AD 2006-07-15 Airworthiness Directives; Thrush Aircraft, Inc. Model 600 S2D and S2R (S-2R) Series Airplanes

Models named: S2R-T15, S2R-T34. Read the applicability below — it usually turns on serial or part numbers too.

This AD affects the following airplane models and serial numbers that are certificated in any category. The table also identifies the group that each airplane belongs in when determining inspection compliance times: Table 1.—Applicability and Airplane Groups Model Serial Nos. Group (1) S-2R 5000R through 5100R, except 5010R, 5031R, 5038R, 5047R, and 5085R 1 (2) S2R-G1 G1-101 through G1-106 1 (3) S2R-R1820 R1820-001 through R1820-035 1 (4) S2R-T15 T15-001 through T15-033 1 (5) S2R-T34 6000R through 6049R, T34-001 through T34-143, T34-145, T34-147 through T34-167, T34-171, T34-180, and T34-181 1 (6) S2R-G10 G10-101 through G10-136, G10-138, G10-140, and G10-141 2 (7) S2R-G5 G5-101 through G5-105 2 (8) S2R-G6 G6-101 through G6-147 2 (9) S2RHG-T65 T65-002 through T65-018 2 (10) S2R-R1820 R1820-036 2 (11) S2R-T34 T34-144, T34-146, T34-168, T34-169, T34-172 through T34-179, and T34-189 through T34-232, and T34-234 2 (12) S2R-T45 T45-001 through T45-014 2 (13) S2R-T65 T65-001 through T65-018 2 (14) 600 S2D All serial numbers beginning with 600-1311D 3 (15) S-2R 1380R, 1416R through 2592R, 3000R, and 3002R 3 (16) S2R-R1340 R1340-001 through R1340-035 3 (17) S2R-R3S R3S-001 through R3S-011 3 (18) S2R-T11 T11-001 through T11-005 3 (19) S2R-G1 G1-107, G1-108, and G1-109 4 (20) S2R-G10 G10-137, G10-139, and G10-142 4 (21) S2R-T34 T34-225, T34-236, T34-237, and T34-238 4 (22) S2R-G1 G1-110 through G1-115 5 (23) S2R-G10 G10-143 through G10-165 5 (24) S2R-G6 G6-148 through G6-155 5 (25) S2RHG-T34 T34HG-102 5 (26) S2R-T15 T15-034 through T15-040 5 (27) S2R-T34 T34-239 through T34-270 5 (28) S2R-T45 T45-015 5 (29) S-2R 5010R, 5031R, 5038R, 5047R, and 5085R 6 Note 1: The serial numbers of the Model S2R-T15 airplanes could incorporate T15-xxx and T27-xxx (xxx is the variable for any of the serial numbers beginning with T15- and T27-). This AD applies to both of these serial number designations as they are both Model S2R-T15 airplanes. Note 2: The serial numbers of the Model S2R-T34 airplanes could incorporate T34-xxx, T36-xxx, T41-xxx, or T42-xxx (xxx is the variable for any of the serial numbers beginning with T34-, T36-, T41- and T42-). This AD applies to all of these serial number designations as they are all Model S2R-T34 airplanes. Note 3: Any Group 3 airplane that has been modified with a hopper of a capacity more than 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. Inspect the airplane at the Group 1 compliance time specified in this AD. Note 4: Group 6 airplanes were originally manufactured with turbine engines, but were converted to radial engines. They are now configured identical to Group 3 airplanes.

To address the problem, do the following: (1) If you have already done an inspection per AD 2003-07-01, identify the number of hours time-in-service (TIS) since your last inspection per AD 2003-07-01. You will need this to establish the inspection interval for next inspection required by this AD. (2) Inspect the 1/4 -inch and 5/16 -inch bolt hole areas on each wing lower spar cap for fatigue cracking using magnetic particle, ultrasonic, or eddy current procedures. If Kaplan splice blocks, part number (P/N) 22515-1/-3 or 88-251 per Quality Aerospace, Inc. Custom Kit No. CK-AG-30, dated December 6, 2001, are installed, inspect the three bolt hole areas on each wing lower spar cap for fatigue cracking using magnetic particle, ultrasonic, or eddy current procedures. Use the compliance times listed in paragraph (e)(3) of this AD for the initial inspection and the compliance time listed in paragraphs (e)(5), (e)(6), or (e)(7) of this AD for the repetitive inspections. 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. You must inspect both of those areas. (i) If using the magnetic particle method for the inspection, inspect using the “Inspection” portion of the “Accomplishment Instructions” and “Lower Splice Fitting Removal and Installation Instructions” in Ayres Corporation Service Bulletin No. SB-AG-39, dated September 17, 1996. You must follow American Society for Testing and Materials E 1444-01, using wet particles meeting the requirements of the Society for Automotive Engineers AMS 3046. CAUTION: You must firmly support the wings during the inspection to prevent movement of the spar caps when the splice blocks are removed. This will allow easier realignment of the splice block holes and the holes in the spar cap for bolt insertion. (ii) The inspection must be done by or supervised by a Level 2 or Level 3 inspector certified following the guidelines established by the American Society for Nondestructive Testing or MIL-STD-410. (iii) If using ultrasonic or eddy current methods for the inspection, a procedure must be sent to the FAA, Atlanta Aircraft Certification Office (ACO), for approval before doing the inspection. Send your proposed procedure to the FAA, Atlanta ACO, Attn: Cindy Lorenzen, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349. You are not required to remove the splice block for either the ultrasonic or eddy current inspections, unless corrosion is visible. (iv) If you change the inspection method used (magnetic particle, ultrasonic, or eddy current), the TIS intervals for repetitive inspections are based on the method used for the last inspection. (3) If airplanes have not reached the threshold for the initial inspection required in AD 2003-07-01, AD 2000-11-16, AD 97-17-03, or AD 97-13-11, initially inspect following the wing lower spar cap hours TIS schedule below or within 50 wing lower spar cap hours TIS after April 18, 2006 (the effective date of this AD), whichever occurs later: Table 2.—Initial Inspection Airplane group Initially inspect within the following lower wing spar cap hours TIS (i) Group 1 2,000 hours TIS. (ii) Group 2 1,400 hours TIS. (iii) Group 3 6,400 hours TIS. (iv) Group 4 2,500 hours TIS. (v) Group 5 6,200 hours TIS. (vi) Group 6 (A) Serial number (S/N) 5010R: 5,530 hours TIS.   (B) S/N 5038R: 5,900 hours TIS.   (C) S/N 5031R: 6,400 hours TIS.   (D) S/N 5047R: 6,400 hours TIS.   (E) S/N 5085R: 6,290 hours TIS. (4) Airplanes in all groups must meet the following conditions before doing the repetitive inspections required in paragraphs (e)(5), (e)(6), or (e)(7) of this AD: (i) No cracks have been found previously on wing spar; (ii) Small cracks have been repaired through cold work (or done as an option if never cracked) per SB-AG-39; (iii) Small cracks have been repaired by reaming the 1/4 -inch bolt hole to 5/16 inches diameter (or done as an option if never cracked) per Ayres Corporation Custom Kit No. CK-AG-29, Part I, dated December 23, 1997; (iv) Small cracks have been repaired through previous alternative methods of compliance (AMOC); or (v) Small cracks have been repaired by the installation of Kaplan splice blocks, P/N 22515-1/-3 or 88-251 (or done as an option if never cracked) per Quality Aerospace, Inc. Custom Kit No. CK-AG-30, dated December 6, 2001. (5) Repetitively inspect Groups 1, 2, 3, and 6 airplanes that do not have butterfly plates, P/N 20211-09 and P/N 20211-11, installed per Ayres Corporation Custom Kit No. CK-AG-29, Part II, dated December 23, 1997, and meet the conditions in paragraph (e)(4) of this AD. Follow the wing lower spar cap hours TIS compliance schedule below: Table 3.—Repetitive Inspections for Airplane Groups 1, 2, 3, and 6 Without Butterfly Plates When airplanes accumulate the following hours TIS on the wing lower spar cap, since the last inspection required in AD 2003-07-01, Inspect within the following hours TIS after April 18, 2006 (the effective date of this AD), Inspect thereafter at intervals of . . . (i) Magnetic particle inspection 250 hours TIS. (A) 450 or more hours 25 hours TIS (B) 350 through 449 hours TIS 50 hours TIS (C) 175 through 349 hours TIS 75 hours TIS (D) Less than 175 hours TIS upon accumulating 250 hours TIS (ii) Ultrasonic inspection 275 hours TIS. (A) 500 or more hours TIS 25 hours TIS (B) 400 through 499 hours TIS 50 hours TIS (C) 200 through 399 hours TIS 75 hours TIS (D) Less than 200 hours TIS upon accumulating 275 hours TIS (iii) Eddy Current inspection 350 hours TIS. (A) 625 or more hours TIS 25 hours TIS (B) 500 through 624 hours TIS 50 hours TIS (C) 275 through 499 hours TIS 75 hours TIS (D) Less than 275 hours TIS upon accumulating 350 hours TIS (6) Repetitively inspect Groups 1, 2, 3, and 6 airplanes that have butterfly plates, P/N 20211-09 and P/N 20211-11, installed per Ayres Corporation Custom Kit No. CK-AG-29, Part II, dated December 23, 1997, and meet the conditions in paragraph (e)(4) of this AD. Follow the wing lower spar cap hours TIS compliance schedule below: Table 4.—Repetitive Inspections for Groups 1, 2, 3, and 6 With Butterfly Plates When airplanes accumulate the following hours TIS on the wing lower spar cap, since the last inspection required in AD 2003-07-01, Inspect within the following hours TIS after April 18, 2006 (the effective date of this AD), Inspect thereafter at intervals of . . . (i) Magnetic particle inspection 450 hours TIS. (A) 800 or more hours TIS 25 hours TIS (B) 650 through 799 hours TIS 50 hours TIS (C) 375 through 649 hours TIS 75 hours TIS (D) Less than 375 hours TIS upon accumulating 450 hours TIS (ii) Ultrasonic inspection 475 hours TIS. (A) 825 or more hours TIS 25 hours TIS (B) 675 through 824 hours TIS 50 hours TIS (C) 400 through 674 hours TIS 75 hours TIS (D) Less than 400 hours TIS upon accumulating 475 hours TIS (iii) Eddy Current inspection 625 hours TIS (A) 1125 or more hours TIS 25 hours TIS (B) 900 through 1124 hours TIS 50 hours TIS (C) 550 through 899 hours TIS 75 hours TIS (D) Less than 550 hours TIS upon accumulating 625 hours TIS (7) Repetitively inspect Groups 4 and 5 airplanes that meet the conditions in paragraph (e)(4) of this AD. Follow the wing lower spar cap hours TIS compliance schedule below: Table 5.—Repetitive Inspection for Groups 4 and 5 When using the following inspection methods, Repetitively inspect at intervals of . . . (i) Magnetic particle inspection 900 hours TIS. (ii) Ultrasonic inspection 950 hours TIS. (iii) Eddy current inspection 1,250 hours TIS. Note 5: Groups 4 and 5 airplanes had the butterfly plates installed at the factory. (f) If any cracks are found in any inspection required by this AD, you must repair the cracks or replace the lower wing spar before further flight. (1) Use the cold work process to ream out small cracks as defined in Ayres Corporation Service Bulletin No. SB-AG-39, dated September 17, 1996; or (2) Ream the 1/4 -inch bolt holes to 5/16 inches diameter as defined in Part I of Ayres Corporation Custom Kit No. CK-AG-29, dated December 23, 1997; or (3) Install Kaplan Splice Blocks as defined in Quality Aerospace, Inc. Custom Kit No. CK-AG-30, dated December 6, 2001; or (4) Replace the affected spar cap in accordance with the maintenance manual. Note 6: If a crack is found, the reaming associated with the cold work process may remove a crack if it is small enough. Some aircraft owners/operators were issued alternative methods of compliance with AD 97-17-03 to ream the 1/4 -inch bolt hole to 5/16 inches diameter to remove small cracks. Ayres Corporation Custom Kit No. CK-AG-29, Part I, dated December 23, 1997, also provides procedures to ream the 1/4 -inch bolt hole to 5/16 inches diameter, which may remove a small crack. Resizing the holes to the required size to install a Kaplan splice block may also remove small cracks. If you use any of these methods to remove cracks and the airplane is re-inspected immediately with no cracks found, you may continue to follow the repetitive inspection intervals for your airplane listed in paragraphs (e)(5), (e)(6), or (e)(7) of this AD. (g) For all inspection methods (magnetic particle, ultrasonic, or eddy current), hours TIS for initial and repetitive inspections intervals start over when wing spar is replaced. (1) If the wings or wing spars were replaced with new or used wings or wing spars during the life of the airplane and logbook records positively show the hours TIS of the wings or wing spars, then initially inspect at applicable wing or wing spar times in paragraph (e)(3) and repetitively inspect at intervals in paragraphs (e)(5), (e)(6), or (e)(7) of this AD. (2) If the wings or wing spars were replaced with new or used wings or wing spars during the life of the airplane and logbook records cannot positively show the hours TIS of the wings or wing spars, then inspect within 25 hours TIS after April 18, 2006 (the effective date of this AD), unless already done, and repetitively inspect at intervals in paragraphs (e)(5), (e)(6), or (e)(7) of this AD. (h) Report any cracks you find within 10 days after the cracks are found or within 10 days after April 18, 2006 (the effective date of this AD), whichever occurs later. Send your report to Cindy Lorenzen, Aerospace Engineer, ACE-115A, Atlanta ACO, One Crown Center, 1895 Phoenix Blvd., Suite 450, Atlanta, GA 30349; telephone: (770) 703-6078; facsimile: (770) 703-6097; e-mail: cindy.lorenzen@faa.gov. The Office of Management and Budget (OMB) approved the information collection requirements contained in this regulation under the provisions of the Paperwork Reduction Act and assigned OMB Control Number 2120-0056. Include in your report the following information: (1) Aircraft model and serial number; (2) Engine model; (3) Aircraft hours TIS; (4) Left and right wing lower spar cap hours TIS; (5) Hours TIS on the spar cap since last inspection; (6) Crack location and size; (7) Procedure (magnetic particle, ultrasonic, or eddy current) used for the last inspection; and (8) Information on corrective action taken, whether cold working has been done or modifications incorporated such as installation of butterfly plates, and when this corrective action was taken. Alternative Methods of Compliance (AMOCs) (i) The Manager, Atlanta Aircraft Certification Office, FAA, ATTN: Cindy Lorenzen, Aerospace Engineer, ACE-115A, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Blvd., Suite 450, Atlanta, GA 30349; telephone: (770) 703-6078; facsimile: (770) 703-6097; e-mail: cindy.lorenzen@faa.gov ; or Mike Cann, Aerospace Engineer, ACE-117A, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Blvd., Suite 450, Atlanta, Georgia 30349; telephone: (770) 703-6038; facsimile: (770) 703-6097; e-mail: michael.cann@faa.gov , has the authority to approve AMOCs for this AD, if requested using the procedures in 14 CFR 39. (j) AMOCs approved for AD 2003-07-01, AD 2000-11-16, AD 97-13-11, and/or AD 97-17-03 are approved as AMOCs for this AD. Material Incorporated by Reference (k) You must do the actions required by this AD following the instructions in Ayres Corporation Service Bulletin No. SB-AG-39, dated September 17, 1996; Ayres Corporation Custom Kit No. CK-AG-29, dated December 23, 1997; and Quality Aerospace, Inc. Custom Kit No. CK-AG-30, dated December 6, 2001. (1) As of July 25, 2000 (65 FR 36055), the Director of the Federal Register previously approved the incorporation by reference of Ayres Corporation Service Bulletin No. SB-AG-39, dated September 17, 1996; and Ayres Corporation Custom Kit No. CK-AG-29, dated December 23, 1997, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (2) As of May 20, 2003 (68 FR 15653), the Director of the Federal Register previously approved the incorporation by reference of Quality Aerospace, Inc. Custom Kit No. CK-AG-30, dated December 6, 2001, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (3) To get a copy of this service information, contact Thrush Aircraft, Inc. at 300 Old Pretoria Road, P.O. Box 3149, Albany, Georgia 31706-3149 or go to http://www.thrushaircraft.com. To review copies of this service information, go to the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html or call (202) 741-6030. To view the AD docket, go to the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-001 or on the Internet at http://dms.dot.gov. The docket number is FAA-2006-23649; Directorate Identifier 2006-CE-08-AD. Issued in Kansas City, Missouri, on March 28, 2006. David R. Showers, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 06-3162 Filed 4-3-06; 8:45 am] BILLING CODE 4910-13-P

This AD is the result of the analysis of data from 112 cracks found in the last 8 years on similar design Model 600 S2D and S2R (S-2R) series airplanes, and FAA's determination that an immediate initial inspection and more frequent repetitive inspections are necessary to address the unsafe condition for certain airplanes. We are issuing this AD to prevent lower wing spar cap failure caused by undetected fatigue cracks. Such failure could result in loss of a wing with consequent loss of airplane control.