D12-5 Explosion on Take Off

[Squatchy]

We had a great weekend of launching- couldn't have asked for better weather. Everything was going smoothly until we launched my Quest Grunt on an Estes D12-5. Then THIS happened.



I'm glad I was able to catch that with my camera! Tore the engine mount up, burnt the shock cord, and blew holes in my nose cone. When we started checking things out we noticed the engine casing was totally empty. It was quite the sight, but stinks that it blew up my rocket.




On a side note, we also found a D12-5 where the exhaust nozzle wasn't big enough and we couldn't put an igniter in it.

 

[RWmarlow]

Sounds like it's time to file a M.E.S.S report with the NAR and An Email to Estes.....Quest is a Quandry....it IS a Mfg. Rec. Motor

 

[Salvage-1]

That is an awesome photograph

 

[FequalsMA]

I had a D12-0 Cato just above the launch rod in a Flis Kits Nomad 3-stage years ago. Spectacular. The booster was violently slammed back down on the launch pad but the Cato still lit the second stage going up vertical. The sustainer lit and recovery was nominal. It's pretty unusual for a Cato to result in a successful flight!

 

[Barracuda]

Sorry for the loss but sweet smoke trail

 

[pick1e]

That is a major bummer but sweet photo! This happened to me with an E9 in my Vagabond this spring. I contacted Estes and they replaced the rocket and some motors. I would definitely get ahold of them and let them know about this, they're very cool about it.

 

[Squatchy]

I did contact Estes but so far have heard nothing from them. Never heard from them when we contacted them about parachute lines getting ripped out on two different pro series rockets during their first flights either though.

At least I got a pretty neat photo out of it!

 

[DAllen]

Was this motor ever subjected to freeze/thaw cycles?

 

[blackbrandt]

Sorry for the loss.
But that is one of the sweetest photographs I have ever seen!
Thought about submitting it for the TRF calendar?

 

[Squatchy]

Was this motor ever subjected to freeze/thaw cycles?

No, not while we have had it anyway- it has been stored in our house since we bought it last month.

But that is one of the sweetest photographs I have ever seen!
Thought about submitting it for the TRF calendar?

Lol, no, but we are pretty new to the forum so I didn't even know there was a calendar.

 

[blackbrandt]

Here is the link.

 

[Squatchy]

Here is the link.

Thanks! I submitted it.

 

[JRL303]

I've never heard back from Estes. Lousy customer service in my opinion.

 

[luke strawwalker]

Sweet photo... Explosion on Take Off... EATO... I like it... should keep certain folks here on the forum from having a coronary...

Sorry about your rocket... As far as Estes customer service is concerned, well, I've heard this sort of thing before... I don't know who all actually handles customer service issues at Estes, but basically the person you want to talk to is CHRISTINE. I've heard of quite a few stories of folks having their customer service issues slipping through the cracks, but if you talk to Christine, you'll be all set.

Good luck! OL JR

 

[JumpJet]

I sent a private email message to both Squatchy and JRL303 asking for contact information for Estes Customer Service department but since my sent message box contains no such messages as a confirmation that they were sent I thought i would post this message asking them to send me a private message with contact information to take care of their Customer Service Requests.

John Boren
Estes R&D

 

[shreadvector]

freeze thaw cycles do nothing to D12 motors. High temperature followed by firing them at 75F lower temperature than the peak temp they reached will cause problems.

Was this motor ever subjected to freeze/thaw cycles?

 

[Squatchy]

I sent a private email message to both Squatchy and JRL303 asking for contact information for Estes Customer Service department but since my sent message box contains no such messages as a confirmation that they were sent I thought i would post this message asking them to send me a private message with contact information to take care of their Customer Service Requests.

Thank you John, I have responded to your message.

 

[JRL303]

I've sent a private message response too, John.

 

[boomtube]

I’d venture a guess and say that the motor had been subjected to a violent shock, jarring or blow.

This could have shattered much of the black powder casting, making the motor in effect a mini pipe-bomb.

 

[skybuster]

Sorry about that, but that's an awesome photo. I'd contact Estes as well, I read that they have good QC on their engines to have a realy low failure rate. Their coustomer service is great, they'll probably replace your rocket since they all have a warranty, and maybe they'll throw in some engines

 

[Squatchy]

I did hear from Estes today, thank you John. They will be shipping out a new rocket for me tomorrow!

 

[JRL303]

Good to hear you got a response.

 

[shreadvector]

No. Testing has proven that jarring will not cause this and 'shock' is not defined. A sharp blow with a hammer will crack a grain (which is not "cast") and lead to a failure, but that failure is usually a split casing. Not always, but 'usually'. A manufacturing defect can also leave a 'void' but for black powder motors the most common way to get a crack or void-like feature is for a foregin object to get into the propellant when it is being rammed into the casing. Often this is a bit of cardboard from the inside edge of the casing that gets torn off and rammed in.

The photos provided indicate a propellant grain blow through with nozzle blow out. The casing is intact. This is a failure of the propellant to casing mechanical bond (the bond is created by the pressure of loading the powder and pressing it into the cardboard casing). Flame propagates up the sides of the propellant grain and the resulting overpressure blows out the nozzle and the propellant/delay grain (with ejection charge). In the case of a void or crack, you can get a similar overpressure, but the intact propellant to casing bond allows the pressure to build quite a bit hihger - until something fails such as the casing itself or, if the casing is strong, the nozzle and grain will finally blow out very, very violently. The large roman candle looking fireball coming out the top is the main propellant grain with delay on top. Flaming bits coming out the bottom and that hit the deflector and flew in several directions on the ground are more unusual, as the nozzle usually is the only thing that blows out the bottom and hits the deflector. This is the main bit of evidence that perhaps part of the propellant grain did indeed have a crack in it and that portion blew out the back (taking the nozzle with it) and blasted into bits when it hit the deflector.

I’d venture a guess and say that the motor had been subjected to a violent shock, jarring or blow.

This could have shattered much of the black powder casting, making the motor in effect a mini pipe-bomb.

 

[cerving]

OK, you win hands-down for the coolest looking BP CATO I've seen. The fiery streamers coming out the side are a nice touch. The only better one I've seen was a L2 CATO (I think it was cert attempt, too) in which the forward closure let loose and the whole thing burned to the ground on the pad. It warped the rail.

I had an E12 go Roman Candle on me earlier this year, I got two Estes kits out of it since I didn't want the D12's (they don't ship E12's in the mail so they'll either give you two packs of D12's or a $30 rocket). Despite some of the rumblings that I've heard about Estes' customer service, they were very quick and efficient.

 

[JPVegh]

Yep, that's a sick motor alright, spewing from both ends.

 

[Getmore]

I had a E-9 do that last month it was a home made rocket so I didn't persue to get anything replaced. It was a cool rocket looked like a nike smoke and it happend on the first flight.

 

[hornet driver]

Sweet photo... Explosion on Take Off... EATO... I like it... should keep certain folks here on the forum from having a coronary...

Sorry about your rocket... As far as Estes customer service is concerned, well, I've heard this sort of thing before... I don't know who all actually handles customer service issues at Estes, but basically the person you want to talk to is CHRISTINE. I've heard of quite a few stories of folks having their customer service issues slipping through the cracks, but if you talk to Christine, you'll be all set.

Good luck! OL JR

EATO--I like it---but it's explosion at take off---still, I think we should use it---until someone says "I had and EATO at take off"---now it sounds like a snack chip---anyway -----sorry Squatchy for your loss, but hey, it's part of our hobby. If your like most of us you'll just build again --that really pisses off the rocket gods---H

 

[GDJ]

PatH and I have had CATO's on old Canaroc engines and one Estes E9, but hearing about a D12 is fairly rare in my experience. Usually those never mess up.

 

[MasonH]

Sorry to hear about this, but good reflexes with the camera!!

 

[SteveA]

That is an awesome photograph

Agreed! Sucks about the rocket though.