Separate/Backup CDO/HSI

[danceskater]

We are starting to do some long range planning for our RV-10 wiring and panel. The current plan is for a VP-X, the Dynon Skyview system with two panels, a GNS-430 for NavComm 1 and a SL-30 for NavComm 2. We plan on a backup AI (electric), Altitude ind., and Air Speed ind. As I read the GNS-400 series installation manual I get the strong impression that, as a device approved for terminal procedures, you also have to install an approved CDI/HSI device to complete the capability. Altho the PFD Localizer/GS display on the VS system would likely be primarily used for approaches, I understand it is not a certified system. Does this mean that I will be required to install a separate CDI/HSI? As I look at the many pictures of RV-10 panels I haven't seen any CDI/HSI's. Am I overlooking something?

Jim

 

[dynonsupport]

So some of the language that you'll encounter in certified avionics manuals assumes that the equipment is going into a type certificated aircarft, in which case all the panel-mounted bits need to be certified. But nothing we've ever seen in the regulations claim that the indicator itself (CDI/HSI) need be certified in an experimental aircraft. The GPS itself does - that part is very clear, and why you need a 430 or GTN to do IFR GPS work. But of the things that people get resistance on from shops/DARs/etc, I don't think this has ever been one of them.

 

[DBRV10]

Jim

Having an IFR RV10 and a really functional ergonomic and effective panel, can I suggest you contact me to discuss things, dispell myths and so on.

Check your PM's

 

[danceskater]

David Brown:

Some background - I am an ATP, have owned and flown a BE-58 for over ten years and have zero experience with experimental aircraft. I am a retired EE and being bored stiff have been talked into being a "build partner" on an RV-10 project, but it is not "my" project. I am, however, doing all of the electrical and avionics design. The "owner" is really trying to keep costs down. Originally wanting almost zero backup. But I am slowly talking him into some basic items. The backup CDO/HSI is simply another thing I am trying to talk him into. If I were to be flying this plane in the future (IFR) I would insist on it. I was sort of hoping that the regs might require it, but this seems to be a bit of a slippery issue.

 

[cmarbach]

If you have two Skyviews, why do you need mechanical backup instruments? Each Skyview can have its own 1 hour backup battery, and I have two ADHRS. Exactly what failure are we thinking about?

My RV-7 has the same or more redundancy with the two SKyviews than most larger aircraft I fly.

 

[dynonsupport]

If you're truly aiming at minimizing costs and need to prioritize to that level where you're not doing multiple displays on SkyView and multiple ADAHRS (which in turn gets you the sort of redundancy that Carl is talking about above), do make sure that you're prioritizing backup gyro instruments above backup CDI/HSI, whether the backup instrument is a standalone inexpensive EFIS (we like the D6 for this purpose ) or a steam backup of some kind. When things start to fail in IMC, it's definitely most important to be able to keep the right side up above all else.