99-684. Airworthiness Directives; Ayres Corporation S2R Series and Model 600 S2D Airplanes  

  • [Federal Register Volume 64, Number 8 (Wednesday, January 13, 1999)]
    [Proposed Rules]
    [Pages 2157-2161]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 99-684]
    
    
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    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 39
    
    [Docket No. 98-CE-56-AD]
    RIN 2120-AA64
    
    
    Airworthiness Directives; Ayres Corporation S2R Series and Model 
    600 S2D Airplanes
    
    AGENCY: Federal Aviation Administration, DOT.
    
    ACTION: Notice of proposed rulemaking (NPRM).
    
    -----------------------------------------------------------------------
    
    SUMMARY: This document proposes to supersede Airworthiness Directive 
    (AD) 97-17-03, which currently requires inspecting the \1/4\-inch and 
    \5/16\-inch bolt hole areas on the lower spar caps for fatigue cracking 
    on Ayres S2R series and Model 600 S2D airplanes, and replacing any 
    lower spar cap where fatigue cracking is found. That AD resulted from 
    an accident on an Ayres S2R series airplane where the wing separated 
    from the airplane in flight. The proposed AD would retain the initial 
    inspection and possible replacement requirements of AD 97-17-03, would 
    require the inspections to be repetitive, would add certain Ayres 
    airplanes to the Applicability of the AD, would change the initial 
    compliance time for all airplanes, and would arrange the affected 
    airplanes into four groups instead of three based on usage and 
    configurations. The actions specified by the proposed AD are intended 
    to detect fatigue cracking of the lower spar caps, which could result 
    in the wing separating from the airplane with consequent loss of 
    control of the airplane.
    
    DATES: Comments must be received on or before March 15, 1999.
    
    ADDRESSES: Submit comments in triplicate to the Federal Aviation 
    Administration (FAA), Central Region, Office of the Regional Counsel, 
    Attention: Rules Docket No. 98-CE-56-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 the Ayres Corporation, P.O. Box 3090, One Rockwell Avenue, Albany, 
    Georgia 31706-3090. This information also may be examined at the Rules 
    Docket at the address above.
    
    FOR FURTHER INFORMATION CONTACT: Satish Lall, Aerospace Engineer, FAA, 
    Atlanta Aircraft Certification Office,
    
    [[Page 2158]]
    
    One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 
    30349; telephone: (770) 703-6082; facsimile: (770) 703-6097.
    
    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-56-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-56-AD, Room 1558, 601 E. 12th Street, Kansas 
    City, Missouri 64106.
    
    Discussion
    
        AD 97-17-03, Amendment 39-10105 (62 FR 43926, August 18, 1997), 
    currently requires the following on Ayres S2R series and Model 600 S2D 
    airplanes:
    
    --Inspecting the \1/4\-inch and \5/16\-inch bolt hole areas on the 
    lower spar caps for fatigue cracking; and
    --Replacing any lower spar cap where fatigue cracking is found.
    
        AD 97-17-03 superseded AD 97-13-11 (62 FR 36978, July 10, 1997), 
    which required the same actions but contained an incorrect designation 
    of the Model S2R-R1340 airplanes.
        Accomplishment of the inspection is required in accordance with 
    Ayres Service Bulletin No. SB-AG-39, dated September 17, 1996. This 
    inspection utilizes magnetic particle procedures and must follow 
    American Society for Testing Materials (ASTM) E1444-94A, using wet 
    particles meeting the requirements of the Society for Automotive 
    Engineers (SAE) AMS 3046. This inspection is to be accomplished by a 
    Level 2 or Level 3 inspector certified using the guidelines established 
    by the American Society for Nondestructive Testing or MIL-STD-410.
        Accomplishment of the replacement, if necessary, is required in 
    accordance with the applicable maintenance manual.
        That AD resulted from an accident on an Ayres S2R series airplane 
    where the wing separated from the airplane in flight. Investigation of 
    all resources available to the FAA at the time of the accident showed 
    nine occurrences of fatigue cracking in the lower spar caps of Ayres 
    S2R airplanes, specifically emanating from the \1/4\-inch and \5/16\-
    inch bolt holes. Investigation of the above-referenced accident 
    revealed that the cause can be attributed to fatigue cracks emanating 
    from the \1/4\-inch and \5/16\-inch bolt holes in the left lower spar 
    cap. Because the Ayres Model 600 S2D airplanes have a similar type 
    design to that of the S2R series airplanes, they were included in the 
    Applicability of AD 97-17-03.
        Data accumulated by the FAA indicates that the fatigue cracks on 
    these Ayres S2R series airplanes become detectable at different times 
    based upon the type of engines and design of the airplane. With this in 
    mind, the FAA categorized these airplanes into three groups for the 
    Applicability of AD 97-17-03:
    
    --Group 1 airplanes have steel spar caps with aluminum webs. These 
    airplanes are capable of carrying heavier loads and data indicated that 
    the inspections in the affected areas of the lower spar caps required 
    by AD 97-17-03 should begin upon the accumulation of 2,700 hours time-
    in-service (TIS);
    --Group 2 airplanes have steel spar caps with steel webs. Because of 
    the steel webs as opposed to aluminum, data indicated that the 
    inspections in the affected areas of the lower spar caps required by AD 
    97-17-03 should begin upon the accumulation of 4,300 hours TIS; and
    --Group 3 airplanes, which are the ones manufactured first, have steel 
    spars with aluminum webs and low horsepower radial engines, and thus do 
    not have the ability to carry as much weight as airplanes in the other 
    two groups. Data indicated that the inspections in the affected areas 
    of the lower spar caps required by AD 97-17-03 should begin upon the 
    accumulation of 9,000 hours TIS.
    
        Manufacture of the affected airplanes began in 1965 with the 
    airplanes incorporating the lower horsepower radial engines. Many of 
    the airplane models referenced in AD 97-17-03 are still currently in 
    production. These airplanes are used in agricultural operations and 
    average 500 hours TIS annually. With this in mind, some of the earlier 
    manufactured airplanes could have as many as 16,000 hours total TIS.
    
    Actions Since Issuance of Previous Rule
    
        Since the issuance of both AD 97-13-11 and AD 97-17-03, the FAA has 
    received data specifying 29 additional occurrences of fatigue cracks 
    found in the lower spar caps of Ayres S2R and Model 600 S2D airplanes. 
    The data from these occurrences indicate the following:
    
    --Several of these occurrences involved airplanes that had not 
    accumulated enough hours to require the initial inspection of AD 97-17-
    03;
    --Detectable cracks could still develop after the initial inspection on 
    the affected airplanes; and
    --The following airplanes were recently manufactured and have a similar 
    type design to that of the airplanes affected by AD 97-17-03:
    
    ------------------------------------------------------------------------
                   Model                            Serial numbers
    ------------------------------------------------------------------------
    S2R-T34............................  T34-227 through T34-232, T34-234,
                                          and T34-236.
    S2R-G6.............................  G6-147.
    S2R-G10............................  G10-139, G10-140, and G10-141
    ------------------------------------------------------------------------
    
    Relevant Service Information
    
        The Ayres Corporation has issued Service Bulletin No. SB-AG-39, 
    Rev. 1, dated December 12, 1997, which adds the above-referenced 
    airplanes, specifies that the inspection be repetitive, and references 
    different compliance times for the repetitive inspections depending on 
    whether the method used is magnetic particle, ultrasonic, or eddy 
    current. Procedures for the inspection are contained in Ayres Service 
    Bulletin No. SB-AG-39, dated September 17, 1996. Ayres Custom Kit No. 
    CK-AG-29, dated December 23, 1997, includes procedures for reworking 
    the spar cap if a small crack is found in the \1/4\-inch spar cap hole; 
    and includes procedures for replacing the butterfly center splice
    
    [[Page 2159]]
    
    plate, part number 20211-3, from the aft surface of the wing spar join 
    area.
    
    The FAA's Determination
    
        After examining the circumstances and reviewing all available 
    information related to the incidents described above, the FAA has 
    determined that:
    
    --The above-referenced airplanes should be added to the Applicability 
    of AD 97-17-03;
    --The inspections should be repetitive;
    --The initial compliance time should be changed for all airplanes;
    --The affected airplanes should be arranged into four groups instead of 
    three based on usage and configurations; and
    --AD action should be taken to continue to detect fatigue cracking of 
    the lower spar caps, which could result in the wing separating from the 
    airplane 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 Ayres 600 S2D and S2R airplanes of the same 
    type design, the FAA is proposing AD action to supersede AD 97-17-03. 
    The proposed AD would retain the inspection and replacement (if 
    necessary) of the lower spar caps that are currently required in AD 97-
    17-03; and would make these inspections repetitive, would add 
    additional airplanes to the Applicability of the AD, would change the 
    initial compliance time for all airplanes, and would arrange the 
    affected airplanes into four groups instead of three based on usage and 
    configurations.
        Accomplishment of the actions specified in this NPRM would be 
    required in accordance with the service information previously 
    referenced, as applicable.
    
    Cost Impact
    
        The FAA estimates that 1,000 airplanes in the U.S. registry would 
    be affected by the proposed AD, that it would take approximately 3 
    workhours per airplane to accomplish the proposed initial inspection, 
    and that the average labor rate is approximately $60 an hour. Parts to 
    accomplish the proposed initial inspection cost approximately $417 per 
    airplane. Based on these figures, the total cost impact of the proposed 
    AD on U.S. operators is estimated to be $597,000, or $597 per airplane. 
    This figure only takes into account the cost of the proposed initial 
    inspection and does not take into account the cost of proposed 
    repetitive inspections. The FAA has no way of determining how many 
    repetitive inspections each owner/operator of the affected airplanes 
    would incur.
        In addition, these figures are based upon the presumption that no 
    affected airplane operator has accomplished the proposed inspection, 
    and does not take into account the cost for replacement if a crack is 
    found. The FAA has no way of determining the number of wing spar caps 
    that may need to be replaced based upon the results of the proposed 
    inspections.
    
    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 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. 106(g), 40113, 44701.
    
    
    Sec. 39.13  [Amended]
    
        2. Section 39.13 is amended by removing Airworthiness Directive 
    (AD) 97-17-03, Amendment 39-10105 (62 FR 43926, August 18, 1997), and 
    by adding a new AD to read as follows:
    
    Ayres Corporation: Docket No. 98-CE-56-AD; Supersedes AD 97-17-03, 
    Amendment 39-10105.
    
        Applicability: Airplanes with the following model and serial 
    number designations with or without a -DC or -X suffix, certificated 
    in any category:
    
                                Group 1 Airplanes
    ------------------------------------------------------------------------
                   Model                            Serial numbers
    ------------------------------------------------------------------------
    S-2R...............................  5000R through 5099R, except 5010R,
                                          5031R, 5038R, 5047R, and 5085R.
    S2R-R1340..........................  R1340-011, R1340-012, R1340-019,
                                          R1340-020, R1340-024, R1340-025,
                                          and R1340-027.
    S2R-R1820..........................   R1820-001 through 1820-035.
    S2R-T34............................  6000R through 6049R, T34-001
                                          through T34-143, T34-145, T34-147
                                          through T34-167, T34-171, T34-180,
                                          and T34-181*.
    S2R-T15............................  T15-001 through T15-033**.
    S2R-T11............................  T11-001 through T11-005.
    S2R-G1.............................  G1-101 through G1-106.
    ------------------------------------------------------------------------
    *The serial numbers of the Model S2R-T34 airplanes could incorporate T34-
      xxx, T36-xxx, T41-xxx, or T42-xxx. This AD applies to all of these
      serial number designations as they are all Model S2R-T34 airplanes.
    **The serial numbers of the Model S2R-T15 airplanes could incorporate
      T15-xx and T27-xx. This AD applies to both of these serial number
      designations as they are both Model S2R-T15 airplanes.
    
    
                                Group 2 Airplanes
    ------------------------------------------------------------------------
                   Model                            Serial numbers
    ------------------------------------------------------------------------
    S2R-R1340..........................  R1340-028 through R1340-035.
    S2R-R1820..........................  R1820-036.
    S2R-T65............................  T65-001 through T65-017.
    S2RHG-T65..........................  T65-002 through T65-017.
    S2R-T34............................  T34-144, T34-146, T34-168, T34-169,
                                          T34-172 through T34-179, and T34-
                                          189 through T34-232, T34-234*.
    S2R-T45............................  T45-001 through T45-014.
    S2R-G6.............................  G6-101 through G6-147.
    S2R-G10............................  G10-101 through G10-138, G10-140,
                                          and G10-141**.
    S2R-G5.............................  G5-101 through G5-105.
    ------------------------------------------------------------------------
    * The serial numbers of the Model S2R-T34 airplanes could incorporate
      T34-xxx, T36-xxx, T41-xxx, or T42-xxx. This AD applies to all of these
      serial number designations as they are all Model S2R-T34 airplanes.
    ** The bolt holes in the Model S2R-G10 airplanes, S/N's G10-137, G10-
      140, and G10-141 only, have been cold worked at the Ayres factory. The
      repetitive inspection intervals for the airplanes incorporating these
      three serial numbers should follow those given for cold worked holes
      presented in the Repetitive Inspections chart in the Compliance
      section of this AD.
    
    
    [[Page 2160]]
    
    
                               Group 3 Airplanes*
    ------------------------------------------------------------------------
                   Model                            Serial numbers
    ------------------------------------------------------------------------
    600 S2D............................  All serial numbers beginning with
                                          600-1311D.
    S-2R...............................  1380R and 1416R through 4999R.
    S2R-R1340..........................  R1340-001 through R1340-010, R1340-
                                          013 through R1340-018, R1340-021
                                          through R1340-023, and R1340-026.
    S2R-R3S............................  R3S-001 through R3S-011.
    ------------------------------------------------------------------------
    * Any Group 3 airplane that has been modified with a hopper of a
      capacity over 410 gallons, a piston engine greater than 600
      horsepower, or any gas turbine engine makes the airplane a Group 1
      airplane for the purposes of this AD. The owner/operator must inspect
      the airplane at the Group 1 compliance time specified in the
      Compliance section of this AD.
    
    
                                Group 4 Airplanes
    ------------------------------------------------------------------------
                   Model                            Serial numbers
    ------------------------------------------------------------------------
    S-2R...............................  5010R, 5031R, 5038R, 5047R, and
                                          5085R.
    S2R-T34............................  T34-236.
    S2R-G1.............................  G1-107, G1-108.
    S2R-G10............................  G10-139.
    ------------------------------------------------------------------------
    
        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: Initial and repetitive inspections required as 
    indicated below, and any necessary replacement required prior to 
    further flight as indicated in the body of this AD. The initial 
    inspection may already have been accomplished in accordance with AD 
    97-17-03, which is superseded by this AD; or in accordance with AD 
    97-13-11, which was superseded by AD 97-17-03.
    
    Initial Inspections
    
    --Group 1 Airplanes: Required upon the accumulation of 2,000 hours 
    time-in-service (TIS) on each lower spar cap or within 50 flight 
    hours after the effective date of this AD, whichever occurs later, 
    unless already accomplished (compliance with AD 97-17-03 or AD 97-
    13-11), and thereafter at intervals specified in the Repetitive 
    Inspections chart in this section of the AD.
    --Group 2 Airplanes: Required upon the accumulation of 2,200 hours 
    TIS on each lower spar cap or within 50 flight hours after the 
    effective date of this AD, whichever occur later, unless already 
    accomplished (compliance with AD 97-17-03 or AD 97-13-11), and 
    thereafter at intervals specified in the Repetitive Inspections 
    chart in this section of the AD.
    --Group 3 Airplanes: Required upon the accumulation of 6,400 hours 
    TIS on each lower spar cap or within 50 flight hours after the 
    effective date of this AD, whichever occurs later, unless already 
    accomplished (compliance with AD 97-17-03 or AD 97-13-11), and 
    thereafter at intervals specified in the Repetitive Inspections 
    chart in this section of the AD.
    --Group 4 Airplanes: As presented below.
    
        For S/N's T34-236, G1-107, G1-108, and G10-139: Required upon 
    the accumulation of 2,600 hours TIS on each lower spar cap or within 
    the next 50 hours TIS after the effective date of this AD, whichever 
    occurs later; and thereafter at intervals specified in the 
    Repetitive Inspections chart in this section of the AD.
        For S/N 5010R: Required upon the accumulation of 5,530 hours TIS 
    on each lower spar cap or within the next 50 hours TIS after the 
    effective date of this AD, whichever occurs later; and thereafter at 
    intervals specified in the Repetitive Inspections chart in this 
    section of the AD.
        For S/N 5038R: Required upon the accumulation of 5,900 hours TIS 
    on each lower spar cap or within the next 50 hours TIS after the 
    effective date of this AD, whichever occurs later; and thereafter at 
    intervals specified in the Repetitive Inspections chart in this 
    section of the AD.
        For S/N's 5031R and 5047R: Required upon the accumulation of 
    6,400 hours TIS on each lower spar cap or within the next 50 hours 
    TIS after the effective date of this AD, whichever occurs later; and 
    thereafter at intervals specified in the Repetitive Inspections 
    chart in this section of the AD.
        For S/N 5085R: Required upon the accumulation of 6,290 hours TIS 
    on each lower spar cap or within the next 50 hours TIS after the 
    effective date of this AD, whichever occurs later; and thereafter at 
    intervals specified in the Repetitive Inspections chart in this 
    section of the AD.
    
    Repetitive Inspections
    
        The following gives the required repetitive inspection intervals 
    based on the situation found during the last inspection and the 
    method of inspection utilized:
    
    ------------------------------------------------------------------------
                                         Magnetic                    Eddy
                Situation                particle    Ultrasonic    current
                                       (hours TIS)  (hours TIS)  (hours TIS)
    ------------------------------------------------------------------------
    No cracks........................          500          400          450
    No cracks; and cold work
     accomplished per SB-AG-39*......        1,500        1,200        1,300
    No cracks; cold work accomplished
     per SB-AG-39; and butterfly
     plates, part number (P/N) 20211-
     09 and 20211-11 installed per CK-
     AG-29, Part II**................        2,500        1,950        2,150
    Small crack found; cold work to
     remove crack accomplished per SB-
     AG-39***, or CK-AG-29, Part I,
     accomplished to remove crack,
     and then cold work accomplished
     per SB-AG-39****................          950          750          825
    Small crack found; cold work to
     remove crack accomplished per SB-
     AG-39***, or CK-AG-29, Part I,
     accomplished to remove crack,
     and then cold work accomplished
     per SB-AG-39; and butterfly
     plates, part number (P/N) 20211-
     09 and 20211-11, installed per
     CK-AG-29, Part II...............        1,550        1,200       1,350
    ------------------------------------------------------------------------
    * Aircraft S/N's G10-137, G10-140 and G10-141 were cold worked at the
      factory and may follow this repetitive inspection interval.
    ** Aircraft S/N's T34-236, G1-107, G1-108, and G10-139 were cold worked
      and had the butterfly plates installed at the factory and may follow
      this repetitive inspection interval.
    *** If a crack is small enough, it may be removed through the reaming
      associated with the cold work process.
    **** Some aircraft owners/operators were issued alternative methods of
      compliance with AD 97-17-03 to ream the \1/4\-inch bolt hole to a \5/
      16\-inch diameter.
    
        To detect fatigue cracking of the lower spar caps, which could 
    result in the wing separating from the airplane with consequent loss 
    of control of the airplane, accomplish the following:
        (a) Inspect, using magnetic particle, ultrasonic or eddy current 
    procedures, the \1/4\ inch and \5/16\ inch bolt hole areas on each 
    lower spar cap for fatigue cracking. Accomplish the inspection in 
    accordance with Ayres Service Bulletin No. (SB) SB-AG-39, dated 
    September 17, 1996, and SB SB-AG-39 Rev. 1, dated December 12, 1997. 
    The cracks may emanate from the bolt hole on the face of the spar 
    cap or they may occur in the shaft of the hole; both areas must be 
    inspected.
        (1) The magnetic particle inspection must follow American 
    Society for Testing Materials (ASTM) E1444-94A, using wet particles 
    meeting the requirements of the Society for Automotive Engineers 
    (SAE) AMS 3046.
    
        Caution: The wings must be firmly supported during the 
    inspection to prevent movement of the spar caps when the splice
    
    [[Page 2161]]
    
    blocks are removed. This will allow easier realignment of the splice 
    block holes and the holes in the spar cap for bolt insertion.
    
        (2) Ultrasonic or eddy current inspection procedures must be 
    approved by the FAA. To obtain FAA approval, send your proposed 
    procedure to the Manager, Atlanta Aircraft Certification (ACO), One 
    Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 
    30349. Removal of the splice block is not required for either the 
    ultrasonic or eddy current inspections, unless corrosion is visible.
        (3) All inspections required by this AD shall be accomplished by 
    a Level 2 or Level 3 inspector certified for that inspection method 
    using the guidelines established by the American Society for 
    Nondestructive Testing or MIL-STD-410.
        (b) If any cracking is found during any inspection required by 
    this AD and if the crack is too large to be removed by the reaming 
    used in the cold work process of Ayres SB No. SB-AG-39, dated 
    September 17, 1996, or by using the method specified in Part I of 
    Ayres Custom Kit No. CK-AG-29, dated December 23, 1997, prior to 
    further flight, replace the affected lower spar cap in accordance 
    with the applicable maintenance manual. Upon replacement of a spar 
    cap, total hours TIS starts over for that particular lower spar cap. 
    Use the compliance time specified in the Repetitive Inspection chart 
    in the Compliance section of this AD to determine when the 
    inspection is required.
        (c) If any cracking is found during the inspections required by 
    this AD, submit a report of inspection findings to the Manager, 
    Atlanta ACO, One Crown Center, 1895 Phoenix Boulevard, Suite 450, 
    Atlanta, Georgia 30349; facsimile: (770) 703-6097; at the applicable 
    time specified in paragraph (c)(1) or (c)(2) of this AD. The report 
    must include a description of any cracking found; the airplane 
    serial number and engine model number; the total number of flight 
    hours on the lower spar cap that is found cracked; time since last 
    inspection, if applicable; and the time on the spar cap when the 
    bolt holes were cold worked or when the butterfly plate was 
    installed, if applicable. Information collection requirements 
    contained in this regulation have been approved by the Office of 
    Management and Budget (OMB) under the provisions of the Paperwork 
    Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been 
    assigned OMB Control Number 2120-0056.
        (1) For airplanes on which the inspection is accomplished after 
    the effective date of this AD, submit the report within 10 days 
    after performing the inspection required by paragraph (a) of this 
    AD.
        (2) For airplanes on which the inspection has been accomplished 
    in accordance with AD 97-17-03, which is superseded by this AD; or 
    by AD 97-13-11, which was superseded by AD 97-17-03, submit the 
    report within 10 days after the effective date of this AD, unless 
    already accomplished.
        (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 to 
    accomplish the modification requirements of this AD provided the 
    following is followed:
        (1) The hopper is empty.
        (2) Vne is reduced to 126 miles per hour (109 knots).
        (3) Flight into known turbulence is prohibited.
        (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, Atlanta ACO, One 
    Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 
    30349.
        (1) The request shall be forwarded through an appropriate FAA 
    Maintenance Inspector, who may add comments and then send it to the 
    Manager, Atlanta ACO.
        (2) Alternative methods of compliance approved in accordance 
    with AD 97-17-03, which is superseded by this AD; or in accordance 
    with AD 97-13-11, which was superseded by AD 97-17-03, are approved 
    as alternative methods of compliance with this AD unless otherwise 
    noted by this AD.
    
        Note 2: Information concerning the existence of approved 
    alternative methods of compliance with this AD, if any, may be 
    obtained from the Atlanta ACO.
    
        (f) All persons affected by this directive may obtain copies of 
    the documents referred to herein upon request to Ayres Corporation, 
    P.O. Box 3090, One Rockwell Avenue, Albany, Georgia 31706-3090; 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.
        (g) This amendment supersedes AD 97-17-03, Amendment 39-10105.
    
        Issued in Kansas City, Missouri, on January 6, 1999.
    Michael K. Dahl,
    Acting Manager, Small Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 99-684 Filed 1-12-99; 8:45 am]
    BILLING CODE 4910-13-U
    
    
    

Document Information

Published:
01/13/1999
Department:
Federal Aviation Administration
Entry Type:
Proposed Rule
Action:
Notice of proposed rulemaking (NPRM).
Document Number:
99-684
Dates:
Comments must be received on or before March 15, 1999.
Pages:
2157-2161 (5 pages)
Docket Numbers:
Docket No. 98-CE-56-AD
RINs:
2120-AA64: Airworthiness Directives
RIN Links:
https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives
PDF File:
99-684.pdf
CFR: (1)
14 CFR 39.13