Updating an Older Airplane

A forty year old Cessna 172gets a facelift and a new heart

April, 2005

Stan Cooper

A Metamorphosisfrom This… …to This

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N2686U – A ’63 Cessna 172D

• 2200 Hours Airframe Total Time• 220 Hours SMOH – Continental O-300-C• Original “Shotgun” Panel• Avionics Stack Limited to ½ Height (“T” Control

Column)• Optional 35 Amp DC Generator Electrical

System• Circuit Protection: AGS Fuses• Dual Narco Mark 16 360 Channel NavComs• 30 Years at SNA (Orange County) – Lots of

Surface Corrosion• Two previous owners (17 years) were A&P

mechanics and CFIs who taught their wives and children to fly in the airplane

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Why A 1963 Model?

• ’63 was the first year the 172 had the “Omni-Vision” rear window – looks similar to the new 2003 172S

• Higher gross weight (2,300 lbs vs. 2,250 lbs) with same empty weight, resulting in higher useful load than earlier years

• The ’63 still had manual flaps – simpler, faster to deploy and retract, and arguably more reliable than electric flaps

• Continental O-300 six cylinder engine (some will debate whether this is an asset or a liability)

• At $26,500 I could afford it ☺

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The Project Scope• Replace the instrument panel with a new STC’d one from Avion

Research conforming to FAR 23.1321, including new AI and DG• Update the electrical system from DC generator to 50 amp STC’d

Skytronics alternator; replace fuses with circuit breakers• New avionics stack-

– PS Engineering 6000 Audio Panel/Intercom– King KLX 135A GPS/Com– King KY97A Comm– Narco NAV 121 VOR Receiver– Monroy ATD300 Traffic Detector– Garmin GTX 320A Solid State Transponder– S-TEC 30 Autopilot– King KMD 150 MFD/GPS

• New electronic tach, volt/ammeter, and chronometer• Strip old paint, remove corrosion, prime and paint• New interior, including B.A.S. shoulder harnesses• Six new ECi “TITAN” cylinders with Real Gaskets pushrod tubes

A Few Words to the Wise

• Before beginning major work on any certificated airplane, discuss the project with your A&P/IA and your local FSDO inspector.

• Tell them exactly what you want to do and how you plan to do it.

• Find out what paperwork will be required and agree on who’s going to do what.

• After you’ve described what you’re going to do, don’t make any changes.

• Keep the FSDO inspector informed of your progress and invite him/her to stop by any time to inspect the work.

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The Mid-eighties Paint Job

….. It probably looked great at the time.

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The 1963 Vintage “Shotgun” Panel

’63 was the last year the 172 used a “T” control column.

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The “U” Column Permits a Full HeightCenter Avionics Stack

… and the ’64“U” Control

Column

The ‘63 “T” Control Column

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Hmmm.. Do I Really Want To Do This?? Original “T” Control Column

(Limits avionics stack tohalf height)

Original Defroster Nozzle(Interferes with new gyro

instrument vacuum fittingsand hoses)

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Getting There..New Defroster Nozzle(Prevents interference

with AI and DG vacuumfittings and hoses)

New “U” Control Column(Permits full height

Avionics stack)

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Testing the avionics andPre-wiring the panel…

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• Avionics and harness bench tested before installation• All panel instrument and avionics grounds terminate

on a copper buss connected directly to negativebattery pole (fuselage not used for ground return – toomuch noise)…

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The New Electrical Wiring Diagram

VA-1A-50

AVIONICSMASTER

MASTER

ALT

BAT

FIREWALL

ALTERNATOR

A

C

D

B

JASCOJ12M20SP

12VCONTROLLER

REDORG

GRN

BLK

YEL

PRI

MARY

BUS

AVI

ONICS

BUS

8 AWG SHIELDED 50

ALT

AMMETER

OUTPUT(WHITE)

REG(AUX)(RED)

ALT FIELD(GRN)

GROUND(BLK)

18 AWG

20 AWG

REG

7

5

ALTFIELD

18 AWG

STARTER"T" HANDLE

10

CABINLIGHTS

18 AWG EB1 R

L

FUEL GAUGES

EB5

EB4

EB2

FUEL GAUGE TRANSMITTERS

CESSNA DWG 0500062 PAGE 8.1REV D 9-11-62

CABINLIGHTS

18 AWG LA7MAP LIGHT

18 AWG LA1

DOME LIGHTCESSNA DWG 0500062 PAGE 11.1 REV D 9-11-

62

INSTRLIGHTS

10 18 AWG LB1INSTR

LIGHTS

18 AWG LB2INSTRLIGHTINSTR & COMPASS

LIGHTS

RADIO LIGHTS

18 AWG LB3 18 AWG LB4

COMPASSLIGHT

22 AWG P1A, KLX135A22 AWG P97A1, PIN B, KY97A22 AWG P101, PIN 4, AT50A22 AWG P810, PIN 27, NAV121

10

NAVLIGHTS

NAVLIGHTS

18 AWG LD2

18 AWG LD4

18 AWG LD11

PORT

STARBOARD

TAIL

CESSNA DWG 0500062PAGE 11.2 REV D 9-11-62

CESSNA DWG 0500062PAGE 11.4 REV D 9-10-62

STROBEBCN

16 AWG LF2

FLASHING BEACONCESSNA DWG 0500062

PAGE 11.5 REV D 9-11-62

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LANDINGTAXI

LANDINGTAXI LANDING

TAXI

OFF

14 AWG LC2

14 AWG LE1

LANDING (INBOARD)

TAXI (OUTBOARD)CESSNA DWG 0500062

PAGE 11.3 REV D 9-10-62

2TURN COORD

18 AWG FA1 + -TURN & BANK

18 AWG FA2 CESSNA DWG 0500062PAGE 9.1 REV D 9-10-62

18 AWG FC23STALL WARN

WARNINGHORN

18 AWG FC3

STALL SWITCHLEFT WING LEADING EDGE

CESSNA DWG 0500062PAGE 15.1 REV D 9-10-62

AUX POWER10 18 AWG CIGAR LIGHTER RECEPTACLE CESSNA DWG 0500062

PAGE 13.1 REV D 9-11-62

RADIO 1

RADIO 2

RADIO 3

RADIO 4

3

10

7

5

18 AWG

20 AWG

20 AWG

PIN 20, J1, PMA 6000 AUDIO PANEL - PS ENGINEERING DOCUMENT 200-066-0002 REV. 2, MAY 1999

PIN 7, P810, NAV121 VOR RCVR - NARCO NAV121 MAINTENANCE MANUAL 03723-0600, 9/79, TABLE 2.2A & FIG. 2-9

PIN 26, P810, NAV121 VOR RCVR - NARCO NAV121 MAINTENANCE MANUAL 03723-0600, 9/79, TABLE 2.2A & FIG. 2-9

18 AWG

18 AWG

18 AWG

PIN 6, P4001, KLX135A GPS/COMM - ALLIED SIGNAL INSTALLATION MANUAL 006-10500-0003, REV. 3, AUG 1995, FIG. 2-1, SHEET 3 OF 5

PIN 7, P4001, KLX135A GPS/COMM - ALLIED SIGNAL INSTALLATION MANUAL 006-10500-0003, REV. 3, AUG 1995, FIG. 2-1, SHEET 3 OF 5

PIN 8, P4001, KLX135A GPS/COMM - ALLIED SIGNAL INSTALLATION MANUAL 006-10500-0003, REV. 3, AUG 1995, FIG. 2-1, SHEET 3 OF 5

18 AWG

18 AWG

PIN R, P97A1, KY97A COMM - ALLIED SIGNAL INSTALLLATION MANUAL 006-00674-0003, REV. 3, APR 1994, FIG. 2-8

PIN 14, P97A1, KY97A COMM - ALLIED SIGNAL INSTALLATION MANUAL 006-00674-0003, REV. 3, APR 1994, FIG. 2-8

18 AWG PIN 16, P101, AT50A TRANSPONDER - NARCO AT50A MAINTENANCE MANUAL 03604-602, SEPT 1972, FIG. 2-1

CENTER PIN, POWER JACK, ATD-300 - MONROY ATD-300 OWNERS MANUAL MA-300, REV 1.6, 1-2004, F IG. 622 AWG

6 AWG

18 AWG

4 AWG

STARTER

+

-

D.C. POWER WIRING - CESSNA 172D N2686US/N 17250286 S. COOPER REV. 7/13/2004

AMMETERSHUNT

18 AWG

18 AWG

10

STROBEBCN

OFFSTROBE (NC)

BCNFLASHER

ASS'Y

LAMP

DIMMERMODULE

LM 150K

V IN

1 F 2 - 11 VDCOUTPUT

ADJUSTMENT

CASE IS OUTPUT

13.8 VDC

240

.1 F

5 K

INSTRUMENT LIGHTS DIMMERMODULE

BATTERY CONTACTOR

DIMMERMODULE

S50ORG

BRN

BLK WH/RED

1 AFUSE

RED

WH/BRNCLOCKLIGHT

1

TACHWHITE

BLK

TACHOMETER

P-1000

IGNITION SWITCHL R

L.H. MAGR.H. MAG

CESSNA DWG 0500062PAGE 5.1 REV D 9-11-62

FAA Form 337, Block 8 U

.S.A. N2686U

Date July 13, 2004

AVIONICSFAN

2A FUSE

TROLLFN-200

18 AWG PIN 37, 37 PIN CONN, KMD 150 MFD/GPS - ALLIED SIGNAL INSTALLATION MANUAL 006-10607-0000, REV. 0, NOV 1999, FIG. 2-10

5S-TEC 30 AUTOPILOT

18 AWGAP/TURN COORD PIN 14AP/PITCH COMP PIN 1

Fitting the New Panel and Avionics

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Avionics Interconnection DiagramPMA6000TOP (J2)

BOTTOM (J1)

3C1A5E6F910K

4DN12

9

PR19L

10

HV16MT

12

20

322W

8Y

1Z

ATD-300

KY97AJ97A1

P1

CO-PILOT PHONES HICO-PILOT PHONES LOPASS PHONES HIPASS PHONES LO

PASS 1 PHONES

PASS 2 PHONESPASS 1 MIC HIPASS 1 MIC LOPASS 2 MIC HIPASS 2 MIC LO

CO-PILOT MIC AUDIOCO-PILOT MIC PTTCO-PILOT MIC LO

CO-PILOT MICCO-PILOT PTT INCONTROL WHEEL

EXTERNAL ENTERTAINMENT

KLX135A AUDIO HIKLX135A AUDIO LOKLX135A MIC AUDIO HIKLX135A MIC KEY

KLX135A SPKR LOAD

KY97A AUDIO HIKY97A AUDIO LO

H7J9E5R14F6S

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KY97A MIC AUDIO HIKY97A MIC KEY

KY97A SPKR LOAD

TRAFFIC ANNUNCIATOR

600 OHM AUDIO(RING OF "PHONE-SPEAKER" JACK)

12 VDC POWER"RADIO 3" CKT BRKR

NAV121 AUDIO HI

PILOT PHONES HIPILOT PHONES LOSPKR HISPKR LO CABIN SPEAKERPILOT MIC AUDIOPILOT MIC PTTPILOT MIC LO PILOT PTT IN

CONTROL WHEEL

AIRFRAME GROUND

AVIONICS INTERCONNECT WIRING - CESSNA 172D N2686US/N 17250286 S. COOPER REV. 5/28/2004

NAV121J810

3672619

MOUNTINGSTUD

12 VDC POWER - "RADIO 1" CKT BRKR

12 VDC POWER - "RADIO 1" CKT BRKR

12 VDC POWER - "RADIO 4" CKT BRKR

FAA Form 337, Block 8, Item

3 U.S.A. N

2686U Date July 13, 2004

KLX135AP4001

13143PN

678FJ

12 VDC POWER - "RADIO 2" CKT BRKR

DATABASE OUT

2JK15

DATABASE IN

GROUND

TO RS232 JACKON PANEL

(GPS DATA LOADER)

KMD150P1

3725131230

12 VDC POWER - “RADIO 4” CKT BRKRGROUND

+ RT+ LT

S-TEC 30

653

35109

19422021

GPS GAINJMPR

CUT FORDG

DG52D54

EBDA

SIG REFEXC REFAC HDG

S-TEC 30 Autopilot Installation

Panel Showing Turn Coordinator/Roll Computer and DG with Heading Bug

Pitch Computer Pitch Servo Pressure Transducer Roll Servo16

Solid State Dimmers Replace Rheostat

- Instruments- Radios

Same circuitas in new 172R,except set upfor 12 V systeminstead of 24 Vsystem –

Safer and moreefficient thanrheostats

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Item Maximum Current Load

1. PMA 6000 Audio Panel 1.00 Ampere2. KLX 135A GPS/Comm 6.30 Amperes (Tx)*3. KY97A Communications Transceiver 1.10 Amperes (Rx)4. GTX 320A Transponder 2.00 Amperes5. ACK A30 Encoder 0.30 Ampere6. NAV 121 VOR Receiver 0.87 Ampere7. KMD 150 MFD/GPS 1.50 Amperes8. S-TEC 30 Autopilot 5.00 Amperes9. ATD-300 Traffic Detector 0.20 Ampere10. P-1000 Tachometer 0.20 Ampere11. VA-1A-50 Volt/Ammeter 0.10 Ampere12. Dome Light (GE 1816 Bulb) 0.33 Ampere13. Map Light (GE 58 Bulb) 0.58 Ampere14. Fuel Quantity Indicators 0.36 Ampere15. Instrument Lights (GE 94 Bulb) 1.10 Amperes16. Compass Light 0.08 Ampere17. Landing Lights (Taxi and Landing) 15.60 Amperes18. Strobe 1.70 Amperes19. Navigation Lights 5.60 Amperes20. Stall Warning Horn 0.25 Ampere21. S-TEC Turn Coordinator 0.30 Ampere

===============TOTAL MAXIMUM LOAD 44.47 Amperes

* KLX 135A draws 6.3 amperes in Transmit, KY97A draws 6.0 amperes transmit. Sinceonly one comm unit transmits at a time, the table shows worst case. Transmit loadis transitory, not continuous.

Electrical System Load Budget

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Weight & Balance

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Weight & Balance (Cont’d)

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Finally!!!

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Millennium Falcon??

Exterior stripped, surface corrosion removed,Alodined, and prepped for primer

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Primed and ready for paint..

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Photo from ’63 Factory Brochure

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…And the New Paint on N2686U

The strip and paint was done by T&P Aero Refinishersin Salinas, CA. I think they did a fantastic job..

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Interior – Before…

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Interior – and After…

Kit by Hangar Bay Aircraft Interiors

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New ECi Cylinders

1. Original Continental Cylinders

2. Baffling, exhaust system,intake system, old cylinders

removed

4. New ECi cylinders with Real GasketsSTC’d pushrod tubes installed

5. All back together with powdercoatedbaffling, new Lord engine mounts

3. Cam and lifters ingood shape

Costs (Labor Not Included)• N2686U . . . . . . . . . . . . . . . $26,500• Avion Panel and Control Wheels . . . . . . . 3,395• New RC Allen AI . . . . . . . . . . . . . 425• New Sigma Tek 4000C DG with Heading Bug . . . . 1,191• King KLX-135A GPS/Comm . . . . . . . . . 2,095• King KY-97A Comm . . . . . . . . . . . . 989• Garmin GTX 320A Transponder . . . . . . . . 1,230• PS Eng PMA6000 Audio Panel/Intercom . . . . . . 904• Narco NAV121 VOR Rcvr . . . . . . . . . . 1,149• King KMD 150 MFD/GPS . . . . . . . . . . 2,875• S-TEC 30 Autopilot . . . . . . . . . . . 7,845 • Skytronics/Jasco Alternator . . . . . . . . . 724• Monroy ATD-300 Traffic Detector . . . . . . . 595• Horizon Tach, EI Volt/Ammeter, Clock . . . . . . 861• Miscellaneous (wire, breakers, hoses). . . . . . 500• Strip and Paint (includes labor) . . . . . . 13,000• New Interior and B.A.S. Harnesses . . . . . . 2,500• Six ECi TITAN cylinders and STC’d pushrod tubes . 5,000

=======TOTAL $71,778

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LET’S GO FLYING!

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