Instructions for Continued Airworthiness No. ICA17025

2) Remove the fuel tank cover skin. 3) Retain and secure the 0.040” formed aluminum angle stiffener (p/n 17025- 40//57) on the rear spar at the outboard corner of the fuel tank bay. This angle becomes free when the screws are removed. Refer to Figure 2. 2.6 Fuel Tank Cover - INSTALLATION: 1) Position the angle stiffener on the aft spar at the outboard corner of the fuel tank bay (between wing stations 40 and 57.125), ensuring that the fastener holes are aligned with the holes in the spar. 2) Place the cover skin in position and secure it finger tight using the removed fasteners, ensuring that the longer -0812 screws are installed in their correct locations. 3) Confirm that the angle stiffener is properly in place. (The angle stiffener is secured using 6 MS27039-0808 machine screws.) Refer to Figure 2. 4) Tighten all fasteners (7-15 in.lb.). Required fasteners are: MS27039-0808 (NAS220-8) MS27039-0812 (NAS220-12) Refer to applicable aircraft Illustrated Parts Catalog for quantities specific to your fuel tank configuration. Air Research Technology Inc. Instructions for Continued Airworthiness No. ICA17025 Issue 9, July 13, 2022. page 6 of 9 3 PERIODIC INSPECTION The following items must be inspected at the annual inspection: Item Area to be Inspected Inspection Action Corrective Action 1 Main Spar lower surface stainless steel strap reinforcement at Wing Station 100 if applicable. (see Fig. 3) Visually inspect for loose or missing fasteners, cracks, and corrosion. Loose rivets must be replaced with CR3243-6-6 or -7 as applicable. See notes below. 2 Wing internal inspection including upper main spar reinforcement at Wing Station 128 to 160. (see Fig. 4) Remove all lower wing skin inspection panels and visually inspect spars, skins, ribs and stringers for loose or missing fasteners, deformation, cracks, and corrosion. See notes below. 3 Fuel tank well cover inspection on aircraft not equipped with wet wings at aft upper spar cap from wing station 40 to 57.25. (see Fig. 2) Visually inspect for loose or missing fasteners, cracks, and corrosion and to ensure that angle stiffener is present along the aft upper spar cap. Replace any missing fasteners or angle stiffener. See notes below. 4 WingExtensions (see Fig. 1) Visually inspect for skin damage, loose or missing fasteners, cracks, and corrosion. Replace any missing fasteners. See notes below. 5 Markings and Placards Visually inspect to ensure that the required cockpit markings and placards are present and legible (see Section 5 for required placards and markings) Replace any missing or illegible placards. Apply missing range marking to airspeed indicator. See Section 5 for replacement of placards and application of markings. Notes: 1) Visual corrosion inspection shall be in accordance with FAA AC 43.13-1B Chapter 6, Section 5. 2) Treatable corrosion is limited to general surface corrosion as defined by FAA AC 43.13-1B Chapter 6, Section 2. More serious forms of corrosion are cause for rejection of the affected wing structure. 3) Corrosion removal and treatment must be in accordance with FAA AC43.13-1B Chapter 6, Sections 6 through 8. 4) Visible cracks are not permitted in any wing structure. 5) Repairs and modifications to wing spars require specific approval. Contact Air Research Technology for guidance before attempting any wing spar repairs or modifications. 6) For general sheet metal repairs see Section 6. Air Research Technology Inc. Instructions for Continued Airworthiness No. ICA17025 Issue 9, July 13, 2022. page 7 of 9 Fig 3: Stainless Strap (under leading edge skin at wing station 100) RH Wing shown, looking forward Refer to Air Research Technology Inc. Wing Extension and Spar Reinforcement Installation Guide #172 Part III for applicability of this reinforcement to your aircraft. Fig. 4 Main Spar Upper Reinforcement Air Research Technology Inc. Instructions for Continued Airworthiness No. ICA17025 Issue 9, July 13, 2022. page 8 of 9 4 WEIGHT AND BALANCE The following typical weights are provided for reference only. USE ACTUAL MEASURED WEIGHTS Item Total Weight (lbs) Arm (in. aft of datum) Moment (in.lbs.) WingExtensions 16 52 832 5 REQUIRED MARKINGS AND PLACARDS The following placards must be installed in full view of the pilot when the WingExtensions are installed: Missing or damaged placards must be replaced. Replacement self-adhesive placards are available from Air Research Technology Inc. For Cessna R172K, 172RG, 172R and 172S only, the airspeed indicator must be marked with a red radial line at 160 KIAS. If the airspeed indicator is replaced, or if this range marking is missing, refer to Air Research Technology Inc. Wing Extension and Spar Reinforcement Guide #172, Part VII for instrument marking instructions. 6 REPAIRS Repairs to the sheet metal structure may be accomplished in accordance with AC 43.13-1B, Chapter 4, Section 4. For parts, placards, or information contact Air Research Technology Inc. (See contact information on page 1.) Air Research Technology Inc. Instructions for Continued Airworthiness No. ICA17025 Issue 9, July 13, 2022. page 9 of 9 7 AIRWORTHINESS LIMITATIONS SECTION There are no Airworthiness Limitations introduced by this modification. The Airworthiness Limitations section is approved by the Minister and specifies maintenance required under any applicable airworthiness or operating rule, unless an alternative program has been approved by the Minister. The Airworthiness Limitations section is FAA approved and specifies maintenance required under §§43.16 and 91.403 of Title 14 of the Code of Federal Regulations unless an alternative program has been FAA approved.