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Author Topic: A loss, with a dramatic ending!  (Read 231 times)

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Offline Deerslayer

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A loss, with a dramatic ending!
« on: July 10, 2018, 11:41:13 AM »
"My purpose in Life is to serve as a warning to others".

Well, here is a little story which may actually have some benefit to someone else that is mucking around with FPV and perhaps other forms of RC flying.

This past Saturday, I lost my Penguin FPV plane.  :o  :'(  :'(  :'( Very disappointing, to say the least, as we watched (or more correctly, DIDN'T watch) about $800 disappear. As well as that loss, a sense of fear sets in - what if it comes down and hurts someone or causes some kind of accident due to some driver(s) becoming distracted?

In the aftermath of this loss, I did a lot of thinking and wrote down my analysis. I have now decided to share it with whoever may care to read.

Oh, by the way, a strange thing happened later that same day! ;D  ;D  ;D  ;D

 After I had left the field, a farmer named Kyle (did not leave his full name, unfortunately) showed up with my FPV plane in his possession. One of the fellows now has it and we will be reunited. I wish I knew how to locate the finder as I would like to offer some sort of reward. As well, I am curious as to just where the plane went down. All we know is that he was out working in a field and saw it land. Apparently, it was in a location where it would probably never have been observed, had he not happened to be nearby! It's a Festivus Miracle (a few months early, but I'll take it anyway).

My analysis has caused me to rethink a lot of things that I have done, or failed to do, and will now apply to this and other FPV (and soaring) flights from now on.




I made a  number of mistakes. The bottom line was - Complacency! Things had been going too smoothly for us and I lost my "edge". Perhaps that edge is a bit duller that I would like to think?

1. My Vector controller has been flaky w.r.t. retaining its GPS-based Home position. I could not figure out why. Again yesterday, after I powered up, it found the satellites and set its Home. Great. Then, just before launch, it reported that it had lost that lock. I should have stopped right then and got it reset - open up the plane, recycle power, etc., bit of a pain. Instead, I flew, knowing that RTH was not likely to work. Besides, I was only going to be flying close to home and with an experienced spotter. What could go wrong?

2. I have not been testing RTH recently, even if the Home fix was believed to be OK, as I had been keeping fairly close to the field. For FPV, this should really be tested EVERY flight. Similarly for the Loiter mode on the Vector. This would also make it more likely that, in a panic situation, I would think to use one or both of these modes. That is why you practice emergency actions in fullsize aircraft, even as simply touching any control or item which may suddenly become very important to activate.  I did eventually try Loiter, after the plane had disappeared but far too late. I never even considered RTH, even though it MIGHT have worked - I will never know.

3. The Vector is quite complex and I have been learning/trying various features over time - a rather slow learner here! I never did set up Failsafe such that it invokes RTH. There are different approaches to setting this up, and I could not decide upon the best strategy. In fact, I just figured out how to do it. I even had my little procedure in my book of field notes and was thinking of testing it yesterday . But, I got enthusiastic and Dumb! The downside of having such a capable and complex system is that you can easily lose track of the fundamentals.

4. I lost Situational Awareness during a great flight. I realized too late that I was flying too high to expect you to keep the plane in constant sight. A couple of times, my spotter mentioned having difficulty in locating it, mostly due to sun glare, but I got preoccupied with the video getting fuzzy and I locked into that problem. Note: the 5.8 GHz video link has MUCH shorter range than our 2.4 GHz control link. I lost track of where I was, becoming further distracted by the video issue while circling to try to locate familiar landmarks. We got concerned about being too far out, downwind and possibly too low. I was trying to fly back home, as I knew the general sector in which I was flying. I did not realize that I was probably in a strong thermal. the Vector was reporting about 1000 feet AGL, which would still have been well below cloudbase but near the limit of visual location. Cloudbase was likely at 3000 feet AGL or higher, but condensation can begin to form much lower, further obscuring things, especially as we get drifted downwind.

5. I completely lost video and my spotter lost direct visual contact at about the same time. I delayed much too long in giving up on the video, hoping it would return and perhaps I could figure out where I was. When I finally gave up, it was obvious that neither of us would be able to acquire the plane again. Game over!

6. As expected, yesterday was good and improving throughout the day. I had earlier done some RC soaring with my Heron sailplane. The ground wind switched to SW, which fooled me, as in my full scale days at Gan airport this has always meant the thermals get killed due to the lake effect wind. This does not really occur, or not as much, out at our field. I never really considered the possibility of encountering strong thermals at the start of my flight, as the wind had switched from NW to S quite awhile ealier.

7. When I finally dumped the goggles, I assumed that the plane might still be receiving commands, despite possibly having gotten near or into cloud. Note: Our 2.4 GHz stregth is greatly attenuated by moisture. I did briefly set the Vector into Loiter mode, hoping that we might get some glimpse. I never even considered trying RTH. Why? Lapse of thinking, perhaps, or figuring that it wouldn't work properly anyway. Worry about the plane coming down and possibly hitting someone or something weighed heavily on my mind. I had much earlier commanded the motor to disarm. I had gone through the motions of forcing it to spin. (I have done that in a full scale sailplane after having entered cloud in extremely strong lift. Initiate a spin, wait until you fall out of the cloud and then do the recovery.)

8. Identification. I never did get around to putting my name and telephone # somewhere on the plane. Inside is probably not the best place, at least for this plane, as someone might not think to look for it.


Well, that is about all I can think of now!!!!
« Last Edit: July 10, 2018, 12:45:29 PM by Deerslayer »
My purpose in Life is to serve as a Warning to others

Offline Deerslayer

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Re: A loss, with a dramatic ending!
« Reply #1 on: July 12, 2018, 05:56:24 AM »
Well, Mark handed my wayward birdie over to me yesterday. Thank you, Sir!

I am trying to locate the fellow who found and returned it, to thank him and to see where the plane landed. He is a farmer, perhaps 30 to 40, first name is Kyle and may live near Yarker. Any ideas who this may be?


Apart from a couple of very minor bruises, easily steamed out, it is in perfect condition. Even the paralleled LiPos were still good, at about 3.7 volts per cell. Obviously, the failsafe shut down the motor and/or the low voltage setting in the Vector cut power to the servos. Since the plane was returned within a couple of hours of its loss and Mark immediately unplugged the batteries, all is good.

Had I been desperate (and foolish) enough, we could have popped in a fresh battery and done a flight right then.

Now, I will do a thorough inspection and testing of everything, on the bench. Plus, review the above root cause analysis and  come up with a better plan for future use.

As one of my favorite TV people, Jim Jeffries, says,
"We can all do better".
My purpose in Life is to serve as a Warning to others

Offline Deerslayer

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Re: A loss, with a dramatic ending!
« Reply #2 on: July 12, 2018, 12:37:24 PM »
I have had a couple of Eagle Tree Guardians for many years. My Vector is just a couple of months old, although the product has been out for many years. ET has a great reputation, overall.

So, when I encountered this problem of the Vector "losing" its Home position, I finally got around to inserting a ticket into their support system. Within an hour or so, I got a response. I think this may clear up the mystery. The next time I get out flying, I will do some testing to find out.

The particular error I experienced is actually a "feature", I suppose! When you power up the system, it locates a suitable number of GPS satellites and records the location, Home. Now, if you simply move the plane more than 300 feet (according to the Error Message explanation) before applying power to the motor, it will decide not to use the Home position just established.
I assume this is some sort of safety feature.

This could explain why my system has had this loss occasionally, but not always, as sometimes I have been where it was suitable to power up the system and then only move the plane a few feet before taxiing. A couple of simple tests will show.

Assuming this is the answer, it looks like ET could/should change their manual to reflect a much shorter than 300 feet distance.

There is still a lot to learn!

(Latest struggle: Set up DX9 Sequencers so that one push of a momentary switch, such as I, CLEAR or BACK will toggle a channel - for Vector's Mode - 10 times within 2 seconds. There actually is a solid reason for wanting to do this!)


My purpose in Life is to serve as a Warning to others