My first CATO

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rockets

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Well, this was one of the saddest moments in my rocket flying days.
I went to fly my first HPR rocket. It was a Binder Design Bat flying on a H115DM motor.
And, right on the pad, the rocket motor CATO'd.
I have to say, that is very hard to watch $120 burn right there on the pad..

I have filled out the MESS report, and will contact AT soon.

[video=youtube;IiMMyac-_nA]https://www.youtube.com/watch?v=IiMMyac-_nA&list=PLn_c2scXZwnCabgqFTeXU565ikzTmM_Fs&index=1&t=0s[/video]

More info on this later.


Thanks,
 
Sorry to hear little man! How old was the motor? AT had an advisory bulletin about those motors regarding the thrust ring.
 
Sorry about your rocket. My DMS H219T-14's got 11/07/17 in ink written on the data label. Is that still good?
 
Did not appear to be a thrust ring failure, more likely a forward or aft closure, hard to tell much from the video ( at least on a phone screen).
 
Sorry about your rocket. My DMS H219T-14's got 11/07/17 in ink written on the data label. Is that still good?

All I could get off the burnt label on the motor casing was 1??307. The two digits I just couldn't get off the label.


Thanks,
 
Sorry about your rocket. Glad you filled out a Mess report

I would recommend to all flyers that they keep a log of all motors flown. This should include manufacturer, motor name, vendor, and any lot numbers in the motor. This will help track down issues when you fill out mess reports.


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Sorry to hear that Andrew..


But, if it makes you feel any better.. "Welcome to the club"!


I hope you were able to save a few pieces, so you can rebuild her! turn that Bat into a Phoenix!

(The mythical bird who rises from the ashes, not an AIM-54! :D )
 
Yeah, not sure how much I can salvage from it. The nose cone seems to be the only thing that's reusable.
BD_BAT.png




Thanks,
 
Still an L0 club, crack a bottle of coke and think how you can pick up the pieces then make the next flight better, faster, or cheaper. Kid, you've done more at 14 than I ever did then. You understand high power rockets and you just learned about a motor manufacture defect that caused a structural failure of a casing under very high pressure at aft closure which then in a engineering FMEA chart transferred to a failure of a higher order system of airframe failure by fire of fuel grain. Casing likely failed at defect from tooling marks or epoxy bonding or fuel grain defect.

Any rocket launch you can walk away from is a great one, anything reuseable is a better one, and anything successful is a miracle.

You know what engineering is? It's solving problems with math and with inventing/building stuff too.
My first hpr scratch multistage rocket for competition was in pieces too after launch. Crap happens. I designed a new rocket the next day. We flew the next rocket and got nationals. At least you can say your build skills weren't bad, blame the motor!
 
Sorry for you loss man. My first gut feeling is a clogged nozzle. Looks like it popped right when the motor came up to pressure. Do you have photos of the case? Is it split?


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Was the motor temperature cold before insertion? The reason I ask is I've never seen the inside of a DMS, but I suspect there's a rubber o-ring around the nozzle at aft closure. And that o-ring is non user serviceable in a single use casing. And O-rings hate cold temperature. It might not have sealed right and blew the entire aft closure out. But hey I'm not Aerotech... I think a nozzle clog would rupture the sidewall of casing instead.
 
Pretty unusual for that motor, I've flown plenty of the H115's as have most of my buddies. It's a great little motor for those late-day flights... just shove it in and fly.
 
The LCO mentions ground fire before the flight, and sure enough, there is fire. Weird.

Your sigh at the end of the audio says it all. Sorry, dude.

Single use motors are probably the best option for your age and income level, but as you move up in the hobby, reloads will be the better and more reliable choice. I tend to stay away from Aerotech single use, Econojet, Economax, LMS, DMS, PMS, ABC, XYZ, RIP motors. A motor I built myself never failed me.
 
Sorry to see this Andrew. Hopefully you will be able to build a new rocket soon and overcome this and be a Jr Lvl 1.
 
Sorry for you loss man. My first gut feeling is a clogged nozzle. Looks like it popped right when the motor came up to pressure. Do you have photos of the case? Is it split?


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The aft closure part of the motor is blown off. The nozzle looks like it's kinda chipped. Pics coming soon.
Was the motor temperature cold before insertion? The reason I ask is I've never seen the inside of a DMS, but I suspect there's a rubber o-ring around the nozzle at aft closure. And that o-ring is non user serviceable in a single use casing. And O-rings hate cold temperature. It might not have sealed right and blew the entire aft closure out. But hey I'm not Aerotech... I think a nozzle clog would rupture the sidewall of casing instead.
The motor temperature was normal. The outside temps were in the low 40's.
The LCO mentions ground fire before the flight, and sure enough, there is fire. Weird.

Your sigh at the end of the audio says it all. Sorry, dude.

Single use motors are probably the best option for your age and income level, but as you move up in the hobby, reloads will be the better and more reliable choice. I tend to stay away from Aerotech single use, Econojet, Economax, LMS, DMS, PMS, ABC, XYZ, RIP motors. A motor I built myself never failed me.
The fire crew was ready to go because it was a skidmark motor, and it could start a fire.



Thanks,
 
Found this tip from the Wildman Wild Thang Jr vs Scarab 54 thread... Their motor in question was a H123W.

Sorry about your WildThang issue.
FYI:

I have seen this type of motor burn [road-flare] many, many times over the years. In every instance I witnessed, it was caused by not inserting the starter/igniter all the way to top of motor. Sometimes the wire will catch in joint between the grains, making flier "think" he hit the top.

Motor grains starts burning down low, not developing enough pressure to lift rocket, it sits on pad burning like a road flare.

The only reason I re-posted it is it startled me this kind of failure could occur of any rocket motor.
 
With the YMDDMY scheme, the only way the second M would be a 0 is if it was 10, so seems like 10/2017 to me, just not sure of the day. But yeah, doesn't seem like thrust ring since as I understand it the result would generally be the motor shooting through the top part of the rocket. I've seen the FG cases fail at the top, guess it could happen at the bottom also, though I would wonder about the ignitor being all the way up. And with a recent build date I'd have hoped their vendor is paying attention to the FG wind angle on all cases now (the more common failure with older DMS case separations). A good picture of the case would probably show what the wind angle was.
 
yea. That sucks. forward took off and everything else is from the road flare.

You took it better than a lot of grown men have.
 
I have just gotten word from Aero-Tech that they'll be replacing the motor & giving me a Aerotech Arreauxbee Hi rocket kit! :)



Thanks,
 
Glad to hear they are making it right, and even sweetening the pot for you Andrew. Enjoy :)
 
I was LCO on that particular flight and it pains me to see this, especially to Andrew. It does happen and will happen to all of us if we launch long enough. Kudos to AT for their replacement plan!
 
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