for this 
action is contained 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding the following new AD to read 
as follows:

94-07-10  Fairchild Aircraft: Amendment 39-8868; Docket No. 93-CE-
21-AD.

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

------------------------------------------------------------------------
        Model                              Serial Nos.                  
------------------------------------------------------------------------
SA226-T                 T201 through T275, and T277 through T291.       
SA226-T(B)              T(B)276, and T(B)292 through T(B)417.           
SA226-AT                AT001 through AT074.                            
SA226-TC                TC201 through TC419.                            
SA227-TT                TT421 through TT541.                            
SA227-AT                AT423 through AT631, and AT695.                 
SA227-AC                AC406, AC415, AC416, and AC420 through AC789.   
SA227-BC                BC420 through BC789.                            
SA227-CC                CC784, and CC790 through CC822.                 
SA227-DC                DC784, and DC790 through DC822.                 
------------------------------------------------------------------------

    Compliance: Required initially upon the accumulation of 2,500 
hours time-in-service (TIS) or within the next 100 hours TIS after 
the effective date of this AD, whichever occurs later, unless 
already accomplished, and thereafter as indicated in the body of the 
AD.
    To prevent failure of the wing skin at the top aft outboard 
corner of the battery box, which could result in structural damage 
to the wing, accomplish the following:

    Note 1: The paragraph structure of this AD is as follows:
    Level 1: (a), (b), (c), etc.
    Level 2: (1), (2), (3), etc.
    Level 3: (i), (ii), (iii), etc.
Level 2 and Level 3 structures are designations of the Level 1 
paragraph they immediately follow.

    (a) Visually inspect the right and left upper skin by the top 
aft outboard corner of the battery box for cracks in accordance with 
Figure 1 and the Accomplishment Instructions, A. Inspection, section 
of whichever of the following is applicable: (1) Fairchild Service 
Bulletin (SB) 226-57-018, Issued: January 28, 1993, Revised: June 3, 
1993 (pages 4 through 11 and 13 through 15), Revised: July 1, 1993 
(page 12) and Revised: October 25, 1993 (pages 1 through 3);
    (2) Fairchild SB 227-57-005, Issued: December 21, 1992, Revised: 
June 3, 1993 (pages 2 through 11 and 13 through 15), and Revised: 
July 1, 1993 (pages 1 and 12); or
    (3) Fairchild Aircraft SB CC7-57-002, Issued: January 28, 1993, 
Revised: June 3, 1993 (pages 2 through 11 and 13 through 15), and 
Revised: July 1, 1993 (pages 1 and 12).
    (b) If cracks are not found during the visual inspection 
required by paragraph (a) of this AD, within 500 hours TIS after 
this initial visual inspection, accomplish one of the following: (1) 
Reinspect the right and left upper wing skin by the top aft outboard 
corner of the battery box for cracks in accordance with Figure 1 and 
the Accomplishment Instructions, A. Inspection, section of the 
applicable service information presented in paragraphs (a)(1), 
(a)(2), and (a)(3) of this AD, and reinspect thereafter at intervals 
not to exceed 500 hours TIS; or
    (2) Modify the upper wing skin in accordance with the 
Accomplishment Instructions, B. Removal and C. Installation, section 
of the service information referenced in paragraphs (a)(1), (a)(2), 
or (a)(3) of this AD, as applicable. Accomplishing this modification 
terminates the repetitive visual inspections that are specified in 
paragraph (b)(1) of this AD, and the modification may be 
accomplished at any time to eliminate this repetitive inspection 
requirement.
    (c) If cracks are found during the inspection required by 
paragraph (a) of this AD, prior to further flight, dye penetrant 
inspect the 27-31130 straps in accordance with the Accomplishment 
Instructions, B. Removal section, paragraph (7), of the service 
information referenced in paragraphs (a)(1), (a)(2), or (a)(3) of 
this AD, as applicable.
    (1) If cracks are found in either of the 27-31130 straps during 
the inspection required by paragraph (c) of this AD, prior to 
further flight, accomplish the following: (i) Repair the 27-31130 
strap in accordance with a scheme obtained from the manufacturer 
through the Fort Worth Airplane Certification Office at the address 
specified in paragraph (d) of this AD; and
    (ii) Modify the upper wing skin in accordance with the 
Accomplishment Instructions, B. Removal and C. Installation, section 
of the service information referenced in paragraphs (a)(1), (a)(2), 
or (a)(3) of this AD, as applicable.
    (2) If no cracks are found in either of the 27-31130 straps, 
within 150 hours TIS after the initial dye penetrant inspection 
required by paragraph (c) of this AD, accomplish one of the 
following
    (i) Reinspect (dye penetrant) the edges of the spar straps (27-
31130) in the wheel wells for cracks in accordance with the 
Accomplishment Instructions, B. Removal, section of the service 
information referenced in paragraphs (a)(1), (a)(2), or (a)(3) of 
this AD, as applicable, and if no cracks are found, continue to 
reinspect at intervals not to exceed 150 hours TIS; or
    (ii) Modify the upper wing skin in accordance with the 
Accomplishment Instructions, B. Removal and C. Installation, section 
of the service information referenced in paragraphs (a)(1), (a)(2), 
or (a)(3) of this AD, as applicable. Accomplishing this modification 
terminates the repetitive dye penetrant inspections that are 
specified in paragraph (c)(2)(i) of this AD, and the modification 
may be accomplished at any time to eliminate this repetitive 
inspection requirement.

    Note 2: Certain Limited Approve Repair (LAR) and Approved Repair 
Procedure (ARP) documents issued by Fairchild Aircraft specify 
procedures for accomplishing the same modification referenced in 
paragraphs (b)(2), (c)(1)(ii), and (c)(2)(ii). Check with the Fort 
Worth Airplane Certification Office at the address presented in 
paragraph (e) of this AD to find out which LAR's and ARP's are 
considered ``unless already accomplished'' as they relate to 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, FAA, 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 Airplane Certification Office.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Fort Worth Airplane Certification Office.

    (f) The inspections and modification required by this AD shall 
be done in accordance with Fairchild Service Bulletin 226-57-018, 
Issued: January 28, 1993, Revised: June 3, 1993 (pages 4 through 11 
and 13 through 15), Revised: July 1, 1993 (page 12), and Revised: 
October 25, 1993 (pages 1 through 3); Fairchild Service Bulletin 
227-57-005, Issued: December 21, 1992, Revised: June 3, 1993 (pages 
2 through 11 and 13 through 15), and Revised: July 1, 1993 (pages 1 
and 12); or Fairchild Aircraft Service Bulletin CC7-57-002, Issued: 
January 28, 1993, Revised: June 3, 1993 (pages 2 through 11 and 13 
through 15), and Revised: July 1, 1993 (pages 1 and 12). This 
incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 
51. Copies may be obtained from Fairchild Aircraft, P.O. Box 790490, 
San Antonio, Texas 78279-0490. Copies may be inspected at the FAA, 
Central Region, Office of the Assistant Chief Counsel, room 1558, 
601 E. 12th Street, Kansas City, Missouri, or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (g) This amendment (39-8868) becomes effective on May 27, 1994.

    Issued in Kansas City, Missouri, on March 24, 1994.
Bobby W. Sexton,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. 94-7616 Filed 3-31-94; 8:45 am]
BILLING CODE 4910-13-U