I recently decided to replace my attitude indicator and directional gyro with a pair of Garmin GI-275 units. I chose that model over the G5's because of the 275's ability to drive my Century IIB autopilot without retaining any of the old vacuum system.
As my shop slot has arrived, I've begun to study the manual and AFM supplement in greater detail, and I have some questions that I could use your help with (these will be the first 275's installed by my local shop and they are not a good source of detail right now). I've called Garmin Aviation tech support and they not only couldn't answer the original questions, they generated more questions.
First, a question about the menu structure. I held off for nearly a year due to the original clumsy menu structure of the 275 where it took a button push and 5 screen taps to switch back and forth between Nav and Hdg modes to drive the autopilot. I decided to pull the trigger last June when I corresponded with Garmin sales and they assured me that updated firmware 2.3 eliminated that problem and the AP Ref switch (between Nav and Hdg) was now in the top level menu (one button push and one screen tap to switch). But as I read the AFM supplement, section 4.2.3 pretty clearly indicates that the AP Ref switch between Nav (GPSS) and Hdg modes is still buried in the menus and not at the top level. Would someone with these units and firmware 2.3 or higher let me know where this menu switch is located? BTW, they did allow for installation of a panel switch to make this change, but my panel in that area is already too full of lights and switches and I did not want to any any more beyond the Reversion mode switch required for the dual 275 installation.
Second, a question about the minimum databases required to run the units. I plan to initially have the 275's configured as a basic attitude indicator (no airspeed, altitude, turn coord., but with magnetic heading) and a basic HSI (no map). I had been told by Sales that no databases other than the 5 year magnetic direction database would be required for this configuration. And that I could even reconfigure to add the airspeed, alt., TC display to the Basic AI without needing any databases. But when I called Garmin about Question 1, I also asked them to reconfirm about the databases. I was told that a Nav database subscription was required for all 275 ADI/HSI installations??? So, 275 owners, if the 275's are configured as a Basic AI and Basic HSI, what, if any, database subscriptions are needed?
Third, I purchased the 275's as part of Garmin's promotional bundle this spring/summer. The web listing indicated that it came with OAT as part of the bundle. But Garmin Tech support told me that it did not include an OAT capability (he was adamant). Could you let me know whether or not the Garmin promotional bundle comes with OAT? If not, then I need to have the shop get on ordering one or risk delaying my installation.
As my shop slot has arrived, I've begun to study the manual and AFM supplement in greater detail, and I have some questions that I could use your help with (these will be the first 275's installed by my local shop and they are not a good source of detail right now). I've called Garmin Aviation tech support and they not only couldn't answer the original questions, they generated more questions.
First, a question about the menu structure. I held off for nearly a year due to the original clumsy menu structure of the 275 where it took a button push and 5 screen taps to switch back and forth between Nav and Hdg modes to drive the autopilot. I decided to pull the trigger last June when I corresponded with Garmin sales and they assured me that updated firmware 2.3 eliminated that problem and the AP Ref switch (between Nav and Hdg) was now in the top level menu (one button push and one screen tap to switch). But as I read the AFM supplement, section 4.2.3 pretty clearly indicates that the AP Ref switch between Nav (GPSS) and Hdg modes is still buried in the menus and not at the top level. Would someone with these units and firmware 2.3 or higher let me know where this menu switch is located? BTW, they did allow for installation of a panel switch to make this change, but my panel in that area is already too full of lights and switches and I did not want to any any more beyond the Reversion mode switch required for the dual 275 installation.
Second, a question about the minimum databases required to run the units. I plan to initially have the 275's configured as a basic attitude indicator (no airspeed, altitude, turn coord., but with magnetic heading) and a basic HSI (no map). I had been told by Sales that no databases other than the 5 year magnetic direction database would be required for this configuration. And that I could even reconfigure to add the airspeed, alt., TC display to the Basic AI without needing any databases. But when I called Garmin about Question 1, I also asked them to reconfirm about the databases. I was told that a Nav database subscription was required for all 275 ADI/HSI installations??? So, 275 owners, if the 275's are configured as a Basic AI and Basic HSI, what, if any, database subscriptions are needed?
Third, I purchased the 275's as part of Garmin's promotional bundle this spring/summer. The web listing indicated that it came with OAT as part of the bundle. But Garmin Tech support told me that it did not include an OAT capability (he was adamant). Could you let me know whether or not the Garmin promotional bundle comes with OAT? If not, then I need to have the shop get on ordering one or risk delaying my installation.
