Outcome of my GTX330 enigma: it detects Airbone automatically upon take-off (>500 ft/min) IF the flight timer had been reset to zero (by pushing CLR).
As indicated by Jesse, it does NOT detect landing; one needs to switch off the timer manually with START/STOP, and reset with CLR afterwards.
Wiring with the GNS430W is either wrong or non-existing.
Jesse
You point to the biggest problem of all the avionics shops in the UK, and that is they all have to quote for the most basic of all installations to have a chance of getting the job.
This forum has a lot more knowlage than the average UK light aircraft owner, most of them want the newest Avionic kit but don’t want the cost, so not understanding the way the kit works results in a very basic installation with very basic functionality.
A classic example of this is the King KN62/64 installation, go to almost any flying club and the aircraft won’t have the remote selection enabled, all because of the cost of eight wires and a switch !
Niner_Mike wrote:
However, how to switch on the Automatic Airborne Detection from its default “OFF” state? Is it the undocumented trick to hold “STBY” during a couple of seconds?
No, this is set in the configuration menu as well. AUTO FLT TMR is likely set to manual (MAN). When set to clear (CLR) it will start the timer when airborne is detected. Note, it can not detect landing in this situation where airborne is detected on altitude encoder input. So you should stop the timer manually after landing.
Thank you Jesse.
I just found that sensitivity parameter back in the installation manual (“VS RATE”).
However, how to switch on the Automatic Airborne Detection from its default “OFF” state? Is it the undocumented trick to hold “STBY” during a couple of seconds?
Thanks.
The automatic flight timer on the GTX can use
The encoder option can only start the flight timer, as it doesn’t have a sense on when it is back on the ground. In the configuration one can select the vertical speed rate which starts the timer (default 500 Ft / min when the automatic airborne detection is enable.
As default the automatic airborne detection is switched off in the configuration.
Many customer requested the least expensive installation with no options. It could be that your aircraft is not wired for this. Likely the automatic airborne detection is left in the default manual (off) mode.
You can find the GTX330 IM online and I have one old one here
Start with the back page and look for the interconnection you want.
The KLN94-GTX330 one shown doesn’t work 
But I would expect the Garmin GPS ones to work. However you need not just the wires; the config also needs to be done right.
430w and 330 combo is definitely a supported configuration. It is of course possible that they aren’t even connected to each other at all!
@a_and_c
I have an open action item to check if the GNS430w is properly cabled and configured with the GTX330, indeed.
Niner_mike.
It sounds to me as if the the initial set up of the interface between the 430 and the 330 did not have an option checked.
You need to be very precise with Avionic technicians as to what you want the interfaces to do on the inital set up as if the guy is not a pilot he is unlikely to understand what you need in the air.
Jesse is the expert here but the GS based method of auto switching from GND to AIR mode uses a figure like 50kt so it should represent airborne time only.
However I am not sure whether the GTX330 has a provision for showing the airborne time based on this switch, too. I’ve never heard of that.
