SB A40-29-03 Page 1 of 8 

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THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 Refer to applicable government agency regulations and requi rements and make sure that the work described in this Service Bulletin is performed in compliance with manufacturer’s recommendations and/ or acceptable industry standards. This document is proprietary to Bombardi er Inc. and/or its affiliates and may not be reproduced or copied in any form or by any means without the prior wr itten consent of Bombardier Inc. and/or its affiliates. © 2006, Bombardier Inc. All rights reserved. Challenger*, Global Express*, Learjet* , are Trademarks of Bombardier Inc. 

### LEARJET 40 ALERT SB A40-29-03 

# SERVICE BULLETIN

If you cannot do all steps in this service bulletin because of an STC change to the aircraft, speak to the STC holder or the regional Federal Aviation Administration (FAA) office for information and disposition.

HYDRAULIC POWER - INSPECTION/REPLACEME NT OF THE LEFT HYDRAULIC PUMP CASE DRAIN TUBE

1. Planning Information

A. Effectivity (1) Learjet 45-2001 thru 45-2063.

B. Reason (1) The left engine hydraulic pump case drain tube has been found to be chafing on the lower forward cowl latch structure on the inboard side of the engine. This condition may cause premature failure of the drain tube, and possi ble leakage of hydraulic fl uid within the engine cowling.

C. Description (1) This service bulletin provides instructions to inspect the left engine hydraulic pump case drain tube for chafing or other damage. Instructions are also provided to either reposition or replace the tube, based on inspection results.

D. Compliance (1) Recommended - Bombardier Learjet Inc. recommend s that you do this serv ice bulletin in less than 50 flight hours from the initial distribution date of this service bulletin. CONTACT INFORMATION DISTRIBUTION DATE

Business Aircraft Learjet Inc. MS 53 P.O. Box 7707 Wichita, Kansas 67277-7707 (316) 946-2421 December 26, 2006SB A40-29-03 Page 2 of 8 

### LEARJET 40 SERVICE BULLETIN

THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 E. Approval (1) The Federal Aviation Administration (FAA) has ap proved the technical content in this publication that has an effect on the airplane type design. (2) The European Aviation Safety Agency (EASA) has accepted the technical content in this publication that has an effect on the airplane type design.

F. Labor Hours - Estimated Accomplishment Time

NOTE: These labor hours are an estimate and ar e for planning purposes only. Facility and personnel capabilities may caus e the labor ho urs to change.

G. Expense Coverage (1) Labor Coverage - Labor coverage applies to all aircraft included in this service bulletin.

NOTE: For labor coverage to apply, you must do this service bulletin at a Bombardier Business Aviation Service Facility or at a Bomb ardier Learjet Authorized Service Facility. You must do this service bulletin within 12 mont hs from the release date of this service bulletin basic issue, December 26, 2006.

(2) Material Coverage - Material coverage applies to all aircraft included in this service bulletin.

NOTE: For material coverage to apply, you must place an order for the parts in this service bulletin from Bombardier within 12 months fr om the basic issue distribution date of this service bulletin, December 26, 2006.

(3) Smart Parts (a) During or after the above free period, Smart Parts Plus does not pay for any parts to do this service bulletin. AIRCRAFT THAT REQUIRE MODIFICATION AIRCRAFT THAT DO NOT REQUIRE MODIFICATION TASK

0.5 0.5 Labor hours to gain access.

1.0 0.5 Labor hours to do the aircra ft inspection/modification.

2.0 N/A Labor hours to do a functional test/operational check.

0.5 0.5 Labor hours to return the aircraft to airworthy status.

4.0 1.5 Total Labor HoursSB A40-29-03 Page 3 of 8 

### LEARJET 40 SERVICE BULLETIN

THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 H. Material Required to do this Service Bulletin (1) There are no kits associated with this service bulletin. (2) Other parts that may be necessary to do this service bulletin.

NOTE: The above price can change.

To place an order for these material/parts, please call Bombardier Aerospace Parts Logistics Business Aircraft Customer Serv ice at 1-888-222-1428 in North America or 1-316-946-2377 outside North America for information.

I. Tooling (1) None.

J. Weight and Balance (1) Negligible.

K. References (1) Learjet Maintenance Manual, Chapters 20, 24, and 71.

L. Other Publications Affected (1) Learjet Illustrated Part s Catalog, Chapter 29.

2. Accomplishment Instructions

A. Gain Access (1) Disconnect the external electrical power and the main and emergency batteries from aircraft. (Refer to Learjet Maintenance Manual, Chapter 24.) (2) Remove the left engine lower cowling (450CL). (Refer to Learj et Maintenance Manual, Chapter 71.)

B. Inspection/Modific ation of Aircraft (1) Inspect the left engine hydraulic pump case drain tube as follows; (a) Examine the tube for chafing and/or other damage in the critical inspection area shown. (See Figure 1, View B-B.)

NOTE: Damage must not be more than 20% (.004 in [0.10 mm]) of the wall thickness of the tube. PART NUMBER NAME QTY PRICE

4529101090-005 Tube Assembly 1 $285.00

4529101090-001 Tube Assembly (Alternate for 4529101090-005) 1 $285.00SB A40-29-03 Page 4 of 8 

### LEARJET 40 SERVICE BULLETIN

THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 (b) On aircraft where the tube is damaged more than the acceptable limits, replace the tube. (See Figure 1, View C.)

NOTE: It may be necessary to reposition the flexible hose assembly to facilitate connection of the new hydraulic pump case drain tube assembly. (See Figure 1, View BB.)

(c) On aircraft where damage to the tube is within acceptable limits, proceed to paragraph 2.B.(2). (d) On aircraft where there is no damage to the tube, no further action is required. Proceed to paragraph 2.D. to return the aircraft to airworthy status. (2) On aircraft that require the tube to be repositioned due to chafing or other damage, position the tube as follows; (a) Loosen the clamp that secures the tube so th e tube can be moved within the clamp. (See Figure 1, View B-B.) (b) Loosen the B-nut on the end of the flexible hose that is attached to the union installed in the top of the hydraulic pump case.

NOTE: Loosen the B-nut only enough to move the hose within an arc of approximately 30 degrees.

(c) Position the flexible hose as necessary to pr ovide clearance for the tube. (See Figure 1, View B-B.) (d) Tighten the B-nut of the flexible hose in the position that provides the best clearance of the tube. (e) Torque the B-nut as necessary. (Refer to Learjet Maintenance Manual, Chapter 20.)

NOTE: Make sure the position of the hose does not change when you torque the B-nut.

C. Functional Test/Operational Check (1) On aircraft that were required to reposition or replace the tube, do the checks that follow;(a) Connect the main and emergency batteries to the aircraft. (Refer to Learjet Maintenance Manual, Chapter 24.) (b) Connect external electrical power. (Refer to Learjet Maintenance Manual, Chapter 24.) (c) Start the left engine. (d) Make sure the main hydraulic system pressure shows 3000 PSI ± 100 PSI [20684 ± 689 kPa] on the EICAS system. (e) Examine for leaks around the tube and flexible hose fittings. (f) Shut down the left engine.

D. Return Aircraft to Airworthy Status (1) Install the left engine lower co wling (450CL). (Ref er to Learjet Mainten ance Manual, Chapter 71.) (2) On aircraft that were not required to reposition or replace the tube, connect the main and emergency batteries to the aircraft. (Refer to Learjet Maintenance Manual, Chapter 24.)SB A40-29-03 Page 5 of 8 

### LEARJET 40 SERVICE BULLETIN

THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 E. Compliance Response Form (1) Complete the compliance response form. (2) Send the compliance response form to Learjet Inc. as soon as possible.

F. Aircraft Maintenance Records (1) Complete the Aircraft Maintenance Records.

NOTE: To complete the aircraft maintenance records, refer to FAR/CFR 43.9.

3. Material Information

A. Parts Required (1) There are no kits for this serv ice bulletin. Refer to paragraph 1.H. for more material/parts necessary to do this service bulletin.

B. Parts Removed List

PART NUMBER QTY NOMENCLATURE DISPOSITION EFFECTIVITY REPLACED BY

4529101090-001 1 Tube Assembly Destroy All 4529101090-005

or 4529101090-001 (Alternate for 4529101090-005)SB A40-29-03 Page 6 of 8 

### LEARJET 40 SERVICE BULLETIN

THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 Left Hydraulic Pump Case Drain Tube Installation Figure 1 (Sheet 1 of 3)SB A40-29-03 Page 7 of 8 

### LEARJET 40 SERVICE BULLETIN

THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 Left Hydraulic Pump Case Drain Tube Installation Figure 1 (Sheet 2 of 3)SB A40-29-03 Page 8 of 8 

### LEARJET 40 SERVICE BULLETIN

THIS SERVICE BULLETIN IS AVAILABLE AT: www.cic.bombardier.com Basic Issue: Dec 26/06 Left Hydraulic Pump Case Drain Tube Installation Figure 1 (Sheet 3 of 3)

## SERVICE BULLETIN COMPLIANCE RESPONSE

It is necessary that Bombardier Learjet re cord aircraft having complied with this Service Bulletin. Please fill in the Se rvice Bulletin and aircraft information below, sign and date the form in the space provided, fold on dotted lines, seal with tape, and mail completed form to Bombardier Learjet Maintenance Engineering. If mailed within the United States, this form may be mailed to Bombardier Learjet Maintenance Engineering using business reply mail (see reverse). This form may be faxed or e-mailed if preferred. (See mailing information provided.)
WARRANTY - Completion of this response form is required in order to process the warranty claim. Therefor e, if a warranty allowance is provided in the Service Bulletin, return a copy of this form with the warranty claim.
SMART PARTS - Completion of this response form is required in order to remain, enroll, or re-enroll in the Smart Parts Program. 

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Mailing Information:

Bombardier Learjet Maintenance Engineering (MS #78) (FAX 316 946-2305) fracas_usa@aero.bombardier.com Customer Support Learjet, Inc.

Service Bulletin Informati on Aircraft Information

Service Bulletin No. A40-29-03 Model
Rev No. Basic Date December 26, 2006 Serial No. Service Facility Information Flight Hours Facility Incorporating Bulletin Landings

Compliance Information The above referenced Service Bulletin was complied with on the re ferenced serial number aircraft at the listed aircraft flight hours/landings:

Actual hours to accomplish Service Bulletin: Access _______ SB _______ Test(s) _______ Restore _______

Signature Title Date

Comments

# SERVICE BULLETIN EVALUATION SHEET

YOUR COMMENTS WILL HELP US IMPROVE OUR SERVICE BULLETINS 

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SERVICE BULLETIN A40-29-03 REVISION: Basic DATED: December 26, 2006 TITLE: Inspection/Replacement of the Left Hydraulic Pump Case Drain Tube

LEARJET CONTACT INFORMATION TELEPHONE: (316) 946-2421 FACSIMILE: (316) 946-2002

HOW EASY IS THE BULLETIN TO UNDERSTAND? POOR FAIR GOOD VERY
GOOD EXCELLENT

COMMENTS

DOES THE BULLETIN TELL YOU ALL YOU NEED TO KNOW ABOUT THE JOB?
COMMENTS

DO YOU THINK THE BULLETIN CONVEYS THE BEST WAY TO DO THE JOB?
COMMENTS

HOW REALISTIC ARE THE LABOR-HOUR ESTIMATES?
COMMENTS

WHAT IS YOUR APPRECIATION OF THE ILLUSTRATION (S), FIGURE (S) AND/OR KIT DRAWING (S)?
COMMENTS

Actual hours to accomplish Service Bulletin: Access _______ Modify _______ Test(s) _______ Restore _______

PLEASE SUPPLY THE FOLLOWING DATA: NAME:

OPERATOR: TELEPHONE:
AIRCRAFT: FACSIMILE: UPON COMPLETION OF THE EVALUATION FORM, PLEA SE FAX TO (316) 946-2002 OR FOLD AND RETURN TO ADDRESS ON THE REVERSE SIDE.