CTI 38mm CATO Report

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Aaaaaaahhhh,
A bit of advice, save the motor grain paperwork in a folder until the motor is flown. If a CATO occurs, the specific manufacturers numbers are available for perusal otherwise, I'd say it's a waste of time to send in a report that doesn't identify the batch of
propellant. Kurt

That's true iff the problem is related to the batch, but a more nearly complete set of MESS reports could also help identify problems with instructions. I suspect one reason people don't file them is because they think they did something wrong in preparation of the motor. Those data have value also.
 
I truly think a user friendly app would allow users to enter information onsite, immediately, and allow photo attachments to show you what is left. I bet most people, myself included, simply forget to fill it out when they get home or to the hotel, whatever. I send warranty info in immediately so I don't forget. Same goes for cert specials. And yes, I know the website loads on a cell phone but an app with saving user information can reduce the typing requirements. I personally think the web page is difficult to navigate with a phone.
 
I do not get the discussion about MESS reports an statistically relevance.
We had 3 Motors out of 3 H123-SK from the same production date fail in the same way. We still have 6 of the motors, I would bet they will all show the same failure.
It is not important if 1000000 other motors not from this batch work. Additional in this thread there are 4 other failures of the same type with production dates in September 2015.
The 3 H123-SK catos were reported to CTI a month ago and there was no reaction.
 
T
So in summary, in 2013 potential issues were reported to Estes and CTI. They were investigated and it was concluded without more data, no further action was warranted.

The take away: If a motor fails and you don't report it, it didn't happen. At least not to the certifying authorities and manufacturers.

YMMV but please folks, please stay on the meds, and see you psychologist if you believe everyone is conspiring against you, because quite frankly we just don't care what you think. We only deal with data and facts. :wink:

The trouble with the entire report is it does not prove itself statistically significant. As you've said this is only whats reported. Unless you can at least compare it to warranty claims, it's just a random sample of failures. The numbers on the Estes failures, you're comparing the reported failures to the full production of E's.

The claim "if you don't report it, it didn't happen" is false. You can not disregard events simply because you can not observe them. The unreported failures still happen, and that makes anything generated off bad numbers, just as bad.

If you deal in data and fact, you need to find a way to get better data and fact. Pressuring people into filing MESS reports without sharing any info is obviously not working. Either getting data from the manufacturers regarding warranty claims, or finding an easier/more open and engaging method of collecting data is needed. I'm willing to bet most individual vendors replaced more than 12 CTI motors in 2013, Hell I know of at least 5 CTI failures in our club alone that year (unaware if anything was filed, I was even more noob then than I am now).


I do believe outside tracking of motor issues is a good idea. I believe that the current "file it and hear nothing back" model is why you're getting low reporting rates. I believe the low reporting rates makes the resulting data of questionable value. I believe more open reporting, coupled with a more engaging site, will result in much better reporting and involvement. If people file a report, and see nothing come of it...why waste the ten minutes next time?
 
We never heard of the final findings of what really happened, although it was my belief at the time NAR/TRA were going to investigate and let us know. We were left in the dark again.

This was the last I heard of it, and while not final, it's not exactly in the dark-

image001.gif@01D12B87.B3549820

National Association of Rocketry

21 November 2015
Greetings,
As I reported on the NAR Facebook page last Sunday, I regret to have to inform you that a fatal on-field rocketry accident occurred in California last Saturday. I want to bring you up to speed on the status of our investigation.
When I made the first announcement, there were few details available. We have since been working to understand what happened, so that we may all learn from it and prevent it from happening again. Our Association has no standing in the matter except as concerned and experienced enthusiasts, but I've been in contact with law enforcement and witnesses and have a preliminary set of facts to share.
First, to the best of our knowledge, no NAR or TRA members were involved in this incident, certainly not directly involved. No kids were involved, except, unfortunately, as witnesses.
The deceased, Mike Bentley, a very experienced adult Scout leader, was at an annual BSA Council-sponsored rocketry and camping event for multiple scout troops called Rocket Rave, which has been conducted for at least several years. During the weekend, scouts complete tasks required for their Space Exploration merit badge, which requires two model rocket launches. During the launches, it has also been common for adults to launch their own, larger rockets.
Around noon on Saturday, Mike engaged in a drag race with a second adult. Winds were likely within limits, safe distances were at least close to being met, and both rockets probably met the weight and power limits defined by the NAR Model Rocket Safety Code. The drag race was conducted from a dedicated area, to one side of the primary launch pads for the scouts to use to fly their conventional A through C powered model rockets, and about two dozen people were in the immediate vicinity.

Mike's rocket was powered by a small APCP motor; the other rocket was powered by at least one, and possibly more, black powder motors. Both rockets launched; while Mike was watching his rocket, the other rocket arced over and came down ballistically, striking him in the face and causing severe injuries. Despite the best efforts of scouts, law enforcement, and medical professionals both at the scene and afterwards, his injuries were ultimately fatal.
We know that the rocket that struck Mike was about four feet long and four inches in diameter. It had a cardboard body tube and a plastic nose cone. We don't know much else for sure. It is possible that the rocket was designed to fly on a cluster of motors, but at least one picture of the flight does not clearly show more than one motor firing. No parachute was deployed; none was seen at the accident site. At least one report indicates the rocket was damaged prior to flight. We don't know what motor(s) were used and whether they all ignited and functioned as designed. We don't know if applicable local laws were fully observed.
I do know that the investigating law enforcement authority is not pursuing a criminal investigation at this time. The lack of an investigation will likely leave questions unanswered for some time. We don't know if the rocket would have been allowed to fly at a NAR launch; we can't definitively say whether the NAR safety code was observed or not. We will continue to gather information to the best of our ability, and we'll pass on significant new findings to you.
Where does this leave us? We know that rocketry remains orders of magnitude more safe than any other outdoor activity we can name, provided the safety codes are followed. But it is not without risks; the safety code is our primary means of mitigating those risks.

Everything in the safety codes is there for a reason, and I urge you to continue to observe-and when prudent, exceed-their recommendations every time you fly.

  • Do preflight inspections of every rocket. Be especially careful with complex rockets. Pay special attention to the recovery system.
  • Tilt your launch guides away from the crowds: Plan to have good flights, but also plan for bad flights to end in safe places.
  • Add to the safe distance standards when lots of observers are present.
  • Make sure launch controllers and ignition methods are appropriate for the motor(s) being used.
  • Have a spotter for every rocket in a drag race, near enough to the RSO to be able to get a warning out if necessary.
  • Have people point at malfunctioning rockets if they see them.
  • Make sure the crowd can hear the RSO.
  • Confirm the stability of untested designs.
  • If rockets are flying over spectators, stop and fix the problem.
  • Offer to help people and groups who are just starting down the path that we have trod. Set a safe, positive, and helpful example.
Please consider contributing to Mike's memorial fund through his gofundme site.

I'll continue to keep you informed, so that we can learn what we can from this unfortunate accident, and be safer because of it.
Sincerely,

Ted Cochran
President, National Association of Rocketry

----------------------



Again, no indication of it being Vmax, and the photo I saw appeared to be a white lightning load. My guess is, everyone involved considered the matter closed, and having no authority the TRA/NAR investigations ended at this point, hence no further info has come about.
 
Last edited:
This was the last I heard of it, and while not final, it's not exactly in the dark-

image001.gif@01D12B87.B3549820

National Association of Rocketry

21 November 2015
Greetings,
As I reported on the NAR Facebook page last Sunday, I regret to have to inform you that a fatal on-field rocketry accident occurred in California last Saturday. I want to bring you up to speed on the status of our investigation.
When I made the first announcement, there were few details available. We have since been working to understand what happened, so that we may all learn from it and prevent it from happening again. Our Association has no standing in the matter except as concerned and experienced enthusiasts, but I've been in contact with law enforcement and witnesses and have a preliminary set of facts to share.
First, to the best of our knowledge, no NAR or TRA members were involved in this incident, certainly not directly involved. No kids were involved, except, unfortunately, as witnesses.
The deceased, Mike Bentley, a very experienced adult Scout leader, was at an annual BSA Council-sponsored rocketry and camping event for multiple scout troops called Rocket Rave, which has been conducted for at least several years. During the weekend, scouts complete tasks required for their Space Exploration merit badge, which requires two model rocket launches. During the launches, it has also been common for adults to launch their own, larger rockets.
Around noon on Saturday, Mike engaged in a drag race with a second adult. Winds were likely within limits, safe distances were at least close to being met, and both rockets probably met the weight and power limits defined by the NAR Model Rocket Safety Code. The drag race was conducted from a dedicated area, to one side of the primary launch pads for the scouts to use to fly their conventional A through C powered model rockets, and about two dozen people were in the immediate vicinity.

Mike's rocket was powered by a small APCP motor; the other rocket was powered by at least one, and possibly more, black powder motors. Both rockets launched; while Mike was watching his rocket, the other rocket arced over and came down ballistically, striking him in the face and causing severe injuries. Despite the best efforts of scouts, law enforcement, and medical professionals both at the scene and afterwards, his injuries were ultimately fatal.
We know that the rocket that struck Mike was about four feet long and four inches in diameter. It had a cardboard body tube and a plastic nose cone. We don't know much else for sure. It is possible that the rocket was designed to fly on a cluster of motors, but at least one picture of the flight does not clearly show more than one motor firing. No parachute was deployed; none was seen at the accident site. At least one report indicates the rocket was damaged prior to flight. We don't know what motor(s) were used and whether they all ignited and functioned as designed. We don't know if applicable local laws were fully observed.
I do know that the investigating law enforcement authority is not pursuing a criminal investigation at this time. The lack of an investigation will likely leave questions unanswered for some time. We don't know if the rocket would have been allowed to fly at a NAR launch; we can't definitively say whether the NAR safety code was observed or not. We will continue to gather information to the best of our ability, and we'll pass on significant new findings to you.
Where does this leave us? We know that rocketry remains orders of magnitude more safe than any other outdoor activity we can name, provided the safety codes are followed. But it is not without risks; the safety code is our primary means of mitigating those risks.

Everything in the safety codes is there for a reason, and I urge you to continue to observe-and when prudent, exceed-their recommendations every time you fly.

  • Do preflight inspections of every rocket. Be especially careful with complex rockets. Pay special attention to the recovery system.
  • Tilt your launch guides away from the crowds: Plan to have good flights, but also plan for bad flights to end in safe places.
  • Add to the safe distance standards when lots of observers are present.
  • Make sure launch controllers and ignition methods are appropriate for the motor(s) being used.
  • Have a spotter for every rocket in a drag race, near enough to the RSO to be able to get a warning out if necessary.
  • Have people point at malfunctioning rockets if they see them.
  • Make sure the crowd can hear the RSO.
  • Confirm the stability of untested designs.
  • If rockets are flying over spectators, stop and fix the problem.
  • Offer to help people and groups who are just starting down the path that we have trod. Set a safe, positive, and helpful example.
Please consider contributing to Mike's memorial fund through his gofundme site.

I'll continue to keep you informed, so that we can learn what we can from this unfortunate accident, and be safer because of it.
Sincerely,

Ted Cochran
President, National Association of Rocketry

----------------------



Again, no indication of it being Vmax, and the photo I saw appeared to be a white lightning load. My guess is, everyone involved considered the matter closed, and having no authority the TRA/NAR investigations ended at this point, hence no further info has come about.



I seen that, but still leaves many unanswered questions, and as stated " We will continue to gather information to the best of our ability, and we'll pass on significant new findings to you." If the investigation did end at that point, they could have let us know that that is all they could find out about the incident.
 
I do not get the discussion about MESS reports an statistically relevance.
We had 3 Motors out of 3 H123-SK from the same production date fail in the same way. We still have 6 of the motors, I would bet they will all show the same failure.
It is not important if 1000000 other motors not from this batch work. Additional in this thread there are 4 other failures of the same type with production dates in September 2015.
The 3 catos were reported to CTI a month ago and there was no reaction.
Thomas

CTI warrantee claims are honored by the retailer you purchased the motors from. Have you contacted them and supplied them with the lot number information?

Please go to https://www.motorcato.org/ and fill out the on-line MESS form. It will provide CAR, the certifying authority, with the information on the motor problems. https://www.motorcato.org/MESSForm.aspx is the on-line form. You can directly submit the info on-line or print it out and mail it to NAR HQ.

The CAR website is https://www.canadianrocketry.org/ André Choquette is the director of engine certification committee in Canada (CAR MTC). Please contact him directly about this at https://www.canadianrocketry.org/message.php?id=975

I have a few questions for you.
  1. How did the motors fail and/or what was the malfunction?
  2. Were the failed motors flown by the same individual or by different individuals?
  3. Had the individuals assembled and flown Pro38 motors before?
  4. Was the delay grain drilled and shortened?
  5. Had the grain assembly been taken apart and reassembled?

Most of the 38mm motor failures I have observed were cause by the assembler not properly seating the reload in the motor tube, and when the nozzle was threaded on the aft end of the casing, the nozzle did not thread all the way to the casing. The threads are a fail-safe mechanism and they should fail before the casing in the event of an overpressurization, however it the nozzle not threaded into the casing fully because the delay cartridge is not fully seated in the reload, the nozzle will spit out on ignition.

I also saw an ejection charge fire at the end of the motor burnout. The problem was a defective delay shortening tool. Years ago, CTI receive a lot of tools with the improperly positioned drill bits. The delay tools drilled the delay grains too deeply and shortened the delay an additional 5 to 7 seconds more than expected so the ejection charge fired early, usual at max-V.
 
I suspect that this is not the problem being experienced here, but just in case ....

One thing I have noted with the CTI 38mm reloads is that it has become more difficult over the past few years to get the liner all of the way into the tube (as you mentioned, Bob). If you push on the grains, the delay element section will separate and then seat against the end of the case, but the liner still won't be fully inserted. I used to use my thumb nails to try to push in the liner, but our local motor vendor pointed out that the "trick" is to use a casing spacer, since it's the same diameter as the liner. I bought a spacer just for this purpose. Usually with this problem it isn't possible to get the rear closure threads to "catch" at all. However, I wonder if some of the problems reported here are due to that problem. I know for sure this happened on an L1 flight I saw maybe six months ago. After the fact (a roman candle-type flight), the flier acknowledged that he hadn't been able to screw in the closure very far. This might have been a cross-thread problem rather than a tight liner - hard to say - but the result would be the same I guess.

Jim
 
CTI warrantee claims are honored by the retailer you purchased the motors from. Have you contacted them and supplied them with the lot number information?


As stated before it were not my motors, so I am not the guy to fill out the MESS.
But the flyer has contacted the dealer with the information.
The dealer was on site, so he was contacted directly. But CTI has removed the dealer from the dealer list in the meantime, so we have no idea how the warranty will be processed.

How did the motors fail and/or what was the malfunction?
Complete burn through on the delay element side. I posted a video of the cato in this thread.
Were the failed motors flown by the same individual or by different individuals?
Same individual. As Louis said we had planed to launch 6 of the motors in a cluster.
Had the individuals assembled and flown Pro38 motors before?
Yes, and we had several guys including some TAPs observe the assembly of the third motor.
Was the delay grain drilled and shortened?
On the first motor it was drilled, on the second and third it was completely unmodified to exclude any problems with the drilling.
Had the grain assembly been taken apart and reassembled?
I do not know, the delay element was removed from the liner an inspected but showed no optical defects.
 
As stated before it were not my motors, so I am not the guy to fill out the MESS.
But the flyer has contacted the dealer with the information.
The dealer was on site, so he was contacted directly. But CTI has removed the dealer from the dealer list in the meantime, so we have no idea how the warranty will be processed.

How did the motors fail and/or what was the malfunction?
Complete burn through on the delay element side. I posted a video of the cato in this thread.
Were the failed motors flown by the same individual or by different individuals?
Same individual. As Louis said we had planed to launch 6 of the motors in a cluster.
Had the individuals assembled and flown Pro38 motors before?
Yes, and we had several guys including some TAPs observe the assembly of the third motor.
Was the delay grain drilled and shortened?
On the first motor it was drilled, on the second and third it was completely unmodified to exclude any problems with the drilling.
Had the grain assembly been taken apart and reassembled?
I do not know, the delay element was removed from the liner an inspected but showed no optical defects.
I looked at your video and it is very clear than the motor had a failure of the forward closure assembly seals on ignition. There are only a limited number of ways that this can happen so if you can look at Figures 1 and 2 in https://pro38.com/pdfs/Pro38Instns.pdf you will see the insides of the Pro38 motor.

1.) The delay grain shown in Figure 2 has an o-ring that makes a seal with the ID of the motor liner. If that o-ring is missing, or damaged or the liner interior is damaged you can have a hot gas leak. The same effect will happen if the delay grain is not fully inserted into the liner tube.

2.) If the bond between the delay grain the housing is bad, the propellant will burn along the wall-grain interface and fail the forward seal.

3.) If the delay grain is drilled to deep, it could fail and set of the BP.

4.) If the motor casing is longer than the reload, and a spacer is not inserted into the casing before inserting the reload, the delay element will be pushed forward and the seal will fail.

Please contact Andre at CAR if your dealer is not longer on the CTI approved dealer list.

Bob
 
Seems most of the problems with CATO's lately between the 2 major motor manufactures are related to bad designs or QC problems. A person should not have to force liner assemblies into casings, tape loose delay liners to fit properly and seal, use pennies and epoxy to secure the fore end from blow by. There also seems to be part bonding problems with both manufactures. Did all this extra fooling around have to be done when the motors were certified? I guess the hobby divisions don't get the same QC as the military/commercial divisions do. Must say they are good on warranties, but those do nothing for the lost rocket and other components.
 
Seems most of the problems with CATO's lately between the 2 major motor manufactures are related to bad designs or QC problems. A person should not have to force liner assemblies into casings, tape loose delay liners to fit properly and seal, use pennies and epoxy to secure the fore end from blow by. There also seems to be part bonding problems with both manufactures. Did all this extra fooling around have to be done when the motors were certified? I guess the hobby divisions don't get the same QC as the military/commercial divisions do. Must say they are good on warranties, but those do nothing for the lost rocket and other components.

There are also massive differences in cost. We're paying $20-$500 for reloads. I bet Mil/Com are paying thousands, and ordering many less motors. Makes it easier to do hardcore QC. When doing hobby profits, you're not tossing a load of liners for being a little tight.

If you want someone to make a custom, handmade and checked load, there are those that will custom make motors. Its not cheap.

I'm not forgiving slop.... but you have to expect some deviations at this price point.
 
Well, there is Loki. He does this :)

I'm trying to be a newer, more subtle fanboi ;)

Loki is likely the best place to be getting commercial motors if you want precise work and stuff someone really took the time to go over it all. It's one guy and he does it all, so you know it's not new hire bob checking fit. Even still, he'll be the first to tell you sourcing metal from one place, Convolute liners from another and casting tubes from another is frustrating. On the longer motors you've still gotta grease the snot out of the liners and glue the grains in unless they're tight (read directions for more precise descriptions :p )
 
Add one more mfg date for h123 skid failures. Nov. 4 2015. Identical blowby failure on Thursday at ldrs. Luckily i flew it in an old rocket which is now toast.
 
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Add one more mfg date for h123 skid failures. Nov. 4 2015. Identical blowby failure on Thursday at ldrs. Luckily i flew it in an old rocket which is now toast
 
Sorry to stick my nose in here, but I was brought up in the comments above.

DavidMcCann said:
If you want someone to make a custom, handmade and checked load, there are those that will custom make motors. Its not cheap.

Well, there is Loki. He does this :)

This is true in both commercial hobby reloads as well as customized reloads. See the link below.
https://www.facebook.com/LokiResearch/posts/497086687147486?notif_t=like&notif_id=1466277488939999
 
I looked at your video and it is very clear than the motor had a failure of the forward closure assembly seals on ignition. There are only a limited number of ways that this can happen so if you can look at Figures 1 and 2 in https://pro38.com/pdfs/Pro38Instns.pdf you will see the insides of the Pro38 motor.

1.) The delay grain shown in Figure 2 has an o-ring that makes a seal with the ID of the motor liner. If that o-ring is missing, or damaged or the liner interior is damaged you can have a hot gas leak. The same effect will happen if the delay grain is not fully inserted into the liner tube.

2.) If the bond between the delay grain the housing is bad, the propellant will burn along the wall-grain interface and fail the forward seal.

3.) If the delay grain is drilled to deep, it could fail and set of the BP.

4.) If the motor casing is longer than the reload, and a spacer is not inserted into the casing before inserting the reload, the delay element will be pushed forward and the seal will fail.

Please contact Andre at CAR if your dealer is not longer on the CTI approved dealer list.

Bob

No 2 it was: https://www.pro38.com/pdfs/Bulletin-Pro38_Forward_Clousre.pdf
 
I looked at your video and it is very clear than the motor had a failure of the forward closure assembly seals on ignition. There are only a limited number of ways that this can happen so if you can look at Figures 1 and 2 in https://pro38.com/pdfs/Pro38Instns.pdf you will see the insides of the Pro38 motor.

1.) The delay grain shown in Figure 2 has an o-ring that makes a seal with the ID of the motor liner. If that o-ring is missing, or damaged or the liner interior is damaged you can have a hot gas leak. The same effect will happen if the delay grain is not fully inserted into the liner tube.

2.) If the bond between the delay grain the housing is bad, the propellant will burn along the wall-grain interface and fail the forward seal.

3.) If the delay grain is drilled to deep, it could fail and set of the BP.

4.) If the motor casing is longer than the reload, and a spacer is not inserted into the casing before inserting the reload, the delay element will be pushed forward and the seal will fail.

Please contact Andre at CAR if your dealer is not longer on the CTI approved dealer list.


Bob

Agreed, our two Cato's (the ones that started this thread) were #2 above.
 
Add one more mfg date for h123 skid failures. Nov. 4 2015. Identical blowby failure on Thursday at ldrs. Luckily i flew it in an old rocket which is now toast

Wildman replaced the case, the spacer and the reload under warranty at LDRS. However, the replacement has the same mfg date as the one that failed. I might remove the BP and pot it with epoxy as described above by Jim Jarvis.
 
It will be a while for me to get any, as I have no reason to order until propellant is being produced. Freight is too expensive.

CTI should pay the freight on the replacement forward closures. They manufactured a faulty part, which needs to be replaced.
 
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