SERVICE BULLETIN 

SB900-099Rl 

DATE: 27 DECEMBER 2006 

PAGE 1 OF 8 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

THRUSTER EXTENSION AND VORTEX GENERATOR 

INSTALLATION 

* Supersedes Service Bulletin SB900- 099 dated 09 May 2006. Revised to change time of I 

compliance and add a note for the installation of new thruster extension fairings. Aircraft that are 

in compliance with Service Bulletin SB900-099 meet the intent of this revision, please complete 

and return compliance form. 

1. PLANNING INFORMATION 

A. Aircraft Affected: 

All MD900 helicopters, serial number 900-0008 thru 900-0116. 

Serial numbers 900-0117 and subsequent will have the Thruster Extension and Vortex 

Generators installed prior to delivery. 

B. Assembly/Components Mfected By This Notice: 

90005420100-103, -105 Thruster Buildup Installation, 90001300205-109 Tailboom 

Buildup Assembly, 90007610300-105 General Cowling and Fairing Installation, and 

900F3441025-101 NOTAR® Fan Felt Seal. 

C. Reason: 

To correct a discrepancy between the helicopter capability and the Rotorcraft Flight Manual 

(RFM) controllability envelope (Ref. RFM Figure 2-2) by improving the low speed 

controllability characteristics of the anti-torque control system. 

Failure to comply with the requirements of part 1 and part 2 of this Bulletin may result in 

reduced anti- torque control during certain combinations of high gross weight, density 

altitude, and wind critical conditions. Also, the maximum gross weight of the helicopter will 

be lowered if this Service Bulletin is not complied with. 

D. Description: 

Procedures in this Bulletin require owners and operators to adjust directional control 

system rigging, install the Thruster Extension Kit (which includes vortex generators), and 

verify t hat t he 900F3441025- 103 NOTAR® Fan Felt Seal is installed. 

Part 1 requires rigging adjustment of the directional control (fan and thruster) system. 

Part 2 requires installation of the Thruster Extension Kit and Fan Felt Seal part number 

verification. The Thruster Extension Kit requires installation of vortex generators on the 

tailboom, installation of the thruster extension and new fairings, installation of a new 

configuration tailboom bumper, directional control rod replacement, and adjust rigging of 

anti-torque fan and directional control thruster. 

E. Time of Compliance: 

Perform the requirements of this Bulletin according to the schedule indicated: 

Part 1 Adjust directional control system rigging no later than 09 July 2006. I 

Part 2 Install Thruster Extension Kit and verify Fan Felt Seal part number no later than 

28 February 2007. I 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 
SB900-099Rl 

DATE: 27 DECEMBER 2006 

PAGE 2 OF 8 SERVICE BULLETIN 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

F. FAA Approval: 

The technical design aspects of this Bulletin are FAA Approved. 

G. Manpower: 

Part 1 of this Bulletin requires approximately 8 man-hours to complete. 

Part 2 of this Bulletin requires approximately 32 man-hours to complete if the Fan Felt 

Seal requires replacement, 24 man-hours for the Thruster Extension Kit only. 

H. Interchangeability: 

None 

I. Material/Part Availability: 

Contact the MDHI Warranty and Repair Department. 

REPLACEMENT PARTS/SUPPLIES 

Nomenclature Part No. Qty. Source 

Thruster Extension Kit SBK-009 1 MD HI 

Felt Seal , NOTAR® Fan 900F3441025-103 1 MD HI 

NOTE: The following materials must be ordered in addition to the SBK009 Thruster Extension Kit 

to comply with part 2 of this Bulletin. 

MATERIAL 

Nomenclature Part No. Qty. Source 

Sealing Compound MDM16-1097T1 CB1/2 2 oz PRC Desoto International, Inc. 

MIL-S-8802 T1 CB1/2 (60 cc) 5454 San Fernando Rd . 

890 Glendale, CA 91203 

(818) 240-2060 

Adhesive, Acrylic (Note 1) Loctite® 330TM 250ml kit Loctite Industrial Products 

800-562-8483 

or www.loctite.com/int_henkel/loctite/entry.cfm 

Adhesive, Epoxy (Note 2) MDM16-1068 C12 2 oz Dexter Adhesive & Coating Systems, Hysol 

EA9321 {60 cc) & Frekote Products 

One Dexter Dr. 

Seabrook, NH 03874-4018 

(800) 254-2636 

Resin, Epoxy MDM16-1115 T3 AR Fiber-Resin Corporation 

Araldite 501 20701 Nordhoff St. 

Chatsworth, CA 91311 

(800) 624-9487 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 
SERVICE BULLETIN 

SB900-099Rl 

DATE: 27 DECEMBER 2006 

PAGE 3 OF 8 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

MATERIAL (Cont.) 

Nomenclature Part No. Qty. Source 

Solvent Cleaner Desoclean 45 16 oz PRC Desoto International, Inc. 

or equivalent (473 cc) 5454 San Fernando Rd . 

Glendale, CA 91203 

{818) 240-2060 

Sandpaper, Non Aluminum 180 Grit AR Commercial 

Oxide 

NOTES: 

(1) Preferred adhesive. Has a fixture time of 30 seconds to 5 minutes, full cure in 24 hours. 

(2) Has a fixture time of 24 hours, full cure in 5 to 7 days. 

J. Warranty Policy: 

The MDHI Warranty and Repair Dept. will provide the Thruster Extension Kit SBK-009 

and Fan Felt Seal at no cost to the operator. MDHI will also provide, to authorized Service 

Centers, up to 32 hours of labor warranty (spares credit) for installation of the Thruster 

Extension Kit and Fan Felt Seal. 

NOTE: 

• Schedule parts from MDHI no later than 30 June 2006. 

• Install the Thruster Extension Kit and Fan Felt Seal no later than 28 February 2007. I 

• Submit to MDHI Warranty and Repair Department, the Service and Operations Report 

(SOR) form with parts removed, the ''Bulletin Compliance Recording Form" completed and 

signed with the part invoice attached, within 30 days after accomplishing part 2 of this 

Service Bulletin. 

K. Disposition of Parts Removed: 

Fax a mi2Y of the completed Service and Operations Report (SOR) form to MDHI Warranty 

Repair Dept. DATAFAX: (480) 346- 6813. 

Ship removed parts; old control rod and tailboom bumper (cut in half), along with the 

(original) completed Service and Operations Report (SOR) form to MDHI Warranty Repair 

Dept. 

L. Tooling: 

TOOLS AND EQUIPMENT 

Nomenclature Source 

Vortex Generator Locating Template, MDHI (Included in Thruster Extension Kit, 

PN 9000531 OOOO-AT1 PN SBK-009) 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 
I 

SB900-099Rl 

DATE: 27 DECEMBER 2006 

PAGE 4 OF 8 SERVICE BULLETIN 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

M. Weight and Balance: 

Thruster Extension Kit installation moves the thruster assembly aft 21 in. This results in 

the weight and balance change shown in the table below. 

Record the following weight and balance data in the helicopter Log Book. 

Weight Long Arm Lat Arm Long Moment Lat Moment 

Add/Subtract (lbs.) (inches) (inches) (inch-pounds) (inch-pounds) 

Add 13.83 475.56 0 6577 0 

N. Electrical Load Data: 

N/A 

0. Other Publications Affected: 

CSP-900RMM-2, Rotorcraft Maintenance Manual, Reissue 1, Revision 27, or later revision 

incorporated. 

CSP-900IPL-4, Illustrated Parts List Reissue 2, Revision 10, or later revision incorporated. 

P. Referenced Publications: 

CSP-900RMM-2, Rotorcraft Maintenance Manual, Reissue 1, Revision 27, or later revision 

incorporated. 

CSP-900SPM, Standard Practice Manual, Original Issue, Revision 14, or later revision 

incorporated. 

Q. Compliance Record: 

Make sure that compliance with Parts 1 and 2 of this Service Bulletin are recorded in the 

Compliance Record section of the helicopter Log Book and on the Bulletin Compliance 

Recording Form at time of completion of each Part. 

R. Points of Contact: 

For further assistance, contact the Field Service Department at MDHI, Mesa, Arizona. 

Telephone 1-800-388-3378 or (480) 346-6387. DATAFAX: (480) 346-6813. 

2. ACCOMPLISHMENT INSTRUCTIONS 

A. Part 1. Adjust Rigging: 

(1). Verify that revision 27 or later is incorporated into CSP-900RMM-2, Rotorcraft 

Maintenance Manual. 

(2). Adjust rigging of anti-torque fan and directional control thruster (Ref. 

CSP-900RMM-2, Section 67-20-00, Anti-Tor que/Directional Control System Rigging). 

(3). Record compliance to Part 1 of this Bulletin in t he Rotorcraft Logbook. 

(4). Complete Part 1 of the Bulletin Compliance and Recording Form (attached) and FAX to 

MDHI Field Service Dept. 

B. Part 2. Install Thruster Extension Kit and Verify Fan Felt Seal Part Number: 

NOTE: 

• Step 1 of this Part applies to MD900 helicopters serial numbers 900-00008 thru 

900-00047. 

• Aircraft serial numbers 900-000008, -00010, -00011, -00015, -00022, 00030, -00031, 

-00040, -00041, and -0004 7 already comply with step 1 of this Part. 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 
SB900-099Rl 

SERVICE BULLETIN DATE: 27 DECEMBER 2006 

PAGE 5 OF 8 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

(1). Verify that PIN 900F3441025-103 NOTAR® Fan Liner (Felt Metal Seal) is installed. 

(Ref. Figure 1) 

(a). If necessary, replace with a P/N 900F3441025-103 Fan Liner (Felt Metal Seal) (Ref. 

CSP-900RMM-2, Section 64-30-00). 

~ 

0.66 in _--+1- --·-11 FORWARD EDGE OF MA- (16.76 mm) " - . ~ CHINED SURFACE 

c -------------, 

900F3441025-101 FAN FELT SEAL 

0.42in ----!-.--1 FORWARD EDGE OF MA· 

(10.67 mm) I _____.J<_ CHINED SURFACE c ·----------------

900F3441025-103 

~ FAN FELT SEAL 

9864-197 

Figure 1. Fan Felt Seal Identification 

(2). Verify that revision 27 or later is incorporated into CSP-900RMM-2, Rotorcraft 

Maintenance Manual. 

(3). Remove t ailboom covers and fairings, SL1, SR1, S2, S4 (Ref. CSP-900RMM-2, Section 

06-00-00 and 53-40-00). 

(4). Remove Thruster Assembly (Ref. CSP-900RMM-2, Section 67- 20- 00). 

(5). Remove Tailboom Bumper (Ref. CSP- 900RMM- 2, Section 53- 40- 00). 

(6). Remove Rotating Cone Control Rod Assembly (Ref. CSP- 900RMM-2, Section 

67-20-00). 

(7). Install vortex generators on tailboom using vortex generator locating template, PN 

90005310000-AT1 (Ref. CSP-900RMM- 2, Section 53- 40- 00, Vortex Generator 

Installation). (Instructions for template use provided with template.) 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 
SB900-099Rl 

DATE: 27 DECEMBER 2006 

PAGE 6 OF 8 SERVICE BULLETIN 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

(8). Modify thruster assembly. 

(Ref. Figure 2) 

(a). Trim thruster control rod pass thru hole per View D-D and View E-E and seal any 

exposed fibers with Epoxy Resin, refer to resin manufacturer's instructions. 

(b). Verify that installed thruster control sector assembly is PN 900C2010392-109. If 

the PN is not correct, contact MDHI Field Service Department. 

(c). Using permanent ink, reidentify modified thruster assembly, at location of existing 

part number, as PN 90005310000-101. 

(9). Install new Tailboom Bumper (thruster extension) (Ref. CSP-900RMM-2, Section 

53-40-00). 

(10). Install new Rotating Cone Control Rod Assembly (thruster extension) (Ref. 

CSP-900RMM-2, Section 67-20-00). 

(11). Install Thruster Extension (Ref. CSP-900RMM-2, Section 53-40-00). 

(12). Install Thruster Assembly (Ref. CSP-900RMM-2, Section 67-20-00). 

I NOTE: Make screw holes in new fairings SL8 and SR8 to match attach holes in helicopter. 

(13). Install tailboom fairings, SL1, SR1, S2, S4, SL8, and SR8 (Ref. CSP-900RMM-2, 

Section 06-00-00 and 53-40-00). 

(14). Install vortex generators on thruster fairings and thruster extension fairings using 

vortex generator locating template, PN 90005310000-AT1 (Ref. CSP-900RMM-2, 

Section 53-40-00, Vortex Generator Installation). (Instructions for template use 

provided with tool.) 

(15). Adjust rigging of anti-torque fan and directional control thruster (Ref. 

CSP-900RMM-2, Section 67-20-00, Anti-Torque/Directional Control System Rigging). 

(16). Remove rotating cone assembly and verify there is clearance (no contact) between sector 

assembly and rotating cone control rod assembly through full directional control travel. 

Install rotating cone assembly. 

(17). Perform helicopter weight and balance calculation and record in helicopter Basic Weight 

and Balance Record. 

(18). Record compliance to Part 2 of this Bulletin in the Rotorcraft Logbook. 

(19). Complete Part 2 of the Bulletin Compliance and Recording Form (attached) and FAX to 

MDHI Field Service Dept. 

NOTE: If owners and operators want to take advantage of the increased gross weight capability of 

this configuration, they must comply with the latest revision of SB900-102, Increased 

Gross Weight Capability 6251-6500 lbs With LH Middle Aft Truss Assembly Replacement. 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 
SB900-099Rl 

SERVICE BULLETIN DATE: 27 DECEMBER 2006 

PAGE 7 OF 8 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

TAILBOOM BUMPER 

2.391N. (60.71 MM) 

DIRECTIONAL CONTROL ROD ASSY - THRUSTER EXTENSION 

SCREW (32 PLCS) 

_-'lb.,,,._ --..._ ~..::c•-..--WA-S~Hl 32 PLCSJ 

RH FAIRING ASSY (SR8) 

LH FAIRING ASSY (SL8) (NOT SHOWN FOR CLARITY) 

THRUSTER CONTROL 

SECTOR 

2.881N. (73.15 MM) 4 X R 0.50 IN. 

(12.7MM) 

EXISTING CUTOUT 

VIEW D- D 

(LOOKING DOWN) 

VIEW E- E 

(LOOKING AFT) 

Figure 2. Thruster Extension Modification 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

9b53-195 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 
I 

SB900-099Rl 

DATE: 27 DECEMBER 2006 

PAGE 8 OF 8 SERVICE BULLETIN 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II 

Bulletin Compliance Recording Form 

Service Bulletin SB900-099R1, Thruster Extension and Vortex 

Generator Installation 

FAX this form to MDHI (480) 346-6813 or 

Email to ServiceEngineering@mdhelicopters.com 

MD Helicopters, Inc. 

Field Service Department 

4555 E. McDowell Road 

Mesa, AZ 85215-9734 

800-388-3378 phone (U.S. and Canada) 

480-346-6387 phone (International) 

480-346-6813 Fax 

Dear Sir: 

This is to inform you that the Service Bulletin has been complied with as indicated below: 

Customer/Operator Name: 

Aircraft Serial No: 

Address: 

Phone: 

PART 1 Completed 

Helicopter Total Time: __________ Date: 

Location: _____________________________ ___ 

Signature of Person Confirming Compliance: ________________ _ 

PART 2 Completed 

Helicopter Total Time: _ _________ Date: 

Location: ______________________________ _ 

Signature of Person Confirming Compliance: ________________ _ 

Copyright 1999-2006 by MD Helicopters Inc. 

This document may be reproduced and distributed provided no fee is charged, 

the text is not modified, and this copyright notice is included. 

II MANDATORY 11111111111111 MANDATORY 11111111111111 MANDATORY II