Page 1 of 9 

DRIVE TRAIN ONE-TIME 

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IMPLEMENT 

RECURRING 

INSPECTION

269C-1 ALERT 

SERVICE BULLETIN 

WARNING: THIS DOCUMENT, OR AN EMBODIMENT OF IT IN ANY MEDIA, DISCLOSES INFORMATION WHICH IS PROPRIETARY, IS THE PROPERTY OF SIKORSKY AIRCRAFT 

CORPORATION AND/OR ITS SUBSIDIARIES, IS AN UNPUBLISHED WORK PROTECTED UNDER APPLICABLE COPYRIGHT LAWS, AND IS DELIVERED ON THE EXPRESS CONDITION 

THAT IT IS NOT TO BE USED, DISCLOSED, REPRODUCED, IN WHOLE OR IN PART (INCLUDING REPRODUCTION AS A DERIVATIVE WORK), OR USED FOR MANUFACTURE FOR 

ANYONE OTHER THAN SIKORSKY AIRCRAFT CORPORATION AND/OR ITS SUBSIDIARIES WITHOUT ITS WRITTEN CONSENT, AND THAT NO RIGHT IS GRANTED TO DISCLOSE OR 

SO USE ANY INFORMATION CONTAINED HEREIN. ALL RIGHTS RESERVED. ANY ACT IN VIOLATION OF APPLICABLE LAW MAY RESULT IN CIVIL AND CRIMINAL PENALTIES. 

EXPORT WARNING: THESE COMMODITIES, TECHNICAL DATA OR SOFTWARE ARE SUBJECT TO THE EXPORT CONTROL OF EITHER THE INTERNATIONAL TRAFFIC IN ARMS 

REGULATIONS (ITAR) OR THE EXPORT ADMINISTRATION REGULATIONS (EAR) AND CANNOT BE EXPORTED WITHOUT THE AUTHORIZATION OF EITHER THE DEPARTMENT OF 

STATE OR THE DEPARTMENT OF COMMERCE PRIOR TO EXPORT. EXPORT INCLUDES DISCLOSURE AND OR ACCESS TO COMMODITIES, TECHNICAL DATA OR SOFTWARE BY 

FOREIGN NATIONALS WHETHER LOCATED IN THE UNITED STATES OR ABROAD. THIS REQUIREMENT APPLIES EQUALLY TO FOREIGN NATIONAL EMPLOYEES OF U.S. 

COMPANIES AND THEIR FOREIGN SUBSIDIARIES. 

C1B-036.1 

February 13/12 

Revision 1 February 24/12 

SUBJECT: DRIVE TRAIN - Tail Rotor Drive Shaft Splined Fittings – Perform a One-Time Inspection and 

Implement a Recurring Inspection for Wear 

Section 1. PLANNING INFORMATION 

A. Effectivity All Schweizer model 269C-1. 

B. Purpose To perform a one-time inspection of tail rotor drive shaft splines for wear and to 

implement a recurring visual inspection of the tail rotor drive shaft splines. 

C. Description The tail rotor drive shaft splines are cleaned, inspected and lubricated. Splined 

components that exceed wear limits are removed from service and returned to 

Sikorsky Aircraft Corporation. 

Excessive spline wear in the forward and aft tail rotor drive shaft splined fittings 

can lead to decoupling of the tail rotor drive shaft. A one-time inspection is required 

to check for excessive spline wear and to assure the drive shaft is properly 

lubricated. Follow-on 100 hour periodic inspections of these components are 

required in accordance with HMI CSP-C1-2 Appendix B, Table B-2. 

The implementation of the recurring inspection shall be accomplished subsequent 

to the one-time inspection. 

D. Compliance Compliance is essential. The one-time inspection outlined herein shall be 

accomplished within 100 flight hours or 60 days from the original release date of 

this Alert Service Bulletin (ASB), whichever occurs first. 

E. Approval Inspection Item. 

Sikorsky Aircraft Corporation

6900 Main Street P.O. Box 9729 

Stratford, Connecticut 06615-9129 

(203) 386-4000
269C-1 ALERT C1B-036.1 

SERVICE BULLETIN February 13/12 

Revision 1 ! February 24/12 

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Section 1. PLANNING INFORMATION (Continued) 

F. Manpower (Estimated) 

Task No. of Men No. of Hours Man-Hours* 

Remove tail rotor drive shaft 2 .25 .50 

Clean/inspect spline cavities 1 .50 .50 

Lubricate spline cavities 1 .25 .25 

Install tail rotor drive shaft 2 .30 .60

Total Man-Hours 1.85 

*Estimate does not include time required to prepare helicopter or return it to flight status. 

G. Material 

None. 

H. Tooling 

(1) Lubrication Tool (locally fabricated) 

I. Weight and Balance 

Not affected. 

J. Electrical Load Data 

Not affected. 

K. Software Load Data 

Not applicable. 

L. References 

(1) 269C-1 Basic HMI CSP-C1-2. 

M. Publications Affected 

None. 

N. Attachment 

None. 
C1B-036.1 269C-1 ALERT

February 13/12 SERVICE BULLETIN 

Revision 1 ! February 24/12 

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Section 2. MATERIAL INFORMATION 

A. Basis for Material Data 

Per helicopter. 

B. Bill of Material 

None. 

C. Consumable Material 

Qty Nomenclature Part No. Source

As Req’d Solvent Stoddard Solvent, MIL-PRF-680, 

Type I, or equivalent 

(Alternate) Varsol, MIL-PRF-680, 

Type II, or equivalent 

(1) 

As Req’d Grease Syn-Tech NS-3913-G1, or equivalent (2) 

As Req’d Polypropylene Plastic Sheet, 

0.125-inch thick 

Commercial grade or equivalent (3) 

As Req’d PVC Pipe, 0.75-inch diameter Commercial grade or equivalent (3) 

As Req’d PVC Adhesive Commercial grade or equivalent (3) 

(1) Stoddard solvent is available from www.sciencestuff.com. 

Varsol is available from www.exxonmobilechemical.com. 

(2) Syntech is available from www.syn-techlube.com. 

(3) Procure from local supply. 

OBSERVE ALL CAUTIONS AND WARNINGS ON CONTAINERS 

WHEN USING CONSUMABLES. WHEN APPLICABLE, WEAR 

NECESSARY PROTECTIVE GEAR DURING HANDLING AND USE. IF 

A CONSUMABLE IS FLAMMABLE OR EXPLOSIVE, MAKE CERTAIN 

CONSUMABLE AND ITS VAPORS ARE KEPT AWAY FROM HEAT, 

SPARK AND FLAME. MAKE CERTAIN FIREFIGHTING EQUIPMENT 

IS READILY AVAILABLE PRIOR TO USE. FOR ADDITIONAL 

INFORMATION ON TOXICITY, FLASHPOINT AND FLAMMABILITY 

OF CHEMICALS, CONSULT YOUR MEDICAL PEOPLE OR THE 

MANUFACTURER OF THE CONSUMABLE. 
269C-1 ALERT C1B-036.1 

SERVICE BULLETIN February 13/12 

Revision 1 ! February 24/12 

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Section 3. ACCOMPLISHMENT INSTRUCTIONS 

A. Prepare helicopter for inspection: 

(1) Turn off all helicopter electrical power. 

(2) Remove tail rotor drive shaft from helicopter. Reference Applicable Basic HMI, Section 10. 

(3) Using cleaning solvent, remove all grease from spline cavities of tail rotor drive shaft 

forward and aft end fittings and main rotor transmission pinion splined drive sleeve and 

driven spline adapter of tail rotor transmission. Blow dry with clean, compressed air. 

B. Perform tail rotor drive shaft splined fitting inspection as follows: 

(1) Visually inspect internal splines of forward and aft drive shaft fittings for excessive wear, 

galling, spalling, chipping, distortion, corrosion, heat discoloration or any defect that 

indicates inadequate spline engagement or lack of lubricant. 

(a) Measure internal splines of fittings for excessive wear. Reference Applicable Basic 

HMI, Section 10. 

NOTE: The main transmission pinion drive spline sleeve and the tail rotor transmission 

driven spline have identical external spline dimensions. The overall pin 

dimension inspection applies to both. 

(2) Visually inspect external splines of drive sleeve on main rotor transmission pinion and 

external splines of driven spline on tail rotor transmission input shaft for excessive wear, 

galling, spalling, chipping, distortion, corrosion, heat discoloration, or any defect that 

indicates inadequate spline engagement or lack of lubricant. 

(a) Measure for excessive wear over two 0.1200 inch diameter gage pins placed 180° 

apart in external splines. Reference Applicable Basic HMI, Section 10. 

(3) If tail rotor drive shaft is equipped with grease fittings, inspect grease fittings for security, 

presence of check balls inside fittings, and for proper operation and seating of check balls. 

Replace any grease fittings that are loose, are missing check balls, or are suspected of 

improper operation. 

(4) If wear is found in splines of drive shaft fittings, splined drive sleeve or splined adapter 

which meets serviceable limits, copy and fill out the Customer Reply Form and mail to 

address shown on form. 

NOTE: Contact HSI for return and evaluation. 

(5) Remove from service any components that exceed wear limits and send to Helicopter 

Support Inc. (HSI). Fill out Component Return Form and place in shipping container and 

ship components to address shown on form. 
C1B-036.1 269C-1 ALERT

February 13/12 SERVICE BULLETIN 

Revision 1 ! February 24/12 

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Section 3. ACCOMPLISHMENT INSTRUCTIONS (Continued) 

(6) Service drive shaft fittings as follows: 

(a) Service drive shafts that are not equipped with grease fittings as follows: 

1. Fabricate and assemble Lubrication Tool (Figure 1 Sheet 1 and Sheet 2). 

2. Apply grease (Syn-Tech NS-3913-G1 grease or equivalent) to drive shaft 

fittings (Figure 1, Sheet 2). 

3. Adjust grease volume in fittings by inserting tool until legs of Lubrication Tool 

plates bottom against safety wire flanges on exterior of splined fittings (Figure 

1, Sheet 2). 

4. Rotate tool a minimum of 180°. Verify grease coverage and depth as required 

in HMI. Reference Applicable Basic HMI, Section 10.

(b) Service drive shafts equipped with grease fittings with grease (Syn-Tech NS-3913-

G1 grease or equivalent). Grease aft fitting first and avoid aft preloading by 

alternately greasing fittings at both ends. Reference Applicable Basic HMI, Section 

10. 

(7) Install tail rotor drive shaft in helicopter. Reference Applicable Basic HMI, Section 10. 

B. Implement recurring tail rotor drive shaft inspection as follows: 

(1) Review and comply with Applicable Basic HMI Appendix B, Table B-2. 

C. Record of compliance: 

(1) Make helicopter logbook entries to show compliance with this ASB as follows: 

(a) Make helicopter level logbook entry on form SA7343-15. 

(b) When ASB modifies a component that can be removed from this helicopter: 

1. Make component log card entries on forms SA7343-22 & SA7343-21 as 

applicable. 

(2) Upon compliance with this ASB, complete attached ALERT SERVICE BULLETIN 

COMPLIANCE RECORD CARD and return it to Sikorsky Aircraft Corporation. 
269C-1 ALERT C1B-036.1 

SERVICE BULLETIN February 13/12 

Revision 1 ! February 24/12 

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Section 3. ACCOMPLISHMENT INSTRUCTIONS (Continued) 

LUBRICATION TOOL – FABRICATION OF DETAIL PARTS 

FIGURE 1 (SHEET 1 OF 2) 

SA

C1B-022_4

FABRICATE

TWO PLATES

SLOT DETAIL OF -5 PLATE SLOT DETAIL OF -3 PLATE

FABRICATE

TWO PLATES

SLOT DETAIL OF -5 PLATE SLOT DETAIL OF -3 PLATE

LUBRICATION TOOL DETAILS FOR FORWARD SPLINED FITTING

LUBRICATION TOOL DETAILS FOR AFT SPLINED FITTING

1.19

1.85

 0.06

0.13

0.13

0.06

0.74

2.88

1.50

0.88

2.50

0.22

0.37

1.25

0.66

0.13

0.06

1.25

1.70 1.70

1.25 0.06

2.38

0.81

0.68

0.19

(TYP)

0.53

(TYP)

1.32 2.38

0.86

1.19

NOTES

 1. SUGGESTED MATERIAL IS 1/8 INCH

THICK POLYPROPYLENE PLASTIC

SHEET AND 3/4 INCH PVC PIPE. ANY

SUITABLE MATERIAL MAY BE USED.

 2. FABRICATE - 1 PVC PIPE HANDLE AS

SHOWN IN SHEET 2 WITH SLOTS 90

APART. SLOT WIDTHS ARE TO MATCH

MATERIAL THICKNESS.

 3. ASSEMBLE PARTS AS SHOWN IN

SHEET 2 AND BOND ASSEMBLY

TOGETHER USING APPROPRIATE

ADHESIVE FOR PVC PIPE.
C1B-036.1 269C-1 ALERT

February 13/12 SERVICE BULLETIN 

Revision 1 ! February 24/12 

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Section 3. ACCOMPLISHMENT INSTRUCTIONS (Continued) 

SA

C1B-022_5

ASSEMBLY OF LUBRICATION TOOL

LUBRICATION TOOL (REF)

SAFETY WIRE FLANGE (REF)

0.13

(TYP.)

0.06

(TYP.)

-3

-1

-5

2.00

0.50

FOR AFT SPLINED FITTING SHOWN

SPLINE FITTING (REF)

GREASE (REF)
269C-1 ALERT C1B-036.1 

SERVICE BULLETIN February 13/12 

Revision 1 ! February 24/12 

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LUBRICATION TOOL – ASSEMBLY AND USE 

FIGURE 2 (SHEET 2 OF 2) 

COMPONENT RETURN FORM 

Customer Name: _____________________________________ Helicopter Model: ______________ 

Customer Address: ___________________________________ Helicopter Serial No: ___________ 

 ___________________________________ Component Time: ______________ 

 ___________________________________ 

 ___________________________________ 

 ___________________________________ 

Ship To: Helicopter Support Inc. 

 124 Quarry Rd. 

 PO Box 11068 

 Trumbull, Connecticut, 06611 USA 

 Attn: Customer Service 

 Fax: (203) 416-4291 Telephone: (203) 416-4000 

 HSI Website: www.HSIUS.com

COMPONENT RETURN FORM 

Customer Name: _____________________________________ Helicopter Model: ______________ 

Customer Address: ___________________________________ Helicopter Serial No: ___________ 

 ___________________________________ Component Time: ______________ 

 ___________________________________ 

 ___________________________________ 

 ___________________________________ 

Ship To: Helicopter Support Inc. 

 124 Quarry Rd. 

 PO Box 11068 

 Trumbull, Connecticut, 06611 USA 

 Attn: Customer Service 

 Fax: (203) 416-4291 Telephone: (203) 416-4000 

 HSI Website: www.HSIUS.com
C1B-036.1 269C-1 ALERT

February 13/12 SERVICE BULLETIN 

Revision 1 ! February 24/12 

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CUSTOMER REPLY FORM 

Customer Name: _____________________________________ Helicopter Model: ______________ 

Customer Address: ___________________________________ Helicopter Serial No

: ___________ 

 ___________________________________ 

 ___________________________________ 

 ___________________________________ 

 ___________________________________ 

COMPONENT: 

Drive Shaft FWD Splined Fitting: 

 Wear: _________________ Total Time: ____________________ 

Drive Shaft AFT Splined Fitting: 

 Wear: _________________ Total Time: ____________________ 

Main Trans. Pinion Drive Splined Sleeve: 

 Dimensions: ______________ Total Time: ____________________ 

Tail Gearbox Driven Spline Adapter: 

 Dimensions: ______________ Total Time: ____________________ 

Mail To: Helicopter Support Inc. 

 124 Quarry Rd. 

 PO Box 11068 

 Trumbull, Connecticut, 06611 USA 

 Attn: Customer Service 

 Fax: (203) 416-4291 Telephone: (203) 416-4000 

 HSI Website: www.HSIUS.com
(Fold over and tape closed) 

SIKORSKY AIRCRAFT CORPORATION 

FACSIMILE NUMBER (860) 998-7565 

EMAIL ADDRESS: GPSIKSASProductSafet@utc.com 

ATTENTION: SAS PRODUCT SAFETY MANAGER 

SIKORSKY AEROSPACE SERVICES 

(Fold Up to Arrows)

IMPORTANT NOTICE 

Upon COMPLIANCE with the attached ASB, Sikorsky requests your cooperation in completing and 

returning this ENTIRE PAGE by MAIL, FAX, or scan & EMAIL. 

If you have internet access, you may go to www.sikorsky.com to record your compliance. 

Please fill in the requested information at the bottom of the page, so we may maintain 

proper records documenting the configuration of your aircraft. This information is useful 

when determining configuration and effectivity of issues affecting fielded aircraft. 

This request is in keeping with our policy to assure that our customers receive the latest 

information applicable for the maintenance of your aircraft. Thank you. 

ALERT SERVICE BULLETIN: 

 ________________ 

 Compliance Record Card 

TITLE: ___________________________________________________________________ 

 ___________________________________________________________________ 

 ___________________________________________________________________ 

OWNER/OPERATOR: _____________________________________________________ 

SUBMITTED BY: ___________________________ DATE: ____________________ 

FOLLOWING SERIAL NUMBERS ARE NOT AFFECTED BY THIS ASB 

ASB HAS BEEN COMPLIED WITH ON THE FOLLOWING SERIAL NUMBERS 

 ___________ ___________ ___________ ___________ ___________ ___________ 

 ___________ ___________ ___________ ___________ ___________ ___________ 

ASB No. C1B-036.1 

DRIVE TRAIN – Tail Rotor Drive Shaft Splined Fittings – Perform a One-Time 

Inspection and Implement a Recurring Inspection for Wear 
No Postage 

Necessary 

BUSINESS REPLY MAIL 

FIRST-CLASS MAIL PERMIT NO. 432 BRIDGEPORT CT 

POSTAGE WILL BE PAID BY ADDRESSEE 

SIKORSKY AIRCRAFT CORPORATION

P.O. BOX 9729 

6900 MAIN STREET 

STRATFORD, CONNECTICUT 06615-9129 U.S.A.

MAILSTOP: S328A

ATTENTION: SAS PRODUCT SAFETY MANAGER 

 SIKORSKY AEROSPACE SERVICES 

Please complete the form on the reverse side and FAX to 

FACSIMILE NUMBER (860) 998-7565 

Or scan and email to: 

EMAIL ADDRESS: GPSIKSASProductSafet@utc.com 

or fold and return ENTIRE form to Sikorsky Aircraft Corporation