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Old Apr 15, 2012, 12:57 PM
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Maple Valley, WA
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Originally Posted by sanman55 View Post
Did you give up on the bungie launch??
Yes, for this bird. It's too unstable at the point of launch (no matter the method assuming you are minus gear) but the bungie will work great for other EDFs.

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Originally Posted by sanman55 View Post
...still waiting to try mine with the stableization system...this might be the trick to recover before it gets into these situations?
I'm sure it couldn't hurt, that's for sure!

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Originally Posted by sanman55 View Post
It also seems that even with all that power it still gets into places that it will not recover...interesting.
It's one of the things that makes it so challenging. Even with a pretty robust 1,600 watts, she's still just as unstable at the point of launch as if I was running on the old stock setup. I was hoping all that power would get me out of any sticky hand toss but that's obviously not the case, lol.

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Originally Posted by sanman55 View Post
The video was great...I would have liked it without the music so I could hear the comments and the engine noise to tell when power was added..maybe a 2 parter{ one with and one without}...cause it was GREAT music.for the situation..I just like to hear whats going on and when power is applied and how much..It looked pretty windy by the sock???
Thanks for sharing....
Yes it was windy but worse it was a swirling wind with up drafts and down drafts so that certainly didn't help although I don't blame the wind for yesterday's "adventures". No real surprises on the noise. I am throttling to WOT right before I toss her. I dropped the throttle quickly on the bad hand toss from yesterday as soon as I saw her pitch up. It really saved the plane in that case.

Yesterday was also the first flat spin I've ever had with the SR-71. I've tipped stalled her but never a flat spin. I still can't believe it did that just from a dead stick but then again I was STILL a touch tail heavy. Today should be much better now that I have added another half-an-ounce in the nose. Now she balances perfectly.

I was looking at her last night in my garage and it's pretty sad knowing that it's just a matter of time before I gut out the electronics. This is one kick @ss looking jet both static and in the air but the air frame just isn't meant for every day RC flying. At least not in my 6 years worth of experience with her.
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Old Apr 15, 2012, 04:36 PM
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Thanks for the response...good info.....
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Old Apr 15, 2012, 04:45 PM
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Maple Valley, WA
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Today my SR-71 Blackbird died a spectacular death.

I brought her to the local school and decided to hand toss her and fly without the distractions of anyone around. Wind was moderate but not too bad. The first hand toss it flew smack down to the ground. I repaired the wing with some gorilla tape, checked the lateral stability (it was fine) and tried again.

No guts, no glory, right?

The second hand toss went without a problem (why do some hand tosses work great and others do not? I think I am pretty consistent with my technique), and off she went. The flight was going great but the wings were rocking pretty good even on low rates due to the crosswind that was picking up a little steam. Still, it was overall good flight conditions. As I took her past me for one final lap to setup for final, I was just banking to turn so I applied a little power and suddenly I heard this strange slipping sound, kind of like one of the motors or ESCs hiccuped or lost power just long enough to go into a vicious unrecoverable tip stall.

I have to tell you from my vantage point the crash was pretty spectacular. I was sure that there would be no pieces left larger than a baseball. Surprisingly the back end was somewhat intact. However, this officially ends my adventure with this air frame. My all-time favorite plane just happens to be the most unpredictable and unstable RC jet on the market.

I've posted the video below without music. I am interested to see if anyone can try to diagnose what they think occured at the fateful moment. So I didn't want music to get in the way. You can also hear what sounds like the motors were a bit out of synch from the start. Not sure if that in normal or an indicator for what was soon to come. I know nothing of electronics so maybe one of you may be able to point something out that I would never catch.

So I wanted to again thank those of you who chipped in to buy seventh and final air frame for me. I am still so touched by your generosity. I am officially retiring from the Maxjet and/or LX 64MM SR-71 Blackbird. Too much heartache and not enough reward. I will use the whole power setup and afterburnerz for a different EDF. One much more stable. Maybe a twin F/A-18 or the Banana Hobby A-10.

Thank you all for your insight, help, encouragement and support. I will definitely stop by now and then to see how other's are doing with her. Hopefully much better than I was ever able to manage.

Here's the video. I look forward to any comments, thoughts, theories...

Final Flight of my 64MM SR-71 Blackbird (3 min 23 sec)
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Old Apr 15, 2012, 04:53 PM
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Aros...sorry to see that happen, sir...RIP to your Habu...hopefully, you'll find something more rewarding to fly...
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Old Apr 15, 2012, 04:58 PM
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Thank you. Me too!
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Old Apr 15, 2012, 05:18 PM
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Originally Posted by Aros View Post
Today my SR-71 Blackbird died a spectacular death.
]



Let me know if I need to tend to the afterburnerz. Sorry to hear of the demise. The afterburnerz can be split up into two different single fan airplanes if you wish. All it needs is another controller and if you run 4s, a voltage module.
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Old Apr 15, 2012, 05:22 PM
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Thanks Joe! I'll let you know if I need to have the setup modified. Great product! Great support!
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Old Apr 15, 2012, 05:25 PM
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Dam, so sorry to hear about your loss there Aros, but I must say, it was a fun ride! So it wasn't a total loss. Had a lot of fun helping you with the videos, and I look forward to filming more of your flights. No matter what you get next (Crosses fingers hoping that he gets the A-10).
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Old Apr 15, 2012, 05:31 PM
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Sacramento CA
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I could detect no motor or esc issue with the the clip you provided. Your throttle setting tells all...the last low pass was at almost zero throttle, then a climb out without any increase in power and...power wasn't applied until it was too late.

Not criticizing, just my opinion to what the clip shows. Watch Ben's vids with the volume on and you'll see that the throttle is never less then 3/4's and never at 'coast', like in your clip. You'll see other posts by successful pilots warn about flying at low throttle settings...

Why is this plane so sensitive to throttle settings? Has to be the 25 ounces+ psf on the wing loading. This is the only model I've seen where no one talks about wing loading but, rather how many batt packs and monster motors and this and that- someone mentioned 90mm's for this bird!- every component was weighed on our model...we spent big bucks on the batts, they are 1/4 pound less than the same size cheapo's. The details we added to make it look better were carefully considered and rejected if too heavy. We needed a bit of weight on the tail for better CG, so the AB's from Joe were perfect.

After further review...your first few low passes were done by the book...full throttle before you even leveled out and stayed on the throttle through climb out. The last pass was at idle, then some throttle was added, a few clicks, barely above half anyway, doomed the climb out...remember, jets have a 'spool up' time, even though the motor is screaming, the lag time is critical with the wing loading we are flying.

Pick up an airframe now while they are under $60 bucks, stow it and later, with some heavy edf planes under your belt, you'll be glad you did.
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Old Apr 15, 2012, 07:55 PM
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Thank you for your valuable insight redlite. I agree with the throttle settings and I should not have lowered the throttle as much as I did. I know this bird requires constant speed and perhaps I was too liberal in my throttle management. However, I absolutely am convinced 100 percent that something else happened. I'm surprised you don't hear it on the video. That's not me touching the throttle at the end. I had enough air speed to keep her going in the turn but I heard a sound that sounded to me like a motor or ESC surging which immediately caused the SR-71 to roll. I think you raise excellent points about low throttle settings but something else occurred here. I will submit that a lower throttle setting didn't help the situation and made it unrecoverable but something else was the catalyst that started the chain of events. For that I am positive.

I appreciate your thoughts but this bird is just too touchy for my tastes. Thanks again.
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Old Apr 15, 2012, 08:43 PM
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I appreciate your thoughts but this bird is just too touchy for my tastes. Thanks again.
It can be tamed. It's all in the tuning. Well.... that and don't cut power until you are on the ground.
The airframe has alot of drag and slows down quickly when you cut power. I did hear the noise. To me it sounded like one of the ESCs was at the low throttle threshold and toggled between off and on. Did you happen to check that each esc was programmed identical and that they were programmed to the throttle range of the transmitter?


I second the motion for getting another airframe and stow it away. At some point, you will be glad you did. I will say the most reliable one was my pusher prop version. It's so much lighter and no chance of one fan cutting out and creating an adverse yaw event. It's just not the coolness factor of EDFs.
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Old Apr 15, 2012, 09:24 PM
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Thank you Joe, I was beginning to think I was nuts. I knew I heard something like a cutoff which immediately threw her into a deadly tip stall. My throttle was about 50% and I was getting ready to give her more throttle when the noise and event occurred. I don't want to minimize redlite's point however and that is that this bird needs constant power and doesn't have the wing surface to deal with slowing down.

I do believe I was in the acceptable throttle range when it happened. As far as the programming, no I did not check that Joe. That's something I didn't even think about since they were tested from Don.

If I do buy another airframe and stow it away, I'm not going to tell anybody. It's just too embarrassing at this point.

LOL!!
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Old Apr 15, 2012, 09:36 PM
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For those of you who dig this sort of thing...

Final Moments of my SR-71 Blackbird (Slo Mo) (0 min 30 sec)
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Old Apr 15, 2012, 10:46 PM
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Sorry it went down. Hopefully the electronics are still all OK. It almost sounded like one motor started to shut down like a LVC as it quit as you powered up. Each fan/motor wants to pull ~60 amps so ~120 total amps so it is possible on a 4S 4000 the voltage may have dipped a little to low and started to shut down one fan unit.
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Old Apr 15, 2012, 11:02 PM
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Don...good theory...I think Aros had the right parts and setup, though...
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