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**~** 

## Bell Helicopter No. 407-06-72 

### ALERT SERVICE 

# BULLETIN-~ DATE A Subsidiary ofTextron Inc. DATE SEP 12, 2006 1 of8



# ~ REV

MODEL AFFECTED: SUBJECT: HELICOPTERS AFFECTED: PAGE

407 HORIZONTAL STABILIZER 407-023-801-109, INSPECTION AND REPLACEMENT OF All Model 407 listed in Table 1 and all Model 407 that had the stabilizer 407-023-801-109 replaced after March 01, 2004. 

# ~

**~** TABSLTEA1B:

### 1 LLiiZstEoRf affected horizontal stabilizers 407-023-801-109 and



# ~- the helicopterserial numberthey were installed on at delivery. , ORIGINAL STABILIZER ORIGINAL S/N ALLOCATION S/N ALLOCATION



## ~ BP725 53603 BP780 53643 _, BP750 53628 BP781 53645 BP751 53620 BP785 Note BP752 53621 BP787 53647 BP753 53624 BP788 53650 - BP756 53626 BP789 Note - BP758 53627 BP790 53652 BP760 Note BP795 53657 BP765 53631 BP796 53658 BP769 Note BP797 53659 - BP770 53634 BP800 Note - BP771 53637 BP801 Note BP775 Note BP802 Note BP776 53639 BP803 53663 BP778 Note BP805 53661

**~** BP779 53644 BP829 Note , NOTE:

- These stabilizers were sold in Spare and may have been installed on any fielded 407

IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEWOWNER AN APPROPRIATE ENTRY SHOULD BE MADE IN THE AIRCRAFT LOGBOOK UPON ACCOMPLISHMENT

**~....,~....,~~~**

**...., ~~....,~....,....,....,** ASB 407-06-72 Page 2 of 8 COMPLIANCE:

DESCRIPTION: PART I AND PART II Within the next 100 hours but no later than 30 days after receipt of this bulletin and every 600 hours or annual inspection thereafter until PART Ill is accomplished . PART 

### Ill No later than September 30, 2008. It has been determined by Bell Helicopter that the horizontal stabilizers 407-023-801- 109 as listed in Table 1 , may have flaws present on the inside surface of the upper and/or lower skin at the tailboom attachment inserts area. Over time the flaws may produce cracks in the upper and/or lower skin . PART I of this bulletin provides instructions to verify the serial number ofthe horizontal stabilizer. PART II of this bulletin introduces a first inspection and a recurring 600 hour I annual inspection that have to be performed until PART Ill can be accomplished. PART Ill of this bulletin mandates the replacement of all affected stabilizers. This will be considered as the terminating action for the recurring inspection introduced by PART II of this bulletin . APPROVAL: The engineering design aspects ofthis bulletin are Transport Canada approved. MANPOWER: Approximately 2.5 man-hours are required to complete Part I ofthis bulletin. Approximately 4.0 man-hours are required to complete Part II of this bulletin. Approximately 8.0 man-hours are required to complete Part Ill of this bulletin. Manhours are based on hands-on time, and may vary with personnel and facilities available.WARRANTY: ASB 407-06-72 Page 3 of 8

Owner I Operators of aircraft that have the subject serial numbers installed on their aircraft or that have the one or more of the subject serial numbers in their stock that comply with the instructions outlined in this bulletin are eligible for 100% credit for the replacement part mentioned in the "Required Material" section ofthis bulletin . To Receive This Credit: • Purchase the required part from an approved BHTI supply source. • Comply with this bulletin no later than 30 September, 2008. • Submit a completed MMIR report to BHTI no later than 30 days after completion of this bulletin. Customers that fail to comply with the instructions outlined in this bulletin before September 30, 2008 are not eligible for the special warranty provisions listed above. Exclusions To Warranty: Warranty consideration for parts found in the "Consumable Material" section of this bulletin and labor to inspect or remove and replace the horizontal stabilizer are not a subject ofthis ASB. MATERIAL: Required Material: The following material is required for the accomplishment of this bulletin and may be obtained through your Bell HelicopterTextron Supply Center. Part Number Nomenclature Quantity 407-023-801-109 Horizontal stabilizer 1 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.ASB 407-06-72 Page 4 of 8

Part Number EC2216 8/A TAN N/S 299-947-1 OOTY2CL2G50 MIL-PRF-81733 TY2 PT ACETONE GALLON EWDE072 299-947-11 OTY3CL1 21 PETROLATUM 13 OZ P-P-1 01 CCCC0046 Notes: Nomenclature Adhesive Adhesive Sealant Acetone (per Q-A-51) Primer Teflon tape (2 inch wide) Petrolatum jelly Aluminum oxide sandpaper Cheesecloth 1 . As an alternate, use Methyl Ethyl Ketone (C-309) 2. As an alternate, use MIL-P-23377 SPECIAL TOOLS: None required WEIGHT AND BALANCE: Weigh and balance is not affected . ELECTRICAL LOAD DATA: Not affected REFERENCES: BHT-407-MM-5, Rev 19, Maintenance Manual , chapter 53. PUBLICATIONS AFFECTED: BHT-407-MM-1, Rev 21, Maintenance Manual, chapter 4. Quantity Reference 1 C-322 50 g C-317 1 pint C-392 I gallon C-316(Note 1) 1 quart C-204(Note2) 1 roll C-460 13 oz C-008 1 C-423 1 C-486ACCOMPLISHMENT INSTRUCTIONS: PART 1: Horizontal stabilizer serial number verification ASB 407-06-72 Page 5 of 8

1 . Determine ifyou have an affected horizontal stabilizer as listed in Table 1 . Refer to Figure 1. Part number and serial number can be found on identification tag (24) that is located centerline on the upper surface ofthe stabilizer (7).-NOTEHorizontal stabilizer does not require to be removed from tailboom . CAUTION Protection underneath stabilizer is required to avoid damage to stabilizer or tailboom when stabilizer is detached from upper supports. Slat may remain installed 1"\owever side movement will be limited. Ensure no damage to slats and/or tailboom surfaces.-NOTEDo not damage liquid shim compound between upper and lower supports (4 and 5) and stabilizer (7) . If liquid shim is damaged during removal of the parts, the shimming procedure shall be repeated as described in BHT-407-MM-5. 2. Remove the screws (9) and the washers (12) from the LIH and R/H lower supports (5). Remove the nuts (22) , washers (21) , and screws (20). 3. Remove LIH and R/H lower supports (5) . 4. Protect tailboom (6) underneath stabilizer (7) with padding or equivalent. 5. Hold the stabilizer (7) . Remove the screws (9) and the washers (12) that attached the LIH and R/H upper supports (4) to stabilizer (7). 6. Carefully lower stabilizer and get access to the identification tag (24). Record the serial number. 7. Ifthe serial number ofthe stabilizer is not listed in Table 1, reinstall the stabilizer in accordance with BHT-407-MM-5 and make an entry to indicate that this bulletin has been accomplished . 8. Ifyou have an affected horizontal stabilizer, accomplish Part II immediately or Part Ill if a replacement stabilizer is available.ASB 407-06-72 Page 6 of 8 PART II: Horizontal stabilizer- First inspection and recurring 600 hour 

### I annual inspection 1. Refer to figure 1 . Inspect the horizontal stabilizer (7) as follows:-NOTEHorizontal stabilizer does not require to be removed from tailboom. CAUTION Protection underneath stabilizer is required to not damage stabilizer or tailboom when stabilizer is detached from upper supports. Slat may remain installed however side movement will be limited . Ensure no damage to slats and/or tailboom surfaces.-NOTEDo not damage liquid shim compound between upper and lower supports (4 and 5) and stabilizer (7) . If liquid shim is damaged during removal of the parts, the shimming procedure shall be repeated as described in BHT-407-MM-5. 2. Remove the screws (9) and the washers (12) from the LIH and R/H lower supports (5) . Remove the nuts (22), washers (21) and screws (20). 3. Remove LIH and R/H lower supports (5) . 4. Protect tailboom (6) underneath stabilizer (7) with padding or equivalent. 5. Hold the stabilizer (7). Remove the screws (9) and the washers (12) that attached the LIH and R/H upper supports (4) to stabilizer (7) . 6. Carefully lower stabilizer (7) and move to left side. 7. Refer to Figure 1 Detail B. Clean and prepare surface of the stabilizer for inspection using cheesecloth (C-486) moistened with acetone (C-316) . 8. Inspect stabilizer in area ofthe inserts (23), on upper and lower surfaces for cracks and deformation using a 1 OX power magnifying glass. Inspect the area around each inserts and between inserts for debonding using tap test method . 9. If any damage is found , the stabilizer is not repairable. Accomplish Part Ill immediately. 1

O

. lf no damage is found, continue with the inspection .11 .Carefully move stabilizer (7) to the right side with care. ASB 407-06-72 Page 7 of 8

12.Repeat step 7 to 9 for the R/H side of stabilizer in area of inserts (23) . 13. 1f any damage is found , the stabilizer is not repairable . Accomplish Part Ill immediately. 14. 1f no damage is found, reinstall horizontal stabilizer in accordance with BHT-407- MM-5. 15. Make an entry in the helicopter records to indicate that Part II of this bulletin has been accomplished and that a recurring 600 hour or annual inspection is required until Part Ill is accomplished . PART Ill: Replacement of horizontal stabilizer 1 . Remove and retire from service affected horizontal stabilizer. Install a serviceable horizontal stabilizer in accordance with BHT-407-MM-5. 2. Make an entry in the helicopter records to indicate that this bulletin has been accomplishedASB 407-06-72 Page 

### 8 of 

### 8

1 . Finlet 2. Slat assembly 3. Rivet 4. Upperatlachmentsupport 5. Loweratlachmentsupport 6. Tailboom 7. Horizontal stabilizer 8. Rivet 9. Screw 10. Support bracket 11. Screw 12. Washer NOTES 

# LG EFFECTIVITY (38.1 mm)

13. Washer 14. Washer 15. Screw 16. Upper and lowerdoubler 17. Casting supports 18. Flap 

# ffi 19. Spacer (left side only) 2 20. Screw 21. Washer 22. Nut 23. Inserts 24. Identification tag Aircraft Serial Numbers 53057 and subs. Aircraft Serial Numbers 53000 to 53056 PostTB 407-96-2. 

# 0 SEALANT MIL-PRF-81733 (C-392) 

# 0 20 TO 25 IN-LBS (2.26 TO 2.83 Nm)



# ffi Tallboom spacer effectivity: PIN 407-030-801-201, 407-030-801-203, 407-030-801-205. 06536001 Figure 1 - Horizontal stabilizer, first inspection and 600 hour I annual inspection