A Ch-750 aircraft, piloted by our friend Herb, made an off-field landing close to Deland in Florida. The landing did result in the airplane nosing over due to Herb misjudging the slope of the field. However, congratulations to him for safely landing the aircraft and without himself, or his passenger getting hurt.  
This airplane is about 5 years old and was originally built by another friend, Vernon Knott. It is equipped with one Advanced Auto parts lithium battery, one Shorai lithium battery, a Viking 110 engine, an electrical power panel and some other equipment.  
Viking Aircraft Engines has been asked to participate in an FAA fact finding session to determine the reason for the off airport landing. This will happen no later than Monday.
After talking to Herb, a few things have already become evident:
  • The reason for the landing was a gradual loss of electrical power in the aircraft, resulting in eventual engine stoppage.  
  • A dual electrical system was installed; however, operated as a single system with 2 batteries on all the time
  • Electrical issues became evident recently, after the master switches were left on and the lithium batteries completely drained during a weeks worth of sitting in a hangar.
  • The aircraft is in a partnership and the second partner charged the batteries. The batteries did not take full charge and a second attempt was done.  
  • The owners became skittish about the system and decided the electrical system could not be trusted for anything but pattern work until confidence could be re-gained with the alternator, battery one and battery two / aircraft wiring in general.  
  • During an EAA function, everyone wanted to see Herbs' airplane and they walked to the hangar. Herb forgot that they had restricted the aircraft to pattern flights only and accepted the request to give a ride as a birthday wish.  
  • During the flight, they left the airport area, likely drained the batteries and landed off field. More shortly.

As we are not members of all groups throughout Facebook and beyond. Please feel free to share. 

Jan Eggenfellner 
Viking Aircraft Engines

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Aviation Safety Officer for 20+ years.  Maybe change wiring to have covered toggle switch for alternator and key for engine start/run.  There would not be many scenarios where the need to disconnect the alternator from the power circuit. 

The key used to crank, run and connect the alternator leaves too many opportunities for human error especially with an unlabeled switch.  


Jan -

Nice job getting ahead of the trolls.  I run dual buss Shorai batteries and they have been trouble free on my 110. If they get run down to <11 volts, you want to use their charger to get full capacity back, not a traditional wet cell charger.

Brad Rawls

If batteries are properly maintained and periodically tested, they should be the most reliable source of power available.

If batteries are properly wired to the engine independent of each other, the chances of abruptly losing power to the engine should be as close to zero as it is possible to get.

If there is a working voltmeter, the pilot should know immediately if the alternator quits charging, giving him time to get down without an emergency.

Based on Jan's initial post, it would seem that all three of these principles were violated, so loss of battery power is not surprising. At least one question remains: Why didn't the alternator keep the engine running?

" At least one question remains: Why didn't the alternator keep the engine running?"

No. This was obvious, the alternator switch was set to off. When the batteries were depleted, the engine stopped. If the alternator switch was on, the engine would have continued to run.

Just found Jan's video. Mystery solved.

I applaud Jan's excellent video and analysis!

The video demonstrated that the plane's panel had a number of switches that were unlabeled or had what might have been labels at one time, but were now totally illegible.  Not to be too critical, but I think that speaks volumes.



Agreed and thank you, in addition to the violation of operating procedures that rendered the entire dual battery system incapable of saving the day. 


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