Citation

SERVICE BULLETIN

REVISION

Revision 1 SB680-24-11

TRANSMITTAL SHEET

This sheet transmits Revision 1 to SB680-24-11 which:

(1) Changes Step 13 to add clarity.

NOTE: This revision replaces the original issue of SB680-24-11 in its entirety.

NOTE: Change bars and pointing hands are not used in this publication to denote revised material. This

transmittal sheet provides a complete description of the changes made by this revision, except

for editorial changes.

REVISION COMPLIANCE

MANDATORY. Airplanes previously modified by this service bulletin need to do Step 13 of this revision.

SUMMARY OF REVISIONS

Original Issue Dec 16/2010

Revision 1 Nov 15/2011

Citation SERVICE BULLETIN

SB680-24-11

TITLE

ELECTRICAL POWER - FUEL CROSSFEED IMPROVEMENT

EFFECTIVITY

MODEL SERIAL NUMBERS

680 (Citation Sovereign) -0001 thru -0289, -0291 thru -0296

REASON

The crossfeed valve can open uncommanded and a boost pump activated during a one side electrical

emergency situation.

DESCRIPTION

This service bulletin contains parts and instructions to add diodes to the fuel crossfeed wiring.

COMPLIANCE

MANDATORY. This service bulletin must be accomplished within 400 flight hours or one year from the

date of receipt, whichever occurs first.

A service bulletin published by Cessna Aircraft Company may be recorded as "completed" in an aircraft

log only when the following requirements are satisfied:

1) The mechanic must complete all of the instructions in the service bulletin, including the intent

therein.

2) The mechanic must correctly use and install all applicable parts supplied with the service bulletin

kit. Only with written authorization from Cessna Aircraft Company can substitute parts or rebuilt

parts be used to replace new parts.

3) The mechanic or airplane owner must use the technical data in the service bulletin only as

approved and published.

4) The mechanic or airplane owner must apply the information in the service bulletin only to aircraft

serial numbers identified in the “Effectivity” section of the bulletin.

5) The mechanic or airplane owner must use maintenance practices that are identified as acceptable

standard practices in the aviation industry and governmental regulations.

No individual or corporate organization other than Cessna Aircraft Company is authorized to make or

apply any changes to a Cessna-issued service bulletin, service letter, or flight manual supplement without

prior written consent from Cessna Aircraft Company.

Cessna Aircraft Company is not responsible for the quality of maintenance performed to comply with this

document, unless the maintenance is accomplished at a Cessna-owned Citation Service Center.

FLIGHT CREW OPERATIONS

No Changes

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Cessna Aircraft Company, Citation Marketing Division, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-6000, Fax 1-316-517-8500

COPYRIGHT © 2010
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Citation SERVICE BULLETIN

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APPROVAL

Cessna received FAA approval for the technical data in this publication that changes the airplane type

design.

The accomplishment instructions in the service bulletin are an amendment to the applicable maintenance

manual or Instructions for Continued Airworthiness (ICA), and you must complete them for ongoing

airworthiness compliance as required per 14 CFR, Part 43.13.

MANPOWER

WORK PHASE MAN-HOURS

Modification *

MATERIAL - Cost and Availability

PART NUMBER AVAILABILITY COST

SB680-24-11 * *

* Refer to the Manpower, Material - Cost and Availability, and Warranty sections in the attached Service

Bulletin Supplemental Data sheet.

CHANGE IN WEIGHT AND BALANCE

Negligible

REFERENCES

Cessna Model 680 Maintenance manual

PUBLICATIONS AFFECTED

Cessna Model 680 Wiring Diagram Manual

Cessna Model 680 FAA Approved Airplane Flight Manual (68FM-09)

Cessna Model 680 FAA Approved Airplane Flight Manual (68FM-10)

ACCOMPLISHMENT INSTRUCTIONS

1. Prepare the airplane for maintenance.

A. Make sure that all switches are in the OFF/NORM position.

B. Disconnect electrical power from the airplane.

(1) Disconnect the airplane batteries.

(2) Disconnect external electrical power.

C. Attach maintenance warning tags to the batteries and external power receptacle that have "DO NOT

CONNECT ELECTRICAL POWER - MAINTENANCE IN PROGRESS" written on them.

2. Get access to the aft J-Box.

A. Remove the access panels 311ABC. (Refer to the Model 680 Maintenance Manual, Chapter 6,

Access Plates And Panels Identification - Description And Operation.)

B. Remove the covers from the left and right J-Box.
Citation SERVICE BULLETIN

SB680-24-11

3. Get access to the left and right relay rack.

A. (Refer to Figure 1, Views D-D and E-E.) Remove and keep the two inboard retaining screws from

the left and right circuit breaker panel to access the relay racks.

B. Remove the left relay rack and keep the screws.

C. Remove the right relay rack and keep the screws.

4. (Refer to Figure 2, Sheet 1 and Sheet 2.) Install the diodes to the left and right motive flow relays. (Refer

to the Model 680 Wiring Diagram Manual, Chapter 20, Wiring - Maintenance Practices.)

NOTE: The 1N4006 Diodes must be installed properly or the operational check will fail.

5. Install the left and right relay rack with the kept screws.

6. Install the inboard retaining screws that were kept in the left and right circuit breaker panels.

7. Prepare the airplane for power.

A. Remove maintenance warning tags from the batteries and external power receptacle.

B. Make sure that all switches are in the OFF/NORM position.

C. Connect electrical power to the airplane.

(1) Connect the airplane batteries.

(2) Connect external electrical power.

8. Do an operational check of the fuel cross feed.

A. Power the airplane on.

B. Place the Left electrical bus in EMER.

C. Cyan FUEL CROSS FEED & FUEL BOOST PUMP ON R CAS messages should not appear.

D. Return the Left electrical bus to normal.

E. Place the Right electrical bus in EMER.

F. Amber FUEL CROSS FEED TRANSIT & Cyan FUEL BOOST PUMP ON L CAS messages should

not appear.

G. Return the Right electrical bus to normal.

H. Turn the CROSSFEED switch to R TANK to L ENG.

I. A Cyan or Amber CAS message for FUEL CROSS FEED and FUEL BOOST PUMP ON R should

appear.

NOTE: An Amber CAS message will only be present if cross feeding from the tank with less fuel.

J. An amber FUEL MOTIVE VLV FAIL L Fail message should not appear.

K. Turn the CROSSFEED switch to off.

L. Turn the CROSSFEED switch to L TANK to R ENG.

M. A Cyan or Amber CAS message for FUEL CROSS FEED and FUEL BOOST PUMP ON L should

appear.

NOTE: An Amber CAS message will only be present if cross feeding from the tank with less fuel.

N. An amber FUEL MOTIVE VLV FAIL R CAS message should not appear.

O. Turn the CROSSFEED switch to off.

P. Turn airplane power off.

9. Disconnect external electrical power.

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Citation SERVICE BULLETIN

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10. Disconnect the airplane batteries.

11. Install the J-Box covers.

12. Install the access panels that were removed. (Refer to the Model 680 Maintenance Manual, Chapter 6,

Access Plates And Panels Identification - Description And Operation.)

13. Update the 680 FAA Approved Airplane Flight Manual (68FM).

A. For Airplanes that use the 680 FAA Approved Airplane Flight Manual (68FM-09)

(1) Make sure that Temporary Changes 68FM TC-R09-09, 68FM TC-R09-10, 68FM TC-R09-11,

and 68FM TC-R09-12 are removed from the 680 FAA Approved Airplane Flight Manual

(68FM-09).

(2) Make sure that Temporary Change 68FM TC-R09-13 is inserted into the 680 FAA Approved

Airplane Flight Manual (68FM-09).

B. For Airplanes that use the 680 FAA Approved Airplane Flight Manual (68FM-10)

(1) Make sure that Temporary Changes 68FM TC-R10-01, 68FM TC-R10-02, and 68FM

TC-R10-03 are removed from the 680 FAA Approved Airplane Flight Manual (68FM-10).

NOTE: The intent of 68FM TC-R09-13 has been incorporated in 68FM-10.

14. Record that this service bulletin has been completed.

A. Complete a Maintenance Transaction Report.

B. Put a copy of the completed Maintenance Transaction Report in the airplane logbook.

C. Send a copy of the completed Maintenance Transaction Report to: CESCOM C/O Camp Systems

International, 8200 East 34th Street North, Building 1600 Suite 1607 Wichita, KS 67226.

MATERIAL INFORMATION

Order the kit below to install this modification.

NEW P/N QUANTITYKEY WORD OLD P/N INSTRUCTIONS/

DISPOSITION

SB680-24-11 1 Kit, consisting of the following

parts:

D436-0098 2 Sleeve

D609-04 4 Splice

1N4006 2 Diode

SB680-24-11 1 Instructions
Citation SERVICE BULLETIN

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Figure 1. Fuel Crossfeed Improvement (Sheet 1)

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Figure 1. Fuel Crossfeed Improvement (Sheet 2)
Citation SERVICE BULLETIN

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Figure 1. Fuel Crossfeed Improvement (Sheet 3)

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Citation SERVICE BULLETIN

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Figure 2. Fuel Crossfeed Improvement (Sheet 1)
Citation SERVICE BULLETIN

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Figure 2. Fuel Crossfeed Improvement (Sheet 2)

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