For a PowerPoint rendering, that's a remarkable effort; well done!
I'll offer some comments, questions and suggestions. Feel free to accept, reject or mock them, as you wish!
1. Since you have Lane switches, I presume that you're using a Rotax iS engine. The ECU and Fuse Box for those engines manage DC power generation without pilot intervention. Alternator switches are not required.
- The plan is to run an Edge Performance EP912STi. Is neither alternator switch required? or just not the primary alternator?
2. If you
are using a Rotax iS engine, then you also need Start Power and Battery Backup switches (they can be combined in a single switch). Perhaps that's your "Ignition" toggle? If so, the Battery Backup side should be maintained, not momentary.
- Again, EP912STi. There's not nearly as much info on these as Rotax engines, but from the pics I've seen online they don't use the same starting method. I could be totally out to lunch here though.
3. I don't see an Engine Start switch.
- That's my bad, the ON-OFF-ON momentary toggle marked "ignition", should be marked "STARTER", because that's what it is lol
4. If this is a VFR airplane, why install a very expensive standby EFIS? If you're VMC, then there's zero need for an emergency attitude indicator. You might consider a multi-function instrument like the
MGL Blaze ASV-2 or the
Radiant Instruments UMFI-22-GEN2 as cheaper alternatives that will provide altitude, vertical speed and airspeed.
- You're absolutely right. I just went off the first example a buddy of mine sent me without doing enough research myself, I'll definitely look into your suggestions.
5. Do you have a diagram of your electrical system design? I ask because I've never seen an airplane with two Master Switches and it seems unnecessarily complex. Consider reading Bob Nuckolls' book,
The AeroElectric Connection. Since publishing the book, he's developed a new electrical architecture (
Z-101B) that he considers state-of-the-art for Experimental aircraft. It's not directly applicable to Rotax engines, but it's a good starting point and a valuable learning tool.
- I have not yet sketched up the electrical system. I figured once the panel was laid out I could do a proper power audit and flowchart/wiring diagram, this step is likely a ways off for me. I'm currently building an all electric tiny house, so I'm thankfully not a complete stranger to this world now. I will absolutely read The AeroElectric Connection. As for the 2 masters, unless I'm missing something critital, I don't think it's all that complicated. I don't plan to run backup power for the Dynon suite if I run a second paralleled battery. I figured if I'm going to haul around extra battery weight, it might as well help with both the efis AND the engine...plus it'll help get the CoG a little more rearward, which, if I'm reading things correctly, is something people need to get creative doing (short of just adding dumb weight).
6. Keep in mind that the Kitfox is not a "load-hauler" airplane; you're working within a limited max gross weight. Given that the iS engines include two stators, carrying two main batteries
and an avionics backup battery is probably overkill for even an IFR platform, let alone VFR. The likelihood of losing two stators
or two batteries in the same flight are near zero. Recommend eliminating one battery and sizing the remaining one IAW Rotax guidance (see chapter 24 of the
engine installation manual).
- I'm not sure if the EP912STi has 2 stators, I will definitely look into this. Wont be running an avionics backup battery, just two Master batteries....but again, very open to being talked into a single larger battery, or single normal size battery.
7. Why install a heated pitot tube (and associated wiring and warning light) in a VFR airplane? Unless you plan to install an external alternator -- a third(!) source of power -- this will be a significant portion of your available amps.
- Heated pitot tube is more of a future proofing thing in the event I want to configure for IFR in the future; plus the cost differential is pretty negligible. I believe the EP912STi comes with a single alternator, with the option to bolt on a second. It has been recommended to run a 32A alternator, and bolt on an 18A as backup. I like the piece of mind a 2nd alternator adds as well. Open to suggestions!
8. Radiant Instruments' catalog is sprinkled with re-badged off-the-shelf products from other companies. Their
USB charger is one example. It's a
Molex product that Radiant resells. Buy it from
Digi-Key at half of Radiant's price. Here is the
Molex Mini50 connector to feed power to the unit, and here are the
crimped sockets to populate the connector (buy ten; you'll need to practice crimping them to find the right crimping tool die and to master the technique).
- Absolutely will do this....I just discovered DigiKey relatively recently and I love that place. Fair prices, good inventory, fast shipping. I should probably look for non-illuminated switches there as well!
9. Consider eliminating the Avionics Master switch. It's a single point of failure for all avionics wired through it and it's a very old idea that hasn't been necessary to protect avionics for at least several decades. Same with the Radio switch. A properly sized and maintained main battery will barely notice a few minutes with the Master Switch on (all avionics powered) to collect ATIS and talk to Ground.
- So are you saying to have all this power-up with the master? Is 'load shedding' antiquated notion with the lower consumption of modern avionics? This is all very new to me
10. The Dynon EFIS can display and record all necessary engine data through the SV-EMS-221. The Flybox Vigilus is unnecessary. If you want to be able to move engine instruments to another display, it might make more sense to install a 7" HDX screen instead of the Vigilus and iPad.
- The idea behind the vigilus was just to give engine instruments a dedicated display, plus it cooperates well with the Dynon, and can piggyback its sensors. I like the idea of an iPad becomes it's completely independent of the aircraft systems....alright let's be honest, it's so my passengers can watch cat videos on longer flights once they're sick of asking "how fast are we going", "how high off the ground are we". BUTTTTT, you raise a very good point regarding the 7" HDX screen; that could replace the Vigilus and iris EFIS, and serve the function of both.
11. For ergonomics and ease of use, consider putting the SV-AP-PANEL, SV-COM-PANEL and SV-KNOB-PANEL next to the HDX screen. At a minimum, confirm that the viewing angle of the LCD displays on the SV-COM-PANEL will work from a low mounting position.
- Absolutely valid! I wont be putting any pen to paper until I've actual sat in a kitfox, preferably one with a Dynon, and see how it all looks. Super super valid, and my previous designed had them mounted between the iPad and 10" HDX.
12. Unless they can be dimmed, you may find that illuminated switches are annoying at night. It's common practice in airplane design to use a dark cockpit concept. This means that no lights are illuminated in normal operation. When a light comes on, either something is wrong or is in an abnormal configuration.
Consider fuel pumps: if the engine is running then the pumps are on; the lighted switch is a distraction that complicates wiring. Unless the light is wired to a fuel pressure sensor and comes on to indicate low pressure (i.e. pump failure; already indicated on the EFIS), then it provides no useful information.
- Point taken. All illuminated switches will be eradicated...I just got mesmerized by how cool they look. You're absolutely right that they're a distraction and serve no real purpose.
13. If you use illuminated switches for the Lane circuits, then the associated warning lights are redundant. The switch lights can be used for Lane fault indications. In normal operation, no light should be illuminated when a Lane switch is turned on. If you prefer separate Lane Fault lights, then the illuminated switches are unnecessary.
-
Will keep the fault lights up top with the rest, and go with non-illuminated buttons!
14. EMS warnings will be displayed with a blinking red alert on the EFIS, and optionally, an aural alert. The EMS warning light is redundant.
- This idea came from the department of redundancy department. Consider it removed!
15. What are the two warning lights on the left, next to (I think...) the USB data port? Their legends look like "M1" and "M2"...
- M1/M2 are Master 1/Master 2. The internets told me that the BMS internal to the EarthX batteries can be rigged to a fault light. Idea with the dual batteries/master switches is I could just swap to the alternate and flip off the problem battery without any interruption to service. Again, I could be totally out to lunch here.
16. Finally, my most controversial comment: ATC fuse blocks are lighter, simpler and vastly less costly than a VP-X system, and there is significant danger associated with the temptation to reset tripped circuit protection devices in flight. If something goes wrong with a VP-X, your plane is grounded until the box is repaired. If something goes wrong with a fuse or its wiring, you trace the fault, fix it and go flying.
Instrument Panel - Proposed Layout
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I'll address each one of your points one by one so nothing gets missed!
Originally Posted by Eric Page
Re: Instrument Panel - Proposed Layout
