TECHNICAL BULLETIN 206-12-202 30 October 2012 MODEL AFFECTED: SUBJECT: HELICOPTERS AFFECTED: 206A/B (TH-67) FUEL TRANSFER PUMP AND CENTRIFUGAL BOOST PUMP CANISTER, UPGRADE OF Serial numbers 4 through 4690 and 5101 through 5313 that are equipped with boost pumps P/N 206-062-681-101. [Serial number 4691 and subsequent and 5314 and subsequent have the intent of this bulletin accomplished prior to delivery.] COMPLIANCE: At customer s option. DESCRIPTION: Bell Helicopter has been made aware of field reports which indicate possible engine sputtering when operating under low fuel conditions. For aircraft serial numbers 4 through 3041 that have been modified as per Technical Bulleting 206-80- 45 or for aircraft serial numbers 3042 through 4690 that have pump assembly P/N 206-062-681-101Parker Hannifin Corporation have made a change to the design of the canister housings to improve the performance of the umbrella check valve. These valves aid the pump in venting fuel from the pump s motor and impeller cavities and are also essential in ensuring that fuel does not leak from the pump when the cartridge is removed. This technical bulletin informs operators of the availability of an upgrade kit (P/N 2T128-1) that allows the fuel pump to be upgraded to the latest design and provides instructions for installing this canister upgrade kit on to the boost pump. (Refer to Figure 1.) APPROVAL: The engineering design aspects of this bulletin are Transport Canada Civil Aviation (TCCA) approved. Page 1 of 7
CONTACT INFO: For any questions regarding this bulletin, please contact: MANPOWER: Bell Helicopter Product Support Engineering - Light Helicopters Tel: 450-437-2862 / 1-800-363-8023 / pselight@bh.com Approximately 7.5 man-hours are required to complete this bulletin. This estimate is based on hands-on time, and may vary with personnel and facilities available. WARRANTY: There is no warranty credit applicable for parts or labor associated with this bulletin. MATERIAL: Required Material: The following material is required for the accomplishment of this bulletin and may be obtained through your Bell Helicopter Textron Supply Center. One kit is required for each pump. Part Number Nomenclature Qty 2T128-1 Kit 1 Included in the kit are : MS35338-137 Lock Washer 2 A2-80-1 Canister Flange 1 A1-1372-1 Pump Canister Assembly 1 C5-79-1 Spacer Washers 2 MS29513-035 O-Ring 1 For spare parts that are included in this kit, contact Parker Hannifin Corporation Customer Care: Fluid Systems Division, 16666 Von Karman Ave, Irvine, CA, U.S. 92606 Ph: 949 833-3000 Fax 949 851-3788 Website:WWW.Parker.com/ag/nad Page 2 of 7
Consumable Material: The following material is required to accomplish this bulletin, but may not require ordering, depending on the operator s consumable material stock levels. This material may be obtained through your Bell Helicopter Textron Supply Center. Part Number Nomenclature Qty Reference * Perma-Lok HL-126 Permabond Sealant, A/R C-320 Anaerobic, Thread locking, Acetone Solvent A/R C-316 Caps and plugs A/R C-428 * C-XXX numbers refer to the consumables list in BHT-ALL-SPM Standard Practices Manual SPECIAL TOOLS: Vibro etch marker. WEIGHT AND BALANCE: Not affected. ELECTRICAL LOAD DATA: Not affected. REFERENCES: BHT-206A/B-Series-IPB Illustrated Parts Breakdown BHT-206A/B-Series-MM Maintenance Manual PUBLICATIONS AFFECTED: None affected. ACCOMPLISHMENT INSTRUCTIONS: 1. Prepare helicopter for maintenance. a. Defuel the helicopter (BHT-206A/B-Series-MM, Chapter 12). b. Remove the fuel boost pump assembly P/N 206-063-602-001 from aft main fuel cell (BHT-206A/B-Series-MM, Chapter 28). 2. Refer to Figure 2. Remove canister assembly (5) from the fuel boost pump as follows: Page 3 of 7
-NOTE- Screw security is ensured by the application of Perma-Lok HL-126 (C-320) during original manufacture. May require heat application to remove screws. a. Remove both screws (2) and lock washers (3) holding canister flange (4) to pump housing (1). b. Remove and discard canister flange (4), canister (5) and spacer washers (6). c. Remove and discard canister o-ring (7). d. Remove any loose accumulation of foreign material from disassembled parts by washing in clean Acetone (C-316) solvent and drying with clean dry compressed air. 3. Refer to Figure 2. Reassemble fuel canister as follows: a. Install new lubricated o-ring (7) in machined groove of pump housing (1). b. Install canister (5), spacer washers (6) and canister flange (4) chamfer side down. c. Apply Perma-Lok HL-126 (C-320) to the threads of the screws prior to tightening. d. Install lock washers (3) and screws (2) and torque screws to 11-13 inchpounds. 4. Refer to Figure 3. Add serial number and part number suffix as follows: a. Lightly vibro etch suffix FM at the end of the part number. b. Lightly vibro etch suffix SL75 at the end of the serial number (as per Service Letter 75 published by Parker Aerospace for P/N 1C38-1). 5. Reinstall boost pump assembly on aft main fuel cell (BHT-206L-MM, Chapter 28). 6. Make an entry in the helicopter logbook and historical service records indicating compliance with this Technical Bulletin. Page 4 of 7
Figure 1: Field Retrofit of Existing Fuel Boost Pump Assembly Page 5 of 7
Figure 2: Pump Mounting Flange/Housing P/N 206-062-681-101 Page 6 of 7
Figure 3: Serial Number and Part Number Suffix Page 7 of 7