ALERT SERVICE BULLETIN 

DATE

REVISION NOTICE 

A Subsidiary of Textron Inc.

Nov 14, 2005 

TO: All Owners/Operators of Bell 427 Helicopters

SUBJECT: REVISION “A” TO ALERT SERVICE BULLETIN 427-05-12: 

 CLEVIS ASSEMBLY-HYDRAULIC SERVO ASSEMBLY PART NUMBER 

41011300 AND 41011700 

Revision “A” to this Alert Service Bulletin introduces the rewritten Hydraulic Research 

Textron Bulletin. Included in the rewritten bulletin are the following changes: 

• The HR Textron Customer Service telephone number phone number, is added 

in Section 1, Step F. 

• The compliance in Section 2, Step A, is changed. 

• The inspection criteria are clarified in Section 2. 

• HR Textron-Authorized Service Centers telephone and fax number are added 

in Table 1.

• A better graphic view of the proper installation is shown in Figure 1. 

AN APPROPRIATE ENTRY SHOULD BE MADE IN THE AIRCRAFT LOGBOOK UPON ACCOMPLISHMENT 

IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEW OWNER
NO. 

 

DATE 

PAGE 

 DATE 

 REV 

ALERT SERVICE BULLETIN 

A Subsidiary of Textron Inc.

AN APPROPRIATE ENTRY SHOULD BE MADE IN THE AIRCRAFT LOGBOOK UPON ACCOMPLISHMENT 

IF OWNERSHIP OF AIRCRAFT HAS CHANGED PLEASE FORWARD TO NEW OWNER

427-05-12 

Nov 14, 2005 Oct 12, 2005 

A 1 

MODEL AFFECTED: 427

SUBJECT: CLEVIS ASSEMBLY HYDRAULIC SERVO

ASSEMBLY, PART NUMBER 41011300 AND 

41011700 

HELICOPTERS AFFECTED: Model 427 helicopters serial number 56001 

through 56046 and 58001 and 58002. 

[Model 427 helicopters serial numbers 56047 and 

58003 and subsequent will have the intent of this 

bulletin accomplished prior to delivery.] 

COMPLIANCE: See vendor bulletin.

DESCRIPTION: 

The purpose of this bulletin is to achieve complete distribution of the attached vendor

bulletin to the current affected model distribution list on record by Bell Helicopter. 

APPROVAL: 

See vendor bulletin approval. 
SERVICE BULLETIN

CLEVIS ASSEMBLY – HYDRAULIC SERVOACTUATOR, PART NUMBER 41011300

1. Planning Information

A. Effectivity 

This service bulletin applies to the clevis assembly, P/N 41009477-101, used on the 

hydraulic servo assembly, HR part number 41011300-101 (BHT 206-076-062-105 

and -111). The intent of this service bulletin has been incorporated into these servo 

actuators with serial numbers 807 and subsequent. 

B. Reason 

HR has discovered the possibility that the shaft (215) (refer to Figure 1) could be 

loose. The looseness is as a result of lock washer tabs (220), improperly bent over 

the flat surface of the nut (225) or the flat surface of the clevis assembly (205). 

C. Description 

This service bulletin defines mandatory inspection of nut, shaft and, clevis assembly 

for possible looseness as result of improper lock washer installation. This 

discrepancy is not traceable or identifiable except by inspection. This inspection is 

applicable to servos identified in paragraph 1.A.of this bulletin. 

D. Approval 

HR Textron Engineering. 

E. Manpower 

Approximately 2.0 man-hour, are required to remove and reinstall each hydraulic 

servo actuator and approximately 0.5 man-hour is sufficient to conduct visual 

inspection. 

F. Material Price and Availability 

Prior to returning any servo to service center, contact HR Textron Customer Service 

and Field Service Manager at: 25200 West Rye Canyon Road, Santa Clarita, CA 

91355-1265; 661-702-5509, or 661-702-5358 (tel. numbers) 

mhowell@hrtextron.Textron.com (email); or 661-702-5970 (fax). Provide HR 

Textron with the part number, serial number, time since new for new servo and in 

addition time since overhauled or repaired and the facility if the servo was recently 

overhauled or repaired. This applies to servos that are found with loose nut, shaft 

or clevis assembly or improperly installed lock washer only. Warranty claims will be 

handled on a case-by-case basis. 

G. Tooling Price and Availability 

New tools are not required. 

November 9, 2005 41011300-67-01 

EXPORT CONTROL WARNING

This document contains technical data whose export, transfer, disclosure, and further publication are restricted by the applicable 

export laws and regulations of the United States of America, including the Export Administration Act of 1979, as amended, and the

Export Administration Regulations. Violations of these laws and regulations are subject to severe civil, criminal, and administrative

penalties. 

Revision 2 Page 1 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622
SERVICE BULLETIN

H. Weight and Balance 

Not affected. 

I. Electrical Load Data 

Not affected. 

J. References 

67-32-09 Component Maintenance Manual with Illustrated Parts List (for) Hydraulic 

Servo Actuator Assembly part number 41011300-101 (BHT 206-076-062-105 and 

-111). 

K. Other Publications Affected 

The intent of this service bulletin will be incorporated into the next revision of 

67-32-09. 

2. Accomplishment Instructions

A. Within the next 10 flight hours or before December 15, 2005, whichever comes first, 

accomplish this one-time mandatory inspection. 

B. Retract the boot (230) and perform the following inspections: 

1. Applying hand pressure only, and check if the nut, the shaft or the clevis 

assembly is turning independently from one another. 

2. If the shaft will turn independently to the nut or the clevis assembly, prior to 

the next flight, the actuator shall be removed from service and forwarded to 

HR Textron or one of the HR Textron Service Centers listed in Table 1. 

Check step 1.F. for condition. 

3. If the shaft is not turning independently from the nut or the clevis assembly 

proceed with step 2.B.4. 

4. Check if at least one tab of the lock washer is bent flush against one of the 

nut flat surface and if at least one tab of the lock washer is bent flush against 

one of the two flat surfaces of the clevis assembly. Lock washer tab must 

also be in line with the flat surface of the nut and clevis assembly. If the lock 

washer tabs are not bent flush against the nut and clevis assembly or are not 

in line with the flats, proceed with the following steps. 

5. If the lock washer tabs are not bent flush against the nut or clevis assembly 

flat surface, use needle-nosed pliers and make sure the lock washer tab is 

flush against nut or the flat surface of the clevis assembly. 

November 9, 2005 41011300-67-01 

Use or disclosure of data on this page are subject to the restriction on Page 1. 

Revision 2 Page 2 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622
SERVICE BULLETIN 

6. If the lock washer tab is on the edge or not aligned with a flat surface (nut or 

clevis assembly). Within the next 300 hours, but not later than April 30, 2006, 

the actuator shall be removed from service and forwarded to HR Textron or 

one of the HR Textron Service Centers listed in Table 1. Check step 1.F. for 

condition. 

C. If the servo meets all the requirements of the inspection or if the operator can 

accomplish the corrective action, the operator may perform the necessary corrective 

repairs. Remove modification plate from servo and metal-impression stamp or 

vibro-etch an abbreviated service bulletin number (67-01) on modification plate to 

identify compliance with this service bulletin. Modification plates are available; HR 

Textron will provide replacement modification plates if necessary. Corrective action 

accomplished by HR Textron or approved repair station will have the same 

identification added to modification plate. 

Table 1. HR Textron-Authorized Service Centers 

AEM Ltd Helicopter Support Inc. 

8 Wilton Road 116 Quarry Road 

Haine Industrial Estate Trumbull, CT 06611 (USA) 

Ramsgate, Kent CT12 5HE (England) 

Tel; 001-(44)-1-843-591-381 

Fax; 011-(44)-1-843-592-641 

Tel; (203) 416-4300 

Fax; (203) 416-4282 

JAMCO Corp 

Stansted Airport 6-11-25 Osawa Mitaka 

Stansted, Essex CM24 1RB (England) 

Tel; 011-(44)-1-279-680-030 

Fax; 011-(44)-1-279-680-040 

Tokyo 181 (Japan) 

Tel; 011-(81) 422-31-6111 

Fax; 011 (81) 422-32-6998 

HASE Motorflug GmbH

Helicopter Accessory Service Inc. East Baden-Airpark 

10102 Aileron Avenue Gebaude C-312 

Pensacola, FL 32506 (USA) D-77836 Rheinmunster, Germany 

Tel; (850) 456-8339 

Fax; (850) 456-5117 

Tel; 011 (49) 7229-301-430 

Fax; 011 (49) 7229-301-433 

HAS West Ostermans Aero AB 

Helicopter Accessory Service Inc. West Box 116 

10985 Penrose Street SE-190 46 Stockholm-Arlanda 

Sun Valley, CA 91352 (USA) 

Tel; (818) 767-2214 

Fax; (818) 767-2699 

Sweden 

Tel; 011-(46)-8-593-787-00 

Fax; 011-(46)-8-593-787-90 

HELITRADES HELITRADES

18 Terry Fox Drive Site 5, Box 7, RR 2 Airdrie Airport 

Vanleek Hill, Ontario, Canada K0B 1R0 

Tel; (613) 678-3027 

Fax; (613) 678-2776 

Airdrie, Canada K0B 1R0 

Tel; (403) 912-4658 

Fax; (403) 948-6475 

November 9, 2005 41011300-67-01 

Use or disclosure of data on this page are subject to the restriction on Page 1. 

Revision 2 Page 3 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622
Clevis Assembly 

Figure 1 

November 9, 2005 41011300-67-01 

Use or disclosure of data on this page are subject to the restriction on Page 1. 

Revision 2 Page 4 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622
SERVICE BULLETIN

CLEVIS ASSEMBLY – HYDRAULIC SERVOACTUATOR, PART NUMBER 41011700

1. Planning Information

A. Effectivity 

This service bulletin applies to the clevis assembly, P/N 41009477-101, used on the 

hydraulic servo assembly, HR part number 41011700-101 (BHT 206-076-062-109). 

The intent of this service bulletin has been incorporated into these servo actuators 

with serial numbers 230 and subsequent. 

B. Reason 

HR has discovered the possibility that the shaft (215) (refer to Figure 1) could be 

loose. The looseness is as a result of lock washer tabs (220), improperly bent over 

the flat surface of the nut (225) or the flat surface of the clevis assembly (205). 

C. Description 

This service bulletin defines mandatory inspection of nut, shaft and, clevis assembly 

for possible looseness as result of improper lock washer installation. This 

discrepancy is not traceable or identifiable except by inspection. This inspection is 

applicable to servos identified in paragraph 1.A.of this bulletin. 

D. Approval 

HR Textron Engineering. 

E. Manpower 

Approximately 2.0 man-hour, are required to remove and reinstall each hydraulic 

servo actuator and approximately 0.5 man-hour is sufficient to conduct visual 

inspection. 

F. Material Price and Availability 

Prior to returning any servo to service center, contact HR Textron Customer Service 

and Field Service Manager at: 25200 West Rye Canyon Road, Santa Clarita, CA 

91355-1265; 661-702-5509, or 661-702-5358 (tel. numbers) 

mhowell@hrtextron.Textron.com (email); or 661-702-5970 (fax). Provide HR 

Textron with the part number, serial number, time since new for new servo and in 

addition time since overhauled or repaired and the facility if the servo was recently 

overhauled or repaired. This applies to servos that are found with loose nut, shaft 

or clevis assembly or improperly installed lock washer only. Warranty claims will be 

handled on a case-by-case basis. 

November 9, 2005 41011700-67-01 

EXPORT CONTROL WARNING

This document contains technical data whose export, transfer, disclosure, and further publication are restricted by the applicable

export laws and regulations of the United States of America, including the Export Administration Act of 1979, as amended, and the

Export Administration Regulations. Violations of these laws and regulations are subject to severe civil, criminal, and administrative

penalties. 

Revision 2 Page 1 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622
SERVICE BULLETIN

G. Tooling Price and Availability 

New tools are not required. 

H. Weight and Balance 

Not affected. 

I. Electrical Load Data 

Not affected. 

J. References 

67-31-10 Component Maintenance Manual with Illustrated Parts List (for) Hydraulic 

Servo Actuator Assembly part number 41011700-101 (BHT 206-076-062-109). 

K. Other Publications Affected 

The intent of this service bulletin will be incorporated into the next revision of 

67-31-10. 

2. Accomplishment Instructions

A. Within the next 10 flight hours or before December 15, 2005, whichever comes first, 

accomplish this one-time mandatory inspection. 

B. Retract the boot (230) and perform the following inspections: 

1. Applying hand pressure only, and check if the nut, the shaft or the clevis 

assembly is turning independently from one another. 

2. If the shaft will turn independently to the nut or the clevis assembly, prior to 

the next flight, the actuator shall be removed from service and forwarded to 

HR Textron or one of the HR Textron Service Centers listed in Table 1. 

Check step 1.F. for condition. 

3. If the shaft is not turning independently from the nut or the clevis assembly 

proceed with step 2.B.4. 

4. Check if at least one tab of the lock washer is bent flush against one of the 

nut flat surface and if at least one tab of the lock washer is bent flush against 

one of the two flat surfaces of the clevis assembly. Lock washer tab must 

also be in line with the flat surface of the nut and clevis assembly. If the lock 

washer tabs are not bent flush against the nut and clevis assembly or are not 

in line with the flats, proceed with the following steps. 

5. If the lock washer tabs are not bent flush against the nut or clevis assembly 

flat surface, use needle-nosed pliers and make sure the lock washer tab is 

flush against nut or the flat surface of the clevis assembly. 

Use or disclosure of data on this page are subject to the restriction on Page 1. 

November 9, 2005 41011700-67-01 

Revision 2 Page 2 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622
SERVICE BULLETIN 

6. If the lock washer tab is on the edge or not aligned with a flat surface (nut or 

clevis assembly). Within the next 300 hours, but not later than April 30, 2006, 

the actuator shall be removed from service and forwarded to HR Textron or 

one of the HR Textron Service Centers listed in Table 1. Check step 1.F. for 

condition. 

C. If the servo meets all the requirements of the inspection or if the operator can 

accomplish the corrective action, the operator may perform the necessary corrective 

repairs. Remove modification plate from servo and metal-impression stamp or 

vibro-etch an abbreviated service bulletin number (67-01) on modification plate to 

identify compliance with this service bulletin. Modification plates are available; HR 

Textron will provide replacement modification plates if necessary. Corrective action 

accomplished by HR Textron or approved repair station will have the same 

identification added to modification plate. 

Table 1. HR Textron-Authorized Service Centers 

AEM Ltd Helicopter Support Inc. 

8 Wilton Road 116 Quarry Road 

Haine Industrial Estate Trumbull, CT 06611 (USA) 

Ramsgate, Kent CT12 5HE (England) 

Tel; 001-(44)-1-843-591-381 

Fax; 011-(44)-1-843-592-641 

Tel; (203) 416-4300 

Fax; (203) 416-4282 

JAMCO Corp 

Stansted Airport 6-11-25 Osawa Mitaka 

Stansted, Essex CM24 1RB (England) 

Tel; 011-(44)-1-279-680-030 

Fax; 011-(44)-1-279-680-040 

Tokyo 181 (Japan) 

Tel; 011-(81) 422-31-6111 

Fax; 011 (81) 422-32-6998 

HASE Motorflug GmbH

Helicopter Accessory Service Inc. East Baden-Airpark 

10102 Aileron Avenue Gebaude C-312 

Pensacola, FL 32506 (USA) D-77836 Rheinmunster, Germany 

Tel; (850) 456-8339 

Fax; (850) 456-5117 

Tel; 011 (49) 7229-301-430 

Fax; 011 (49) 7229-301-433 

HAS West Ostermans Aero AB 

Helicopter Accessory Service Inc. West Box 116 

10985 Penrose Street SE-190 46 Stockholm-Arlanda 

Sun Valley, CA 91352 (USA) 

Tel; (818) 767-2214 

Fax; (818) 767-2699 

Sweden 

Tel; 011-(46)-8-593-787-00 

Fax; 011-(46)-8-593-787-90 

HELITRADES HELITRADES

18 Terry Fox Drive Site 5, Box 7, RR 2 Airdrie Airport 

Vanleek Hill, Ontario, Canada K0B 1R0 

Tel; (613) 678-3027 

Fax; (613) 678-2776 

Airdrie, Canada K0B 1R0 

Tel; (403) 912-4658 

Fax; (403) 948-6475 

November 9, 2005 41011700-67-01 

Use or disclosure of data on this page are subject to the restriction on Page 1. 

Revision 2 Page 3 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622
Clevis Assembly 

Figure 1 

November 9, 2005 41011700-67-01 

Use or disclosure of data on this page are subject to the restriction on Page 1. 

Revision 2 Page 4 of 4 

25200 W. Rye Canyon Road • Santa Clarita, California 91355-1265 • 661/294-6000 • FAX 661/259-9622