CH750 Off-field Landing

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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Replies to This Discussion

Permalink Reply by John Schaper on September 26, 2018 at 12:10pm

Jan,

If the alternator was working, wouldn't that provide enough power to operate the required engine components to run the engine? (fuel injection, spark & EFM)

Permalink Reply by Jan Eggenfellner on September 26, 2018 at 12:59pm

This is true if: 

  • Alternator was turned on
  • Wiring was still intact
  • Batteries didn't cause some kind of short

Likely having a meeting tomorrow to find out more about what happened. 

Permalink Reply by Jonathan Fay on September 26, 2018 at 4:22pm

I am just wiring up my 130 now. I have two of the EarthX batteries that will run in parallel or independently A/B/AB. If I were flying and found that the ECU cut-out, would turning off battery A, and switching to battery B restart the engine in flight? Or is there a startup procedure that would have to happen?

Thanks

Jonathan

Permalink Reply by Loren Warner on September 26, 2018 at 7:48pm

During test runs of our 130 we found the engine will not run on the alternator alone unless the rpm remains high enough for adequate alternator output.

Permalink Reply by Jan Eggenfellner on September 27, 2018 at 11:45am

The engine would instantly restart as soon as you re applied power to the system.  The scenario could only happen if you somehow completely missed that the alternator went off line 

Permalink Reply by Larry W. Sward on September 26, 2018 at 9:01pm
What is the minimum engine RPM for the alternator to put out enough power to keep the engine running??
Permalink Reply by Loren Warner on September 27, 2018 at 10:08am

I don't know the minimum, but before you fly I suggest testing yourself by turning off both batteries.  I seem to recall it stopped running around 1800 rpm or less.  We wrote into our draft POH for a "loss of batteries procedure" to ensure at least 2500 rpm until on short final.

Permalink Reply by Jan Eggenfellner on September 27, 2018 at 12:01pm

That is not correct.  Something is wrong.  Be sure the alternator is properly grounded. (Remove powder coating from attach areas of mounting brackets)

Permalink Reply by Loren Warner on September 27, 2018 at 12:41pm

When we tested the engine did not have a propeller.  Would that make any difference?

Permalink Reply by Loren Warner on September 28, 2018 at 5:52pm

I need to make a correction to my previous post.   The rpm's were much lower when the engine stopped running (likely under 1000 rpm), and without a propeller.  Test run of our Viking 130 today shows the engine running just fine on the alternator only at 1600 rpm and the entire electrical load turned on, including our Dynon heated pitot tube.

Permalink Reply by Jan Eggenfellner on September 27, 2018 at 11:43am

Yes, without any trouble at all

Permalink Reply by Jan Eggenfellner on September 27, 2018 at 6:02pm

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