SkyView Battery Charging before first flight.

[vlittle]

It's well documented that the Dynon SkyView battery is difficult to charge on the ground and needs several flight hours to bring to full charge.. I worked around this by installing a ground power port for running the SkyView and charging its battery.

Today I learned of an inflight emergency on the first flight of a friend's RV-7A. Due to a misconfiguration of the main electrical system (VPX), the alternator did not come online in flight. First flight is a very stressful time and there were a number of other alarms that masked this until the entire electrical EFIS systems shut down due to low volts and the SV backup battery could not keep it running.

There were no steam gauge back ups, but one radio lasted long enough to get his wingman to take the lead and bring him back to final approach.

The accident train was broken by the wise choice of a chase plane on first flight, but one of the contributing factors was the architectural fault of the SkyView system that makes it difficult to top up the battery on the ground.

I urge all new installations to fully charge the SkyView battery before first flight. This may require a modification to the electrical system to enable this. In my case, I have a separate 14 volt power supply, connector, breaker and relay to allow ground charging.

Vern

 

[lgabriel]

This is an excellent point!  I too have ground power provisions and charged the SV battery completely prior to first flight with the new cockpit.

Come to think of it, I did a rundown battery test prior to that first flight...which necessitated charging it back up.  I think a small clarification in the install manual about this might be warranted.

Something to the effect that "we recommend you do a battery rundown test and complete recharge prior to first flight".

EDIT: The recommendation for the initial test has been included since Rev K--disregard all.

 

[mmarien]

I don't think you need any special equipment. I use a cheap charger, one that doesn't pulse, at 4A to charge the main battery and leave the the master switch and Skyview on to charge the backup battery after doing the annual Skyview backup battery test. Just pull the breaker on everything that doesn't need to be on. Easy to do if you have VP-X.

This is also a good configuration when loading that new terrain database or if you're like me and sometimes spend a lot of time fiddling with the knobs, manual in hand, trying out the new stuff on the ground.

 

[jlakins]

It would appear the RV-7A pilot did not read the manual.
There is pretty good documentation already but adding more will not help if you do not read it.

Page 9-4

Initial/Recurrent Backup Battery Test
Perform this test to ensure each backup battery in the SkyView system is fully functional upon initial installation and yearly thereafter.

An SV-BAT-320 is fully charged when it reaches 12.25 volts. Charging a completely discharged battery may take up to 4 hours. To conserve your aircraft battery, the SV-BAT-320 only charges when SkyView detects that your alternator or generator is running (whenever your engine is running), which is when SkyView’s input voltage is above 12.25V. Alternatively, connecting a battery charger to your aircraft battery will also raise the input voltage to a level that will allow SkyView’s SV-BAT-320 to charge.


Also look at page 9-5 which details the test procedure.

Jim

 

[dynonsupport]

A few notes:

1) With a properly set voltmeter in the EMS, the pilot was getting a voltage warning for a long time during the flight, and before he even took off. Set your voltage warnings at 13V not 11V so they warn you that the alternator is offline, not that your battery is down to 10% charge!

2) A fresh SkyView from the factory warns of the need for a battery test in the message system. This test tells you that the battery will be discharged via this test and needs to be recharged.

3) Charging SkyView is not "architecturally hard." Hook a battery charger to your aircraft battery, turn off the unneeded loads in the plane, and turn on SkyView.

All that being said, it was already on our list to create a warning at boot if the battery is so low that it has less than about 50% charge, and we will up the priority of that. Sounds like one more warning in this plane wouldn't have helped though, but we do hope it helps someone make a smart decision if they are more experienced with the system and don't normally depart with a series of warnings going off.

 

[rfinch]

Due to a misconfiguration of the main electrical system (VPX), the alternator did not come online in flight.

Misconfigurations happen, but significant ones should be discovered on the ground.

• Why wasn't the aircraft battery fully charged before first flight?
• Why wasn't the lack of alternator discovered during an engine runup? Even a minute or two runup would have revealed this. I understand ground runups shouldn't last long, but a few minutes, with a checklist prepared ahead of things to check, is obvious.
• Whoever is flying the aircraft on its very first flight should be able to to do so with no instruments at all. Even if the EFIS was working, how do you know it's accurate? If the owner is not capable of this, they should find someone who is.

Dynon had nothing to do with this mis-adventure...the careless builder/pilot did.

 

[vlittle]

There are a number of contributing factors at play here, but the one that is related to the SkyView is documented here.  The Dynon procedure for charging the battery on the ground may not work for everyone.

In my HR-II case, the original main battery charging port on my aircraft was limited to 7 amps and this was not enough to power up the minimum master bus load and charge the SkyView battery.  I added an independent power port for this purpose which solved the problem. I have an aft battery that would require disassembly of the aircraft to use a high capacity charger.

Also, leaving the Master ON for several hours is uncomfortable, particularly if leaving it unattended.

Now, let's look a little deeper.  The builder of this subject aircraft is not an avionics expert, so he contracted an avionics tech who is experienced with the SkyView and VP systems.  This is a pretty common situation.  There was a lot to absorb for the builder who was experiencing glass technology for the first time outside of Boeing and Airbus.  There was an indication on the screen called 'Batt Volts' which he assumed to be the SkyView battery because he is familiar with 'Buss Volts' as the standard terminology and there was no other voltage indication on the screen.

This confusion was also the reason that the alternator field fault was not found.  In this case confirmation bias kicked in... 'Batt Volts' must be the backup battery because it didn't change with the engine running.

Having no indication whatsoever that the backup battery was incapable of performing for its intended purpose, he flew the aircraft.  I don't know if he got any voltage alarms in flight.

So, Dynon's software amendment is welcomed... Warn the pilot that the backup is inadequately charged before flight.  That will help a lot. A terminology change to 'Buss Volts' may also be advisable because of the potential for confusion as well.

The whole point here is not to assign blame but to look at the chain of events, understand cause and effect and implement changes to improve safety.

 

[vlittle]

Due to a misconfiguration of the main electrical system (VPX), the alternator did not come online in flight.

Misconfigurations happen, but significant ones should be discovered on the ground.

• Why wasn't the aircraft battery fully charged before first flight?
• Why wasn't the lack of alternator discovered during an engine runup? Even a minute or two runup would have revealed this. I understand ground runups shouldn't last long, but a few minutes, with a checklist prepared ahead of things to check, is obvious.
• Whoever is flying the aircraft on its very first flight should be able to to do so with no instruments at all. Even if the EFIS was working, how do you know it's accurate? If the owner is not capable of this, they should find someone who is.

Dynon had nothing to do with this mis-adventure...the careless builder/pilot did.

-Apparently, the main battery was fully charged.
-See previous post about confirmation bias.
-Pilot was more than capable of flying a blank panel and did so safely.  He has several thousand hours flight experience and a great deal of formation time. He has built two RVs.

Vern

 

[dynonsupport]

"Buss" or "Batt" volts is up to the installer. You can name it whatever you want. But it IS the battery voltage in the plane in most installs, and it's up to someone flying a piston plane to understand the acceptable voltages for their plane. If you name it "buss", which buss is that? Avionics, battery, master, and what voltages are OK?

Apparently his pre-flight takeoff checklist didn't cover a check to determine the alternator was functional, and so he had to rely on personal knowlege of a system he didn't build and was unfamiliar with. Additionally, the installer of the system didn't set up the system adequately to warn of a incorrect voltage situation before takeoff, or the pilot was willing to depart with a system in the yellow or red, which are clearly highlighted.

I think the real issue here is that getting systems training on a one off aircraft is hard. We do our best here to help at Dynon, but every plane is different, and at some point you need solid installation advice, and solid checklists and procedures for your aircraft.

 

[mmarien]

So, Dynon's software amendment is welcomed... Warn the pilot that the backup is inadequately charged before flight.

That probably wouldn't help in this case because of all the warnings that were ignored. A good example of complacency that bites back.

The whole point here is not to assign blame but to look at the chain of events, understand cause and effect and implement changes to improve safety.

I agree here. It's a pretty typical chain of events.

• Warnings not understood/ignored
• Get-there-itis in that there is some urgency to have the first flight
• No backup plan or it appears to be no plan at all

It is a good example Vern. Happy to hear it didn't end badly.

 

[vlittle]

I eliminated steam gauges entirely on my second build, confident in the reliability of the SkyView system. However, I knew every wire and every puff of smoke kept therein. This is not typical.

A lot of very competent homebuilders are not comfortable sheparding electrons, so this critical construction phase is often contracted out.

Even with perfect wiring, all of the configuring and programming makes these devices intimidating and complex.

Don't forget the primary error was the misconfiguration of the VPX which has little to do with Dynon. the interactions between all of these complex systems are a bit worrying.

 

[jakej]

Two words come to mind here no matter the experience level, RTFM & AVIATE especially for first flight - the good thing to come out of this is this discussion will get some in a thinking mood.

First flight - be very careful.

Jake J

 

[lgabriel]

It would appear the RV-7A pilot did not read the manual.
There is pretty good documentation already but adding more will not help if you do not read it.

It isn't mentioned in the Pilot's Guide, however.

 

[vlittle]

It would appear the RV-7A pilot did not read the manual.
There is pretty good documentation already but adding more will not help if you do not read it.

It isn't mentioned in the Pilot's Guide, however.

Touche!

 

[TRCsmith]

The whole point here is not to assign blame but to look at the chain of events, understand cause and effect and implement changes to improve safety.

But isn't that the first job of the pilot in command?? To identity and managed the risk? The pilot made several per-depture mistakes! Doesn't matter whose system was installed or by who....... All comes back to the PIC and decision making. That's what the accident report will show.

 

[ckurz7000]

Being a test pilot for an aircraft company, this sounds a lot like what's usually happening when the pressure builds before first flight. Most accidents happen around this time but are easily preventable. The most important point is the mental attitude you have when you go sit in the plane. It should NOT be, "Oh boy, I am so excited! Now I am going to fly the plane for the first time!". You need to make it very clear to yourself that you are only sitting in this plane to find reasons not to fly it today. Only once everything checks out, every warning has been investigated and dealt with are you going to take this plane up.

The critical error in this case was that the pilot wanted to fly his new aircraft so much that he took it up for the first time while unresolved warnings were still flashing on the EFIS.

The second mistake in this case was that the pilot even consented to flying the plane for the first time without being intimately familiar with the single most important instrument: the EFIS.

The third mistake was that operationally important systems like the alternator were not checked out before the flight. Was there even a checklist he followed? On the up side, the pilot was smart enough to have a chase plane fly along. He also was experienced enough to be able to bring her down safely.

Still, the single most important point he missed was being in the proper mental attitude of a test pilot.

-- Chris.

 

[vlittle]

Keep it on the straight and narrow here.  This is about a technical issue that could be improved to enhance pilot decision making.

Years ago, i had a series of switch failures in my RV-9.  After the first one was replaced, was it poor decision making to continue flying with the same brand of switch elsewhere in the cockpit? Turns out they were all suspect and I did eventually replace them all.

If I had a fire due to a bad switch after having trouble previously, would I be to blame?  In fact, I did end up with charred wires on a different circuit due to a second bad switch.

When I built my HR-II, I eliminated all switches that carried large current loads and designed a relay controlled load center.  I considered the VPX but did not want to put my faith in software for the critical aircraft systems.

So yes, even though I know a lot of electrons, some of whom are friends, I will never trust them completely.  An alarm generated by a computer depends on calibration and configuration of thresholds.  The natural tendency in a new aircraft when faced with an alarm is to assume that it has been misconfigured.  In fact, in this RV-7A there are other alarms still present that are due to misconfiguration that can are only apparent in flight.

So please don't recommend wind tunnel testing to find these or infer that it's the pilot's fault for not finding them before flight.  Things happen and if we can help Dynon or VP enhance safety with product improvements, let's do it.

If anyone has read Hitchhiker's Guide to the Galaxy.. Just because Arthur Dent didn't read the public notice about the earth's planned destruction for an intergalactic highway is no excuse.   Sometimes even proper documentation does not make it right.

'Nuff said.

 

[ckurz7000]

Since this forum is about technical things to do with Dynon I don't want to start a big ruckus about the frame of mind and procedures required for a test flight in a never before flown homebuilt aircraft. If you did it wrong and got away with it you were lucky. If you learned something from it even better. But as a test pilot you just flunked.

-- Chris.

 

[rfinch]

the entire electrical EFIS systems shut down due to low volts and the SV backup battery could not keep it running.

There were no steam gauge back ups, but one radio lasted long enough to get his wingman to take the lead and bring him back to final approach.

-Apparently, the main battery was fully charged....
-Pilot was more than capable of flying a blank panel and did so safely.  He has several thousand hours flight experience and a great deal of formation time. He has built two RVs.

"Main battery fully charged"...but it drained on the first flight to shut down the EFIS?

"Pilot was more than capable of flying a blank panel"...but he needed a wingman "to take the lead and bring him back to final approach."

Yes, this is a Dynon forum, not a how-to-screw-up-a-first-flight forum. But your friend, from the description, did everything wrong in spite of his extensive experience. So maybe that's the take-home lesson. Don't get over-confident and careless in your knowledge and experience.

 

[TRCsmith]

Keep it on the straight and narrow here.  This is about a technical issue that could be improved to enhance pilot decision making.

It's a technical issue where you are concern, not where the manual is concern. A lot of us built and wired our planes using the same level of english in the manuals. We are all not avionics experts so if confusion arises we seek out help.
The decision was made to save a few dollars on switches but you ended up spending a few more, welcome to building. Ground testing is the way we look for problems before any flight. A lot of ground testing. You replaced some bad switches yet you didn't blame the manufacture. Someone wants to put blame on Dynon because they say the manual wasn't clear. What is clear? After re-reading or getting clarification often it's quite clear. Yes occasionally clarification is added and needed, but in this case I don't think so, but that's me
It's the test pilots responsibility to follow the checklist prior to that first flight. If something is not working the flight is a no go. Checking charging voltage is like the first thing to check after battery switch is turned on (in mine). A cheep product or failure to follow written instructions in an aircraft is an incident waiting to happen, weather it turns into an accident is another story. I hope the pilot is question is listening, because we don't need any crashes in the homebuilt community. Get it right the first time........ Just my 3 cents...
Fly safe...