Aerotech DMS motor NOT decertified

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An addition from Paul:

The other motor in question, the G78G Mojave Green SU motor WAS found to
have an issue of mislabeling as originally suspected and that problem has
been found to be restricted to that lot (date code 101742, manufactured in
April 2012). All of those motors were thought to have been
returned/retained, this one did not. There are two ways to identify a wrong
label motor, through the lot number as well as nozzle throat size. The G78G
motor has a throat size of .234”, the G75M motor has a .180” throat. If you
find G78G motors with that date code OR with the smaller throat size, either
return it to your dealer for a replacement or fly it as a G75M MetalStorm
sparky motor.

I want to commend Aerotech’s Karl Baumann due diligence and dedication in
the all day testing and detective work in resolving these issues, Tripoli
has a commitment to insure our flyers have motors with fully identified
characteristics for the safety of our flyers and fields, and Aerotech has
come through once again in that support.

Please pass this word on to all our flyers, not ‘connected’.

Paul Holmes
Chairman, Tripoli Motor Testing
 
cerving said:
Be sure to let Aerotech know and file a MESS report (if you're NAR).
Click to expand...
Anyone can submit a MESS report- https://www.motorcato.org/

The Malfunctioning Engine Statistical Survey (MESS) is a joint organization program that allows NAR Standards & Testing, Tripoli Motor Testing and the CAR Motor Certification Committee to track field trends in the reliability of sport rocket motors.
Click to expand...
 
The data NAR collects is shared with CAR and TRA.

https://www.motorcato.org is intentionally organization agnostic, in an effort to give hobbyists one place to go to file a report, with the information going to all the organizations.

-Kevin
 
troj said:
The data NAR collects is shared with CAR and TRA.

https://www.motorcato.org is intentionally organization agnostic, in an effort to give hobbyists one place to go to file a report, with the information going to all the organizations.

-Kevin
Click to expand...
To expand on this, NAR has traditionally maintained the Combined List of Currently Certified Motors for the 3 major North American Hobby Rocketry Organizations. Similarly NAR has maintained a MESS Reporting system for NAR, TRA and TMT certified motors for many years however many hobbyists thought it was only for NAR certified motors. A discussion among the S&T, TMT and MTC administrators agreed that a non-sectarian webpage might produce more motor problem reports than the 125-150 per annum that the NAR MESS form generated so we opened https://motorcato.org/

The administrators of NAR S&T, TRA TMT and CAR MTC have good inter-organization communications and maintain a confidential e-mail list so we all know what's going on and to see if we are all in agreement of key issues before making policy decisions or statements to the organizations members or the general public. If statements are made in confidentiality to the members, it is expected that they remain confidential and not be posted in public forums.

S&T, TMT and MTC each have confidential member lists to communicate with their members on testing dates and results prior to publication. Each organization also maintains confidential lines of communications with each individual manufacturer to discuss certification needs, results and motor issues.

Bob
 
I thought the whole email was presumptuous and out of proportion. It balled up a bunch of junk into one small issue.... It did say "temporarily Decertified" and that is a term that should require paperwork, investigation, and a clear context way before it is used. In this CONTEXT, it is not proprietary since it affects CROSS-CERTIFICATION.

In other words, this notification should be supplied to the manufacturer only. Then, the association should only issue a WARNING, requiring users to use caution until there is specific information that can be addressed.

Can't wait to fly my J270.. it looks cool.
 
On one hand, I wish there was much less secrecy regarding motor failures/malfunctions/etc/

On the other, this thread has shown exactly why there is.
 
edwinshap1 said:
Prop X =~C*, so they would look very similar, highly aluminized.

I think the bigger issue is that we can't see what's inside a single use motor, and if any problem is widespread enough to cause a decertification, or other such action, the lots in question need to be checked.

Or they can send them out to the west coast because we fly on lake beds where the closest flammable material is a few miles away :)
Click to expand...
Yep. Send them all to me. I will dispose of them properly. :eyeroll:
 
I guess I don't see why we have to blame anyone at all on this. I think appropriate actions were taken by everyone involved. I fly in where there is no such thing as a safe spot for sparky motors, not even by accident. I don't own one of these DMS motors, but I've considered buying them. In my opinion secrecy about a possibly very dangerous motor mislabel is maybe the worst thing that could be done to our hobby. You guys tell me what the result would be from flying a sparky motor and burning up an entire farmer's crop?

It seems to me that Aerotech, TMT and the starter of this thread all did precisely the right things.
 
jimzcatz said:
An addition from Paul:

The other motor in question, the G78G Mojave Green SU motor WAS found to
have an issue of mislabeling as originally suspected and that problem has
been found to be restricted to that lot (date code 101742, manufactured in
April 2012). All of those motors were thought to have been
returned/retained, this one did not. There are two ways to identify a wrong
label motor, through the lot number as well as nozzle throat size. The G78G
motor has a throat size of .234”, the G75M motor has a .180” throat. If you
find G78G motors with that date code OR with the smaller throat size, either
return it to your dealer for a replacement or fly it as a G75M MetalStorm
sparky motor.

I want to commend Aerotech’s Karl Baumann due diligence and dedication in
the all day testing and detective work in resolving these issues, Tripoli
has a commitment to insure our flyers have motors with fully identified
characteristics for the safety of our flyers and fields, and Aerotech has
come through once again in that support.

Please pass this word on to all our flyers, not ‘connected’.

Paul Holmes
Chairman, Tripoli Motor Testing
Click to expand...

HMMMM, I can't win the darn lottery BUT----DSCF0918.jpg---Guess it's a good thing I'm too busy to launch these days---That could have gone really bad--spectacular--but bad!
 
cerving said:
Looks like your forward closure let loose. Be sure to let Aerotech know and file a MESS report (if you're NAR).

This doesn't sound like the issue that they had with the other DMS motor, though.
Click to expand...

I went ahead and sent Aerotech an e-mail and the reply (written by Karl Baumann, who is doing a wonderful job dealing with all of this) was as follows:

"Sorry to hear about your experience with the H135W DMS. We encountered a strange failure route during the change from R & D to production with the delay module, this failure is what you observed during the flight of your rocket. the delay experiences a form of edge burning which compromises the bulkhead allow the hot gases to vent forward terminating the flight. This type of failure has occurred in less 1 1/2% of the initial motor lot production of 500 motors. This issue has been addressed and continuing R & D will result in a better working delay module seal.While I cannot replace your rocket, i can offer you a couple of DMS motors to replace the one you lost due to the forward bulkhead failure."

So, apparently, the seal problem has already been addressed, but it was not an isolated incident.

Just FYI--
 
UpsilonAerospace said:
I went ahead and sent Aerotech an e-mail and the reply (written by Karl Baumann, who is doing a wonderful job dealing with all of this) was as follows:

"Sorry to hear about your experience with the H135W DMS. We encountered a strange failure route during the change from R & D to production with the delay module, this failure is what you observed during the flight of your rocket. the delay experiences a form of edge burning which compromises the bulkhead allow the hot gases to vent forward terminating the flight. This type of failure has occurred in less 1 1/2% of the initial motor lot production of 500 motors. This issue has been addressed and continuing R & D will result in a better working delay module seal.While I cannot replace your rocket, i can offer you a couple of DMS motors to replace the one you lost due to the forward bulkhead failure."

So, apparently, the seal problem has already been addressed, but it was not an isolated incident.

Just FYI--
Click to expand...

I had the same problem with another AT motor, they replace the closure, the reload and the rocket since it was an Aerotech. Same think the delay burn by the edge, I notice when I assemble it that it was more loose than usally..
 
gldknght said:
I guess I don't see why we have to blame anyone at all on this. I think appropriate actions were taken by everyone involved. I fly in where there is no such thing as a safe spot for sparky motors, not even by accident. I don't own one of these DMS motors, but I've considered buying them. In my opinion secrecy about a possibly very dangerous motor mislabel is maybe the worst thing that could be done to our hobby. You guys tell me what the result would be from flying a sparky motor and burning up an entire farmer's crop?

It seems to me that Aerotech, TMT and the starter of this thread all did precisely the right things.
Click to expand...

Exactly...

This is precisely the kind of reason I don't allow HPR activities on my farms...

Later! OL JR :)
 
bobkrech said:
If statements are made in confidentiality to the members, it is expected that they remain confidential and not be posted in public forums.
Click to expand...

Bob and all, just to make sure, in no time I was told to keep this info confidential, actually as you can see in the print screen, Tom Raithby Chair of the Car Motor Certification send that info to 4 publics forums , including 3 yahoo groups. In the watering hole section of the forum , you have many treads who have nothing to do with the hobby, I tough at the time it was relevant information to this forum. If someone pull the trigger too fast , it was not me.

facts.jpg
 
luke strawwalker said:
Exactly...

This is precisely the kind of reason I don't allow HPR activities on my farms...

Later! OL JR :)
Click to expand...
Because a G motor (which is not HPR) was mislabeled? I'm not following your reasoning here...
 
cjl said:
Because a G motor (which is not HPR) was mislabeled? I'm not following your reasoning here...
Click to expand...

He never misses an opportunity to throw that in, regardless of its relavance.:rolleyes: have we not all heard it a thousand times before?
 
I really like OL JR. :) Wish I could spend some time with him kickin' back a few, talking space program and rockets. I think I'd have a great time under the stars...

It is a shame that OL JR might have a great flying venue (I don't actually know), but wouldn't/won't allow HPR flights. We need all the good flyin' fields we can get! But it's his land. His ways. I respect that.

Just sayin' I like him (and all you!) anyway. :)
 
We should simply delete all that tread if you ask me.
 
Nah, no need to delete the thread. There's a lot of good information in here. As others have said, appropriate actions were taken by all those concerned, and the issue was resolved very quickly. This thread does a good job of showing how S&T/TMT/MTC work directly with the manufacturers to identify issues and deal with them accordingly.
 

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