Latest on 8.33 requirements (merged)

Then the GTN-650 can only be used VFR only, as the STC requires backup equipment for IFR, which is just removed, which IMHO makes sense.

… so even if the 2nd Navcomm weren’t removed, the Germans might not give the aircraft an IFR pass on the Nachprüfschein, since the 2nd Navcomm, called for by the STC, is not 8.33 and thus not adequate?

Do the GNS430/GNS430W STCs commonly used also require a backup navigation unit?

Peter wrote:

Do any of the Garmin-supplied STCs, FAA or EASA, require the separate NAV radio?

Yes, It depends on lots of critaria, but depending on the aircraft type and current installation they might require a secondary VHF COM, secondary VHF NAV or secondary VHF GPS.

Bathman wrote:

Also where is the consistency?

There is none, it depends on lot of different things, suchs as approvals, opinion of CAA, opinion of avionics shop etc.

Bathman wrote:

The box 2 is still a narco 12D I asked them about this and they said it’s fine (admittedly they don’t issue the ARC)

I think they are a fair shop. Some are pushing for a secondary radio. IMHO that is upto you, and how you would be willing to face this. When you see PMH opinion further down, he is happy with it, and not willing to change. That is just fine.
As long as some CAA’s says it is fine to keep the secondary radio to 25 kHz I don’t see an issue in this.

boscomantico wrote:

the Germans might not give the aircraft an IFR pass on the Nachprüfschein, since the 2nd Navcomm, called for by the STC, is not 8.33 and thus not adequate?

Than it would have to be 8,33 kHz. As this would become a mandatory radio for such installation. Again it differs from STC to STC and there are lots of variables.

LBA says that a radio which is not mandatory (thus secondary radio, as there is no two radio requirement as basis) does not have to be 8,33 kHz. So when there is no STC requirement, I don’t see why your secondary radio should be 8,33 kHz unless you want it to be. Scandinavian CAA’s seem to think the same way.

Based on this viewing I think it strange that other countries have a different view (The Netherlands) for example. So I will tell my customers about this, and let them decided if they want / need a second 8,33 kHz radio.

Jesse wrote:

secondary VHF GPS

Not exactly my premier field of expertise, thus it might be an embarrassing question, but what is a VHF GPS?

mh wrote:

but what is a VHF GPS?

I have to guess something like one of the Garmin products that combines a VHF radio with a GPS (e.g GNS430 etc).

mh wrote:

but what is a VHF GPS?

My fault… a made a stupid typo here. So either VHF COM, VHF NAV, or GPS

Unfortunately signing an ARC is not a matter of common sense, it is a matter of law ( as interpreted by EASA via the local CAA) and the bottom line is I am not going to have my licence and livelihood taken away just because just because some owner is too much of a cheapskate to buy a new radio or permanently disable the COM side of a non-compliant NAV/COM.

The 8.33 issue has been known about for years and I have little sympathy with those who could have put away modest sums each month to cover the cost ( the CAA in the U.K. Will cover 20%) and then expect someone to put their licence and living at risk because they have not made provision for 8.33.

My opinion is this is not a safety issue, non-compliant can stay on the on the ground until the non-compliance issue is resolved.

boscomantico wrote:

… so even if the 2nd Navcomm weren’t removed, the Germans might not give the aircraft an IFR pass on the Nachprüfschein, since the 2nd Navcomm, called for by the STC, is not 8.33 and thus not adequate?

It depends on the STC. I think it can be argued that 121.5 is sufficient backup. But this problem would have existed even before any frequency spacing conversion, it can’t arise as a result of this regulation.

A_and_C wrote:

As the rules stand I won’t put my pen to any ARC that includes radios that are not compliant and think any engineer who signs an ARC on a non compliant aircraft is likely to find himself in a lot of trouble.

I’ve got to be dreaming. And people then blame this nonsense on EASA. Which document exactly calls for all radios to be 8.33 kHz capable for an aircraft to be airworthy? Did your NAA at least explicitly instruct you to consider it unacceptable? UK CAA has a page about 8.33 and it certainly doesn’t read to me like “remove that old junk or you’re not flying.” And the EU regulation specifically says that these radios can be used for frequencies that will retain 25 kHz spacing.

I do sympathize but it still boggles my mind.

@Jesse wrote:

Then the GTN-650 can only be used VFR only, as the STC requires backup equipment for IFR, which is just removed, which IMHO makes sense.

Are you sure? On reading 2.5.1.3 and Appendix G of the GTN 6XX/7XX AML STC Installation Manual, I see no requirement for a second COM radio, the requirement for a second GPS navigator only applies to plastic aeroplanes, and the requirement for second GPS navigator or VHF NAV radio only applies as follows:

A second GPS navigator (Garmin or non-Garmin) is required if the aircraft requires GPS coaxial cable overbraid (reference Appendix G).
 Either a second GPS navigator (Garmin or non-Garmin) or a separate VHF navigation radio (Garmin or non-Garmin) is required in the following installations:
◦ Aircraft with a maximum certified gross takeoff weight of greater than 6000 pounds.
◦ Turbine-powered aircraft.
◦ Multi-engine aircraft.
◦ Installations in which a CDI is connected to connector P1004 pin 29 (Reference Figure E-9,
Figure E-10, and Figure E-11), and there is no other way of displaying VHF navigation deviation information from the GTN 650/750. This is not required for installations which have a CDI or HSI connected to the Main connector P1001, which can be switched to output either GPS or VHF navigation information.

Have I missed something in this 390-page manual? Is the second COM radio mentioned in Table 1-2 a FAA FAR requirement?

Jacko wrote:

Are you sure?

Yes. It is important to make a difference between different STC’s (Garmin owned and 3rd party), as well as type of aircraft, weight, and the equipment you install. The part that you quote from the manual is either incomplete or from an older revision.