What a are few Avionics “System wide” troubleshooting ideas?

DC Electrical troubleshooting handout book

Electrical Troubleshooting Workbook2

Ring lug bad crimp

https://youtube.com/shorts/cXWvA59PAoM?si=dFQqnw2T9P-mWbuK

Autopilot

AP106

In a WestWind, 4 seconds after “ALT”…”CAP” the pitch mode is in CAPTURE mode.  High gain response from the BARO knob to the Control column.

APPS 80

On the ground

APPS 80 “force” indicators actually indicate. Last integrator output before the servo.

Jumper 7 and 10 to look at the APP valids.

does the batt handle snatch and then release

permanent offset may be NAC or LAC

 

Flight Director.

Fly the aircraft on 1 inverter in NORMAL, 1 in ALTERNATE, the see if it is a inverter sync problem.

 

HF Com

HF950 System

in a F900, Transmitter/Receiver and the PA must be MOD LEVEL so and so because of the distance from the tail to the nose.  the squawk is a tuning tone that will not go away.

Receive problems:

Tune 5000, 10,000, 15,000, or 20,000 for WWV audio.

Remove all connectors  to the P.A.  Install a temporary antenna to the REC/EXT.  try WWV again.

Transmit problems:

AM radio will demodulate the transmitter if it is placed on top of the fuselage.

Watch for 10 to 40 amps on the aircraft load meter while transmitting.

Pin Diode and Headphone works good also.

load resistor

 

VHF com

Whaite Noise? Temporary antenna

ELT reradiate

 

Collins 3 digit boxes – 3 429 in, 2 429 out.

422, 422 strap

 

Audio Integration

 

 

VHF Nav

antenna quality/ Audio Quality

 

 

ADF

MoneyMaker:  ANT(enna) mode rather than ADF mode?

White Noise?  If there is no White Noise, temporary sense antenna.

Audio?

Needles stow at 90/270?  Needled Hunt? Indicator installed upright?

Loop Modulation stronger when TEST needles are swung away from null

Ground power unit affects needles.

Tends to oppoint correctly ForAft? one bad coil

 

Needle points OK erratically. H-C excitation on the needle circuit.

 

 

DME 

Neon lamp at antenna.

GPS

Remove the GPS antenna.  Looking down the coax to the receiver, there should be 5VDC on the center pin.  That proves the GPS is plugged in and powered.

Radar

FSTBY escape for a 880 stsem is “STBY” button 4 times in 3 seconds

Paint ground targets

 TXP:

The cheaper the transponder the more critical the antenna.

Mode C Gillam errors

reply light on all the time

 

Radio Altimeter:

sloped sheet metal

 

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