Rocketman flanged aft closure Q.

Sounds about right, particularly with the smaller motors. The majority I have seen, though, have been of the Alien CATO variety. And when you are talking about K and up motors, it gets real ugly real fast. SssssSSS..BOOOM! Seen stainless blast deflectors twisted up by whatever comes out of the bottom of the self destructing motor hitting them.

Drawback of the system, as the forward motion of the motor is checked by the rear closure. If it comes off, there is nothing to prevent the motor from going forward (unlike, say, brand K motors that have an external thrust ring separate from the rear closure).

Reply to
Tweak
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I bet with a little encouragement, I could get to the truth.. Hey jerry, I have contacts in US Customs also..(;-)

Reply to
W. E. Fred Wallace

Aren't they USR? Aren't you USR?

Reply to
Phil Stein

Fred,

I'll take care of Jerry's consulting fee to you at the next launch. I fIgure it will be so easy that a few beers should cover it. ;-)

Reply to
Phil Stein

I've seen several aft closure / nozzle failures, and only once did the propellant continue burning, flaming out the nozzle. In all other cases it went out. Either way, your rocket is going to have a bad day...

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

If the rear closure comes off, there's not going to be any thrust left to push what's left of the motor forward...

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

Not true.

Reply to
Dave Grayvis

So you have never seen an M motor let the rear closure go? 75mm Redline DESTROYED a friend's L3 attempt, as it aliened it's way completely through the rocket, smashing through 1/2 inch birch caps on the altimeter bay, the electronics, the stainless hardware for the recovery system, while the expelled bits bent the crap out of the launch pad (and sheared off some the 3/8" bolts holding one of the legs on), etc..

Not any thrust left...

It may not be a big deal with a F motor. Big motors break things.

Reply to
Tweak

At the moment the nozzle comes off, the motor casing will momentarily act like a "full diameter nozzle" and develop a thrust based on the open area and the chamber pressure. It won't last long, because there won't be enough burn surface to keep up the pressure behind the larger opening, but there will be that moment of unusually high thrust.

-dave w

Reply to
David Weinshenker

But man...what a moment. Talk about "rapidly deflagrating". Good thing AP is not explosive, because it sure looked like "it done blowed up real good".

;-)

Now, that ex O motor that did the same thing was a sight to behold.

Reply to
Tweak

Agreed. The "failure event" might be violent enough to push the casing forward, but any continued propellant burn is not going to produce any significant sustained thrust.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

Sigh.

Tweak said:

Now where in that did I mention any "significant sustained thrust"? With whom are you disagreeing?

Reply to
Tweak

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