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Bell Helicopter No. 407-06-72 

ALERT SERVICE BULLETIN-~ 

DATE A Subsidiary of Textron 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

the helicopter LLiiZstEoRf serial affected number horizontal they were stabilizers installed 407-023-801-109 

on at delivery. and , 

~-

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 NEW OWNER 

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 of the 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 of this bulletin are Transport Canada approved. 

MANPOWER: 

Approximately 2.5 man-hours are required to complete Part I of this 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 of this 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 of this ASB. 

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. 

Part Number Nomenclature Quantity 

407-023-801-1 09 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 

299-94 7-1 OOTY2CL2G50 

MIL-PRF-81733 TY2 PT 

ACETONE GALLON 

EWDE072 

299-947-11 OTY3CL 1 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-486 
ACCOMPLISHMENT INSTRUCTIONS: 

PART 1: Horizontal stabilizer serial number verification 

ASB 407-06-72 

Page 5 of 8 

1. Determine if you 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 of the stabilizer (7). 

-NOTEHorizontal stabilizer does not require to be removed from tail boom. 

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 tail boom 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. If the serial number of the 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. If you 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 tail boom 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 tail boom (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 of the 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 

accomplished 
ASB 407-06-72 

Page 8 of 8 

1. Fin let 

2. Slat assembly 

3. Rivet 

4. Upperatlachmentsupport 

5. Loweratlachmentsupport 

6. Tail boom 

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 lower doubler 

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 Post TB 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