From the Avionics West site: The FAA Airworthiness Concern Sheet Early this week I head a rumor from an AVweb editor friend of mine that there was a 'Airworthiness Concern Sheet' circulating around that stated there may be an AD issued against the Garmin GNS 430. As you can imagine, this got my attention and I started to investigate the issue.

1. Check Garmin Serial Number

The serial number is a combination of 8 to 9 letters or numbers, without spaces or dashes externally printed on the device. The unit ID is a 10 digit number found internally when viewing system information on your device. The location of this information varies by model.

Finally, I got a copy of the FAA Airworthiness Concern Sheet and talked to a person at Garmin about what was really going on and here's what I found. On or about September 10, 1999, Garmin International found under some conditions that the horizontal and vertical needles of the indicator that the Garmin GNS 430, GNC 420 and GPS 400 were attached to would at times deviate a couple of dots from the actual course. Garmin alerted the FAA on September 10, 1999 and asked them to consider an AD on the product at that time. The FAA has sat on this issue until now, almost two years later.

I tried to call and emailed Mr. Roger Souter of the FAA for clarification on the subject. Souter is the FAA engineer in charge of this project; to date I haven't received a reply back from him. There are 1,985 units that have the potential for this problem to occur according to the FAA ACS. After telling the FAA of the potential problem, Garmin International came up with a fix called 'Mod 1' which is covered under Service Bulletin 9905.

This service bulletin came into effect September 17, 1999; seven days after Garmin told the FAA a problem may present itself in some installations. I wonder why it took the FAA almost two years to shed any light on this issue? On or about September 17, 1999 Garmin International notified the owners of the suspected units that a problem may exist and to have Service Bulletin installed to cure the problem. If you have an early model GNS 430, GNC 420 or GPS 400, check the serial number to determine if mod 1 is needed or has been completed. Hopefully you will have the serial number written in the logbook or on the weight and balance form. If not, the unit must be removed from the aircraft and the serial number verified to see if Mod 1 has been stamped off.

All units manufactured after September 17, 1999 have this modification completed at the factory. DO NOT attempt to remove and reinstall your Garmin product; you could easily damage the pins trying to reinstall it. Believe me, this will make for a really bad day; I'd recommend getting your local Garmin dealer to remove the unit and check for Mod 1 if you don't have that information already. Now let's go over the Service Bulletin that describes Mod 1.

SERVICE BULLETIN NO.: 9905 DATE: 17 SEPTEMBER 1999 SUBJECT: GNS 430, GNC 420, GPS 400 MOD 1 BACKGROUND The GNS 430, GNC 420 and GPS 400 units have been designed and tested to meet or exceed all TSO requirements, including susceptibility to noise being generated from other sources within the aircraft. Recently, GARMIN received a limited number of reports regarding GNS 430 installations where the deviation indicator on the CDI/HSI was offset by a couple of dots from the actual course. Investigation determined that these installations had electrical noise between 1 & 3 volts AC peak-peak induced into the GNS 430 CDI output which came from other items installed in the aircraft. This high level of noise caused an undesirable oscillation of the CDI outputs which resulted in inaccurate course deviation as seen in the CDI/HSI. PURPOSE This modification incorporates circuitry changes to the unit deviation and flag outputs to eliminate the oscillation of the CDI outputs caused by external electrical noise. DESCRIPTION This modification consists of the removal and replacement of six (6) capacitors, the removal of two (2) diodes, the removal and the replacement of two (2) resistors, and the addition of two (2) resistors and two jumpers to the main board.

The removal and replacement of seven (7) capacitors and the addition of four (4) capacitors to the navigation board. The addition of four (4) capacitors to the glideslope board. 171CD's 430 has failed twice in 3 months with a 'VLOC has failed' message.

Has to be sent back to Garmin for repairs. Larry, N171CD From the Avionics West site: The FAA Airworthiness Concern Sheet Early this week I head a rumor from an AVweb editor friend of mine that there was a 'Airworthiness Concern Sheet' circulating around that stated there may be an AD issued against the Garmin GNS 430. As you can imagine, this got my attention and I started to investigate the issue. Finally, I got a copy of the FAA Airworthiness Concern Sheet and talked to a person at Garmin about what was really going on and here's what I found. On or about September 10, 1999, Garmin International found under some conditions that the horizontal and vertical needles of the indicator that the Garmin GNS 430, GNC 420 and GPS 400 were attached to would at times deviate a couple of dots from the actual course. Garmin alerted the FAA on September 10, 1999 and asked them to consider an AD on the product at that time. The FAA has sat on this issue until now, almost two years later.

I tried to call and emailed Mr. Roger Souter of the FAA for clarification on the subject. Souter is the FAA engineer in charge of this project; to date I haven't received a reply back from him. There are 1,985 units that have the potential for this problem to occur according to the FAA ACS. After telling the FAA of the potential problem, Garmin International came up with a fix called 'Mod 1' which is covered under Service Bulletin 9905. This service bulletin came into effect September 17, 1999; seven days after Garmin told the FAA a problem may present itself in some installations. I wonder why it took the FAA almost two years to shed any light on this issue?

On or about September 17, 1999 Garmin International notified the owners of the suspected units that a problem may exist and to have Service Bulletin installed to cure the problem. If you have an early model GNS 430, GNC 420 or GPS 400, check the serial number to determine if mod 1 is needed or has been completed. Hopefully you will have the serial number written in the logbook or on the weight and balance form.

If not, the unit must be removed from the aircraft and the serial number verified to see if Mod 1 has been stamped off. All units manufactured after September 17, 1999 have this modification completed at the factory.

DO NOT attempt to remove and reinstall your Garmin product; you could easily damage the pins trying to reinstall it. Believe me, this will make for a really bad day; I'd recommend getting your local Garmin dealer to remove the unit and check for Mod 1 if you don't have that information already. Now let's go over the Service Bulletin that describes Mod 1. - SERVICE BULLETIN NO.: 9905 DATE: 17 SEPTEMBER 1999 SUBJECT: GNS 430, GNC 420, GPS 400 MOD 1 BACKGROUND The GNS 430, GNC 420 and GPS 400 units have been designed and tested to meet or exceed all TSO requirements, including susceptibility to noise being generated from other sources within the aircraft. Recently, GARMIN received a limited number of reports regarding GNS 430 installations where the deviation indicator on the CDI/HSI was offset by a couple of dots from the actual course. Investigation determined that these installations had electrical noise between 1 & 3 volts AC peak-peak induced into the GNS 430 CDI output which came from other items installed in the aircraft. This high level of noise caused an undesirable oscillation of the CDI outputs which resulted in inaccurate course deviation as seen in the CDI/HSI.

PURPOSE This modification incorporates circuitry changes to the unit deviation and flag outputs to eliminate the oscillation of the CDI outputs caused by external electrical noise. DESCRIPTION This modification consists of the removal and replacement of six (6) capacitors, the removal of two (2) diodes, the removal and the replacement of two (2) resistors, and the addition of two (2) resistors and two jumpers to the main board. The removal and replacement of seven (7) capacitors and the addition of four (4) capacitors to the navigation board. The addition of four (4) capacitors to the glideslope board. I sent Garmin a note this morning and they are sending a new radio out today.

Can't ask for much better service. Larry, N171CD 171CD's 430 has failed twice in 3 months with a 'VLOC has failed' message. Has to be sent back to Garmin for repairs. Larry, N171CD From the Avionics West site: The FAA Airworthiness Concern Sheet Early this week I head a rumor from an AVweb editor friend of mine that there was a 'Airworthiness Concern Sheet' circulating around that stated there may be an AD issued against the Garmin GNS 430.

Having Leq measurement in such instruments is an important feature. Nikon dtm a20 lg.

As you can imagine, this got my attention and I started to investigate the issue. Finally, I got a copy of the FAA Airworthiness Concern Sheet and talked to a person at Garmin about what was really going on and here's what I found.

On or about September 10, 1999, Garmin International found under some conditions that the horizontal and vertical needles of the indicator that the Garmin GNS 430, GNC 420 and GPS 400 were attached to would at times deviate a couple of dots from the actual course. Garmin alerted the FAA on September 10, 1999 and asked them to consider an AD on the product at that time. The FAA has sat on this issue until now, almost two years later. I tried to call and emailed Mr. Roger Souter of the FAA for clarification on the subject. Souter is the FAA engineer in charge of this project; to date I haven't received a reply back from him. There are 1,985 units that have the potential for this problem to occur according to the FAA ACS.

After telling the FAA of the potential problem, Garmin International came up with a fix called 'Mod 1' which is covered under Service Bulletin 9905. This service bulletin came into effect September 17, 1999; seven days after Garmin told the FAA a problem may present itself in some installations. I wonder why it took the FAA almost two years to shed any light on this issue?

On or about September 17, 1999 Garmin International notified the owners of the suspected units that a problem may exist and to have Service Bulletin installed to cure the problem. If you have an early model GNS 430, GNC 420 or GPS 400, check the serial number to determine if mod 1 is needed or has been completed. Hopefully you will have the serial number written in the logbook or on the weight and balance form. If not, the unit must be removed from the aircraft and the serial number verified to see if Mod 1 has been stamped off. All units manufactured after September 17, 1999 have this modification completed at the factory. DO NOT attempt to remove and reinstall your Garmin product; you could easily damage the pins trying to reinstall it. Believe me, this will make for a really bad day; I'd recommend getting your local Garmin dealer to remove the unit and check for Mod 1 if you don't have that information already.

Now let's go over the Service Bulletin that describes Mod 1. - SERVICE BULLETIN NO.: 9905 DATE: 17 SEPTEMBER 1999 SUBJECT: GNS 430, GNC 420, GPS 400 MOD 1 BACKGROUND The GNS 430, GNC 420 and GPS 400 units have been designed and tested to meet or exceed all TSO requirements, including susceptibility to noise being generated from other sources within the aircraft. Recently, GARMIN received a limited number of reports regarding GNS 430 installations where the deviation indicator on the CDI/HSI was offset by a couple of dots from the actual course. Investigation determined that these installations had electrical noise between 1 & 3 volts AC peak-peak induced into the GNS 430 CDI output which came from other items installed in the aircraft. This high level of noise caused an undesirable oscillation of the CDI outputs which resulted in inaccurate course deviation as seen in the CDI/HSI. PURPOSE This modification incorporates circuitry changes to the unit deviation and flag outputs to eliminate the oscillation of the CDI outputs caused by external electrical noise. DESCRIPTION This modification consists of the removal and replacement of six (6) capacitors, the removal of two (2) diodes, the removal and the replacement of two (2) resistors, and the addition of two (2) resistors and two jumpers to the main board.

The removal and replacement of seven (7) capacitors and the addition of four (4) capacitors to the navigation board. The addition of four (4) capacitors to the glideslope board.

The Garmin Nuvi guides you through city streets and down rural roads with accurate directions, traffic updates and a list of points of interest. All Nuvis have a model number that enables you to identify your product. You'll need to know this model number if you want to look up documentation for your device, download updates or contact Garmin for support.

If you know your model number, you can also quickly get service for your device in the event of a product recall. If your Nuvi is attached to a vehicle cradle, you need to remove it to find the model number. Tips. Garmin has recalled several Nuvi models because of a battery that may overheat and cause a fire hazard. These models include the Nuvi 200W, 250W, 260W and 7xx, where 'xx' is a two-digit number.

Check Garmin Serial Number

Garmin also provides the model number on your product's packaging and owner's manual. You may also find the number inside the battery compartment. You can find more information about your Nuvi in the System menu.

To access it, go to 'Tools,' select 'Settings,' select 'System' and choose 'About.' This menu displays your Nuvi's model number, unit ID and software version. You will need to know this information if you update the device's maps or software.