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Autopilot @ GPS
Thinking of using this with a STEC 30 with the GPSS. Is there any reason the GTN 650 would be better or worse?
Thank you,
Bill
- William Mattson
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Re: Autopilot @ GPS
Don
- 9089P
- ICS member
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Re: Autopilot @ GPS
A GPS must of course be certified for IFR in order to used for enroute nav under IFR where the GPS is the primary source of Nav. You must also have an alternate form of Nav available (eg VOR) but I believe under the AIM a WAAS GPS alleviates this requirement.
One thing to watch out for... In order to be certified as an IFR install there must also be an annunciator on the panel in the pilots field of view that tells whether the mode of Nav is GPS or VLOC. For instance on the 530 there is an indicator on the screen but that is NOT good enough for IFR cert of the install. There must be an annunciator on the HSI or VOR head or within 3" of it. Be sure to ask about this.
- Charles
Charles Schefer- Posts: 563
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Re: Autopilot @ GPS
I think that requirement went away as i used to have a seperate annunciator on the glare shield with my kln 89 back in the 90's. bernie
- bernard nowlen
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Re: Autopilot @ GPS
If you have a Garmin VOR head it will have the annunciation within it. Check out their website and you will see what I mean. A little light up "GPS" or "VLOC" will display inside the unit.
In my case, to certify the Garmin as installed for IFR I would have to spend $1K adding an annunciation to the panel. Since I plan to install an Aspen Pro PFD which will have an annunciation built in I decided to leave it as it is for now otherwise that $1K would be throw away. Trust me I looked into this extensively because I felt mine should be an IFR install but legally it's not. The reg is clear that the instrument you are using (VOR/HSI) must have an annunciation within close range showing the nav mode selected.
- Charles
Charles Schefer- Posts: 563
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Re: Autopilot @ GPS
Don
- 9089P
- ICS member
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Re: Autopilot @ GPS
Kristin
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Kristin Winter- ICS member
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- Location: Northern California
Re: Autopilot @ GPS
which assume means the attitude gyro is less than11.8" a seperate annumnciator for gps/vor/loc is not required."
If it's betwen 11.8" and 13.41"you need a basic annunciator which shows what is going to the hsi such as a md 41 (vor/loc/gps). If the distance is greator than 13.41" you need annunciators for all modes of operation. Vor/loc/gps/msg/app/term/enroute/wpt etc that are displayed within your scan area (what ever that is) and i bet it's open to interpetation.
- bernard nowlen
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Re: Autopilot @ GPS
I recall that there was a two tiered requirement. The installation manual for the GNS-480 called out which annunciators were appropriate. The factory center stack installation on a Twinkie allowed me to use the basic annunciator and called out this little STACO switch that I show in the attachment. Needless to say, it was much easier to fit that little guy in the panel than some big thing from Mid-Continent.
Kristin Winter- ICS member
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- Location: Northern California
Re: Autopilot @ GPS
The GTN offers the following:
1. New radio with warrantee.
2. Precision WAAS approaches
3. Completely new simple programing.
4. GTN has features not found on GNS Radios
5. A current production radio which will be support many years into the future.
GNS 430-530
No warrantee
awkward programing
Any repair to the GNS is $1,000 when sent to Garmin.
I have not found used GNS radios to be a good value especially with the high price of USED GNS's
jvb
- VANBLADEREN
- ICS BOD member
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Re: Autopilot @ GPS
I'm not IFR yet hope to soon, but I want it set up correctly. It's amazing the levels and layers of details one must concern themselves with. Just hoping to educate myself enough to ask good questions.
Bill
- William Mattson
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Re: Autopilot @ GPS
- Charles
Charles Schefer- Posts: 563
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Re: Autopilot @ GPS
I don't understand the comment about non-precision enroute. If the GNS530W is installed in accordance with the STC installation manual, the 530W is capable of all Precision Approaches, all GPS approaches with vertical guidance (WAAS) approaches and RNAV point to point enroute navigation, as well as Victor Airway navigation. It is also capable of Arrival Procedures and departure procedures with transitions. Course reversals including procedure turns and holds, as well as missed approach guidance is provided and with GPS Steering will command the auto-pilot to fly these procedures. I tell my wife that I can fly by just pushing buttons, and no need to touch the yoke except for take-off and landing. (This may not keep your skills up but the system is capable if you need it.)
As to annunciation, the Garmin GNS530W STC installation manual provides guidance for installation:
"In accordance with AC 20-138A, for IFR GPS installations the 500W Series unit must be mounted in the aircraft manufacturer’s approved location or other FAA approved location, and the required CDI/HSI must be mounted in the primary field of view. CDI/HSI navigation source selection annunciation must be on or near the affected display and any additional annunciations must be mounted within the normal field- of-view. An FAA issue paper was written to clarify the TSO-C146a annunciation requirement of “on or near the affected display”. This issue paper said, in order to preclude the need for external source selection annunciations (i.e. using the annunciation within the 500W Series unit), the source selection annunciation displayed on the 500W Series unit must be within 13.856 inches of pilot view centerline. If the CDI is to the left or right of centerline, it must favor the same side as the 500W Series unit placement (i.e. typically the radio stack is on the right of the pilot’s view centerline, so the CDI should be on the right side of the basic primary flight instruments). A CDI/HSI with a built-in annunciation may also be used in lieu of a separate external annunciator to satisfy the source selection annunciation requirement. In addition, any required GPS navigation annunciations must be within 16.805 inches of the pilot view centerline. If the 500W Series unit display is within this area, then no external GPS navigation annunciations are required".
According to this guidance, if your HSI is centered with the Yoke and you have a center stack for radio mounting, in our Comanche's the annunciators on the GNS530W should suffice.
Ron Keil
- Ron B Keil
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Re: Autopilot @ GPS
Thanks for this post - I am going to pull that AC and discuss with the local avionics shop at my field. Based on what you posted it seems to me I might be able to get my installation certified IFR as is without spending a bunch more on extra (and IMHO unnecessary) annunciations. However Kristen commented on a 2-tier requirement (maybe covered in that AC you reference?) and I do know the avionics shop I previously consulted in Illinois (not my home field) was clear that an extra annunciation was required. I'm going to look into this again - thanks for the post.
- Charles
Charles Schefer- Posts: 563
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Re: Autopilot @ GPS
The two tier requirement was from the GNS-480 installation manual, but it might reflect something in the advisory circular.
Kristin Winter- ICS member
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Re: Autopilot @ GPS
Charles
Charles Schefer- Posts: 563
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Re: Autopilot @ GPS
My understanding of the 2 tiers is there is a different set of distances if the radios are to the left of the yoke.
Ron
- Ron B Keil
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Re: Autopilot @ GPS
- Charles
Charles Schefer- Posts: 563
- Joined: Mon Mar 12, 2012 7:09 pm