AD 2006-08-09 Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

Models named: AT-802A. Read the applicability below — it usually turns on serial or part numbers too.

(c) This AD affects Model AT-802A airplanes, all serial numbers beginning with 802-0001, that are: (1) Certificated in any category; (2) Engaged in agricultural dispersal operations including those airplanes that have been converted between fire fighting and agricultural dispersal; (3) Not equipped with the factory-supplied computerized fire gate (part number 80540); and (4) Not engaged in full-time fighting only.

(f) At the initial inspection time specified in paragraph (f)(2) of this AD, do the following: (1) For the affected airplanes listed in Table 1 in paragraph (f)(2) of this AD, gain access for the required inspection listed below by installing cover plates following Service Letter #215, page 5, titled “802 Spar Inspection Holes and Vent tube mod,” dated November 19, 2003. (2) For the following airplanes, eddy current inspect the center splice joint outboard two fastener holes in both the right and left wing main spar lower caps for cracks following Process Specification #197. For these airplanes, use the following wing spar lower cap hours time-in-service (TIS) schedule to do the initial and repetitive inspections: Table 1.—Inspection Times Serial No. Condition Initially inspect: Repetitively inspect thereafter at intervals not to exceed: (i) 802-0001 through 802-0091 As manufactured Upon accumulating 1,700 hours TIS or within 50 hours TIS after April 21, 2006 (the effective date of this AD), whichever occurs later 850 hours TIS. (ii) 802-0001 through 802-0091 Modified with cold-worked fastener holes following Service Letter #244 If performing the cold-working procedure in Service Letter #244, it includes the eddy current inspection 1,700 hours TIS. (3) One of the following must do the inspection: (i) A level 2 or 3 inspector certified in eddy current inspection using the guidelines established by the American Society for Nondestructive Testing or MIL-STD-410; or (ii) A person authorized to perform AD work and who has completed and passed the Air Tractor, Inc. training course on Eddy Current Inspection on wing lower spar caps. (g) For all affected airplanes listed in paragraphs (f)(2)(i) and (f)(2)(ii) of this AD as terminating action for the inspection requirements, you may modify your wing by installing part number (P/N) 20997-2 web plate and P/N 20985-1 and 20985-2 extended 8-bolt splice blocks following Drawing 20995, Sheet 2, and cold-working the outboard two fastener holes in both the left and right hand lower spar caps at the center splice joint following Service Letter #240. (h) For all affected airplanes listed in paragraphs (f)(2)(i) and (f)(2)(ii) of this AD, repair or replace any cracked spar cap before further flight after the inspection in which cracks are found. For repair or replacement, do whichever of the following that applies: (1) For cracks that can be repaired by incorporating the terminating action specified in paragraph (g) of this AD, do the actions in paragraphs (g) of this AD before further flight after the inspection in which cracks are found. (2) For cracks that cannot be repaired by incorporating the terminating action specified in paragraph (g) of this AD, replace the lower spar caps and associated parts listed in paragraph (i) of this AD before further flight after the inspection in which cracks are found. (i) For all AT-802 and AT-802A airplanes, upon accumulating the hours TIS on the wing spar lower caps listed in paragraph (i)(3) of this AD or within 50 hours TIS after April 21, 2006 (the effective date of this AD), whichever occurs later, replace the wing main spar lower spar caps, the center joint splice blocks and hardware, the wing attach angles and hardware, and install the steel web splice plate (P/N 21106-1 for serial numbers 0001 through -0091, and P/N 20094-2 for all serial numbers beginning with 0092), unless already done. Replace as follows: (1) For airplane serial numbers 802-0001 through 802-0091, follow Drawing Number 20975, Sheet 3, and Process Specification #204. (2) For airplane serial numbers beginning with 802-0092, follow Drawing Number 20975, Sheet 2, and Process Specification #204. (3) The following presents the safe life and replacements times as required in paragraph (i) of this AD: Table 2.—Safe Life and Replacement Times Serial No. Wing spar lower cap safe-life AT-802-0001 through AT-802-0059 4,132 hours TIS. AT-802-0060 through AT-802-0091 4,188 hours TIS. All begining with AT-802-0092 8,163 hours TIS. AT-802A-001 through AT-802A-0059 4,969 hours TIS. AT-802A-0060 through AT-802-0091 4,531 hours TIS. All beginning with AT-802A-0092 8,648 hours TIS. (j) After replacing the wing spar lower caps and hardware, installing the web splice plate, and cold working the fastener holes by following Drawing Number 20975, Sheet 3 (serial numbers 802-0001 through 802-0091), or Sheet 2 (all serial numbers beginning with 802-0092), and Process Specification #204, the new safe-life for wing spar lower caps is as follows: Table 3.—New Safe Life for Wing Spar Lower Caps Serial No. Wing spar lower cap safe-life All beginning with AT-802-0001 8,163 hours TIS. All beginning with AT-802A-0001 8,648 hours TIS. (k) Report any cracks you find within 10 days after the cracks are found or within 10 days after April 21, 2006 (the effective date of this AD), whichever occurs later. (1) Include in your report the aircraft serial number, aircraft TIS, wing spar cap TIS, crack location and size, corrective action taken, and a point of contact name and phone number. Send your report to Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: (210) 308-3365; fascimile: (210) 308-3370. (2) The Office of Management and Budget (OMB) approved the information collection requirements contained in ths regulation under the provisions of the Paperwork Reduction Act and assigned OMB Control Number 2120-0056.

(d) This AD is the result of fatigue cracking of the wing main spar lower cap at the center splice joint outboard fastener hole. The actions specified in this AD are intended to detect and correct cracks in the wing main spar lower cap, which could result in failure of the spar cap and lead to wing separation and loss of control of the airplane.

(b) As of the issuance of this action, AD 2002-11-05 applies to Models AT-400, AT-401, AT-401B, AT-402, AT-402A, AT-402B, AT-501, AT-802, and AT-802A airplanes. The FAA is revising AD 2002-11-05 to remove the AT-400 series and AT-800 series airplanes from the applicability. The FAA is also issuing another similar AD on the AT-400 series airplanes.