What did the liner look like before the flight? I remember one of the problems being a liner issue....
One other possibility: It could have also been a snap ring issue.
JD
Don't quite know what you mean..... liner looked like a typical new KBA liner. What issue are you referring to?
Snap rings were checked as usual, only the second time used and the sharp face was facing out on both ends, rounded in. They were firmly seated and double checked by a fellow flier as I always do.
BUT:
As I mentioned earlier the casing was clean, only the nozzle and snap ring remained. No charring the interior was shiny liked you just cleaned the case It was obviously near or at burn out, The only thing to come out was the full size smoke grain and front closure and liner. No lit grains or we would have seen green flames. Only white from the smoke grain could be seen.
There was no charring or burnt interior of the rocket. The case is well flared as can be seen in the photo as well as the 1 inch chunk that blew off right at the snap ring groove. It was a brand new nozzle and checked with a gauge to make double sure it was the correct size. The case had 16 or more flights on it and maybe it was just it's time. Really....how long do they last anyway?
I received a phone call from a propulsion expert [manufacturer] after he read my post and after a lengthy discussion & many questions, this plausible explanation could be the culprit.
Barium component in the L-2300 is very hydroscopic . This load was opened and loaded last April. I live in Savannah where humidity is EXTREME. Even though I wrapped the nozzle end in plastic and taped it to the case, apparently moisture can permeate. I have done this before, having loaded motors for over a year without any issues, but they were never green.
This then can cause the propellant to de-bond from the casting tube,causing an over pressurization due to more surface area burning.
Of course there may have been other factors. Really.....don't think we'll ever know FOR sure. It's a rocket motor and things can and do go wrong. I did check it before it flew and there were signs of grain sweating, so I left it open for 24 hrs before flying. Maybe not long enough.
One of the other 2 catos I'm aware of....... the load had also been left open for a lengthily period, but THIS was done by an AT representative and nothing was said about this going to be a problem. [Parts were needed and removed for whatever reason]
As I said before.....I'm not crying over spilt milk or upset in any way. We fly rockets and every now and then something bad will happen...just part of it.
Some of these new motors are on the edge and flying them is a risk we take. As far as I know this is the only L [680lbs of thrust at peak]for this case, so that tells you something right there. I chose to fly it, I took the risk, I suffered the consequences. So be it! Wouldn't have it any other way. I fly way more than the average rocketeer and the law of averages just caught up to me.
At least the rocket survived, truly amazing in it's own right!