Sky High

Fatal Crash Images

The following is the story of the fatal stadium crash and below are the images of the aftermath. The related post below shows recent pictures of the stadium that I flew over again a few days ago with a very successful flight.

One week before Thanksgiving, I was flying over our local basball stadium just fine but that day ended terribly. [sm=disappointed.gif] The night before, I had just used my last 2 rotors to be able to stay in the air. I had taken alot of time to repair those rotors. The next day at the stadium, I was flying out over the center about 200 ft high and was ready to bring it back for a battery change. Well, I heard the infamous frame strikes made by the rotors and shortly after my helo did a nose dive straight to the ground and disappeared behind the concession stand. There was nothing I could do to save it. I just knew that was the end considering the height that it had fallen from. [sm=disappointed.gif][X(] I had to scale the fence to retrieve it, shhh don't tell anyone, and what I found was as bad as I thought it was. It was just terrible. There was a trail of shredded rotors, it severed all landing struts from the from the motor arms down, knocked off the canopy, stripped one battery lead right out of the connector, seperated the glue from the velcro fabric on the battery tray from the impact, broke two frame stiffeners & elbow joints, two motor arms, one motor mount, 3 rotors were destroyed with the rear untouched. The board and camera were both undamaged! It had come to rest in the grass just 3 ft from a concrete slab at the concession area. [sm=eek.gif] Can you imagine what the damage would have been like if it had plowed into the concrete? [:'(] When I finally got my new rotors, I had rebuilt the helo by then and it flew like nothing ever happened, unbelievable folks! This happened before I finally laminated my rotors. That was the LAST time I was going to crash because of frame strikes and shredding rotors in midflight. Many strikes since then but no chips or breaks and most importantly no fatal crashes! I should be getting my report from the NTSB soon.

Relative Post
www.rcuniverse.com/forum/fb.asp?m=3676519

Sky High

Doesn't anyone else have pictures of their DF disasters?

tana

Hi, New here and happy to see a forum for DF flyers. BTW thanks Sky found all your info very helpfull.

No pics but a funny story. I have a DFIII and I'll tell you 1 thing not to do is try to fly with a low radio battery. Well guess what I did After hovering at 6' for about 30 seconds it goes sideways and down right into 1 of my wifes flower gardens. What seemed like forever but was only about 15 seconds the DF's rotors sounding like a weed wacker was chopping and throwing flower parts 3 ft in the air, left ,right and up. It took my wife a couple of days to notice and I blamed it on a squirrel!

av8ersteve

My Feedback: (1)

Well, I crashed last night. I was up pretty high testing out my lights and all of a sudden, I lost control of her. It was like I had gotten out of range because it just stopped responding to my control inputs (controller battery indicater was at 85%). I have all ready ordered the parts to fix it and all in all, not to bad. Only costed $25.00 for the parts I need to fix her. Could have been alot worse. I found it about half a mile from where I was flying. Laying in a ditch about 4 feet from the pavement. Boy I sure am glad it didn't hit that pavement!

Sky High

1/2 a mile?! [X(] Did it drift that far or are you just being funny meaning it was a loooooong way off? I know the feeling when that happens except mine came to rest in the top of a [link=http://www.rcuniverse.com/forum/fb.asp?m=3746138]60 ft tree[/link]. [:@] [&o] Were you using Ti and if so was it cloudy? Clouds will make Ti quirky and control will be latent.

Besides a frame stiffener and the rotor, what else was damaged? I couldn't really tell from the images. I have used wooden skewers from Wal-Mart for temporary frame stiffeners until my real ones came in. They are the perfect diameter but you will have to cut it to length and may have to search through the pack to find a perfectly straight one. Then, you'll need to stiffen it with packing tape by just laying one long piece out and simply rolling the skewer in the tape.

av8ersteve

My Feedback: (1)

It was a good half mile away. It was kind of windy on the ground and I found out that the winds aloft was alot stronger. The wind grabbed her and took her. I couldn't find it last night (10:38 pm was the official time she went down) so I waited till sun up to go looking again (very long night). My wife works third shift and to my surprise, when I woke this morning at 6:00, I got dressed and ready to go looking, my wife came home a little after 7 carrying it in her hand. Seems she went looking for it after she got off work (she does care). The only thing I broke was one motor mount, two frame stiffeners, two props, and the frame center cross piece. It was a perfect cloudless night with temp around 40 degrees but it was a little windy (around 10 knots). I was using Ti, and it seemed to land pretty level, just hard.

Sky High

Yeah, that wind can be deceptively light on the ground where you are standing but when you get above the treeline it can hit that little DF like an arctic blast! When in town I look at flags flying to see the wind strength and when out in in the woods I try to look at the tree tops. But that's not always accurate like when those surprise gusts come out of nowhere. I would definitely put a reward if found decal with your contact info on that battery plate. That way if someone else finds it you can get your $800 investment back and they will know who to sue for you knocking out their car window.

You definitely must have landed hard if you broke the frame hub. [:'(] The worst thing about that, rotor arms and motor mounts is having to resolder the motor connections. [:@]

av8ersteve

My Feedback: (1)

Yep, soldering iron is heating up right now. Got to take her apart and get ready for new parts.

Sky High

Well, I just finished my investigation and have two theories as to why I crashed last night. I had flown this helo for four months doing all kinds of risky maneuvers at both low and high altitudes without incident. All this time, I had knowingly been flying with a motor mount that was glued together from a previous modest crash even further in the past and gotten away with it. Last night was just like any other except I added some new light sticks that I had just bought. They are very light weight and easy to use. They collectively weigh as much if not less than the new camera system so I know it wasn't too heavy. I had 3 perfect flights at low and high altitudes but the fourth was to be a disaster. I was simply hovering at around 30 ft when all of the sudden the helo started losing its hover and oscillating uncontrollably and would not recover no matter what I did. Suddenly it just nose dived and plowed straight into the track below. [X(] The damage would not have been nearly as bad if it had gone down in the grass just 10 ft away! [:@] Anyway, it was horrific, just like the other [link=http://www.rcuniverse.com/forum/fb.asp?m=3680056]fatal crash[/link] months ago but not as high. The noise of it hitting just resonated in my head and then watching it splinter into many pieces completed the nausea. I walked over for a closer look and just couldn't believe the amount of damage from such a short fall. What made it worse was I didn't even know why it had happened. After collecting all of the pieces I have two theories as to why this happened. One is that the added weight of those light sticks was just enough to change the flight characteristics and I overworked the motors and the other is that the lights' added weight put more stress on that glued mount than it could tolerate. I did smell something like burned plastic at the site and didn't know what it was. When I finally got home under some light, I discovered a burned up and severed capacitor on the the severed motor, the same motor that was in that glued mount. That's doesn't necessarily mean anything but is interesting. Strangely enough, the fuse did not blow! I must have cut the power just before the impact. I still can't figure out why that capacitor burned up though. Maybe it acted as the fuse since the fuse did not blow but the capacitor is just for one motor. So, I don't know if it was a motor/capacitor failure or if that motor mount came unglued and allowed the motor to oscillate therefore allowing the rotor to violently thrash around hitting the frame and bring it down. If the motors get too hot or overworked, could that have burned up the capacitor? I'm thinking it was the motor mount and therefore my damn fault for not changing it out. My circuit board was bent AGAIN! [:@] The vertical board and the Ti board were both independently slightly bent. I have carefully bent them back and am hoping it isn't shot. But, that damn CMOS video camera survived untouched AGAIN! Other than all this, I'd say I walked away pretty lucky.

Damage Report: (more images in post #10)

1 laminated rotor
2 landing struts
2 elbows
1 motor mount
1 main rotor gear
1 decapitated nylon bolt (my first one!)
1 severed motor with burnt capacitor and bent pinion shaft
Detached canopy with 2 ripped mounting holes
Bent vertical cuircuit board 1-2 degrees right and bent Ti board slightly off horizontal
Decapitated power switch (just knocked that sucker clean off)


Discussion Thread
www.rcuniverse.com/forum/fb.asp?m=4097060

Sky High

More images

techrtr

I had a pretty good crash this weekend from about 25 or 30 feet. It was near the end of the flight and I knew that the battery must be getting pretty low. A flock of Canada Geese were approaching at about 50 feet and I couldn't resist going up to try to fly along side them (against my better judgement). Anyhow, the DF climbed all right to the height of the geese and they scattered. As I started to come in for a landing, all of a sudden at about 25 feet the rotors stopped completely. I guess I pushed the battery life a bit too far. The DF come straight down and hit the ground pretty much flat. Fortunately, I was flying over a soccer field and not a parking lot. Anyhow, there was no damage which surprised the heck out of me. Put another battery in and made another flight.

I've crashed onto pavement from lower heights (12 to 15 feet) and have broken arms, gears, and motor mounts. DFs don't look that robust, but they do take an impact pretty well. I added a frame bracing kit and found that it does make a difference.

Fesfly

Yup seen it...I would post my own pics but these pics look like all my crashes. Although - I have one where I lost power at about 50 feet and it was coming down fast and hard, only to be saved by a clothes line, NO damage. I agree with others who say there should be a better way to deal with the motors (it is a pain to solder each time to remove!).

off topic: When I first purchased my DF, I asked about brushless motors and they stated that would be an option in the near future.

Sky High

techtr, I have done the same thing with a flock of small birds. I have also had birds dive bomb my helo when I was too close to the nest. If you haven't seen it, check out my [link=http://www.rcuniverse.com/forum/fb.asp?m=3675858]100 ft freefall DF POV video[/link]. As you will see, it landed perfectly horizontal too with no apparent damage. However, it did pull the battery terminal solder joint loose and cause two subsquent crashes. [:@]

Festus, let's see those crash pictures!

Fesfly

I aim to please, so much so that here is a pic of a crash I had tonight (just for you SKYHIGH[]). I was taking video with the canon camera and for no reason the df power cut out 3 times as I was trying to bring it down. I will post a link to the video where you can hear the motors lose power then witness the motor hanging after the crash. The video is not good as the camera is out of focus and I need to resolve the vibration issue. Well this time I damaged the camera but it still works - I think it can be fixed without too much fuss.


Damage: broken motor mount and CF rod estimated $10 us - bent camera lense $ unknown - waiting for the soldering iron to heat up....priceless

Fesfly

Here is a link to the video http://vssi.ca/dfvideo/ - the video is called crash101.avi - warning its 70Mb. You need to right click and choose save target as to save it (or it will take forever to get it 70 MB!).

Again, please excuse the poor video quality, bad focus, a sh!!y flying.

Clear skies and look out below.

Sky High

Bahahaha! LMAO!

Sky High

festus, those flights had to be without Ti, weren't they? If so that was not bad at all, especially at those heights and with that big ass camera on board.

Fesfly

Ti was on for that one - only one green light when I activated it. I only ever get one green light, the Ti sensors seem to be working, although a bit bent, when I wave my hand in front of them I get both greens. It is always a rough take off because of the trim setting but once in the air a couple of feet it levels off nicely - it seems to fly best when it is above 25 feet or so. Even with Ti on, any course corrections causes enough battery drain to cause the DF to drop a couple of feet then when you compensate it just takes off, up, up and away.

I have decided to end the camera flights - conclusion: it actually works even with a 4oz payload, vibration issues, stability issues need to be resolved. Vibration issue will require added weight such as rubber gromits(spelling?) which will cause even more stability issues. I find the DF to be a joy to fly when it is light as possible - it even makes a difference to remove the plastic dome - although not recommeded as the upside down landings do occur on occasion. I am considering an XPro in the near future but am going to wait until next spring, I have a feeling a new df model will be coming out shortly with brushless motors. Then the camera will fly again....thats if I can fix the lense...

techrtr

I had another nasty crash last night. Went up to about 20 feet, got completely out of control, then slammed into the ground on an angle with a sickening thud. Thought "now that was weird considering I just had a perfectly normal flight." Then it occured to me that I might have turned off the TI switch on the transmitter. Sure enough, I had turned it off for some low level hover practice and forgot to turn it back on. I'm not very good at flying without TI. Sometimes when I have lots of altitude I'll turn it off and fly without for awhile. I find the DF very skittish, however and it's really easy to overcorrect and get out of control when TI is off. I was close enough to the ground that I couldn't recover and in she went. Reminder to self, make sure the TI switch on the transmitter is on before flying (if your intention is to fly with TI). Damage: broken arm and frame bracing corner piece. I'm getting really good at soldering though.

Often when I fly with TI, it's almost impossible to get the trims set properly. My DF wants to fly backwards so I have to counter with forward stick. Other times, it will hover just fine without messing with the trim. Would this be cause by setting self levelling on a less than perfectly level surface?

Sky High

Well, the reason you had one LED is because of those trees in the back yard. That area is too confined for good Ti. I had that happen in an area 100 yards in every direction but it was encircled by trees. I guess they trapped a certain temperature in that circle which confuses Ti's calibration. It will fly better once you clear the tree tops but you will have to adjust the trims again once up there because it was calibrated at ground level.

Fesfly

I think you're right, once I got above the trees the DF flew well.

TheHindmost

Here's a link to an old on-board crash video from my first camera flight back in March...I posted it on putfile.com back then, but it has expired there, so I put it up on YouTube:

[link=http://www.youtube.com/watch?v=xpOTAqvb5XQ]DF Crash[/link]

Amazingly, the username "Draganflyer" was available at YouTube (and TheHindmost wasn't!).

Also, here's the [link=http://www.rcuniverse.com/forum/m_4047709/anchors_4047709/mpage_1/key_/anchor/tm.htm#4047709]old thread[/link] where the crash itself is described...

Will

13BRV3

Hi Will,

Great choice of music, and I loved the on-screen commentary

It'remarkable how tough these are compared to the old Roswell Flyer I used to have.

Cheers,
Rusty (DF V ti and spares on the way)

(Edited to remove the question about what caused the crash, since I went back and read the original thread.)

TheHindmost

Glad you liked it, Rusty! I had to make some fun of myself after that. I'm a much better pilot now, with just a little more experience (I didn't fly my DF for months while recovering from a shoulder injury and some inertia after my initial poor showing, but am now back into it).

I'll look forward to hearing about your experiences with the DF!

Will

13BRV3

This is probably the thread I'll be posting my "experiences" in [sm=biggrin.gif]

Cheers,
Rusty (dang Benny Hill tune is stuck in my brain)