Garmin 330 Not Ready For Prime Time?

[Bravo3]

I'm reluctant to start a new thread, but I'm not seeing anything too pertinent on this topic.

Here's the deal: I'm in the process of buying a C182P and want to get it set-up for IFR training and flying.

I want to upgrade the existing KT76 transponder (not sure if I really need to) with either a GTX 270 or 330. My CFII says the 330 is not ready for prime time, but I like that it has altitude alert and traffic. I'm willing to pop for the extra $$$.

Also, I plan to put in a GPN 530W and a JPI EDM700.

The existing panel contains:
PS Engineering 8000B Audio Panel with 4 Plane Intercom
(2) King KX 155 Nav Com w/ GlideSlope
King KT76 Transponder
S-Tec 40 with Heading Bug and Nav Couplers

So, any input on my panel upgrade ideas would be greatly appreciated.

I'm not posting this as a back-handed brag post--nor a poor pitiful me pity post. I'm just looking for solid input from those in the know for this wet-behind-the-ears aspiring skygod about 2 weeks out from getting his PPL and buying his first plane (the family C182).

Also, if anyone knows if I should hang onto the S-Tec 40 or think about upgrading, that would be bonus info. Thanks in advance to all you propeller-heads with more knowledge than moi.

 

[wsuffa]

I've had a 330 for several years now. It's been rock solid save for one AD that required it to go back to the factory - the avionics shop *assured* me that they would save & restore the settings when reinstalling. They failed to do so, leaving the traffic alert, ground mode switch, and one other function not working. That's all software setup, so it got restored pretty quickly by going into the menus. And it's not a Garmin problem, it's yet another avionics shop problem.

If I were going to buy one today (replace the one I have?), I'd spring for the -ES (extended squitter) version that should work with ADS-B.

Why does your CFI think they're not ready? They've been around for a number of years & have a good track record. Beats the snot out of the old tube-version King transponders.

Sounds like a good panel when you're done. As for the STec-40, it's got a good reputation. If you can get a GPSS (GPS steering adapter) add-on, you'll be much happier with the AP coupling to the Garmin 530.

 

[kontiki]

I wouldn't install an IFR GPS device that didn't put me closer to being compliant with ADS-B requirements, effective Jan 1 2020.

The ADS-B FARs are out in part 91.

We'll need ADS-B in air space that currently requires a Mode A/C transponder today.

If you are not going to operate in Class A, you will can install the UAT format, (vs the 1090 MHz format compatible with existing Mode S Transponder equipment - airline gear).

The FARs describe the hardware requirements by pointing to TSOs.

The TSOs are also on FAA websites, and you can look up what manufacturer products meet those TSOs.

The TSOs will point to RTCA specs that you probably don't want to purchase, but are availabvle from the RTCA.

 

[Bravo3]

If I were going to buy one today (replace the one I have?), I'd spring for the -ES (extended squitter) version that should work with ADS-B.

Not sure what that is but I'll look into it. I'm planning to buy a new 330, so I'm thinking that's included?

Why does your CFI think they're not ready? They've been around for a number of years & have a good track record. Beats the snot out of the old tube-version King transponders.

Not sure if my CFII would appreciate me putting words in his mouth, but I think he figures the extra expense is not worth it for a system not really in place to fully exploit its capabilities.

Personally, I think it'd be nice to have for the altitude alert and traffic alert functions already operational--as I understand it. I'm not pinching pennies here, so maybe he's just looking out for my wallet.

Sounds like a good panel when you're done. As for the STec-40, it's got a good reputation. If you can get a GPSS (GPS steering adapter) add-on, you'll be much happier with the AP coupling to the Garmin 530.

I'm no autopilot expert but I understand the S-Tec 40 is 2-axis, I will have to look into what a 3-axis upgrade would cost me. I will also look into a GPSS upgrade.

Thanks again!

Thanks mucho for the quick reply and valuable feedback.

 

[Bravo3]

I wouldn't install an IFR GPS device that didn't put me closer to being compliant with ADS-B requirements, effective Jan 1 2020

Wow, optimistic aren't we? I figured I had a year and a half to enjoy being an aircraft owner/pilot before the end of the world in 12/2012.

 

[wsuffa]

Not sure what that is but I'll look into it. I'm planning to buy a new 330, so I'm thinking that's included?

There are a couple of versions of the 330. ES is not included unless you ask for it. Note that it will only provide ADSB-OUT, you won't get full ADSB functionality unless you go the UAT route.

Talk to a good avionics shop that's up on the ADSB differences.

Not sure if my CFII would appreciate me putting words in his mouth, but I think he figures the extra expense is not worth it for a system not really in place to fully exploit its capabilities.

Personally, I think it'd be nice to have for the altitude alert and traffic alert functions already operational--as I understand it. I'm not pinching pennies here, so maybe he's just looking out for my wallet.

OK. So there are two components of traffic alerting (which, aside from the ability to get an ES unit, is the big reason to get a 330): approach radar transmission of traffic data and receivers capable of receiving the data. If TRACON doesn't transmit the data (IIRC most CENTER radar doesn't transmit that data), then having the receiver does no good.

You're outside of Flagstaff, right? I don't think that Flagstaff provides the older TIS that a Garmin 330 can receive. (I used to travel over there on occasion, and I don't recall seeing the traffic service available, but I may be wrong). That means, if you travel local to Flagstaff the 330 won't do you much good currently unless you get the ES version capable of ADS-B. If you travel extensively, however, or live in an area where TIS is provided, then the 330 is very much worth it for the traffic capabilities. At least until ADSB is fully deployed & TIS is shut down.

As kontiki noted, below 18,000 feet, you'll have the ability to use UAT for ADS-B, which can provide both ADSB-OUT and ADSB-IN.... You can choose whether to get the bi-directional UAT or not.

So.... find out if TIS is operating in the areas you usually travel. Likewise ADSB. If no TIS, I'd think twice about the 330, preferring to spend money on a bi-directional UAT that will give me traffic in the future. If yes TIS, then I'd probably spring for the 330-ES and think about getting a UAT for the future.

 

[kontiki]

Squitter is a radar technical term for any random or non-random automatic broadcast. It's not activated the way a voice transmission is (that is when human keys a mic).

I'm fairly familiar with airline transponders and ADS-B planning for 1090 MHz, from work. I expect the GA, Universal Access Transciever (UAT) ADS-B format to employ the same principles.

In the airline world, ADS-B transponders (will or are starting to) squit 112 bit messages at some pseudo random rate. Within the 112 bits, there is a 56 bit message field that loops about 5-6 different standard messages. These 56 bit messages contain GPS Lat, Long, GPS Velocity, baro correction, onboard status, 4096 code, flight ID, air/ground status, aircraft category (size), aircraft equippage, GPS antenna offset etc. It's really packed with data.


The GA UAT format probably consists of similar automated broadcast.

Right now, the Mode A/C transponders only send ATC info after the aircraft is interrogated by secondary surveillance radar. That surveillance only exists in terminal airspace or when you're at higher altitudes.

The principle behind ADS-B is that airplanes broadcast a bunch more data continually, and all ATC has to do is set up cheap recievers to listen for aircraft data. The recievers are networked to ATC. It's cheaper than radar and you can be tracked in the air, on the ground, no matter where you are.

It also contains a lot more data (which can be viewed as either good or bad).

I haven't really had the time to dissect the UAT specs. The difference will be the frequencies, UAT uses 978 MHz (vs 1090MHz). I believe UAT uses what's called a VDL-Mode 4 format to modulate the digital data on the 978 MHz. carrier.

I expect the transciever does the TX (down link) & RX (uplink), and GPS data is fed to it or maybe it's all integrated. If you go with separate boxes, make sure the have compatible busses for transferring data.

Extended Squitter term reffers to (non-GA) Mode S Transponders (again a 1090MHz) transponder. The legacy Mode S Squitter was 56 bits. It was extended to 112 bits to contain the 56 bit ADS-B message.

Mode S Transponders are required on aircraft also equipped with TCAS II (Traffic Collision Avoidance Systems). TCAS and Mode S are mandated for large comercial aircraft. TCAS II is different from the GA anticollision gear you see from outfits like Zaxon.

I hope this helps. I tend to run on about this sometimes.

 

[wsuffa]

Extended Squitter term reffers to (non-GA) Mode S Transponders (again a 1090MHz) transponder. The legacy Mode S Squitter was 56 bits. It was extended to 112 bits to contain the 56 bit ADS-B message.

Mode S Transponders are required on aircraft also equipped with TCAS II (Traffic Collision Avoidance Systems). TCAS and Mode S are mandated for large comercial aircraft. TCAS II is different from the GA anticollision gear you see from outfits like Zaxon.

I hope this helps. I tend to run on about this sometimes.

If I'm not mistaken, the FAA rules require ES on any transponder used above 18,000 ft (us turbocharged aircraft will need 'em, assuming we can still get 100LL or equiv), and it PERMITS ES in lieu of UAT for ADSB-out below 18,000. UAT is permitted in lieu of ES only up to 18,000. And UAT-in (or ADSB-in) provides additional features.

 

[Bravo3]

Wow, guys, thanks for all the info. {wraps head in blanket to prevent explosion}

I'll keep this all in mind in the days head.

 

[kontiki]

Bill,

Thats my read too. If you operate in Class A you need to have 1090MHz ADS-B. That will be the the 1090ES. I don't always separate high alt complex aircraft from GA just to cut down on typing.

 

[SCCutler]

BTW, your S-Tec 40 is a single-axis (roll-only), rate-based and capable of tracking a nav source or following a heading bug. Pretty good stuff.

You can add on S-Tec's PSS, which adds altitude hold and some other functions- good setup.

And, as noted above, for just a *leetle* more, you can also add on GPS Steering.

S-Tec's running a great special to upgrade a 30 or a 50 to a 55X for ten grand; not sure whether your 40 provides a path through this upgrade (you'd have to add a pitch servi), but if I was spending the big bucks, I'd ask.

 

[John Collins]

There are no products available on the market today that meet the TSO for ADSB required in the FAR's. I would not mess with ADSB until there are some products available. The Trig TT31 is about half the price of the GTX330ES and a better buy IMHO.

If your existing transponder is giving you good performance, there is very little buying a GTX330 will add unless you can take advantage of the current Mode S TIS. A GTX330ES will do nothing for you except cost more.

I would recommend you spend your money on a GPSS rather than wasting it on the GTX330 or GTX330ES, as it will glue your new GNS530W to your Stec 40. Your Stec 40 is a one axis autopilot. The axis that is being controlled by the autopilot is the roll axis. Having a wing leveler function, a heading hold function, and a navigation function all manipulate the roll axis. If a pitch servo is added to the autopilot, then it will be a two axis autopilot. This is an expensive upgrade. In the Stec world, the third yaw axis can be controlled via a yaw damper, but it doesn't qualify as a true three axis autopilot as required in some of the FAR's.

 

[weilke]

Why upgrade anything beyond adding a current WAAS IFR GPS ?

Sounds like a perfectly functional panel, the plane won't go any faster or higher after you spend all the money you are proposing.

Something to think about: Cobham offers an upgrade from any STEC to a 55X for $9900 right now. It would give you a new computer, GPSS, altitude select and a couple of other modes to play with. Together with a 530W you would gain a lot. For your current AP, yu would have to add a GPSS adapter anyway ($2500 or so) so the price differential to the 55X may not be that onerous.

All the ADS-B stuff will come down in price, no need to be at the bleeding edge of innovation for currently little return.

 

[AcroBoy]

I've had two GTX330's in the two planes that I own since they came out, and they are great. It is amazing how much traffic that's out there that you would never see, even within a mile or less. There are times and places where there is no coverage, but when it's available it is very valuable.

Until ADSB if fully implemented, the extra cost of the 330 is miniscule over the next 8 years. Look at how long if ever the 406mhz ELT "requirement" has been discussed and never mandated. TIS was going to be the wave of the future, and even though it was only partially done, when it is available it works great.

 

[kontiki]

If you look at the preamble to the final rule for ADS-B, it's in the federal register (available for download), the FAA tells you their plan is to eventually disable TIS and replace it with ADS-R (for ADS-B Repeat).

I'm guessing where TIS is an uplink of data obtained from radar survaillance, ADS-R is going to be the uplink of recieved ADS-B (out) data from the the other side of the ADS-B fence.

 

[John Collins]

If you look at the preamble to the final rule for ADS-B, it's in the federal register (available for download), the FAA tells you their plan is to eventually disable TIS and replace it with ADS-R (for ADS-B Repeat).

I'm guessing where TIS is an uplink of data obtained from radar survaillance, ADS-R is going to be the uplink of recieved ADS-B (out) data from the the other side of the ADS-B fence.

ADSR doesn't replace TIS. TISB sort of replaces TIS in the ADSB world as both are based on mode C transponder targets, with TISB only being transmitted if the aircraft is not ADSB Out capable. As you point out ADSR is to repeat the other frequency.

When I upgrade to ADSB, I want to add ES to my GTX330 and have a dual UAT/1090ES receiver only product that would never need to receive ADSR messages and would provide visibility to ADSB traffic outside of the service volume of the GBT (Ground Based Transceiver).

 

[Bravo3]

Thanks, again, for all your thoughts, guys. At this point I'm leaning toward getting the "almost new" GNS 530W for $8995, the JPI EDM700 for $2100, and go ahead and add the GTX 330. I would save $3K on the 530w from the new price and just parlay that into the GTX 330. I'm trying to stay around $15K on the panel upgrade. I know installation will jack things up a bit, too.

I don't want to go hog wild on my new purchase until I see if any mechanicals crop up after I take delivery.

I'm excited to think that the STec 40 is upgradeable, though, but it'll probably have to wait. I want to build up some hours in the 182P, fly the family to several goal destinations here in the SW, and then step up to the IR.

I feel way more educated now. Thanks muchisimo!

 

[Bravo3]

I'm wondering if my CFII was referring to articles like the one below when suggesting I save my money on the GTX330ES:

http://goliath.ecnext.com/coms2/gi_0199-12566722/Garmin-s-GTX330ES-transponder-for.html

At first blush, the GTX330ES seems an easy way to enter the ADS-B world. A CTX330ES along with an approved interface will result in a partial ADS-B status. But because it won't receive other ADS-B data, don't expect to see the same thing you would if you flew with a full-up UAT system similar to Garmin's existing GDL-90, a dedicated ADS-B system with full input and output capability.

It's early in the ADS-B transition to bank on a sure-thing equipment suite. The majority of consumers we spoke with also seem certain that the alphabet groups will delay the requirements for ADS-B equipage. Industry reps predict a widespread ADS-B Safe Flight 21 ground infrastructure by 2013. The proposed compliance mandate isn't until January 2020. While some owners we spoke with are anxious to load ADS-B in their aircraft, and users of UATs enjoy some benefit, ADS-B data broadcast offers little if any operational benefit to existing missions right now.

If it were us, we'd resist the temptation to invest in any ADS-B gear for now if fulfilling the mandate was our only agenda--it's just too early. We remain advocates of TIS traffic, and still recommend it as a reliable traffic minder that's cheaper than other systems in areas where there is TIS coverage. But we think spending the extra grand for the ES model is still a gamble. If the Extended Squitter remains the basic way to fulfill ADS-B equipage requirements, the box can be painlessly upgraded for a minimal investment later on.

On further reflection . . . Think I'm gonna go with the GNS530W, JPI EDM700, KEEP the existing King KT76 transponder, and upgrade the STec40 to GPSS.

That ought to keep me good for a while.

 

[kontiki]

I think If I was seriously considering a purchase equipment, I'd want to press the seller for their technology roadmap for eventual full compliance for the rules that are out there now and support beyond, because it's never going to end. We are only scratching the surface of CDTI (Cockpit Display of Traffic Information) with applications like TIS.

The UAT transciever needs inputs from various devices.

GPS devices need to be compatible electrically, and meet performance requirements for accuracy. There are also new air data requirements. I don't believe the FARs will let you use a blind encoder to report pressure altitude (like Mode C) any more. They want MSL.

The whole setup needs to meet performance requirements for latency and availability. If the current gear doesen't do it now, exactly what will the upgrade path be?

You obviously don't want to scrap your entire setup because one data source couldn't be upgraded.

I know on airliners we use ARINC 429 buses for GPS data. We're now seeing requirements for a second clock bus, so the units can calculate the age of the GPS position/velocity data. Some applications (maybe surveillance for closely spaced parrallel approaches) can't use position/velocity data that's 2 seconds old.

I wouldn't give anyone money for new gear if they couldn't tell me how their line can be upgraded to meet the known published regulatory requirements that are out there now.

(Launch into another direction here, it's my way)

I also think all general aviation operators need to insist that hardware and electrical interfaces all conform to some sort of open standard industry specifications. That way if supplier X goes out of business, you can use replace it with equipment from supplier Y. Yes, there are maybe certification issues, but you want it to be electrically compatible and use standard data bus word formats.

Open standards encourage competition and that competition helps keep prices down and encourages inovation. I keeps operators from being locked into into any specific product, because replacement requires massive rewiring. It helps people dealing with fleet standardizations. It removes one more obstacle making it easier for inovative companies to get their product out there. If the standards are recognized, it makes FAA certifications easier too.

I don't know what GA avionics standards exist. I'm not familiar enough with what goes on in the GA world right now. In the world of large aircraft, the airlines and the airframe OEMs insist on compliance to ARINC specs. In fact ARINC serves the airlines for developing standards not the manufacturers.

 

[weilke]

I also think all general aviation operators need to insist that hardware and electrical interfaces all conform to some sort of open standard industry specifications. That way if supplier X goes out of business, you can use replace it with equipment from supplier Y. Yes, there are maybe certification issues, but you want it to be electrically compatible and use standard data bus word formats.

At this point, there is only one supplier of GA avionics left, and that particular company is not exactly into open standards.

Unless the Aspen folks manage to come up with a GPS and some com radios, I dont see that changing.

 

[John Collins]

At this point, there is only one supplier of GA avionics left, and that particular company is not exactly into open standards.

Unless the Aspen folks manage to come up with a GPS and some com radios, I dont see that changing.

With the exception of XM weather, Garmin follows open standards and interoperates with other vendors equipment. Examples include Stormscope, TCAS and TCAD systems, air data systems, and fuel systems. There are no standards for interfacing FISB data derived from a UAT ADSB unit even though the data itself is standardized.

 

[Henning]

I faced that question last year when I did my panel and decided to keep my GTX 320 since the 330 is not going to end up ADS-B compliant from the best I could find out (including from Garmin) so I decided to hold off on it, though it would be nice..