Don

Don

Well Known Member
I have been planning, grudgingly, to put a Garmin 430 in my panel. I am getting near to the point where I'll need to write a check for the equipment and likely the wiring too. Garmin's website says they'll stop accepting orders for the 430 in 2012. I have been torn about putting in the 430 now that a new GPS COM is coming out (and I don't trust Garmin to support the 430 for as long as I'd plan to fly with it) and I can't see spending $9,100 (from Stark) for the 650 which is basically a touch screen 430. The 430 seemed over-priced, imo.

As I explore my options, and at first there didn't seem to be many, I discovered two companies that sell ADS-B transceivers with WASS GPS at about half the price of the 430 (or less). It seems to me, this option, along with a VOR receiver, will let me fly IFR, including precision approaches. I believe Todd said there's even plans to write the software to couple their AP units for this.

It would appear to me that I've avoided using Garmin for the GPS but will get WASS GPS. I get free weather and traffic where ADS-B is available, and I don't need to send XM radio a check every month. This seems to me to be a no brainer...so what am I over-looking?
 
While you could use that GPS for a backup or situational awareness, it would not be legal for IFR approaches.

There is much more to an approach certified GPS than WAAS...

You could fly some ILS approaches with the NAV reciever but only those that don't require something else for fixes....

Talk to Stein. You may be surprised on what you might get a 430W for...this box is the most popular ever, support for it ain't going away anytime soon.
 
Last edited:
How much IFR do you plan to do? With an SL-30 you will have VOR/LOC/GS
and with one of the protable GPS's available you can everything else (except
IFR approved GPS). I don't think they will be getting rid of the ILS any
time soon. With any number of EFISs, this makes for a very capable panel.
 
Chino Tom said:
How much IFR do you plan to do? With an SL-30 you will have VOR/LOC/GS
and with one of the protable GPS's available you can everything else (except
IFR approved GPS). I don't think they will be getting rid of the ILS any
time soon. With any number of EFISs, this makes for a very capable panel.
Click to expand...

While I agree with you conceptually Tom, I'd advise folks to look at the approaches at the destinations where they usually fly "IF" they intend to really use the airplane IFR. Louise's RV-6 has what you describe - an SL-30, Dynon's - and 396 GPS. We can find our way anywhere, but legally, well...College Station, Texas, where Louise works, has about six approaches - and only ONE of them can be flown without a DME or IFR GPS. Puts a crimp in the old IFR option.

Just saying....look at the available approaches in your area.

Paul
 
Yep like Paul sez and I mentioned above, there are tons of ILS's out there that require more than a NAV radio to be flown and a non certified GPS legally won't cut the mustard.
 
I'll try to keep this short...and ask for a bit of trust here!

This is one of those things that if you're going to do, you should do it right or not at all (or wait until the budget or CFO says you can). The GPS's in the ADSB boxes don't yet legally or functionally count just because there really isn't a GPS that's "almost" certified, or "almost as good as"....period.

A 430 is a great box, but right now I can get you into a GTN-650 for almost the same price ($1k rebate on them). As Paul & Brian have said, an SL30 will make you minimally legal, but it'll also make you minimally capable. You'd still need a MKR BCN, and remember that there are now more active GPS procedures than others (ILS/VOR, etc.) and the activation of new GPS proc's relative to ILS is very lopsided and likely to get more so.

Anyway, we're still selling 430's, but with the rebate the GTN is pretty attractive. Waiting is a fine option too, but remember that no matter what you do, there will always be something newer. In the end, it sorta depends on your budget and timeline. Either way, I'd try to come up with the bucks (now or later) to go all in. I can't recall ever having a customer regretting the bigger boxes and wanting to move down in functionality, but I have a whole bunch that call back to order a retrofit 430 or GTN and say "I wish I'd have just bought the big box to begin with". Where do you think all those SL30's that I sell cheap come from!?! :) Retrofits are not terrible, but they can be a bit of a pain. I know all of us hate laying on our backs under panels!

My 2cents as usual!

Cheers,
Stein
 
In my -7A, I started with an SL30 and CDI for IFR capability, partly because finances wouldn't support a 430. Then I picked up a Garmin TSO 155XL to get legal IFR GPS enroute and approaches. I plays well with my G3X.

One neat thing the 155XL/G3X combo gives me is that I can import a flight plan into the G3X, including approaches, and then use either the internal G3X gps or the 155XL to drive my TruTrak autopilot. Since I keep the 155XL database current, I don't even bother to keep the G3X nav database current.

I also can get a poor man's coupled VOR/LOC approach by entering the fixes from the 155XL and having the autopilot fly it, leaving me to monitor the course and manage the descent.

Now that getting an all-in-one box is possible, I kinda like not having all of my eggs in one basket. That combo takes me everywhere I want to go up and down the east coast in IFR conditions.

Good luck on your decision.

Mike
 
don, i have been flying behind a 430, TT AP, and 496 for many years and could not be happier. great support from both companies. holding my ground for many years to come. the 430 is almost considered old school now.
img2294a.jpg
 
I appreciate all of the comments so far. I am attempting to sort out fact from fiction on what is required for a GPS unit to be legal to use for IFR.

I spoke with Freeflight this morning and I think I understand where Stein is coming from and I am trying to speak with him also to get a non-vendor perspective and glean some of his wisdom and knowledge. Freeflight said they have an ADS-g transceiver with WAAS (and RAIM) capability, now. They indicated it would be legal for IFR use enroute, terminal, and for non-precision approaches. This unit is shipping now but it isn't fully complete - which I think is what Stein was getting at.

Two things are missing. The ADS-B out has received TSO approval but the ADSB in has not received it yet. I am not really clear what this means EXACTLY because you can get weather and traffic on it now. The other incomplete element is there are different levels of WAAS. Their was provides mostly lateral guidance and isn't providing sufficient vertical guidance to allow precision approaches. When this becomes available, it will not be a simple upgrade. Now I'm wondering what the WAAS capability of the GRT GPS is (precision or non-precision)?

Their GPS provides position, velocity, and time to an EFIS. The EFIS has to provide the navigation capability.

FWIW, Freeflight offers the Ranger ADS-B transceiver in 2 flavors - the non-TSO'd E version for experimental aircraft for $3,500 and a TSO's version for twice as much. The non TSO'd can be upgraded to the TSO'd version by paying the difference in price.

One lingering question in my mind is does the ADS-B/GPS unit have to be TSO'd in an experimental aircraft to be legal for IFR use? If not, then for $3,500 (they do not anticipate a price increase when the unit is completed), I can use a GTX 327 instead of a GTX 330 and still get traffic (a $1,500 savings), and I don't have to pay XM Radio for weather every month. Moreover, the initial cost is lower. The downside is, the equipment is NOT fully implemented yet.

I know timetables slip but Freeflight seemed confident that the ADS-B in would be available by OSH 2012. The WAAS for precision approaches, who knows. I think Ironflight's comment applies here - what is it I will really use where I fly.

I'm posting this because it seems the information I'm getting from manufacturers contradicts some of the information I am getting here. I'm early in the learning phase on this aspect of the build. So, I'm not arguing against anyone, I'm just trying to sort out the truth of the matter.
 
Don,
I have been looking at many of the same issues you are discussing myself. I am not an IFR pilot but have been taking Instrument ground school and am contemplating upgrading my VFR panel so that I can start training and eventually get my ticket. I am not all that interested in flying IFR on a regular basis but would like to get the ticket so I can file IFR if needed.

With this in mind I have talked with NavWorx and GRT both at SnF and OSH over the past two years concerning ADS-B and the GPS capability both companies offer. As far as ADS-B, you are in a better position to make this move since you live near the east coast. Here in the Midwest there are vast expanses of the country that have no ADS-B coverage. This has kept me from pulling the trigger on ADS-B. I like the on-board Wx and the traffic it provides but do not feel I would be getting it until they get coverage in this part of the country.

I have a VFR qualifying GPS and am also contemplating putting in the SL30 but do understand where Paul Dye is coming from. I can be legal with the SL30 but that is about it. I have been informed by a CFII that I can file using the VOR and then request direct GPS using my existing GPS once airborne. That may get me in-route direct GPS navigation but, as has been stated already in this thread, I am not legal to shoot GPS approaches with this setup. If I am going to continue on with IFR training I would like to be able to do it right.

I don't have any answers but am following this thread with interest as the topic is down the same path of reason I am debating.
 
Regarding the requirements to use a GPS unit for IFR flight, it matters not what type of airworthiness certificate is issued because you are playing with everybody else in the airspace. Asking for different opinions is helpful, but the AIM provides a nice summary:

1. Authorization to conduct any GPS operation under IFR requires that:

(a) GPS navigation equipment used must be approved in accordance with the requirements specified in Technical Standard Order (TSO) TSO-C129, or equivalent, and the installation must be done in accordance with Advisory Circular AC 20-138, Airworthiness Approval of Global Positioning System (GPS) Navigation Equipment for Use as a VFR and IFR Supplemental Navigation System, or Advisory Circular AC 20-130A, Airworthiness Approval of Navigation or Flight Management Systems Integrating Multiple Navigation Sensors, or equivalent. Equipment approved in accordance with TSO-C115a does not meet the requirements of TSO-C129. Visual flight rules (VFR) and hand-held GPS systems are not authorized for IFR navigation, instrument approaches, or as a principal instrument flight reference. During IFR operations they may be considered only an aid to situational awareness.


I also think speaking of a GPS position input into ADS-B is mixing apples and oranges as to using a stand-alone GPS receiver that feeds position to ADS-B as also able to provide for IFR navigation. The WAAS input is only a positional input for ADS-B and not a navigation receiver with a current database, RAIM, and the other requirements necessary for the above TSO certification.

I think the chain of logic is this: FAR 91.205 specifies IFR equipment requirements for standard category aircraft; the operating limitations issued to EAB aircraft mandate that for IFR flight, the equipment requirements of FAR 91.205 is to be applied; part of those requirements is for navigation equipment suitable for the flight; required GPS installations therefore have to meet the TSO requirements for an IFR flight as outlined in the AIM paragraph above.

And, by the way, the ADS-B areas of coverage will be expanding rapidly in the next year.
 
Last edited:
WAAS Requirements in AIM

Scott did a good job of extracting the TSO-C129 (non WAAS) requirements from the AIM.

AIM Section 1-1-20 explains that the newer WAAS avionics must be certified in accordance with TSO−C145 or TSO−C146.

Anyone considering acquiring a non-WAAS IFR navigator might want to review the information in the AIM pertaining to IFR operation with WAAS receivers. The improvement in capability and integrity monitoring (over non-WAAS GPS) is quite significant.

Steve
 
Steve, Scott,

I think there's a nuance here that isn't being clearly brought out (and it's possible I'm wrong, too). My understanding is a WAAS GPS used for precision IFR approaches must meet the TSO standard but that is not the same as saying the GPS must be TSO'd.

If you are flying behind a TSO's GPS there is no question about compliance with the standard. Non TSO's units may also meet the standard but it is up to the pilot to be prepared to demonstrated the non-TSO'd unit complies. In most cases this is going to be exceedingly difficult, expensive, or just impossible to do...but not in all cases. For example, Freeflight sells two identical units. One unit, the Ranger, has the TSO sticker and costs $7k. The other unit, designated the Ranger-E, does not have the sticker but is otherwise identical and costs 3.5k. Freeflight will verify the two units are identical and will even TSO the non TSO'd unit if you pay the extra money. In this case, and cases like this one, I think a non TSO'd unit can be practically demonstrated to meet the technical standard required for IFR flight.

Correct me if I'm wrong, but as I read the FAR this would be allowable. FWIW, at this point I am abandoning the ADS-B GPS route. My decision is not based on a TSO but rather that the units are still under development and won't yet do what I want. I'm not sure what direction I will go but I'm getting closer to deciding.
 
If the GPS does not have a database and all the RAIM and a whole book full of other stuff, it won't meet the TSO standards for IFR use as an enroute or approach certified unit.

Their GPS may meet the requirements for a precision position source for ADS-B out but it will not cut it for enroute or approach use.

Technically it is not legal for people to use a VFR gps as sole means of navigation enroute while on an IFR flight plan...people do it however.
 
Last edited:
Who?

Don said:
.......If you are flying behind a TSO's GPS there is no question about compliance with the standard. Non TSO's units may also meet the standard but it is up to the pilot to be prepared to demonstrated the non-TSO'd unit complies.
Click to expand...

Who would ever ask you to demonstrate this? Only if there is a violation or miscommunication with ATC on an IFR flight, would you "talk" with any FAA reps. I'd bet that there are no reps out in the field that even know how to prove or disprove the demonstration.

Best,
 
Certification Required?

Don said:
Steve, Scott,

My understanding is a WAAS GPS used for precision IFR approaches must meet the TSO standard but that is not the same as saying the GPS must be TSO'd.
Click to expand...

Don,

One of the confusing things about aviation rules is that it is sometimes difficult for us to separate guidance from regulation. The paragraph below extracted from the 2011 AIM certainly seems to be clear that WAAS avionics used in IFR conditions must be certified. The follow on quote from a FAA website says the same thing.

I have not, however, been able to find regulations that require that this equipment must be certified (TSO'd) to be used in our non-certified experimental aircraft, so I have to agree with your statement.

Steve

Extracted from AIM
General Requirements
1. WAAS avionics must be certified in accordance with Technical Standard Order (TSO) TSO−C145A, Airborne Navigation Sensors Using the (GPS) Augmented by the Wide Area Augmentation System (WAAS); or TSO−146A, Stand−Alone Airborne Navigation Equipment Using the Global
Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS), and installed in accordance with Advisory Circular (AC) 20−130A...

Quote from FAA website:
Q. What are the differences in capabilities between the various WAAS TSOs?

A. First, the basic information for GPS. To use GPS for navigation, the equipment must be certified in accordance with TSO-C129 and the installation must be done in accordance with AC 20-138 or AC 20-130A. TSO-C115a does not meet the requirements of TSO-C129.
For WAAS, you must use either TSO-C145a or TSO-C146a. Most General Aviation WAAS receivers would comply with TSO-C146a, which applies to panel-mounted navigation equipment (as opposed to sensors that provide data to a flight management system).
 
Brantel said:
If the GPS does not have a database and all the RAIM and a whole book full of other stuff, it won't meet the TSO standards for IFR use as an enroute or approach certified unit.

Their GPS may meet the requirements for a precision position source for ADS-B out but it will not cut it for enroute or approach use.

Technically it is not legal for people to use a VFR gps as sole means of navigation enroute while on an IFR flight plan...people do it thought.
Click to expand...

This the the crux of the matter: the Freeflight precision WAAS sensor is just that: a sensor only. It is useful for providing a WAAS position for ADS-B and, presumably, a WAAS position to an Flight Management System (FMS). For our EAB purposes, installing this box will not give you anything in the way of navigation capability other than, possibly, a precise position input into an EFIS (like Skyview) for moving map position and whatever enroute navigation functions an EFIS box can perform with that information.

Note that the Freeflight is TSO C-145a (WAAS sensor) vs Garmin GNS 430W or GTN 650 which is TSO C-146a (stand alone navigation equipment). Big difference.

The IFR capability of the RNAV approach system, including LNAV, LNAV/VNAV, LP, and LPV SIAPs, is based upon a secured database that provides the approach data to the navigation system (like a GNS 430W or GTN). Trying to use a VFR GPS unit to cobble together a non-precision LNAV-type approach by manually inputting WP data for IFR use is foolhardy and more than risky to that user and all the other users out there in the same airspace.

As was noted earlier...if you want to use GPS for IFR use, do it right or please don't do it at all.

For my money, a GNS 430W or GTN 6xx inputting into a Skyview or other EFIS box gives incredible IFR capability with the mushrooming availability of RNAV SIAPs that provide ILS minimums.
 
Last edited:
DO-229D

I agree with Scott that having a WAAS capable sensor is just the first step in having a system that is capable of flying WAAS IFR approaches.

DO-229D defines the Minimum Operational Performance Standards (MOPS) for TSO C146 systems. There are over 100 pages of requirements and another 100 plus pages of performance and testing requirements.

Certified or not, it is a big job for anyone to create a WAAS IFR navigator that meets the operational needs and requirements to fly these approaches legally.

Steve
 
Likely not an issue for Virginia, but I just experienced what a pain and lost time touch screens are in the cold. I know all you need to do is snip the end of your index finger off your glove.... but when the wind is howling in cold temps this is just not going to happen. I like my old knobs and buttons just fine and much prefer them to any touch screen. I suspect that Garmin will be keeping the 430's in service longer than they might imagine. It would be a shame to discontinue them.
 
F1R said:
Likely not an issue for Virginia, but I just experienced what a pain and lost time touch screens are in the cold. I know all you need to do is snip the end of your index finger off your glove.... but when the wind is howling in cold temps this is just not going to happen. I like my old knobs and buttons just fine and much prefer them to any touch screen. I suspect that Garmin will be keeping the 430's in service longer than they might imagine. It would be a shame to discontinue them.
Click to expand...

The Garmin website say's the 430 will be discontinued in 2012 and they promise continued support but there's not word on how long they'll continue to support it. I've been down this road with them once before.
 
You must log in or register to reply here.