Transponder code reset

[Carl_Froehlich]

I note the transponder code does not go back to 1200 after you power down. Twice now after takeoff I got caught using the last code I had prior to landing. Recommend having the transponder reset to 1200 after power down.

 

[mmarien]

I don't think that is standard practice and may be confusing. Older transponders like the Garmin GTX320 where you dial in each digit don't reset to 1200. Doesn't GND or TWR give you a squawk code before taxi?

 

[dynonsupport]

It's a TSO requirement that the code NOT reset on a power cycle. If there's a momentary interruption of power while in flight it would be a danger to have the code change to 1200. So, as a certified device, the last used code must remain until the user actively changes it.

 

[airguy]

Startup checklist item.

 

[60av8tor]

Startup checklist item.

Here here! I love the new technology as much as the next guy - the auto transponder setting is great! (really missed it from flying the G1000). However, we must remain focused on checking and verifying all operation, automated or not. Definitely a before takeoff checklist item.

 

[dynonsupport]

Here here!  I love the new technology as much as the next guy - the auto transponder setting is great! (really missed it from flying the G1000). 

60av8tor, are you saying the G1000 does change the code back to VFR for you, or are you saying it automatically switches air/ground mode for you? We do automated air/ground switching too and have that fully certified and working in our latest software. It's just changing the code for you when you power cycle that is not allowed.

 

[60av8tor]

Evening Dynon,

As I reread my post, I can see how it was misleading. I was referring to the G1000 switching from sby to alt automatically. Meant that I missed it prior to the latest update. Likewise, I missed the FD of the GFC-700 autopilot, but you all have that covered in the next update. Sorry for the confusion. Keep up the awesome work!

 

[mmarien]

The G1000 and Skyview XPNDR aren't the only units with auto ALT/STBY. The lowly GTX327 can determine airborne status and switches from STBY to ALT and vice versa. It uses GPS ground speed from the NMEA GPRMC sentence. Just connect a NMEA source to the GTX327 RS232 CHNL 2 INPUT. Section 3.3.5 and 3.3.6.2 of the GTX327 install manual. I use the same serial out wire on my GPS495 to feed my radio with VHF and Skyview and GTX327 with GPS NMEA data.

Nice feature but rarely gets used as XPNDR ALT is on the preflight checklist. :-/

Speaking of checklists. When Skyview does get checklists, can acknowledging the XPNDR item in the preflight checklist actually switch the XPNDR to ALT? That would be a nice integrated feature.

 

[dynonsupport]

On SkyView, if you put the transponder in ALT mode manually, you are disabling the auto air/ground mode, which means it will stay in ALT when you land. We recommend you just leave it in AUTO all the time unless specifically directed by ATC to turn off the transponder, or if you are flying formation and only one ship should have a transponder on. Thus, the checklist should not change the mode for you, actually taking off should, just like it does today.

There is a huge certification difference for auto air/ground for a Mode C vs. Mode S for some reason. You are specifically disallowed from using just GPS speed to switch modes on a Mode S.

 

[skysailor]

On SkyView, if you put the transponder in ALT mode manually, you are disabling the auto air/ground mode, which means it will stay in ALT when you land. We recommend you just leave it in AUTO all the time unless specifically directed by ATC to turn off the transponder, or if you are flying formation and only one ship should have a transponder on. Thus, the checklist should not change the mode for you, actually taking off should, just like it does today.

There is a huge certification difference for auto air/ground for a Mode C vs. Mode S for some reason. You are specifically disallowed from using just GPS speed to switch modes on a Mode S.

One small point to remember if you fly to one of the 140 or so airports in the US that have scheduled air carrier service is that Auto will need to be temporarily disabled. These airports have surface movement tracking based on transponder returns (ASDE is the name of the system I believe). These are airports that have low minimum approaches such as Category 2 and 3 ILS. In this case ATIS will have near the end in all weather conditions that all aircraft are to squawk assigned transponder code at all times until shut down. In this case, you need to leave the transponder and Mode C in the transmit mode even during taxi in or out.

Most folks do not frequent these airports so it will not normally be an issue but if you do land at one of them compliance with this policy is mandatory. Just a heads up.

 

[GalinHdz]

On SkyView, if you put the transponder in ALT mode manually, you are disabling the auto air/ground mode, which means it will stay in ALT when you land. We recommend you just leave it in AUTO all the time unless specifically directed by ATC to turn off the transponder, or if you are flying formation and only one ship should have a transponder on. Thus, the checklist should not change the mode for you, actually taking off should, just like it does today.

There is a huge certification difference for auto air/ground for a Mode C vs. Mode S for some reason. You are specifically disallowed from using just GPS speed to switch modes on a Mode S.

One small point to remember if you fly to one of the 140 or so airports in the US that have scheduled air carrier service is that Auto will need to be temporarily disabled. These airports have surface movement tracking based on transponder returns (ASDE is the name of the system I believe). These are airports that have low minimum approaches such as Category 2 and 3 ILS. In this case ATIS will have near the end in all weather conditions that all aircraft are to squawk assigned transponder code at all times until shut down. In this case, you need to leave the transponder and Mode C in the transmit mode even during taxi in or out.

Most folks do not frequent these airports so it will not normally be an issue but if you do land at one of them compliance with this policy is mandatory. Just a heads up.

Houston Hobby (KHOU) is one of these airports and it has a GA fly-in the 3rd Saturday of every month. The 3rd Saturday in August normally focuses on experimental aircraft.

http://www.1940airterminal.org/

 

[dabear]

One small point to remember if you fly to one of the 140 or so airports in the US that have scheduled air carrier service is that Auto will need to be temporarily disabled. These airports have surface movement tracking based on transponder returns (ASDE is the name of the system I believe). These are airports that have low minimum approaches such as Category 2 and 3 ILS. In this case ATIS will have near the end in all weather conditions that all aircraft are to squawk assigned transponder code at all times until shut down. In this case, you need to leave the transponder and Mode C in the transmit mode even during taxi in or out.

Most folks do not frequent these airports so it will not normally be an issue but if you do land at one of them compliance with this policy is mandatory. Just a heads up.

I've flown into IAD (Dulles VA) multiple times.  The Transponder does NOT need to be in ALT mode.  It can (and should be) in Ground (GND) mode. 

The transponder in GND mode will respond to the airport's ground airplane tracking system just fine.  You'll even see the (R) respond indicator. 

So, "auto" works just fine on the Dynon Transponder.

 

[dynonsupport]

Bear is correct. Since the Dynon transponders are full Mode-S transponders, they go to GND mode when on the ground, not SBY. This means they still respond to ground radar interrogations or specifically addressed interrogations, but will not set of TCAS alerts nor respond to airborne radar interrogations. So no need to manually set them to ON or ALT if at an airport with ASDE-X, as this is actually worse than having them in GND mode.

 

[lolachampcar]

Glad Dynon is on top of all this...

 

[skysailor]

I confused GND with STBY. Thanks for the info.