FORM: 2391 DRAWING NO: ICA Cessna Aircraft Company P.O Box 7704 WICHITA, KS 67277

Transcription

1 FORM: 2391 DRAWING NO: ICA Cessna Aircraft Company P.O Box 7704 WICHITA, KS ENGINEERING DRAWING AND PART LIST SIGNATURE AUTHORIZATION Originals Electronically Signed in the VPM System ================================================================================ REVISION: ICA ICA --- PKG: ================================================================================ ORIGINATOR (DRM) Brice Logan (APPROVE 02/27/ :40:51) MAINTENANCE_ENG (ALL) Stephen Taylor (APPROVE 02/23/ :14:19) GROUP (525 SERIES) Arthur Olechowski (APPROVE 02/24/ :11:52) ICA_COORDINATOR (ALL) Michael Bean (APPROVE 02/23/ :42:04) PROJECT (525 SERIES) Neil Hague (APPROVE 02/23/ :37:04) AIRWORTHINESS (ALL) Mark Fuller (APPROVE 02/27/ :37:28) ODA ICA admin (ALL) Doug Carpenter (APPROVE 02/27/ :08:18) ICA_COORDINATOR (ALL) Jason Peterson (APPROVE 02/27/ :52:58) RELEASE (ALL) Gina Owings (APPROVE 02/27/ :03:12)

2 AIRCRAFT DIVISION WICHITA, KANSAS Model Trainer Coniguration ICA Supplement MODEL NO: 525 SUPPLEMENT NO: ICA SUPPLEMENT DATE: 2/27/2017 Cessna Aircraft Company Form 2261 Rev 1

3 AIRCRAFT DIVISION WICHITA, KANSAS REVISIONS ICA Rev: - Date: Feb 27/2017 ICA Summary Pages 1-7 Manuals Affected Description Title Maintenance Manual , Pages 1-3 Optional Observer Audio System - Description and Operation Provides description and operation information for the Observer Audio System Maintenance Manual , Pages Provides troubleshooting for the Observer Audio System Maintenance Manual , Pages Provides instructions for the Observer Audio System components Maintenance Manual , Pages Provides an operational test of the Observer Audio System Maintenance Manual , Pages Provides a detailed inspection of the observer seat Maintenance Manual , Pages Provides a functional test of the Observer Oxygen System Maintenance Manual , Pages 1-2 Provides description of the Observer Oxygen System Maintenance Manual , Page 101 Provides troubleshooting of the Observer Oxygen System Maintenance Manual , Pages Optional Observer Audio System - Troubleshooting Optional Observer Audio System - Maintenance Practices Optional Observer Audio System - Adjustment/Test Passenger Seat - Inspection/Check Oxygen - Inspection/Check Provides instructions for the Observer Oxygen System components Maintenance Manual , Page 201 Optional Observer Oxygen System - Description and Operation Optional Observer Oxygen System - Troubleshooting Optional Observer Oxygen System - Maintenance Practices Optional Observer Oxygen Mask - Maintenance Practices Provides instructions for the Observer Oxygen Mask and stowage box Appendix A: Illustrated Parts Catalog Appendix B: Wiring Diagram Manual NOT USED , Figure , Figure 1 Optional Observer Audio System Optional Observer Oxygen System Page 1 of 7 Feb 27/2017 Cessna Aircraft Company ICA Form 2261 Rev 1

4 AIRCRAFT DIVISION WICHITA, KANSAS ICA Rev: - Date: Feb 27/2017 Appendix C: Interior Maintenance Manual and Illustrated Parts Catalog See attached interior document Provides instructions for interior equipment. Provides Illustrated Parts List for interior equipment installed. Appendix D: Electrical Load Analysis Update See Electrical Load Analysis Table in Appendix D. Provides amended load distributions Cessna Model 525 Aircraft Serial Number only. NOTE: This information is in addition to the Electrical Load Analysis located in the Cessna Model 525 Maintenance Manual, Chapter 24, Electrical Load Analysis - Description and Operation. 1. Export Compliance A. This publication contains technical data and is subject to U.S. export regulations. This information has been exported from the United States in accordance with export administration regulations. Diversion contrary to U.S. law is prohibited. ECCN: 9E Revision Bars A. Revision bars in this ICA supplement identify new ICAs and/or changes to the current ICAs in the released maintenance manual. New ICAs that are not in the current maintenance manual will have a revision bar from top to bottom along the left margin. ICAs that are in the current maintenance manual and have information added, deleted or revised will have a revision bar(s) in the left margin adjacent to the added, deleted or revised information. New or changed illustrations will have a change bar for the entire length of the page. 3. Page Numbering A. The page number system for ICA included in this supplement have three-element numbers that are separated by dashes. The three-element number is found at the bottom right corner of the page, left of the page number. The date is found below the page number. B. When the chapter/system element number is followed with zeros in the section/subsystem and subject/unit element number ( ), the information is applicable to the entire system. C. When the section/subsystem element number is followed with zeros in the subject/unit element number ( ), the information is applicable to the subsystems in the system. Page 2 of 7 Feb 27/2017 Cessna Aircraft Company ICA Form 2261 Rev 1

5 AIRCRAFT DIVISION WICHITA, KANSAS D. The subject/unit element number is used to identify information applicable to units in the subsystems. The subject/unit element number continues in sequence from the number -01- with the number of subsystem units in which maintenance information is necessary. E. All system/subsystem/unit (chapter/section/subject) maintenance data is separated into speciied types of information: Description and Operation, Troubleshooting, Maintenance Practices, etc. Blocks of page numbers that are in sequence are used to identify the type of information: (1) Description and Operation or Troubleshooting information may not be included if the procedure is easy. When subtopics are short, they may be put together into the Maintenance Practices section. Maintenance Practices can have a mix of subtopics that includes information to service, remove, install, adjust, test, clean, paint or do approved repairs. (2) Longer procedures that are not as easy to do may be included in a speciied section. Page 1 through 99 - Description and Operation Page 101 through Troubleshooting Page 201 through Maintenance Practices Page 301 through Servicing Page 401 through Removal/Installation Page 501 through Adjustment/Test Page 601 through Inspection/Check Page 701 through Cleaning/Painting Page 801 through Approved Repairs F. A typical page number: G. Illustrations use the same igure numbers as the page block in which they appear. For example, Figure 202 would be the second igure in a Maintenance Practices section. 4. Supplement Revisions A. Revisions to this supplement may be accomplished if changes to this supplement are required after release of the original issue and prior to incorporation into the manuals listed in the REVISIONS table. B. All revisions to this supplement will have changes identiied in detail in the revision block(s) above. C. All pages in this ICA supplement will have the same date and are valid as of the date shown. 5. ICA Incorporation into Applicable Manuals NOTE: Most ICA supplements will be incorporated in the next available revision to the manuals listed above and should be used in conjunction with those manuals until the next available revision is released. A. The ICA Supplement List located in the Introduction section of each manual listed in the REVISIONS table will indicate the incorporation status as of the release date of the published revision. Page 3 of 7 Feb 27/2017 Cessna Aircraft Company ICA Form 2261 Rev 1

6 AIRCRAFT DIVISION WICHITA, KANSAS B. The manual revision level of the supplement incorporation will be listed in the "Manual Incorporation Status" column in the ICA Supplement List, when those ICAs associated with that manual have been incorporated. After ICAs are incorporated, the manual that they are incorporated in must now be used for those ICAs instead of the supplement. Based on revision cycle times for the affected manuals, MM ICAs, WDM ICAs, etc. in this supplement may be incorporated in the manuals at different times. There will not be a revision to this supplement to indicate incorporation in the manuals. Users are required to check the ICA Supplement List for each manual affected to determine incorporation status. C. This supplement will be completely superseded by the manuals listed in the REVISIONS table when it has been incorporated in all of the manuals. Page 4 of 7 Feb 27/2017 Cessna Aircraft Company ICA Form 2261 Rev 1

7 AIRCRAFT DIVISION WICHITA, KANSAS Purpose INTRODUCTION A. The purpose of this Supplement is to provide the maintenance technician with the information necessary to ensure the correct functionality and performance of the Model trainer coniguration on the Cessna Model 525 until this information gets incorporated into the next revision to the manuals listed in the "REVISIONS" section of this supplement. B. This ICA supplement is designed to satisfy the requirements of 14 CFR "Instructions for Continued Airworthiness" associated with this installation. This document is a supplement to the Model 525 Wiring Diagram Manual (0685 and 0800 & On) and will be incorporated in the next revision to the manual. C. When this information is incorporated in the next revision to the manuals listed in the "REVISIONS" section, those manuals shall take precedence over this supplemental document. Refer to the "ICA Supplement List" in the "Introduction" section of the respective manual for the status of all applicable ICA Supplements. D. Revisions to this supplement may occur if there is a change to any of the ICAs in this supplement prior to incorporation into all of the affected manuals. NOTE: This document must be placed with the aircraft operator's Technical Library CD-ROM or Model 525 Wiring Diagram Manual (0685 and 0800 & On) and incorporated into the operator's scheduled maintenance program. 2. Effectivity A. These Instructions for Continued Airworthiness (ICA) are effective for the following aircraft model and serialization. Model Beginning Effectivity Ending Effectivity Complete ICA Documents A. The following document(s), in conjunction with this supplement, constitute the Instructions for Continued Airworthiness for the Model trainer coniguration. All items must be available to the operator at initial delivery. (1) Model 525 Maintenance Manual (0685 and 0800 & On) (2) Model 525 Wiring Diagram Manual (0685 and 0800 & On) Page 5 of 7 Feb 27/2017 Cessna Aircraft Company ICA Form 2261 Rev 1

8 AIRCRAFT DIVISION WICHITA, KANSAS Model 525 Maintenance Manual LIST OF INSTRUCTIONS FOR CONTINUED AIRWORTHINESS A. Chapter 23 Communications (1) ATA Optional Observer Audio System - Description and Operation (2) ATA Optional Observer Audio System - Troubleshooting (3) ATA Optional Observer Audio System - Maintenance Practices (4) ATA Optional Observer Audio System - Adjustment/Test B. Chapter 25 Equipment/Furnishings (1) ATA Passenger Seat- Inspection/Check C. Chapter 35 Oxygen (1) ATA Oxygen - Inspection/Check (2) ATA Optional Observer Oxygen System - Description and Operation (3) ATA Optional Observer Oxygen System - Troubleshooting (4) ATA Optional Observer Oxygen System - Maintenance Practices (5) ATA Optional Observer Oxygen Mask - Maintenance Practices 2. Appendix B: Model 525 Wiring Diagram Manual (0685 and 0800 & On) A. Chapter 23 Communications (1) ATA Observer Audio System - Wiring Diagram B. Chapter 35 Oxygen (1) ATA Observer Oxygen System - Wiring Diagram 3. Appendix C: Model 525 Interior Maintenance Manual and Illustrated Parts Catalog A. Chapter 25 Equipment/Furnishings (1) ATA Passenger Seats - Maintenance (2) ATA Lowboy Cabinet - Maintenance (3) ATA Passenger Seats - Illustrated Part List (4) ATA Observer Seat - Illustrated Part List (5) ATA Lowboy Cabinet - Illustrated Part List (6) ATA Lowboy Cabinet Components - Illustrated Part List (7) ATA AC Outlet - Wiring Diagram 4. Appendix D: Electrical Load Analysis A. Electrical Load Analysis Table Page 6 of 7 Feb 27/2017 Cessna Aircraft Company ICA Form 2261 Rev 1

9 AIRCRAFT DIVISION WICHITA, KANSAS Continuous Inspection Program INSPECTION PROGRAM AND AIRWORTHINESS LIMITATIONS A. This ICA Supplement does not affect the current inspection program. 2. Airworthiness Limitations A. Cessna Aircraft Company Model 525 Maintenance Manual, Chapter 4, Airworthiness Limitations, contains the system and airframe limitations for the Model 525. NOTE: The Airworthiness Limitations section is FAA-approved and speciies maintenance required under Section and of Title 14 Code of Federal Regulations, unless an alternative program has been FAA approved. (1) There are no new (or additional) airworthiness limitations associated with this equipment and/or installation. Page 7 of 7 Feb 27/2017 Cessna Aircraft Company ICA Form 2261 Rev 1

10 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL 1. Description OPTIONAL OBSERVER AUDIO SYSTEM - DESCRIPTION AND OPERATION A. This section gives a description for the optional observer audio system on the Model 525 M2 trainer coniguration. The line replaceable units (LRU) in the observer audio system are the observer switch panel (PF503), powered headset jack (JF502), phone jack (JF503), microphone jack (JF504), oxygen mask microphone jack (JF504), and microphone select switch (SF501). B. Refer to Figure 1 for a general view of the observer audio system. C. The observer's audio includes a switch panel and an audio panel independently located on the low boy cabinet. The panels are used by the observer to communicate with the crew and to transmit over the radio(s) as necessary. 2. Operation A. Switch Panel. (1) The switch panel utilizes a Push To Talk (PTT) button, which allows the observer to communicate using a headset or the oxygen mask microphone. (2) The OXY MIC/MUTE split alternate action switch isolates the observer's oxygen intercom audio from the cockpit when the audio panel MIC SELECT switch is selected in the OXY MASK position. The OXY MIC/MUTE switch defailts to the un-muted position upon power-up. The PTT and OXY MIC switch text illuminates in white full-time. The lower MUTE text illuminates in green when selected. Illumination intensity is NOT dimmable. (3) The switch panel is powered by a 5 amp "Powered Headset" circuit breaker (HF137) located on the right hand circuit breaker panel. This circuit breaker receives power from the right hand avionics bus. (4) All observer switch panel functionality is lost when on EMER power. The observer switch panel text lighting is not tested during any Garmin Touch Screen (GTC) systems tests. B. Audio Panel (1) The audio panel provides the means for the observer to plug in a standard or powered headset and an oxygen mask microphone. A MIC SELECT switch allows the observer to transfer microphone audio between a standard/powered headset and the oxygen mask. Additionally an oxygen port provides oxygen low to the observers mask. The audio panel text is backlit by electro-luminescent panel that is powered by a 5 amp "Panel Dimming" circuit breaker (HZ074) located on the left hand circuit breaker panel and can be variably dimmed using the cockpit knob. This panel remains illuminated while on EMER power. C. Headset Operation (1) The observer's standard and powered headset microphone squelch and headset volume selections are coupled to the co-pilots intercom selections. The observer's co-pilot's GTC VOX squelch setting defaults to AUTO on power-up. If MANUAL is selected on the co-pilot's VOX MIC intercom page, the squelch slider becomes active and can then manually be set to a squelch threshold that adjusts both the co-pilot and the observer. If OFF is selected on the VOX GTC page, the intercom headset audio is isolated from the co-pilot and observer. The observer can hear all cockpit aural alerts over the headset. The observer also has the ability to transmit over the co-pilot's actively tuned radio by using the switch panel PTT button. Actuation of the pilot's or the co-pilot's PTT switch takes precedence over the observers PTT functionality. When the cockpit EMER COMM switch is selected, the observer loses all ability to communicate with the cockpit and the use of the PTT button. Observer intercom will continue to function and the observer will be unable to mute the oxygen micropone and all selections must be made through the pilot's GTC since the GTC 2 (co-pilots) will not be powered. D. Oxygen Mask MIC Operation (1) The oxygen mask mic operates similarly to the standard and powered headsets. Except, when the observer MIC SELECT switch on the audio panel is selected to the OXY MIC position, the observer's oxygen mask microphone becomes un-coupled with the co-pilot's VOX squelch setting. This results to un-squelch (HOT MIC). Selection of the OXY MIC/MUTE button on Page 1 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

11 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL A A C Lowboy Cabinet B Observer Switch Panel (PF503) Push-To-Talk Switch Oxygen Mask Microphone Mute Switch DETAIL A DETAIL B Observer Audio Panel Powered Headset Jack (JF502) Phone Jack (JF503) Microphone Jack (JF504) Microphone Select Switch (SF501) Oxygen Mask Microphone Jack (JF505) HEADSET ONLY ONE HEADSET PERMITTED HEAD SET OXY MASK POWERED HEADSET PHONE MIC MIC SELECT OXY MASK MIC OXYGEN DETAIL C Observer Audio System Figure 1 (Sheet 1) 6310T1168 A B C Page 2 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

12 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL the switch panel causes the observer's squelch to be set to 100% muted which isolates the observer's intercom audio from being heard by the crew. The OXY MIC/MUTE button defaults to the unsquelched position after each power cycle Page 3 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

13 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL 1. General OPTIONAL OBSERVER AUDIO SYSTEM - TROUBLESHOOTING A. This section gives troubleshooting procedures for the optional observer audio system. B. It is necessary to understand the system before troubleshooting the optional observer audio system. Become familiar with the system components, assemblies, and mechanical functions before you do any of the troubleshooting procedures. For an overview of the observer audio system refer to Chapter 23, Optional Observer Audio System- Description and Operation. C. When you troubleshoot the observer audio system, refer to the Model 525 Wiring Diagram Manual (-0685 and and On). D. When corrective actions are completed, do a check of system operation again, refer to Optional Observer Audio System- Adjustment/Test. 2. Tools and Equipment A. For tools and equipment, refer to Communications - General. 3. Troubleshooting A. Before proceeding with troubleshooting steps, make sure that Garmin SD card is installed. (1) On the GTC Home Screen, select Utilities, then select Setup, then select Avionic Status Page. (2) Make sure GTC screen displays "S/W B " as installed. B. Interphone Operation NOTE: Before troubleshooting the Observer Audio System, become familiar with system operation. Refer to Chapter 23, Optional Observer Audio System - Description and Operation. (1) Make sure that the GMA 36 Integrated Audio System and GIA 63W system is fully functional, if not complete the necessary troubleshooting procedures. Refer to Chapter 23, Garmin GMA 36 Integrated Audio System - Troubleshooting and Chapter 34, Garmin GIA 63W Integrated Avionics Unit - Adjustment/Test. NOTE: Make sure that GIA 1 "FAIL" amber CAS message is not displayed on any PFD. (2) Make sure that the headset used is serviceable and volume is set necessary position. NOTE: It may be necessary to have additional headsets at the pilot and co-pilot position. (3) Check power from circuit breaker HF137 to the switch panel PF503, repair wiring as necessary. Refer to Appendix B. (4) Make sure all 3 audio panels are selected to HEADSET. (5) Make sure that the co-pilot's interphone volume on the GTC is above 40% and selected to AUTO. (6) If problem persists, check wiring connections to the observer audio switch panel. Refer to Chapter 23, Optional Observer Audio System - Maintenance Practices, to get access to the wires. (a) Repair wiring as necessary, refer to Appendix B. (7) If problem persists, replace the observer audio switch panel PF503. Refer to Chapter 23, Optional Observer Audio System - Maintenance Practices Page 101 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

14 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL C. Observer Comm Radio Check NOTE: Before troubleshooting the Observer Audio System, become familiar with system operation. Refer to Chapter 23, Optional Observer Audio System - Description and Operation. (1) Make sure that the GMA 36 Integrated Audio System and GIA 63W system is fully functional, if not complete the necessary troubleshooting procedures. Refer to Chapter 23, Garmin GMA 36 Integrated Audio System - Troubleshooting and Chapter 34, Garmin GIA 63W Integrated Avionics Unit - Adjustment/Test. NOTE: Make sure that GIA 1 "FAIL" amber CAS message is not displayed on any PFD. (2) Make sure that the Push To Talk (PTT) and OXY/MIC text is illuminated in white on the observer switch panel. (a) If OXY/MIC is not illuminated and PTT is illuminated on the switch panel, repair wiring from 9PF503 to splice at 3PF503. (b) Check power from circuit breaker HF137 to the switch panel PF503, repair wiring as necessary. Refer to Appendix B. (c) Check the system ground from Pin 15PF503 to Pin FCDC20, repair wiring as necessary. Refer to Appendix B. (3) Make sure all 3 audio panels are selected to HEADSET. (4) Make sure that the headset used is serviceable. (5) Make sure that both crew PTT/VOX AUTO/ISOLATE yoke switches are in the center position. (6) Make sure that COM1 and MIC are selected as the active audio and that the co-pilots COM 1 volume is above 40% on the GTC. (7) Make sure that the co-pilots radio is tuned to any inactive frequency except MHz, MHz. (8) Make sure that the observer transmission can be heard. NOTE: NOTE: It may be necessary to have additional headsets at the pilot and co-pilot position. Observer transmissions can be heard from the pilot and co-pilot headsets. (9) If unable to communicate from the observer station do the following: (a) Make sure that the co-pilot position can transmit. 1 If co-pilot position is unable to communicate, do the GMA 36 troubleshooting. Refer to Chapter 23, Garmin GMA 36 Integrated Audio System - Troubleshooting. (b) Make sure that the "TX" is displayed on the GTC next to the tuned frequency while the observer's PTT is engaged. NOTE: This makes sure that the transmission was sent. (c) If the "TX" is not displayed on the GTC next to the tuned frequency check the wiring from 2PF503 to 50PI48, repair wiring as necessary. Refer to Appendix B. (10) Make sure observer station oxygen mask can transmit, do the following: (a) Select OXYMIC on the Observer MIC Select Switch SF501. NOTE: Transmissions when oxygen masks are being used can be heard over the cockpit speaker system. (b) (c) Make sure the observer station can be heard over the interphone/cockpit speakers. 1 Make sure the oxygen mask microphone is serviceable. 2 If the observer station can not be heard, check the wiring from 17PI550 to 10PF503, repair wiring as necessary. Refer to Appendix B. Make sure the observer station MUTE selection squelches the observer station. 1 If the MUTE function does not squelch the observer station, check the wiring from 17PI550 to 10PF503, repair wiring as necessary. Refer to Appendix B Page 102 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

15 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (d) Make sure that the "TX" is displayed on the GTC next to the tuned frequency while the observer's PTT is engaged. NOTE: This makes sure that the transmission was sent. (e) If the "TX" is not displayed on the GTC next to the tuned frequency check the wiring from 17PI550 to 10PF503, repair wiring as necessary. Refer to Appendix B. (11) If unable to communicate from the observer station, replace the observer audio switch panel PF503. Refer to Chapter 23, Optional Observer Audio System - Maintenance Practices Page 103 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

16 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL 1. General OPTIONAL OBSERVER AUDIO SYSTEM - MAINTENANCE PRACTICES A. This section gives the maintenance procedures for the observer audio system. For a general overview of the observer audio system, refer to Observer Audio System - Description and Operation. 2. Tools and Equipment A. For a list of tools and equipment, refer to Communications - General. 3. Observer Switch Panel Removal/Installation A. Remove the Observer Switch Panel. (1) Disconnect the battery and remove external electrical power. (2) Put the Master Interior Switch, located on the aft side of the pilot sidewall armrest, to the OFF position. (3) Get access to the aft Baggage Compartment. (4) Remove the carpet from the junction box cover with the hook and pile fasteners. (5) Disengage necessary circuit breakers in the Junction Box located in the aft Baggage Compartment (6) Remove the 4 screws on the switch panel (7) Pull out the switch panel and disconnect electrical wiring. NOTE: Make note of wiring to assist in installation. B. Install the Observer Switch Panel (1) Connect the electrical wiring to the switch panel. CAUTION: Make sure electrical wiring is not damaged during installation. (2) Gently push the switch panel into position and install the 4 screws. (3) Engage the necessary circuit breakers. (4) Install the carpet on the junction box cover with the hook and pile fasteners. (5) Close the baggage compartment. (6) Put the Master Interior Switch to the ON position. (7) Connect the battery as necessary. C. Return to Service (1) Do the Optional Observer Audio System test procedures, refer to Chapter 23, Optional Observer Audio System - Adjustment Test. 4. Observer Audio Panel Removal/Installation A. Remove the Observer Audio Panel (1) Remove the observer oxygen outlet valve from the observer audio panel. Refer to Optional Observer Oxygen Outlet Valve Removal/Installation in Chapter 35, Observer Oxygen System - Maintenance Practices. (2) Disconnect the battery and remove external electrical power. (3) Put the Master Interior Switch, located on the aft side of the pilot sidewall armrest, to the OFF position. (4) Get access to the aft Baggage Compartment. (5) Remove the carpet from the junction box cover with the hook and pile fasteners. (6) Disengage necessary circuit breakers in the Junction Box located in the aft Baggage Compartment (7) Remove the 4 screws on the switch panel (8) Pull out the switch panel and disconnect electrical wiring. NOTE: Make note of wiring to assist in installation Page 201 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

17 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL B. Install the Observer Audio Panel (1) Connect the electrical wiring to the switch panel. CAUTION: Make sure electrical wiring is not pinched/crushed during installation. (2) Gently push the switch panel into position and install the 4 screws. (3) Engage the necessary circuit breakers. (4) Install the carpet on the junction box cover with the hook and pile fasteners. (5) Close the baggage compartment. (6) Put the Master Interior Switch to the ON position. (7) Connect the battery as necessary. (8) Mount the observer oxygen outlet valve on the observer audio panel. Refer to Optional Observer Oxygen Outlet Valve Removal/Installation in Chapter 35, Observer Oxygen System - Maintenance Practices. C. Return to Service (1) Do the Optional Observer Audio System test procedures, refer to Chapter 23, Optional Observer Audio System - Adjustment Test. 5. Observer Audio Panel Component Removal/Installation A. Remove the Observer Audio Panel Components (Refer to Figure 201) (1) Remove the observer audio panel from the lowboy cabinet. Refer to Optional Observer Audio Panel Removal/Installation in this section. (2) Remove nuts securing audio panel components. (3) Remove audio panel components. B. Install the Observer Audio Panel Components (1) Install audio panel components. (2) Secure the audio panel components by installing the nuts. (3) Install the observer audio panel in the lowboy cabinet. Refer to Optional Observer Audio Panel Removal/Installation in this section. C. Return to Service (1) Do the Optional Observer Audio System test procedures, refer to Chapter 23, Optional Observer Audio System - Adjustment Test Page 202 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

18 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL A A B Nut Nut Nut Cover Nut Cover Cover Nut DETAIL A Jack (JF502) Switch Panel Key Tab Washer Nut Jack (JF503) Jack (JF504) DETAIL B Switch (SF501) Jack (JF505) Observer Audio Panel Components Installation Figure 201 (Sheet 1) 6310T1168 A B Page 203 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

19 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL 1. General OPTIONAL OBSERVER AUDIO SYSTEM - ADJUSTMENT/TEST A. This section gives the observer audio system operational check. For a description and operation of the observer audio system, refer to Observer Audio System - Description and Operation. 2. Tools and Equipment A. For a list of tools and equipment, refer to Communications - General. 3. Observer Panel Lighting Test A. Prepare to Do the Observer Panel Lighting Test (1) Connect the Ground Power Unit (GPU) to the airplane. (a) Adjust the GPU to 28.5 VDC, +0.5 or -0.5 VDC. (2) On the REV/DIM switch panel, rotate the PANELS knob to the fully clockwise (DAY) position. (3) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the ON position. B. Do the Observer Panel Lighting Test (1) Observe the switches on the observer switch panel. (a) Make sure the PUSH TO TALK (white) light is on. (b) Make sure the OXY MIC (white) light is on. (c) Make sure the MUTE light is off. NOTE: The power-on default state of the oxygen mask microphone mute switch is Talk (MUTE light off). (2) On the observer switch panel, select the oxygen mask microphone mute switch to MUTE position. (a) Make sure the MUTE (green) light comes on. (3) On the REV/DIM switch panel, rotate the PANELS knob to the counter-clockwise (night) position. (a) Adjust the PANELS knob between the highest and lowest intensities. (b) Make sure the observer audio panel dimming intensity follows the position of the PANELS knob. NOTE: The observer switch panel switch lights are not dimmable. (4) Disengage the POWERED HEADSETS circuit breaker on the right circuit breaker panel. (a) Make sure the observer switch panel switch lights go off. NOTE: The the observer audio panel lighting will remain on. (5) Engage the POWERED HEADSETS circuit breaker on the right circuit breaker panel. (6) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the EMER position. (a) Make sure the observer audio panel remains lighted. (7) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the ON position. C. Follow On (1) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the OFF position. (2) Remove external electrical power from the airplane. 4. Observer Intercom Operational Test A. Prepare to Do the Observer Intercom Operational Test (1) Connect an aviation headset into the PHONE and MIC jacks on the pilot's side console panel, copilot's side console panel, and observer audio panel. (2) Connect an oxygen mask into the OXY MASK MIC jack on the observer audio panel. (3) Put the MIC SELECT switch to HEAD SET on the pilot's side console panel, copilot's side console panel, and observer audio panel Page 501 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

20 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (4) Connect the Ground Power Unit (GPU) to the airplane. (a) Adjust the GPU to 28.5 VDC, +0.5 or -0.5 VDC. (5) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the ON position. (6) On the copilot's Garmin Touch Controller (GTC2), push the Audio & Radios button to show the Audio & Radios page. (a) On the Audio & Radios page, select the Speaker to the mute position (grey underscore). (7) On the GTC2, push the Intercom button to show the Intercom page. (a) On the Intercom page, select the pilot-copilot link arrow to active (green arrow). (b) On the Intercom page, push the Copilot Volume button to show the Copilot Intercom Settings page. (c) On the Copilot Intercom Settings page, select VOX Mic to Auto. (d) On the Copilot Intercom Settings page, adjust the Volume to desired headset volume level. B. Do the Observer Aviation Headset Test (1) Do an intercom check between the observer and the copilot. (a) Make sure the copilot audio is clearly heard in the observer's headset. (b) Make sure the observer audio is clearly heard in the copilot's headset. (2) Do an intercom check between the observer and the pilot. (a) Make sure the pilot audio is clearly heard in the observer's headset. (b) Make sure the observer audio is clearly heard in the pilot's headset. (3) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the EMER position. (a) Make sure the observer switch panel switch lights stay on. (4) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the ON position. C. Do the Observer Mask Microphone Test (1) Put the MIC SELECT switch to OXY MASK on the observer audio panel. (2) On the GTC2, push the Audio & Radios button to show the Audio & Radios page. (a) On the Audio & Radios page, make sure the Speaker button is not muted (green underscore). (b) On the Audio & Radios page, adjust the Speaker - Volume to 50%. (3) Speak into the observer's mask microphone and make sure that the audio is crisp and clear in the cockpit speakers. (4) On the observer switch panel, put the oxygen mask microphone mute switch to the MUTE position. (5) Speak into the observer's mask microphone and make sure that the audio cannot be heard in the cockpit speakers. D. Follow On (1) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the OFF position. (2) Remove external electrical power from the airplane. (3) Disconnect and stow the aviation headsets. (4) Disconnect and stow the observer oxygen mask. 5. Observer Radio Transmission Test NOTE: The procedure requires a compatible VHF ground station tuned to any inactive frequency except MHz. A. Prepare to Do the Observer Radio Transmission Test (1) Connect an aviation headset into the PHONE and MIC jacks on the copilot's side console panel and the observer audio panel. (2) Put the MIC SELECT switch to HEAD SET on the copilot's side console panel and the observer audio panel. (3) Connect the Ground Power Unit (GPU) to the airplane. (a) Adjust the GPU to 28.5 VDC, +0.5 or -0.5 VDC. (4) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the ON position. (5) On the copilot's Garmin Touch Controller (GTC2), push the COM1 - STBY button to show the COM1 Standby page. (a) On the COM1 Standby page, key in any inactive frequency except MHz. (b) On the COM1 Standby page, select the XFER button to save the new COM1 frequency Page 502 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

21 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (6) On the GTC2, push the COM2 - STBY button to show the COM2 Standby page. (a) On the COM2 Standby page, key in any inactive frequency except MHz. (b) On the COM2 Standby page, select the XFER button to save the new COM2 frequency. (7) On the GTC2, push the Audio & Radios button to show the Audio & Radios page. (a) On the Audio & Radios page, select the copilot's COM1 and MIC as the active radio (green underscores). (b) On the Audio & Radios page, adjust the copilot's COM1 - Volume to 70%. B. Do the Observer Radio Transmission Test (1) Do a radio check between the observer and the ground station. (a) Make sure the observer audio is clearly heard at the ground station. (b) Make sure that sidetone is present in the observer's headset. (c) Make sure the ground station audio is clearly heard in the observer's headset. (2) Do a radio check between the observer and the ground station and make sure it passes. (3) On the right tilt switch panel, put the EMER COMM switch to the NORM position. C. Follow On (1) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the OFF position. (2) Remove external electrical power from the airplane. (3) Disconnect and stow the aviation headsets Page 503 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

22 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL 1. General PASSENGER SEAT - INSPECTION/CHECK A. This section gives the procedures to do an inspection of the passenger seats and controls for correct installation and operation. Task Passenger Seat and Restraint System Detailed Inspection NOTE: This inspection is applicable to Airplanes with the Optional Observer Seat installed. A. Complete a Passenger Seat and Restraint System Inspection. NOTE: Unless there is damage seen, the passenger seats are not removed for inspection. Some disassembly is required, however, to do the inspection. (1) Recline the seat back and remove the seat cushion. (2) Examine all of the restraint system attach points for correct installation and damage. (3) Examine the seat belts and shoulder straps for frayed edges and cuts. (a) Replace frayed or cut belts. (4) Examine the inertia-reel-lock mechanism. (a) Pull the shoulder harness belt slowly to make sure that the belt extends smoothly. (b) Make sure that the shoulder harness belt retracts onto the inertia reel when the belt is released. (c) Pull the shoulder harness belt out quickly from the inertia reel and make sure that the inertia reel locks. (d) Relax the belt and make sure the locking mechanism releases the shoulder harness belt. (5) Visually examine the seat cushions for rips, tears, cleanliness, correct installation of attached components, and other damage. (6) Replace seat covering material, if necessary. NOTE: For the FAA ire-block criteria, seat cushions are available from Cessna Aircraft Company. All seat cover materials that you purchase from Cessna Aircraft Company are ire-block certiied with the cushion materials. (7) Replace the seat cushion(s), if necessary. (a) New cushions must either be purchased from Cessna Aircraft Company or the new cushions be dynamically certiied by the facility that does the interior refurbishment. Make sure that the new cushion certiication is tested in the same seat into which they will be installed and agree with the applicable FAR requirements for the airplane. Also, the new cushion installed in the selected cover material must agree with the ire-blocking requirements. If the seats do not agree with the dynamic certiication requirements detailed in 14 CFR , the airplane does not agree with the original certiication criteria. (8) Replace the seat structure components, if necessary. (a) Replace the seat structure if there are any broken or damaged parts. NOTE: The only method of seat structure repair is part replacement. (b) (c) Order the replacement parts from Cessna Aircraft Company. If these conditions are not followed for repair or parts replacement, the airplane will no longer be certiied. Install the replacement part(s) in accordance with the original installation method. NOTE: If the seats do not agree with the dynamic certiication requirements detailed in 14 CFR , the airplane does not agree with the original certiication criteria Page 601 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

23 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (9) Examine the exterior of the rollers, pins, adjustment levers, guides, and other components for damage. (10) Examine the hydrolock assemblies for correct installation, cleanliness, corrosion, wear, interference, or other damage. Do a check for luid leakage from the hydrolock assemblies. (11) Examine the seat control cables and cable clevises for correct installation and condition of safety pins, cotter pins, etc. (12) Make sure that the cable shows freedom of movement when the applicable handle/lever is operated. (13) Do a check for cable or cable clevis interference. (14) Examine the seat frame exterior and structure for damage. (15) Examine for correct installation and condition of the seat belt inertia reels installed in the base of the seat. (16) Install the seat cushion. B. If installed, do the Optional Observer Seat Detailed Inspection. CAUTION: Use cotton gloves when you remove and install the observer seat to keep the surfaces and seat upholstery clean. CAUTION: Put a protective cover on the observer seat to prevent damage during removal, storage, and installation. CAUTION: Make sure that you use two persons to remove and install the observer seat to prevent damage to the lowboy cabinet. CAUTION: Do not lubricate the washers, axle bolts, or bushings on the observer seat to prevent unserviceable components. Lubricants will collect dust and other particles that will prevent free movement. CAUTION: Keep the fasteners with their observer seat when you remove and install the observer seat to prevent incorrect operation of the observer seat. It is necessary that you only use the observer seat fasteners on the observer seat. (1) Operate the forward-aft adjustment, seat back tilt adjustment, and the up-down adjustment on the observer seat to make sure that they operate correctly. (2) Make sure that the armrest movement is adjusted correctly. (3) Pull the shoulder harness out slowly. (a) Make sure that the shoulder harness comes out smoothly. (b) Make sure that the shoulder harness retracts into the inertia reel when you release it. (4) Pull the shoulder harness out quickly. (a) Make sure that the inertia reel locks and stops the movement of the shoulder harness. (b) Make sure that the shoulder harness retracts into the inertia reel when you release it. (5) Remove the observer seat from the airplane. (6) Examine shoulder harness and seat belts for rips, cuts, tears, frayed edges, clean surfaces, and the general condition. (a) Replace the shoulder harness and seat belts that have rips, cuts, tears, frayed edges, or other damage. (7) Examine the seat belt buckle assemblies for the general condition and make sure that they are tight. (8) Examine the seat belt attach points for damage, tightness, and correct installation. (9) Make sure that the seat belt ends lock into the belt receptacles correctly. (10) Remove the headrest back cover assembly and the headrest cover assembly from the headrest. (11) If necessary, remove the seat back cushion cover assembly and the bottom cushion cover assembly from the observer seat Page 602 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

24 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (12) Visually examine the seat cushion and headrest cover assemblies on the observer seat for rips, tears, clean surfaces, signs of damage, and make sure that they are tight. NOTE: NOTE: If it is necessary to replace the material for the observer seat cover, you must obey the Federal Aviation Administration (FAA) government regulations for ire-resistant material. You can purchase the new seat cover material from Cessna Aircraft Company. All seat cover materials supplied by Cessna Aircraft Company are ire-resistant certiied with the seat cushion materials. An alternative is to purchase the seat cover material from a supplier and certify the new material for resistance from ire with the current existing seat cushions. It is necessary to replace the three burned seat cushions with this alternative. A different alternative is to purchase the seat cover material from a supplier and three seat cushion burn test specimens (coupons) from Cessna Aircraft Company to certify the new material for resistance from ire. If the seat does not obey the dynamic certiication requirements in 14 CFR , the airplane does not obey the initial certiication criteria. If it is necessary to replace the seat cushions, it is necessary to purchase the new seat cushions from Cessna Aircraft Company, or the repair facility that does the repair must dynamically certify the new seat cushions. This certiication makes it necessary to do the test of the new seat cushions in the same seat in which they will be installed and obey the applicable Code of Federal Regulations (CFR) for the Model 525 Airplane. Also, the new seat cushion installed in the seat cover material must obey the regulations for ire-resistant material. If the seat does not obey the dynamic certiication requirements in 14 CFR , the airplane does not obey the initial certiication criteria. (13) Invert the observer seat. (14) Examine the rollers, pins, hydrolok assembly, adjustment levers, guides, and other components. (a) Examine for correct installation, clean surfaces, corrosion, wear, rubs, loose components, or other damage. (b) Examine for signs of luid leakage from the hydrolok assemblies. (15) Examine the control cables and clevises for correct installation and condition of the safety pins, cotter pins, and other components. (16) Examine the cables to make sure that they move freely. (a) Operate the applicable handle or lever and examine for cable and clevis rubs. (17) Examine the observer seat headrest frame assembly and structure. (a) Examine for correct installation, clean surfaces, corrosion, wear, rubs, loose components, or other damage. (b) Make sure that the roll pins and springs are correctly installed. NOTE: If it is necessary to replace unserviceable or damaged seat structure components, the only approved procedure is to replace the components. It is necessary to purchase the components from Cessna Aircraft Company and install them with the initial installation procedure. If you do not obey these conditions for component replacements, the airplane does not obey the initial certiication criteria. If the seat does not obey the dynamic certiication requirements in 14 CFR , the airplane does not obey the initial certiication criteria. (18) Examine the observer seat frame and structure for signs of damage. (19) Examine the rollers on the observer seat for lat spots. (a) Replace the rollers that have lat spots. Refer to the Goodrich Component Maintenance Manual. (b) Make sure that all applicable rollers turn freely on the axle bolts or bushings. (c) Remove, clean, and install the components that do not turn freely. (20) Measure the thickness of the roller housing and the tang on the observer seat. (a) Replace the roller housing if the thickness of the tang is worn to less than 50 percent of the thickness of the roller housing Page 603 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

25 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (21) Examine the springs on the observer seat that keep the seat stop pins engaged in the seat track holes and make sure that they operate correctly. (a) Replace the springs that do not operate correctly. (22) Visually examine the seat tracks for cracks. Replace any seat track that shows signs of crack(s). (23) Visually inspect each seat rail hole for dirt or any debris which may stop engagement of a seat pin. Clean out all holes. (24) Refer to Figure 601. Measure each hole in the seat tracks for excessive wear. Measurement is to be made inch (0.51 mm) below the top surface of the seat rail Page 604 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

26 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL A91382 Nominal Diameter 0.31 Inch (7.87 mm) (NOTE) Maximum Allowable Diameter 0.42 Inch (10.67 mm) (NOTE) NOTE: Measure Diameter 0.02 Inch (0.51 mm) Below Top Surface of Seat Track Cross Section of Seat Track Showing Hole Wear Seat Stop Pin Seat Stop Pin Guide Roller Housing Thickness Roller Housing Minimum Pin Depth Engagement 0.15 Inch (3.80 mm) Tang Thickness Seat Track Observer Seat Track and Seat Base Inspection 6211T Page 605 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

27 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL Figure 601 (Sheet 1) (a) If wear dimension across any hole is more than 0.38 inch (9.65 mm), but is not more than 0.42 inch (10.67 mm), inspect each hole again at 100-hour intervals for excessive wear. (b) If the wear dimension across any hole is more than 0.42 inch (10.67 mm), replace the seat track. (25) Install the observer seat in the airplane. (26) Lift up on the aft edge of seat to stop all vertical play. (27) In the lifted position, measure depth of engagement of seat pin. (a) If engagement of pin is less than 0.15 inch (3.8 mm) repair or replace components as (b) necessary to get seat pin engagement of 0.15 inch (3.8 mm), or greater. If the seat track is worn, engagement dimension is measured from the existing surface, not the manufactured surface. (28) Install the seat back cushion cover assembly and the bottom cushion cover assembly to the observer seat. (29) If necessary, install the headrest back cover assembly and the headrest cover assembly to the headrest. (30) Put the observer seat in the correct position as necessary. End of task Page 606 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

28 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL 1. General OXYGEN - INSPECTION/CHECK A. This section includes the information to inspect the oxygen system. 2. Tools and Equipment A. For tools and equipment, refer to Oxygen - General. 3. Oxygen System Precautions WARNING: Do not permit smoking, open lame, or potential sources of electrical sparks near airplane while maintenance is being performed on the oxygen system. Make sure that all electrical power is disconnected and airplane is properly grounded. A. If maintenance on the airplane oxygen system or any other system, is performed requiring removal of an oxygen system component, strict adherence to procedures and precautions is required. WARNING: The entire oxygen system must be thoroughly clean of oil, grease and solvents to avoid the danger of spontaneous combustion and explosion when in contact with oxygen under pressure. WARNING: The entire oxygen system must be free of moisture to prevent freezing of the oxygen equipment at low temperatures. (1) Use extreme caution to make sure that every port of the system is kept thoroughly clean and free of water, oil, grease, and solvent contamination. All tools used, plus hands, must be clean. WARNING: The entire oxygen system must be free of foreign matter to prevent the contamination of the breathing oxygen with dust, odors and clogging of any of the mechanisms. (2) Cap all openings immediately upon removal of any component. Do not use tape or caps which will induce moisture. 4. Oxygen System Inspection/Check A. Perform an Oxygen Cylinder Inspection. (1) Cylinder speciications are located on a decal on the cylinder body. (2) Hydrostatic test date is stamped on the metallic surface of the neck and shall include the month and year of the hydrostatic test date. B. Inspect Oxygen System Components. (1) Remove side console cover to provide access to the components. (2) Inspect side console components using a mirror. (3) Do a check of the electrical wiring to the altitude pressure switch (UC045) and to the oxygen control valve (VC001) in the left side console. Refer to Chapter 20, Electrical Components Inspection - Maintenance Practices. (4) The iller valve is located in the nose just inside the right nose baggage door. The line to the iller valve and the iller valve contain high pressure oxygen. Cap iller valve at all times, except during servicing operation. (5) Clean oxygen masks periodically after using. During cleaning, check mask for deterioration Page 601 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

29 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL Task Oxygen System Functional Check A. Tools and Equipment: Air Data Tester ( ) External Power (MH32-200K24M or Equivalent) Vacuum Source Flowrator (Commercially Available) NOTE: Before this test is completed, maintenance personnel must refer to the Oxygen System Precaution in this section. B. Complete a Functional Check of the Oxygen System. WARNING: Do not have an open lame or potential sources of electrical sparks near the aircraft during this procedure. Make sure that all electrical power is disconnected and that the aircraft is correctly grounded. WARNING: Do not remove or tighten oxygen system ittings when the system is pressurized. (1) Make sure a leak test is completed. (2) Make sure that the cylinder mounted regulator is ON. (3) Make sure that the cylinder pressure is between 1600 and 1800 psig (11.03 and MPa). (4) Turn the valve on the regulator to the ON position. (5) Turn the control valve to the CREW ONLY position. (6) Put a crew masks bayonet itting into the pilot s and copilot s outlet valves to ind that airlow for each is available. (7) Slowly apply a vacuum on the barometric pressure altitude sensor (UC045) with the altimeter teed into the vacuum line, located on the pilot's side console. (8) Supply 29.0 VDC, +0.5 or -0.5 VDC electrical power to the aircraft. (9) Make sure that the OXY/SEAT BELT circuit breaker on the aft circuit breaker panel is engaged. Refer to Chapter 24, DC Electrical Load Distribution - Description and Operation. (10) Make sure the WARN LTS I, WARN LTS II, and NORM PRESS circuit breakers on the left circuit breaker panel are engaged. (11) Turn the oxygen control valve to the NORMAL position. (12) Push the Press To Test button on the crew mask and make sure there is airlow. (13) Put a crew mask into the copilot outlet valve with the mask in EMER position and make sure there is airlow. (14) Slowly apply a vacuum on the barometric altitude pressure sensor (UC045). Do not go more than 6,000 fpm, and monitor the altimeter until the passenger oxygen masks fall. (15) Make sure that all passenger oxygen masks fell at 13,500, +600 or -600 ft (4114.8, or m). (16) Pull the lanyard and pintle pins from all passenger oxygen masks. (17) Remove each mask and attach it to the Flowrator to examine each mask for airlow. (18) The minimum low on each mask must be 4.5 Liters Per Minute (lpm). (a) Temporarily block the oxygen low through mask where the bag attaches to the mask face piece and measure the time required for the bag to ill. The bag must ill in a maximum time of 17.5 seconds. (19) Slowly release the vacuum. (20) Make sure that the altitude switch closes before the 11,500 feet ( m) (minimum) altitude reading. (21) Make sure that oxygen low to the masks has stopped. (22) Turn the control knob from the NORMAL position to the MANUAL DROP position. (23) Make sure that oxygen low is again supplied to the masks. (24) Replace each pintle pin Page 602 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

30 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (25) Make sure that oxygen low stops at each mask. C. If installed, do the Optional Observer Oxygen System Functional Test. (1) Make sure that the cylinder pressure is between 1600 and 1800 psig (11.03 and MPa). Refer to Chapter 12, Oxygen System - Servicing. (2) If necessary, turn the valve on the regulator to the ON position. (3) On the pilot's side console, turn the control valve to the CREW ONLY position. (4) Put the observer oxygen mask bayonet itting into the observer oxygen outlet valve. (5) Make sure the main battery is connected. Refer to Chapter 24, Nickel-Cadmium Battery - Maintenance Practices or Sealed Lead Acid Battery - Maintenance Practices. (6) Connect the Ground Power Unit (GPU) to the airplane. (a) Adjust the GPU to 28.5 VDC, +0.5 or -0.5 VDC. (7) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the ON position. (8) On the REV/DIM switch panel, rotate the PANELS knob to the fully clockwise (DAY) position. (9) Make sure the observer oxygen shutoff switch OBSERVER OXYGEN (white) light is on. NOTE: The OFF (amber) light may or may not be on depending on last switch position. (10) Select the observer oxygen shutoff switch to the OFF position. (a) Make sure the OFF (amber) light is on. (b) Push the PRESS TO TEST button on the observer mask and make sure there is no airlow. (11) Check for proper dimming of the observer oxygen shutoff switch lights. NOTE: Observer oxygen shutoff switch lights will change to a ixed dimmer intensity. (a) On the REV/DIM switch panel, rotate the PANELS knob counter-clockwise. (b) Make sure the intensity of the switch lights decreases by approximately half. (c) On the REV/DIM switch panel, rotate the PANELS knob to the fully clockwise (DAY) position. (12) Select the observer oxygen shutoff switch to the Normal position (OFF light not on). (a) Make sure the OFF (amber) light is off. (b) Push the PRESS TO TEST button on the observer mask and make sure there is airlow. (13) Do a cockpit annunciator test on the pilot's Garmin Touch Controller (GTC1). (a) On the Home page push the Aircraft Systems button to show the Aircraft Systems page. (b) On the Aircraft Systems page push the Systems Test button to show the Systems Test page. (c) On the Systems Test page push the Annunciator button to start the annunciator test. (d) Make sure the observer oxygen shutoff switch OFF (amber) light is on while the test is active. (14) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the EMER position. (a) Make sure the observer oxygen shutoff switch OBSERVER OXYGEN (white) light is on. (15) On the ELECTRICAL POWER switch panel, put the BATTERY switch to the OFF position. (16) Remove external electrical power from the airplane. (17) Disconnect and stow the observer oxygen mask. (18) On the pilot's side console, turn the control valve to the NORMAL position. (19) If necessary, charge the oxygen cylinder. Refer to Chapter 12, Oxygen System - Servicing. D. Return the Aircraft to Initial Coniguration. (1) Put the cylinder mounted pressure regulator to the OFF position. (2) Put the passenger oxygen select valve to the MANUAL DROP position and pull a couple of pintle pins to vent the oxygen from the low pressure system. (3) Return the passenger oxygen select valve to the NORMAL position. (4) Make sure that all pintle pins are correctly installed. (5) Install the passenger masks in the service units and close doors. (6) Remove the vacuum source. (7) Remove the electrical power. (8) Put the system to the initial coniguration. (9) Charge the oxygen cylinder to 1850 psi (12.75 MPa). Refer to Oxygen System - Servicing Page 603 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

31 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL (10) Put safety wire on the ON/OFF valve at the oxygen cylinder to the ON position. Refer to Safetying - Maintenance Practices. End of task Task Oxygen Bottle and Regulator Assembly - Restoration (Hydrostatic Test) WARNING: Make sure personnel obey the safety precautions. Oxygen System - Maintenance Practices. Refer to Crew CAUTION: Make sure that the oxygen pressure regulators that are removed, repaired, and installed in the ield do not give an opportunity for contaminants to get into the oxygen system. Oxygen cylinders and pressure regulators are given as assemblies by Cessna Parts Distribution. CAUTION: Make sure that unserviceable pressure regulators or pressure regulators that need disassembly are interchanged for replacement oxygen cylinder and pressure regulator assemblies through Cessna Parts Distribution. CAUTION: Make sure that the oxygen cylinder and pressure regulator assemblies are disassembled, repaired, inspected, cleaned, hydrostatically tested, reassembled, and serviced by the manufacturer or other FAA approved facility. NOTE: The hydrostatic test must be done at an authorized overhaul and repair facility. Return the cylinder to service if it passes the requirements of the hydrostatic test. The cylinder must be identiied by date when the hydrostatic test was done. A. Restore the Oxygen Bottle and Regulator Assembly. (1) Get access to the Oxygen cylinder from the right nose compartment door. (2) Remove the access panels (212GZ, 212CZ, and 212DZ). Refer to Chapter 6, Access Plates and Panels Identiication Maintenance Practices. (3) Remove the oxygen cylinder. Refer to Crew Oxygen System - Maintenance Practices, Oxygen Cylinder and Pressure Regulator Assembly Removal/Installation. (4) Send the bottle to an authorized overhaul and repair facility. (5) Install the oxygen cylinder. Refer to Crew Oxygen System - Maintenance Practices, Oxygen Cylinder and Pressure Regulator Assembly Removal/Installation. (6) Do the servicing of the oxygen cylinder. Refer to Chapter 12, Oxygen System - Servicing. (7) Install safety wire on the shutoff valve knob while the knob is in the ON position. Refer to Safetying - Maintenance Practices. (8) Install access panels (212GZ, 212CZ, and 212DZ). Refer to Chapter 6, Access Plates and Panels Identiication - Maintenance Practices. (9) Close and latch the right nose compartment door. End of task Page 604 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

32 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL 1. General OPTIONAL OBSERVER OXYGEN SYSTEM - DESCRIPTION AND OPERATION A. This section gives a description for the observer oxygen system on the Model 525 M2 trainer coniguration. The line replaceable units (LRU) in the observer oxygen system are the observer oxygen outlet valve, observer oxygen shutoff switch (SC013), observer oxygen shutoff valve (VF002), and observer oxygen shutoff relay (KC030). B. Refer to Figure 1 for a general view of the observer oxygen system. 2. Description A. Observer Oxygen Outlet Valve (1) The observer oxygen outlet valve is installed on the observer audio panel on the lowboy cabinet on the right side of the cabin. The valve provides the oxygen supply to the observer oxygen mask through a compatible oxygen outlet. The valve is normally closed, and opens when the oxygen mask bayonet itting is inserted. B. Observer Oxygen Shutoff Switch (1) The observer oxygen shutoff switch is installed on the pilot's side console on the left side of the cockpit. The switch allows the pilot to disconnect the oxygen supply to the observer oxygen mask. The switch is an alternate-action pushbutton with two positions (Normal, OFF) and two indicator lights (OBSERVER OXYGEN, OFF). (a) In the Normal (depressed) position, oxygen is available to the observer oxygen mask. This position is indicated by the absence of the OFF (amber) light. (b) In the OFF (released) position, oxygen is disconnected from the observer oxygen mask. This position is indicated by the presence of the OFF (amber) light. (c) The OBSERVER OXYGEN (white) light is always on in both positions. C. Observer Oxygen Shutoff Valve (1) The observer oxygen shutoff valve is installed behind the passenger compartment sidewall at FS , WL , and RBL The valve opens or closes the oxygen line to the observer oxygen mask depending on the position of the observer oxygen shutoff switch. The valve is normally closed, and opens when power is applied. D. Observer Oxygen Shutoff Relay (1) The observer oxygen shutoff relay is installed behind the left circuit breaker panel on the left side of the cockpit. The relay provides switching for the observer oxygen system Page 1 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1

33 MODEL 525 (SERIALS AND AND ON) MAINTENANCE MANUAL A A C Observer Oxygen Line Observer Oxygen Outlet Valve From Oxygen Cylinder B Observer Oxygen Shutoff Valve (VF002) Left Side Console Panel DETAIL A Nameplate DETAIL C DETAIL B Observer Oxygen System Figure 1 (Sheet 1) Observer Oxygen Shutoff Switch (SC013) 6310T1168 A6391T059-1 B6391T Page 2 Cessna Aircraft Company Feb 27/2017 ICA Form 2261 Rev 1