I have a KCS55A with the boostrap and an ADC-200 with an external temperature probe interfaced to my GNS530W. It will calculate and display a wind vector without any input from me other than the altimeter setting. If you don’t have this or a PFD such as an Aspen or G500, you have to manually enter the data, so if your heading changes from when you last manually entered the data, the wind velocity and direction will be wrong. Without air-data and heading input to the GNS530W, the E6B page only displays correctly when you enter the data and don’t change anything that affects a value you entered. If you see a wind vector on the map page, then you have the air-data and heading inputs to the GNS530.
As Achimha said using pitot static input, using outside air temperature imput and using an heading input. All of these from external sensors. It also uses GPS ground speed and track.
A GNS530 can accept pitot and static data? How? Does it have internal barometers? Does it also have an OAT probe?
I looked quickly at the IM and it doesn’t have those capabilities. Only via an ADC can it get e.g. IAS, never mind TAS.
the Garmin 530 can be connected to an external Air Data Computer (ADC)
Certainly, like almost every other IFR GPS, but the OP suggested there isn’t an ADC present.
Without air-data and heading input to the GNS530W, the E6B page only displays correctly when you enter the data and don’t change anything that affects a value you entered.
I have the same on the KLN94. Without an ADC, that page is just an E6B calculator. With an ADC, the heading, TAS and OAT get filled in automatically and then the wind vector is real-time.
If you see a wind vector on the map page, then you have the air-data and heading inputs to the GNS530.
That would seem to be right. I can’t see certification allowing the display of the wind vector when it isn’t real-time, though I suppose it’s possible. What would happen if you configured the GNS box telling it an ADC is present when actually it isn’t?
A while ago I looked at installing the Digidata ADC (mentioned here) which usefully has a pilot interface (mainly for its flow totaliser function), but they stopped making it. Now I can’t be bothered because there isn’t anything in that knowledge which is going to make me conduct the flight any differently.
I installed the ADC-200 because when I installed the GDL88 ADS-B unit, they required heading in order to display ADS-B traffic on the Map pages. I didn’t want to have to switch to the traffic page for displaying nearby traffic. It should not have been a requirement in the first place, because the traffic positions are not based on my heading, but are received as a precise latitude-longitude. For a TCAD system, I understand the need for a heading input as these targets are relative to own ship heading and position, but I don’t have a TCAD. As it turns out, Garmin will fix this requirement for the GDL88 ADS-B traffic in a software update sometime this year. In any event, I got a very good deal on a used ADC-200 ($750) with a yellow tag. Installing it added the wind vector to the Map pages. It also affects the depiction of holding patterns as the pattern is adjusted to reflect the winds and is not always an oval. This allows my GPSS to do a better job of steering the hold and to lead turns.
It can only CALCULATE TAS if you type in the data for heading and groundspeed! Or you connect it to an ADC
It can only CALCULATE TAS if you type in the data for heading and groundspeed!
I can’t see how.
TAS is impossible unless you have all of
The GNS has the last one, potentially, as any IFR GPS does, for RAIM purposes.
The heading is not relevant to TAS, and neither is the GS.
The ground speed does not need typing in because a GPS already has that.
I suggest something really basic does not add up here 
The GNS430/530 has a screen where you input the TAS and heading and it will give you the wind vector because it knows the GS (a mini E6B). Alternatively, the 430/530 can connect to an external ADC to receive the TAS data.
Either the original poster has an old value for the TAS/heading configured there or he has an ADC which functions incorrectly.
Correct. The GNS can accept air data from several external sensors, as well as out side air temperature from an external sensor. The combined external air data and the external OAT data will make enable it to calculate TAS.
If you don’t have BOTH external sensors, the unit can’t calculate TAS, then it should be entered by the pilot.
Yes, what I wrote is not correct, but
On the Density Alt/TAS/Winds page you manually enter indicated altitude, calibrated airspeed, altimeter setting,, outside air temperature and present heading.
THEN the GNS530 calculates TAS from this data.
Yes, the typical E6B stuff, works exactly the same way
Just like companies that make $100 E6B pocket calculators (for something you can program with 100 lines of code on any smartphone), there are companies selling expensive certified air data computers that take the sensor input and perform the calculations. And then companies like Aspen/Avidyne/Garmin add those 100 lines of code to their glass cockpits and tell you that it has an “integrated ADC” which is a $5000 value so the glass cockpit is actually cheap and not expensive
The preset values I see on my density page are almost correct. Only the indicated altitude may differ of about 100-200 ft so I never change a value to get the TAS. However, I never saw such a wind vector at low altitude.
