Textron Cessna 680 Citation Sovereign

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Citation SERVICE BULLETIN

SB680-34-27

TITLE

NAVIGATION - W

IDE AREA AUGMENTATION SYSTEM (WAAS) INSTALLATION

EFFECTIVITY

MODEL SERIAL NUMBERS

680 (Citation Sovereign) -0001 and On

NOTE: Cessna-owne

d or authorized Citation Service Centers are the only facilities that can complete this

service bulletin.

NOTE: The accomplishment of this service bulletin will have no affect on RVSM operations.

NOTE: SB680-34-20

EPIC Phase 5 Software Upgrade must be accomplished prior to or in conjunction with

this service bulletin, or Epic Phase V software must be installed.

REASON

To add the Wi

de Area Augmentation System (WAAS).

DESCRIPTION

This service bulletin provides parts and instructions necessary to install WAAS.

COMPLIANCE

OPTIONAL. This service bulletin can be accomplished at the discretion of the owner.

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 “Ef fectivity” 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.

Jun 25/2010 680-34-27

Page 1 of 8

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

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This document is a Service Bulletin (SB680-34-27) issued by Cessna Aircraft Company for the Citation Sovereign (Model 680) aircraft, specifically for serial numbers -0001 and On. The primary function of this service bulletin is to provide instructions and parts necessary to install the Wide Area Augmentation System (WAAS) on the aircraft.

Function Description:

The WAAS installation adds the capability for the aircraft to perform Localizer Performance with Vertical Guidance (LPV) approaches. WAAS is a satellite-based augmentation system (SBAS) that improves the accuracy, integrity, and availability of GPS signals. By providing these enhancements, WAAS enables GPS to be used for precision approaches, similar to Instrument Landing System (ILS) approaches, without the need for ground-based navigation aids at every airport. This upgrade enhances the aircraft's navigation capabilities, particularly for instrument flight rules (IFR) operations, by allowing access to more airports and runways with precision approach capabilities. The service bulletin also notes that the accomplishment of this modification will not affect Reduced Vertical Separation Minimum (RVSM) operations.

Important Technical Specifications:

The core of the WAAS installation involves replacing existing GPS modules and antennas.

GPS Modules: The existing 245-604067-001 GPS modules are replaced with upgraded 245-604067-100 GPS modules. These modules are located in the MAU2 (right-hand nose compartment) and MAU3 (aft baggage compartment). Operators have the option to modify their existing -001 modules to the -100 configuration by contacting Citation Parts Distribution.
GPS Antennas: The existing S67-1575-132 GPS 1 and GPS 2 antennas are replaced with S67-1575-135 antennas.
Software Upgrade: The installation requires an update to the APM (Avionics Program Manager) settings for WAAS, using a definition file (MM7031847-012 or later). This involves loading DM7038647-XXX Epic APM options software. A critical setting to be entered is "GPS Sensor Type CMC_C146."
Consumable Materials:
- Sealant Type V Class A (PRC-DeSoto International) is used to seal screw heads.
- Sealant Type I Class B (PRC-DeSoto International) is used to fillet seal the antenna bases.
Tooling: A laptop PC configured for Epic software loading is required to install the new software.

Usage Features:

Upon successful installation and software update, the aircraft gains the ability to perform LPV approaches. This significantly expands the range of precision approaches available to the flight crew, improving operational flexibility and access to airports in various weather conditions. The flight crew will receive a "Flight Crew Operations Summary" detailing the operational changes, specifically highlighting the added LPV approach capability. The service bulletin emphasizes that this summary is informational only and does not supersede any information in the FAA-approved airplane flight manual.

Maintenance Features:

The service bulletin outlines a detailed procedure for installation and verification:

Pre-installation: The aircraft must be prepared by ensuring all switches are in the OFF/NORM position, disconnecting electrical power (airplane battery and external power), and attaching maintenance warning tags. It is also a prerequisite that SB680-34-20 EPIC Phase 5 Software Upgrade or Epic Phase V software is already installed.
Module Replacement: The GPS modules in MAU2 and MAU3 are removed and replaced with the upgraded versions. The removed modules are to be returned to Cessna for modification if not already upgraded.
Antenna Replacement: The existing GPS antennas are removed, and new S67-1575-135 antennas are installed. This involves cleaning sealant, connecting coax connectors, attaching antennas with screws, and applying Type V Class A sealant to screw heads and Type I Class B sealant around antenna bases. A bond meter check is required to ensure Type V electrical bonding between the antenna screw hole and airplane structure.
Software Loading: A laptop connected to the aircraft's LAN port is used to load the new Epic APM options software and update WAAS settings. This process involves navigating through specific software utilities, selecting the correct configuration, and ensuring proper data entry (e.g., GPS Sensor Type CMC_C146).
Verification: After software loading, the airplane's power is cycled, and a system software load check is performed. This includes verifying the software version using the copilot's Cursor Control Display (CCD) and checking SCMS page 1 for correct software and database identifiers. The absence of an "CONFIGURATION MISMATCH" EICAS message is crucial.
GPS Sensor Check: A detailed check of the GPS sensors is performed, including positioning the airplane to receive a GPS signal, verifying ground mode, and checking NAV INDEX menu on MCDU 1. This involves selecting POS INIT, POS SENSORS, and STATUS for GPS 1 and GPS 2, ensuring at least eight satellites are tracked, and performing a PRED RAIM check.
Documentation: The Cessna Model 680 FAA Approved Flight Manual (68FM) must be updated with Supplement 25, Revision 0 or later. A Maintenance Transaction Report must be completed, a copy placed in the airplane logbook, and another copy sent to CESCOM.
Compliance: The service bulletin is OPTIONAL and can be accomplished at the owner's discretion. It can only be recorded as "completed" in the aircraft log when all instructions are followed, correct parts are used, technical data is applied to identified serial numbers, and acceptable maintenance practices are used. Only Cessna-owned or authorized Citation Service Centers are permitted to complete this service bulletin.