About Us Careers Contact Us Customer Care Dealers News and Events Products Sales

Lessons Learned

AOG Technical Support FAQ Lessons Learned Training

TAWS8000 Lessons Learned

Lessons related to the Display interface:: Lesson #1 - Pro-Line 21

When the TAWS8000 or TAWS8100 is displayed on a Collins Pro-Line 21 EFIS system, the ARINC 429 port used as the receiver should be set to high speed and the ARINC 429 port used as the transmitter should be set to low speed.

Lesson #2 - FDS-2000

When the TAWS8000 or TAWS8100 is displayed on a Collins FDS-2000 EFIS system, the ARINC 429 port used as the receiver should be set to low speed and the ARINC 429 port used as the transmitter should be set to low speed.

Lesson #3 - Garmin AT MX-20 or L-3 i-linc

When the TAWS8000 or TAWS8100 is displayed on a Garmin AT MX-20 or L-3 i-linc MFD, the ARINC 429 port used as the receiver should be set to low speed and the ARINC 429 port used as the transmitter should be set to high speed.

Lesson #4 - Pro-Line 21

When interfacing a TAWS8000 or a TAWS8100 to a Collins Pro-Line 21 EFIS system, the Pro-Line IAPS must have a -201 configuration module to make it TAWS Aware. The -200 configuration modules are not TAWS Aware. In a Cessna Citation with Pro-Line 21, the configuration module part number is 822-1484-201.

Lesson #5 - Pro-Line II

When interfacing a TAWS8000 or TAWS8100 to a Collins Pro-Line II EFIS system, a Collins WXA1000A (P/N 822-1360-001) adapter is needed unless the existing Collins Radar system is a WX8xx series Radar. When the WX8xx series Radar is used, the Pro-Line II system is already ARINC 453 capable. Refer to Collins Info Document 0026-01 for more information.

Lesson #6 - No Display

The TAWS8000 and TAWS8100 can be installed without a display. Annunciators will be required, but heading will not be required.

Lesson #7 - RGC-350

When interfacing a TAWS8000 or TAWS8100 to an L-3 AS RGC-350 and a Honeywell Radar Indicator, verify the current mod status of the Radar Indicator to ensure it has the forced standby function.

Lesson #8 - Pro-Line IV

When interfacing the TAWS8000 or TAWS8100 to a Collins Pro-Line IV Four-Tube EFIS system, ARINC 429 Channel 3 of the EFIS system must be set to Terrain Display Right. When interfacing to a Three-Tube system, ARINC 429 Channel 3 must be set to none.

Lesson #9 - Video Relay on Beechjet aircraft

Beechjet aircraft with serial numbers RK-42, RK-45, RK-103, RK-161 and RK-178 have TAWS8000 ARINC 453 Video Relays located in the cabin. All other serial numbers equipped with TAWS8000 have the ARINC 453 video relay located in the nose avionics compartment.
Lessons related to the GPS interface:: Lesson #1 - ARINC 429 format

When configuring a GPS output that is interfaced to a TAW8000, the output should be set to GAMA 429 or ARINC 734A format. The GAMA format will output label 261 for RAIM and the ARINC 734A format will output label 130 for Horizontal Integrity (RAIM) which is required for the TAWS8000 to operate.

Lesson #2 - Bendix/King GNS-Xls

When interfacing a TAWS8000 to a Bendix/King GNS-Xls GPS system, I-7 and I-8 of the GPS must be used for the GAMA 429 output. The GNS-Xls has a separate output labeled EGPWS and uses N-5 and N-6. This cannot be used because it does not output GAMA label 261 (RAIM). This port outputs ARINC 734A label 130 (Horizontal Integrity), but the timing is different than other manufacturers and is therefore incompatible.

Lesson #3 - Universal UNS-1M

When interfacing the TAWS8000 to a Universal UNS-1M GPS, use Pins K and L of the UNS-1M and set the TAWS8000 ARINC 429 receive port for low speed ARINC 734A.
Lessons related to the Power interface:: Lesson #1 - Pin C Power

Pin C of the J2 power connector requires a voltage from a source other than the source providing power to Pin A of J2. Power on Pin C is necessary to provide a ground for the annunciator lamp discrete outputs and lights the sensor fail light in the event of a loss of power on Pin A. Even during normal operation, Pin C power is used for annunciator lamp discrete outputs, therefore, if Pin C power is missing, no annunciator lamps will illuminate.
Lessons related to the ARINC 429 interface:: Lesson #1 - ARINC 429 Receiver Speeds

The TAWS8000 and TAWS8100 have 5 ARINC 429 receivers that are labeled as ports 0-4. Port 0 is paired with Port 1 and Port 2 is paired with Port 3 meaning that they must be set to the same speed (high or low). Port 4 is independent and can be set to either speed regardless of the selected speeds of Ports 0-3.
Lessons related to the ADC interface:: Lesson #1 - Collins ADC-80

TAWS8000 installations in aircraft having Collins ADC-80 models F, H, or N will require either the ADC-80 be upgraded to an ADC-80Q or the installation of a SkyLight converter (P/N 97010003-1) to converter the Manchester Data format to ARINC 429. See Collins Service Bulletin 26 and L-3 AS Service Memo 127 for more information.
Lessons related to the Discrete interfaces:: Lesson #1 - Discrete Types

The Weight-On-Wheels, Gear Position and Flaps are all discrete inputs that can be a ground input or a DC voltage input. The proper signal type must be programmed in the TAWS8000 configuration module. The flap discrete inputs are optional.

Lesson #2 - Weight-On-Wheels

The TAWS8000 will inhibit the self-test while in the air using the status of the Weight-On-Wheels input. The TAWS8100 does not use a Weight-On-Wheels input so it uses navigation data from the GPS.

Lesson #3 - Weight-On-Wheels in Beechjet aircraft

When troubleshooting a TAWS8000 on a Beechjet, the Weight-On-Wheels input source is the copilot's weight-on-wheels switch. This switch is powered by a circuit breaker behind the PS-835 Emergency Power Supply located on the copilot's side that, when tripped, will cause the weight-on-wheels signal to revert to 'on-ground' during flight. This causes the TAWS8000 to fail with a Sensor Fail annunciation in the air, but will not fail on the ground. Aircraft with serial numbers RK-42, RK-45, RK-103, RK-161 and RK-178 do not use the right weight-on-wheels switch and are therefore not affected by this circuit breaker.

Lesson #4 - Audio Inhibit in Learjet aircraft

When troubleshooting a TAWS8000 on a Learjet, the Stall Warning System will put out a ground when the aircraft is on the ground (depending on the position of the stall vane). When the TAWS receives this ground on the Audio Inhibit input for an extended duration, the TAWS will fail and the Sensor Fail Light will illuminate. To prevent this a relay can be installed to open the Audio Inhibit input while the aircraft is on the ground using the weight-on-wheels input as the relay control.
Lessons related to the OAT interfaces:: Lesson #1 - Compatible OAT Probes

Compatible Outside Air Temperature (OAT) probes are Goodrich Sensor Systems Rosemount probe, Honeywell P/N 050-03610-002, or CIC P/N 05257.

TAWS8100 Lessons Learned

Lessons related to the Display interface:: Lesson #1 - Pro-Line 21

When the TAWS8000 or TAWS8100 is displayed on a Collins Pro-Line 21 EFIS system, the ARINC 429 port used as the receiver should be set to high speed and the ARINC 429 port used as the transmitter should be set to low speed.

Lesson #2 - FDS-2000

When the TAWS8000 or TAWS8100 is displayed on a Collins FDS-2000 EFIS system, the ARINC 429 port used as the receiver should be set to low speed and the ARINC 429 port used as the transmitter should be set to low speed.

Lesson #3 - Garmin AT MX-20 or L-3 i-linc

When the TAWS8000 or TAWS8100 is displayed on a Garmin AT MX-20 or L-3 i-linc MFD, the ARINC 429 port used as the receiver should be set to low speed and the ARINC 429 port used as the transmitter should be set to high speed.

Lesson #4 - Pro-Line 21

When interfacing a TAWS8000 or a TAWS8100 to a Collins Pro-Line 21 EFIS system, the Pro-Line IAPS must have a -201 configuration module to make it TAWS Aware. The -200 configuration modules are not TAWS Aware. In a Cessna Citation with Pro-Line 21, the configuration module part number is 822-1484-201.

Lesson #5 - Pro-Line II

When interfacing a TAWS8000 or TAWS8100 to a Collins Pro-Line II EFIS system, a Collins WXA1000A (P/N 822-1360-001) adapter is needed unless the existing Collins Radar system is a WX8xx series Radar. When the WX8xx series Radar is used, the Pro-Line II system is already ARINC 453 capable. Refer to Collins Info Document 0026-01 for more information.

Lesson #6 - No Display

The TAWS8000 and TAWS8100 can be installed without a display. Annunciators will be required, but heading will not be required.

Lesson #7 - RGC-350

When interfacing a TAWS8000 or TAWS8100 to an L-3 AS RGC-350 and a Honeywell Radar Indicator, verify the current mod status of the Radar Indicator to ensure it has the forced standby function.

Lesson #8 - Pro-Line IV

When interfacing the TAWS8000 or TAWS8100 to a Collins Pro-Line IV Four-Tube EFIS system, ARINC 429 Channel 3 of the EFIS system must be set to Terrain Display Right. When interfacing to a Three-Tube system, ARINC 429 Channel 3 must be set to none.

Lesson #9 - Video Relay on Beechjet aircraft

Beechjet Aircraft with serial numbers RK-42, RK-45, RK-103, RK-161 and RK-178 have TAWS8000 ARINC 453 Video Relays located in the cabin. All other serial numbers equipped with TAWS8000 have the ARINC 453 video relay located in the nose avionics compartment.
Lessons related to the GPS interface:: Lesson #1 - Laptop Command for troubleshooting

The laptop command 'gps -g ' can be used to monitor the Freeflight GPS status and information.
Lessons related to the Power interface:: Lesson #1 - Pin C Power

Pin C of the J2 power connector requires a voltage from a source other than the source providing power to Pin A of J2. Power on Pin C is necessary to provide a ground for the annunciator lamp discrete outputs and lights the sensor fail light in the event of a loss of power on Pin A. Even during normal operation, Pin C power is used for annunciator lamp discrete outputs, therefore, if Pin C power is missing, no annunciator lamps will illuminate.
Lessons related to the ARINC 429 interface:: Lesson #1 - ARINC 429 Receiver Speeds

The TAWS8000 and TAWS8100 have 5 ARINC 429 receivers that are labeled as ports 0-4. Port 0 is paired with Port 1 and Port 2 is paired with Port 3 meaning that they must be set to the same speed (high or low). Port 4 is independent and can be set to either speed regardless of the selected speeds of Ports 0-3.
Lessons related to the Discrete interfaces:: Lesson #1 - Discrete Types

The TAWS8000 will inhibit the self-test while in the air using the status of the Weight-On-Wheels input. The TAWS8100 does not use a Weight-On-Wheels input so it uses navigational data from the GPS.

SkyWatch 497 Lessons Learned

Lesson #1 - ARINC 429 Output

To enable the ARINC 429 output of the TRC497, P1-80 must be grounded. Once P1-80 is grounded, the configuration must be ‘saved’ using a laptop. Also, Service Menu access using the WX-1000/SKY497 Display is no longer possible.

Lesson #2 - RF Reply Amplitude

An RF Reply Amplitude value less than 50 or greater than 150 causes the TRC to fail with an RF Amplitude error. Typical causes are defective Antenna RF Cables or bad RF Cable Connections.

Lesson #3 - Audio Volume Adjustment

The TRC497 does not have an internal audio volume adjustment, but the volume can be adjusted in one of two ways. 1) An in-line ¼ watt resistor can be installed on the Audio output of the TRC497 to the aircraft’s audio system. To determine the size of the resistor, a Decade Resistor box can be used to determine size of resistor that provide the desired audio level, then a resistor of that size can be hard-wired in the audio line. 2) A 1kohm potentiometer can be installed where one end of the resistive strip is connected to the TRC497 audio output high and the other side of the resistive strip is connected to the TRC497 audio output low. With this configuration, the TRC497 will always have a 1kohm load on the audio output. The wiper of the potentiometer should then be connected to the aircraft audio amplifier on an unswitched unmated input. The audio low line must be connected to ground for this to operate properly.

Lesson #4 - Gear Position Input

On power up, the TRC497 looks at the weight-on-wheels input and the gear position input. If the weight-on-wheels is grounded and the gear position is open, the TRC497 assumes that the aircraft has fixed gear. For the duration of that power cycle, the TRC497 will ignore the gear position input. This was found as a result of Cirrus engineers trying to use a flap discrete to change the sensitivity level and mute the audio when the flaps are extended > 50%. Unless the flaps were extended > 50% at the time of power up, the sensitivity level would not change and the audio would not be muted at any time during the flight.

SkyWatch 899 Lessons Learned

Lesson #1 - ARINC 429 Output

To enable the ARINC 429 output of the TRC899, the configuration option for alternate display must be selected to anything other than 'None'.

Lesson #3 - Altitude Simulation

When troubleshooting a Skywatch 899, any altitude can be simulated using the command ‘baroalt –s alt=xxxxx’. A new altitude can be selected using the same command again. To revert to normal altitude inputs, cycle power to the TRC899.

WX-1000 Lessons Learned

Lesson #1 - Processor racking after factory service

Some customers have reported that when they receive their WX-1000 processor back from Service, it is inoperative. This may be caused by a mod that replaces the J301 and J302 connectors and backplane. The new connectors are EMI shielded, but have shorter pins. Once re-installed in the aircraft, the pins do not make contact with the connectors installed in the tray. This is dependant on the manufacturer of the pins used in the tray connectors.

WX-500 Lessons Learned

Lesson #1 - Strike Test

The Strike Test of the WX-500 occurs once every second when in the Strike Test mode. During normal operation, the Strike Test occurs once every ten seconds.

Lesson #2 - Antenna Location

WX-500 antennas can be mounted inside the fuselage provided that an electromagnetic transparent window is used to allow the antenna to receive RF either straight up or straight down. Composite materials embedded with copper mesh or aluminum mesh will block the RF signal as will carbon-fiber composite.

Lesson #3 - RS-232 Input

The RS-232 input must be connected to only one transmitter. Even if connected to two transmitters and one of the transmitters is configured to OFF, the WX-500 will fail.

Lesson #4 - RS-232 Output

The RS-232 output can be paralleled to multiple displays.

Lesson #5 - Heading Input

Synchro heading or RS-232 heading must be used if the WX-500 output is to be overlayed on a moving map. Most displays will still show lightning on a dedicated Stormscope page when Stepper or no heading is used, but will not overlay the strikes on the moving map.

Lesson #6 - Heading Input

RS-232 heading cannot be used if the heading source is Ground Track. This can cause strike bearing errors when the aircraft is ‘crabbed’ due to wind.

Lesson #7 - Inhibit Input

If the Comm inhibit line to the WX-500 is grounded for more than 60 seconds, the WX-500 will fail.

Lesson #8 - Fault Log

Error 22 & 23 (Heading) and Error 24 (Stuck Mic Key) are recoverable faults meaning that when the fault condition clears, the WX-500 will resume operation. All other errors are considered fatal faults meaning that the power to the WX-500 must be reset before operation is possible. Recoverable errors are not logged in the Fault Log.

GH-3000 Lessons Learned

Lesson #1 - Heading Input Troubleshooting

When troubleshooting a heading problem on a Citation 550 or 560 aircraft, check the 28VDC input to the Magnetometer while under load. Cessna uses an in-line fuse (soldered in the wire bundle behind the GH-3000 display) that when defective, may continue to conduct, but cause a voltage drop to the Magnetometer. When the voltage drop is great enough, the Magnetometer will have insufficient power to operate. Common squawks are “DG appears above heading tape on GH-3000” and “GH-3000 heading drifts.”

Lesson #2 - Air Data Red X's

Momentary ‘Red X’ing’ of the Air Data tapes followed by a rapid scrolling and clearing of the Red X’s is a result of a software problem in certain ADC’s. In some cases the software must be changed to eliminate the problem. This problem was mostly seen on Citation 550 Bravo aircraft.

GH-3001 Lessons Learned

Lesson #1 - Fast Erect

In the menu for the GH-3001, the selection labeled “FAST ERECT” does not perform a 3 second fast erect like the GH-3000 and GH-3100. The GH-3001 “FAST ERECT” function is a 45 second realignment. When performing a heading calibration on a GH-3001, it is not recommended to perform a Fast Erect (45 second realignment) at each cardinal heading. Instead, the aircraft should remain stationary for 30 seconds at a cardinal heading before entering the heading data for that cardinal heading.

GH-3100 Lessons Learned

Lesson #1 - Alignment

The GH-3100 and GH-3001 has ‘sea-state’ software allowing it to tolerate higher vibration levels during alignment. The GH-3000 does not have this software.

MAG-3000 Lessons Learned

Lesson #1 - Heading on Citation aircraft

When troubleshooting a heading problem on a Citation 550 or 560 aircraft, check the 28VDC input to the Magnetometer while under load. Cessna uses an in-line fuse (soldered in the wire bundle behind the GH-3000 display) that when defective, may continue to conduct, but cause a voltage drop to the Magnetometer. When the voltage drop is great enough, the Magnetometer will have insufficient power to operate. Common squawks are “DG appears above heading tape on GH-3000” and “GH-3000 heading drifts.”

ADC-3000 Lessons Learned

Lesson #1 - Air Data Red X's

Momentary ‘Red X’s’ on the Air Data tapes followed by a rapid scrolling and clearing of the Red X’s is a result of a software problem in certain ADC’s. In some cases the software must be changed to eliminate the problem. This problem was mostly seen on Citation 550 Bravo aircraft.