Carbon Cub EX-3 Engine Failure (N40DT)

[ve6yeq]

One of my long-term goals with my EX-3 is to see Northern Canada, Greenland, and Iceland. All these regions are very sparsely populated and will require long legs (with a fuel belly pod and/or ferry tank), including some over cold water with no diversion opportunities. Hence, my interest in how redundancy has been configured in my current stock, EX-3, with the "IFR" panel.

For my current use while I am building experience, it is not really an issue, as most of my time in southern Canada is spent over farmland, aside from traversing urban areas, so there are many diversion and precautionary landing alternatives. Even here in the TPA area, where I am currently hiding from the weather and short days up north, there is almost always a beach or a sporting field if I can not just make it to one of the many local airports.

However, for my long-term goal, it appears that an alternate power source and a unified backup battery configuration is prudent.

 

[Neal]

Buying time is cheap. Sadly we got a cheap option for backup. Another scenario that would razzle me, having done ocean crossings in A-10's - imagine going across a large body of water?

 

[Neal]

Slightly off topic and I haven't checked the AMM but is there any guidance for maintenance or replacement of the TCW IBBS backup battery? I am not recalling any mention of it. If not I'd suggest 5 years per typical LiFePO4 battery life.

 

[lrobichaux]

Just getting caught up on this very informative thread. Few comments and questions to solicit some feedback.

It is not trivial to fit an IBBS instead of the AGM battery. I have been considering the design options for a while and have decided on, and bench tested, the configuration I plan to use. However, I will not publish anything until it has been tested in the aircraft.

My NXCub has a completely different back-up system than what is being discussed in this thread. From the factory, it has TCW IBBS LiFePO4 3AH batteries for both the IBBS and the right ignition backup. I recently upgraded the right ignition TCW battery to a 6AH. Since the EX-3 that I'm buying has the exact set-up that your FX-3s have (with all of the inadequacies you all have discussed), I'm keenly interested in @Cactus Charlie's thoughts on converting it to an EarthX main battery and two TCW's exactly like is on the X/NXCub. Is it possible to modify the FX-3 electrical system to basically mirror the XCub? Given that the XCub is certified, I have to think that a fair amount of thought went into it. I can load up wiring schematics if that would be helpful.

 

[Cactus Charlie]

Just getting caught up on this very informative thread. Few comments and questions to solicit some feedback.

I'm keenly interested in @Cactus Charlie's thoughts on converting it to an EarthX main battery and two TCW's exactly like is on the X/NXCub. Is it possible to modify the FX-3 electrical system to basically mirror the XCub?

As I posted earlier I have prepared the schematic for, and bench tested, a modification to fit a TCW IBBS to an FX-3 for ignition backup. That may be the easy part as I expect the installation to be non-trivial.

I will not publish any more details until the installation had been implemented and flight tested. I have no schedule and I'm a master of procrastination.

Perhaps worth considering that there are been multiple reports of problems with the LSE ignition system and only one report that I'm aware of where the backup battery was implicated.

If you want the system that you trust on your NXCub you have to change a lot more than the ignition backup battery. The easiest way to do that would be to buy an XCub.