### P.O. BOX 3689 BRISTOL, TE NNESSEE 37625-3689 USA TELEPHONE: 423-538-5151 TOLL FREE: 800-251-7094 TELEFAX: 423-538-8469 E-MAIL: sales@aero-access.com techsupport@aero-access.com 

# ALERT SERVICE BULLETIN
ASB No. AA-07109
No Revision

SUBJECT: High Landing Gear Aft Crosstubes

P/N 412-321-104 / 412-321-304

MODELS AFFECTED: Bell Helicopter Textron model 412, 412EP and 412CF and Agusta S.p.A. model AB412, AB412EP helicopters with Aeronautical Accessories, Inc. P/N 412-321-104 / 412-321-304 High Aft Crosstubes installed in accordance with STC SR01052AT.

COMPLIANCE: Part A: Within the next 50 flight hours, but not later than June 30, 2008, establish a high aft crosstube takeoff/landing life limit of 20,000 on P/N 412-321-304. High aft crosstubes for which flight hours are unknown, or the number of takeoff/landings cannot be determined, must be replaced within the next 450 takeoff/landings. High aft crosstubes with historical information establishing a number of takeoffs/landings greater than 20,000 must be replaced within the next 450 takeoff/landings.

Part B: Prior to 2500 takeoff/landings. High aft crosstubes with historical information establishing a number of takeoffs/landings greater than 2500 must accomplish Part B within 50 flight hours or 250 takeoff/landings, whichever comes first, of the receipt of this bulletin.

Part C: Within 450 takeoff/landings after accomplishment of Part B, and every 450 takeoff/landings thereafter.

IF OWNERSHIP OF AIRCRAFT HAS CHANGED, PLEASE FORWARD THIS BULLETIN TO NEW OWNER412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

Part D: Prior to 2500 takeoff/landings and every 12 months or 2500 takeoff/landings, whichever comes first, thereafter. High aft crosstubes with historical information establishing a number of takeoffs/landings greater than 2500 must accomplish Part D within 1 month of the receipt of this bulletin.

Part E: Prior to 7500 takeoff/landings and every 5000 takeoff/landings thereafter. High aft crosstubes with historical information establishing a number of takeoffs/landings greater than 7500 must accomplish Part E within 3 months of the receipt of this bulletin.

Part F: Within the next 25 flight hours, but not later than May 15, 2008.

DESCRIPTION: Aeronautical Accessories, Inc. has conducted a review of the high aft crosstube in res ponse to three reported field failures. Our analysis indicate s a takeoff/landing life must be assigned to P/N 412-321-304 high aft crosstube and additional scheduled inspecti ons must be conducted on both P/N 412-321-104 and 412-321-304 high aft crosstubes.

Part A of this bulletin establishes a 20000 takeoff/landing life on P/N 412-321-304 high aft crosstube. P/N 412-321-104 high aft crosstube is already subject to the retirement life. This bulletin provides the information necessary to calculate the number of takeoffs/landings. If the total number of takeoff/landings is less than the recommended life, record all takeoff/landings until component life is achieved or component is otherwise removed from service.

Part B of this bulletin provides instructions to clean and inspect two areas on the bottom of the high aft crosstube. Means to protect this area wit h primer and a cl ear coat are also included. P/N 412-321- 104, serial number AA-1274 and subsequent, crosstubes are manufactured with the two inspection areas primed and clear-coated.

Part C of this bulletin provides instructions to conduct a recurring visual inspection of the two primed and clear coated areas of the high aft crosstube after the accomplishment of Part B.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

Part D of this bulletin provides instructions to conduct a recurring dimensional inspection of the skid gear to identify permanent deformation of the crosstube.

Part E of this bulletin provides instructions to conduct a recurring fluorescent penetrant inspection of the high aft crosstube.

Part F of this bulletin provides clarification on helicopter towing instructions to prevent crosstube damage or failure as a result of gr ound handling or towing.

APPROVAL: The engineering aspects of this bulletin are FAA/DER approved.

MANPOWER: PART A : Approximately 0.5 hours.

PART B : Approximately 3.0 hours.

PART C : Approximately 0.5 hours

PART D : Approximately 1.0 hours.

PART E : Approximately 24.0 hours. Manhours are based on hands-on time and may vary with personnel or facilities available.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 4 of 15 MATERIAL: The following Customer supplied material s are required to comply with this bulletin:

TABLE 1 – PARTS LIST CUSTOMER SUPPLIED CONSUMABLE MATERIALS Qty Description AR MIL-R-81294, Type I or II Chemical Paint Remover AR MIL-PRF-85582 Primer (PRC-DeSoto EWDE 072A/B) AR MIL-PRF-85285, Type I Gloss Clear Coat Paint (Deft 03X085) AR MIL-PRF-87937 Cleaning Compound, Aerospace Equipment

NOTE The MIL-PRF-85582 primer (PRC-DeSoto EWDE 072A/B) [packaged as a 1-gallon, 1-qt (Parts A&B) kit (P/N EWDE072)] and the MI L-PRF-85285, Type I clear coat paint (Deft 03X085) [packaged as a 3-qt kit (P/N MIL-PRF-85285)] may be procured from a Bell Heli copter Supply Center. The primer and paint may also be procured [packaged in 1-qt, primer and paint, kits (P/N 1272K)] from Aerospace Products, Inc., 6413 Midway R oad, Halton City, TX 76117 (817-332-1669).

SPECIAL TOOLS REQUIRED: 10X magnifying glass

WEIGHT AND BALANCE: Not affected

PUBLICATIONS AFFECTED:

Installation Instructi ons, report number AA-95005

Instructions for Continued Airwor thiness, report number AA-01136

ADDITIONAL INFORMATION: Any questions regarding this bulletin should be addressed to:
AERONAUTICAL ACCESSORIES, INC. P.O. Box 3689 Bristol, 37625-3689 TN PRODUCT SUPPORT 1-800-251-7094 techsupport@aero-access.com412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 5 of 15 ACCOMPLISHMENT INSTRUCTIONS Upon receipt of this bulletin, determine by part number if affected high aft crosstube is installed. If affected crosstube is installed, perform the actions contained in this bulletin. Any crosstube failing inspection shall be remo ved from service and replaced with an airworthy crosstube.

PART A INSPECTION REQUIREMENTS AND HISTORICAL RECORDS 1. Verify all high aft crosstubes, P/N 412-321-104 and 412-321-304, comply with the inspection criteria of the Instructions for Cont inued Airworthiness report number AA-01136 and BHT-412-MM-2 (Bell He licopter model 412 Maintenance Manual).

A retirement life has been established for the following high skid gear aft crosstubes. A Historical Record is provided (Figure 4) for recording of takeoff/landing operations for the listed life-limited crosstubes.

PART NUMBER (1) COMPONENT LIFE LIMIT (EVENTS) (2) 412-321-104 Aft Crosstube, High Skid Gear 20,000 Takeoff/Landings 412-321-304 Aft Crosstube, High Skid Gear 20, 000 Takeoff/Landings NOTES: (1) The airworthiness limitation for part number listed applies to all successive dash numbers for that component unless otherwise specified. (2) Either landings or takeoff may be counted.

These Airworthiness Limitations ar e FAA approved and specify maintenance required under §§ 43.16 and 91. 403 of the Federal Avia tion Regulations unless an alternative program has been FAA approved.

2. Create a Historical Record form to track P/N 412-321-304 high aft crosstube takeoff/landing life per the compliance sect ion of this bulletin. Those operators that have recorded the number of tak eoff/landings are subject to the 20,000 takeoff/landing limit.

NOTE Helicopters with takeoff/landings that are higher than the average of 10 per hour must subs titute the higher value in all estimated calculations. 3. If the actual takeoff/landing information is not available it is permissible to estimate the number. To determine t he number of takeoff/landings on the crosstube, multiply the airframe hours by a factor of ten. 4. Place the calculated takeoff/landing in formation on the Historical Record form and track the applicable life as per the compliance section of the bulletin. 5. Replace life limited crosst ubes per the Instructions fo r Continued Airworthiness, report number AA-01136.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 6 of 15 NOTE Aeronautical Accessories Inc. has discontinued sale of P/N 412-321-304 high aft crosstube Assembly. P/N 412-321-104 high aft crosstube is completely interchangeable with P/N 412-321-304.

PART B INITIAL INSPECTION REQUIREMENT FOR P/N 412-321-104 AND P/N 412-321-304 CROSSTUBES

NOTE Crosstube visual inspection is conducted with aircraft at rest on skid landing gear; minimum gr oss weight at inspection is 9,000 pounds.

CAUTION Chemical removers shall be used only in areas of adequate ventilation. Suitable goggles or face masks, chemical resistant gloves, boots and clothing shall be worn to avoid contact of ch emical removers with eyes, skin and clothing. Chemical removers shall further be handled in accordance with applicable OSHA regulations, state and local safety codes, and company established safety standards and policies.

NOTE P/N 412-321-104 Crosstubes wit h serial number AA-1274 and subsequent are manufactured with the two inspection areas primed and clear-coated. St eps 1 through 3 of Part B may be skipped unless opaque pai nt has been applied to either inspection area descr ibed below and in Figure 1. 1. Prepare crosstube inspection areas by c hemically removing crosstube paint and primer from an area 2.0 ±0.25 inches wide extending between BL 18 and BL 30 at the center-bottom surfac e of the crosstube on both t he left and the right sides of the crosstube (s ee Figure 1). 2. Apply MIL-R-81294, Type I or II chemical paint remove r with a brush and allow it to set from 15 to 45 minut es to soften paint. 3. Using a stiff fiber brush and clean water, rinse paint from cro sstube. If required, use abrasive pad (Scotch-Brite, Type A) and MIL-R-81294, Type I or II chemical paint remover to aid in lifting paint. Brush crosst ube with abrasive pad in the longitudinal direction, using care so as not to abrade crosstube metal surface. 4. Rinse part clean with clean water and dry thoroughly. Reapplication of chemical paint remover may be required to ensure that paint and primer is completely removed so that the metal surface of the cross tube is clearly visible. 5. Using at least 10X magnification and a strong light source, visually inspect the stripped areas for indications of cracking. If cracking is suspected, fluorescent penetrant inspect crosstube per ASTM E1417, Type I, Method B, C, or D, Level 2 in accordance with Bell Helicopter Standar d Practices Manual (BHT-ALL-SPM).412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 7 of 15 WARNING IF CRACKING IS DISCOVERED , THE CROSSTUBE IS NO LONGER AIRWORTHY AND MUST BE IMMEDIATELY REPLACED. REPLACE CROSSTUBE PER APPLICABLE INSTRUCTIONS IN INSTRUCTIONS FOR CONTINUED AIRWORTHINESS, REPORT NUMBER AA-01136. 6. Following crosstube inspection, coat the stripped crosstube area with MIL-PRF-85582 primer (.0006 – .0009 thick) by spraying in accordance with manufacturer’s instructions. Allow primer to cure per manufacturer instructions.

NOTE The MIL-PRF-85582 primer (PRC-DeSoto EWDE 072A/B) [packaged as a 1-gallon, 1-qt (Parts A&B) kit (P/N EWDE072)] and the MI L-PRF-85285, Type I clear coat paint (Deft 03X085) [packaged as a 3-qt kit (P/N MIL-PRF-85285)] may be procured from a Bell Heli copter Supply Center. The primer and paint may also be procured [packaged in 1-qt, primer and paint, kits (P/N 1272K)] from Aerospace Products, Inc., 6413 Midway R oad, Halton City, TX 76117 (817-332-1669). 7. Following primer cure, paint the area with polyuret hane clear coat paint per MIL-PRF-85285 by spraying in accordance with manufacturer’s instructions. Allow paint to cure per m anufacturer instructions.

8. Annotate aircraft records that Part B of this bulletin has been accomplished.

9. Return aircraft to service.

PART C SCHEDULED VISUAL IN SPECTION REQUIREMENTS FOR P/N 412-321-104 AND P/N 412-321-304

NOTE The following crosstube inspection is to be incorporated into the inspection intervals/methods identified in Instructions for Continued Airworthiness, report number AA-01136.

NOTE Crosstube visual inspection is conducted with aircraft at rest on skid landing gear; minimum gr oss weight at inspection is 9,000 pounds.

1. Use MIL-PRF-87937 cl eaning compound prepared in accordance with the manufacturer’s recommendations to clean all residue and dirt from the cross tube surfaces shown in Figure 1. 2. Using at least 10X magnification and a strong light source, visually inspect the clear coated areas for indications of cracking.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 8 of 15 3. If cracking is suspected, remove clear coat and primer per steps 2 thru 4 of Part B , and fluorescent penetrant inspect crosst ube per ASTM E1417, Type I, Method B, C, or D, Class 2, in accordance with Bell Helicopter Standard Practices Manual (BHT-ALL-SPM). If cracking is not confirmed, reapply clear coat and primer per steps 6 and 7 of Part B . If cracking is confirmed, remove crosstube from service.

WARNING IF CRACKING IS DISCOVERED , THE CROSSTUBE IS NO LONGER AIRWORTHY AND MUST BE IMMEDIATELY REPLACED. REPLACE CROSSTUBE PER APPLICABLE INSTRUCTIONS IN INSTRUCTIONS FOR CONTINUED AIRWORTHINESS, REPORT NUMBER AA-01136

4. Annotate aircraft records to indicate that Part C of this bulletin has been accomplished; and return aircraft to service.

PART D SCHEDULED LANDING GEAR DEFLECTION INSPECTION REQUIREMENTS FOR P/N 412-321-104 AND P/N 412-321-304

NOTE The following crosstube inspection is to be incorporated into the inspection intervals/methods identified in Instructions for Continued Airworthiness, report number AA-01136. 1. Hoist or jack the helicopter until no weight is on the skid gear.

2. Measure the lateral distance bet ween the two forward Crosstube cap assemblies. Measure the lateral dist ance between the two aft Crosstube cap assemblies. Divide these dimensions by two to determine the helicopter centerline, BL 0.00.

3. Measure the Crosstube horiz ontal deflection from the ce nterline of the helicopter, BL 0.00, to the outsi de of the skid tubes.

4. The Crosstube horizontal deflection as measured in step 3 above must be within the limits as shown in Figur e 2. Crosstubes that measure outsi de of the limits must be replaced. 5. Inspect landing gear assembly in acco rdance with Instructi ons for Continued Airworthiness report number AA- 01136 and BHT-412-MM damage limits. 6. Repair or replace components that ar e damaged in excess of repairable limits.

7. Annotate aircraft records to indicate that Part D of this bulletin has been accomplished; and return aircraft to service.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 9 of 15 PART E COMPONENT OVERHAUL REQU IREMENTS FOR P/N 412-321-104 AND P/N 412-321-304 The Component Overhaul Schedule, Table 2, summarizes the overhaul interval for high aft crosstube components.

NOTE Neither the assignment of a time period overhaul of a component nor failure to assign a time period for overhaul of a component constitutes a warra nty of any kind. The only warranty applicable to the co mponent is that warranty included in the Purchase Ag reement for the component. Time between overhauls and inspection peri ods is based upon experience, testing, and engineering judgment and is subject to change at the sole discretion of Aeronautical Accessories Inc. or an appropriate government agency.

WARNING ALL PARTS REMOVED, DUE TO REACHING THEIR LIMITS OR AS A RESULT OF AN ACCIDENT/INCIDENT AND DEEMED UNAIRW ORTHY, SHALL BE PERMANENTLY MARKED AS SCRAP OR PHYSICALLY DESTROYED TO THE EXTENT THAT THERE IS NO CHANCE OF REPAIR OR INSTALLATION ON ANY HELICOPTER OR COMPONENT.

TABLE 2 – COMPONENT OVERHAUL SCHEDULE

PART NUMBER NOMENCLATURE OVERHAUL INTERVAL

412-321-104 Aft Crosstube, High Skid Gear Prior to 7500 Takeoff/Landings and every 5000 Takeoff/Landings thereafter

412-321-304 Aft Crosstube, High Skid Gear Prior to 7500 Takeoff/Landings and every 5000 Takeoff/Landings thereafter

E.1 Disassembly Instructions 1. Remove Aft Crosstube Assembly in acco rdance with Instructions for Continued Airworthiness report number AA-01136. 2. Remove Aft Crosstube Beam Assembly in accordance with Instructions for Continued Airworthine ss report number AA-01136.

NOTE The Upper Center Support on the Aft Crosstube is bonded with structural adhesive and is not designed for removal. 3. Remove both Aft Crosstube Clamp Asse mblies in accordance with Instructions for Continued Airworthiness report number AA-01136.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 10 of 15 E.2 Cleaning and Preparation 1. Remove aged sealant by scraping with a shar p piece of plastic. Finish by lightly sanding with 400 grit abrasive cloth or paper in the longitudinal direction of the crosstube.

WARNING DO NOT SAND CROSSTUBE IN A CIRCUMFERENTIAL DIRECTION. 2. Prepare crosstube by chemically re moving crosstube paint and primer outboard of the Upper Center Support to top of saddles. See Figure 3.

CAUTION Protect Upper Center Support area to prevent contamination by paint strippers and penetrant inspection chemicals. a. Apply MIL-R-81294, Type I or II chem ical paint remover with a brush and allow it to set from 15 to 45 minutes to soften paint. b. Using a stiff fiber brush and clean wa ter, rinse paint from crosstube. If required, use abrasive pad (Scotch-Br ite, Type A) and MIL-R-81294, Type I or II chemical paint remover to aid in lifting paint. Brush crosstube with abrasive pad in the longitudinal directi on, using care so as not to abrade crosstube metal surface. c. Rinse part clean with clean water and dry thoroughly. Reapplication of chemical paint remover may be required to ensure that paint and primer is completely removed so that the (bare) metal surface of the cross tube is clearly visible. 3. When parts are not to be processed immediately after cleaning, apply corrosion preventive oil, to all part s to protect against corrosi on. Wrap parts in barrier material and secure with tape. E.3 Inspection

1. Inspect crosstube outboard of Upper C enter Support area using fluorescent penetrant method per ASTM E1417, Type I, Method B, C, or D, Level 2, in accordance with Bell Helicopter Standar d Practices Manual (BHT-ALL-SPM). Refer to BHT-ALL-SPM for fluoresc ent penetrant inspection procedures. 2. Damage limits are specified in Instruct ions for Continued Airworthiness, report number AA-01136 and BHT-412-MM-2 (Bell He licopter model 412 Maintenance Manual). E.4 Repair 1. Repair damage within repai rable limits in accordance with Instructions for Continued Airworthine ss report number AA-01136.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 11 of 15 2. Refinish crosstube by applying MIL- PRF-85582 primer a nd MIL-PRF-85285 paint (or equivalent) per manufacturer instructions to the stripped areas. The areas to be inspected per Part B should be masked to omit MIL-PRF-85285 paint as shown in Figure 1. Paint inspection areas with MIL-PRF-85285 Type I Gloss Clear coat as described in Part B of this bulletin. E.5 Assembly Instructions 1. Assemble both Aft Crosstube Clamp Asse mblies in accordance with Instructions for Continued Airworthiness report number AA-01136.

2. Assemble Aft Crosstube Beam Assembly in accordance with Instructions for Continued Airworthine ss report number AA-01136. 3. Install Aft Crosstube Assembly to airc raft in accordance with Instructions for Continued Airworthine ss report number AA-01136.

4. Annotate aircraft records to indicate that Part E of this bulletin has been accomplished; and return aircraft to service.

PART F TOWING AIRCRAFT Helicopter towing operations must be conducted in accordance with BHT-412-MM-2 (Bell Helicopter model 412 Maintenance Manual) and 412-OSN-07-32 (Landing Gear Maintenance and Handli ng). Manufacturer towing r equirements are applicable to any aircraft being towed with weight on gear. This includes towing aircraft with ground handling wheels inst alled and aircraft resti ng on moveable platforms.

CAUTION Failure to follow manufacturer towing instructions may result in crosstube damage and/or failure.412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 12 of 15 FIGURE 1 – CLEAR COAT AND INSPECTION AREA412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 13 of 15 “A” “B” Part Number Model Effectivity in. mm in. mm 412-321-104 / 412-321-304 412 Aft Crosstube (High) 57.00 1448 59.00 1499

FIGURE 2 – HIGH LANDING GEAR DEFLECTION LIMITS412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 14 of 15 FIGURE 3 – PAINT REMOVAL AREA412, 412EP, 412CF ALERT SERVICE BULLETIN ASB No. AA-07109 AB412, AB412EP HIGH AFT CROSSTUBE No Revision

AERONAUTICAL ACCESSORIES, INC. April 3, 2008 Page 15 of 15 FIGURE 4 – HISTORICAL SERVICE RECORD