AD 2022-21-11 Airworthiness Directives; Bell Textron Inc. Helicopters and Various Restricted Category Helicopters

Models named: 204B, 205A, 205A-1, HH-1K, SW205A-1, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to the following helicopters with main rotor blade (MRB) part number 204-011-250-001, -005, -009, -113, or -117 installed: (1) Bell Textron Inc. Model 204B helicopters, serial numbers (S/N) 2001 through 2070 and 2196 through 2199, inclusive, certificated in any category; (2) Bell Textron Inc. Model 205A, and 205A-1 helicopters, S/N 30001 through 30332, inclusive, certificated in any category; and (3) Various restricted category helicopters: (i) Model HH-1K helicopters; current type certificate holders include, but are not limited to, Rotorcraft Development Corporation; (ii) Southwest Florida Aviation International, Inc., Model SW205A-1 helicopters; (iii) Model TH-1F helicopters; current type certificate holders include, but are not limited to, Robinson Air Crane Inc.; Rotorcraft Development Corporation; and Tamarack Helicopters, Inc.; (iv) Model TH-1L helicopters; current type certificate holders include, but are not limited to, Bell Textron Inc.; Overseas Aircraft Support, Inc.; and Rotorcraft Development Corporation; (v) Model UH-1A helicopters; current type certificate holders include, but are not limited to, Richards Heavylift Helo, Inc.; (vi) Model UH-1B helicopters; current type certificate holders include, but are not limited to, International Helicopters, Inc.; Overseas Aircraft Support, Inc.; Red Tail Flying Services, LLC; Richards Heavylift Helo, Inc.; Rotorcraft Development Corporation; Southwest Florida Aviation International, Inc.; and WSH, LLC (type certificate previously held by San Joaquin Helicopters); Note 1 to paragraph (c)(3)(vi): Helicopters with an SW204 or SW204HP designation are Southwest Florida Aviation International, Inc., Model UH-1B helicopters. (vii) Model UH-1E helicopters; current type certificate holders include, but are not limited to, Bell Textron Inc.; Overseas Aircraft Support, Inc.; Rotorcraft Development Corporation; Smith Helicopters; and West Coast Fabrications; (viii) Model UH-1F helicopters; current type certificate holders include, but are not limited to, AST, Inc.; California Department of Forestry; Robinson Air Crane, Inc.; Rotorcraft Development Corporation; and Tamarack Helicopters, Inc.; (ix) Model UH-1H helicopters; current type certificate holders include, but are not limited to, Arrow Falcon Exporters, Inc.; Global Helicopter Technology, Inc.; Hagglund Helicopters, LLC; JJASPP Engineering Services LLC; Northwest Rotorcraft, LLC; Overseas Aircraft Support, Inc.; Richards Heavylift Helo, Inc.; Rotorcraft Development Corporation; Southwest Florida Aviation International, Inc.; and Tamarack Helicopters, Inc.; Note 2 to paragraph (c)(3)(ix): Helicopters with an SW205 designation are Southwest Florida Aviation International, Inc., Model UH-1H helicopters. (x) Model UH-1L helicopters; current type certificate holders include, but are not limited to, Bell Textron Inc.; Overseas Aircraft Support, Inc.; and Rotorcraft Development Corporation; and (xi) Model UH-1P helicopters; current type certificate holders include, but are not limited to, Robinson Air Crane, Inc.; and Rotorcraft Development Corporation.

Comply with this AD within the compliance times specified, unless already done.

(1) As of the effective date of this AD, before the first flight of each day: (i) Using cheesecloth, clean the upper and lower skin surfaces of each MRB in the area between blade stations 100 through 215, noting any unsmooth areas and paying attention to the trailing edge and any MRB surface which snag the cheesecloth or cause it to fray, as this may by an indication of a crack or paint chip that could lead to corrosion. (ii) The actions required by paragraph (g)(1)(i) of this AD may be performed by the owner/operator (pilot) holding at least a private pilot certificate, and must be entered into the aircraft records showing compliance with this AD in accordance with 14 CFR 43.9(a) and 14 CFR 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439. (iii) If there is any unsmooth area or the cheesecloth used to clean the MRB is snagged or frayed, remove paint from the area that is unsmooth or caused the snagging or fraying (affected area) by hand sanding in a spanwise direction with an abrasive cloth or sandpaper 220 or smoother grit and either: (A) Visually inspect the affected area for any crack using a 10X or higher power magnifying glass with a flashlight applied at an oblique angle and perpendicular to the crack orientation; or (B) Eddy current inspect the affected area for any crack using a surface probe. (iv) If there is any crack, before further flight, remove the MRB from service. (2) As of the effective date of this AD, at intervals not to exceed 25 hours time-in-service, prepare the upper and lower skin surfaces of each MRB for inspection by wiping the last 4 inches of the trailing edge between blade station 100 and 215 with an isopropyl alcohol-soaked cloth and then drying the area with a clean cloth. Immediately after drying the area, using a flashlight at an oblique angle, inspect the surface for a dark line, as this is an indication that excess isopropyl alcohol is bleeding out of a crack or edge void. If there is a dark line, remove paint from the area where there is a dark line by hand sanding in a spanwise direction with an abrasive cloth or sandpaper 220 or smoother grit and inspect for a crack in the skin. If there is any crack, before further flight, remove the MRB from service.

This AD was prompted by a report of cracks on the MRBs outside of the current inspection area. The FAA is issuing this AD to prevent a failure of an MRB. The unsafe condition, if not addressed, could result in loss of an MRB and subsequent loss of control of the helicopter.

None.