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.
Remember how disappointed when this happened to you?
Help your fellow rocketry community by documenting your unfortunate experience. An unusual number of consumer reported
incidences on a particular engine type or lot number can trigger retesting of the product, manufacturer recall, or even decertification.
Report a Malfunctioning Engine
To report a failure with a model or high-power rocket engine, complete and submit the MESS form. If your browser does not support forms,
you may e-mail the requested information to firstname.lastname@example.org or print out a copy of the form and mail it to the address at the bottom of the page.
Manufacture Notifications and Modification Announcements
Pro38 Bulletin Forward Closure
Cesaroni Pro38 Bulletin
AeroTech DMS&tm; Motor Thrust Ring Advisor
It has come to our attention that there have been two (2) reported instances of the factory glued on thrust rings of 54mm DMS Disposable Motor System single-use rocket motors breaking off the motor casing during flight. One was a K535W, and the other was an L1000W that was flown
at the recent Midwest Power launch. This usually results in the bare motor flying through the rocket and into the air, often in an unstable and unpredictable manner.
Customers are requested to NOT fly 54mm DMS motors using only the factory installed thrust ring and to take one of the following steps before flight to mitigate this problem:
1. Tightly wrap two layers of 1” wide masking tape around the thrust ring and motor case junction, and tightly friction fit the motor into the motor mount tube with masking tape. Using this method, the flyer should still be able to make use of their rocket’s existing motor retainer system.
2. Tightly wrap a layer of 1” wide masking tape around the motor case immediately adjacent to the thrust ring, to a thickness of 1/16”. Install the motor in the motor mount tube and tightly wrap 2 layers of masking tape around the motor and motor mount tube or motor retainer junction.
3. Remove the glued-on thrust ring and tightly wrap a layer of 1” wide masking tape around the motor case, flush with the nozzle end of the case, to a thickness of 1/16”. Install the motor in the motor mount tube and tightly wrap 2 layers of masking tape around the motor and motor mount tube or motor retainer junction.
4. Use a motor block within the motor mount tube that will transfer the thrust of the motor to the airframe and prevent the forward movement of the motor within the tube. Install the motor in the motor mount tube and tightly wrap 2 layers of masking tape around the motor and motor mount
tube or motor retainer junction.
Two of these methods can be viewed on a YouTube video posted at:
AeroTech is continuing to examine and evaluate the situation and is actively working on a solution that we believe will conclusively solve the problem in the near future. Until then, new production 54mm DMS motors will be shipped without thrust rings and customers will need to
apply their own tape thrust rings or use a motor block per steps 3 or 4 above. We are sorry for any inconvenience this may have caused for our dealers and customers. Your understanding and patience is appreciated, and we thank you for your continued support.
AeroTech DMS™ Motor Thrust Ring Advisory
It has come to our attention that there have been two (2) recently reported instances of the factory glued-on thrust rings of high power (H-class and larger) DMS Disposable Motor System single-use rocket motors breaking off the motor casing during flight. This usually results in the bare motor flying through the rocket and into the air, often in an unstable and unpredictable manner.
Customers are advised to examine the strength of the glued-on thrust rings on their DMS motors before flight, and take one or more of the following steps to mitigate this problem:
1. Apply a generous amount of CA (cyanoacrylate) glue to the forward bulkhead side of the thrust ring/motor casing interface. Allow the CA to thoroughly penetrate the space between the ring and case, soak into the ring and allow it to solidify completely before use.
2. Tightly wrap a layer of 3/8” wide or wider masking tape around the motor case immediately adjacent to the thrust ring, to a thickness of 1/16”.
3. Remove the glued-on thrust ring and tightly wrap a layer of 3/4” wide masking tape around the motor case, flush with the nozzle end of the case, to a thickness of 1/16”.
4. Use a motor block within the motor mount tube that will transfer the thrust of the motor to the airframe and prevent the forward movement of the motor within the tube.
AeroTech is continuing to examine and evaluate the situation and will take appropriate action on modifying new production shortly.
Your understanding and patience is appreciated!
May 2, 2013
CTI Pro 38 White Thunder Recall
CTI has announced a recall of Pro-38 White Thunder Reloads with a date code of Feb 20, 2013. Only 38mm reloads are affected -- other sizes and propellant types are not included
in this recall.
A small number of grains may have been contaminated with an oily substance on the inside of the casting tubes. CTI suspects the tubes were contaminated at the source (paper supplier).
Please contact your dealer, not CTI directly, if you have reloads you suspect are included in the recall. If the dealer confirms the reloads are part of the recall, they
will be replaced and you should dispose of the reloads in accordance with the MSDS.
June 21, 2012 10:01 AM
New Aft Closures certified
The new Monster Motor Boat Tail Rear Closures for the 54 and 75 MM RMS motors have been tested and show no deleterious effect on both performance and serviceability of motor
hardware and their reloads. These boat tail closures fill in the area from the edge of the closure to the edge of the nozzle exit with an aerodynamic profile to minimize base
drag for those minimal diameter rockets able to use it. These closures are NOT to be used with Medusa style reloads and there will be warnings to the same on both the closure
documentation and any new production Medusa style nozzle reloads from Aerotech. Any use with improper nozzles will result in the destruction of the closure and most likely
motor/rocket as well. There is also no point of rear motor retention, all retention will need to be either friction fit or front closure retention. Details of these closures
will be posted soon on the Rouse-Tech and Aerotech websites.
Chairman, Tripoli Motor Testing
9/21/2011 AeroTech Releases 54mm RMS™ Delay Drilling Tool
AeroTech is releasing a new delay drilling tool for use with its line of 54mm RMS™ reloadable motors. The 54mm RMS Delay Drilling Tool™ (or RDDT54™, P/N T082510-2) is designed for
shortening RMS delay elements to adjust the time delay of a 54mm AeroTech RMS reloadable motor. The RDDT54 consists of a machined drill tool body and a 1/4” stub drill bit with an
attached knob. The tool also has a provision for calibration, as the tip of the drill bit must be flush with the end of the tool body for accurate use. Though adjusted initially at
the factory, a set screw placed within the knob makes any necessary readjustment easy.
The ends of the tool are counter-bored with recesses that are labeled with 4 or 8 second reductions in the delay time. To use, the RMS delay element is placed into the desired end of
the tool and held firmly in place, the drill bit is inserted and the knob is rotated clockwise until the bit is fully seated in the delay and no resistance is felt. In addition, a
supplied 1/16” thick washer may be placed between the drill tool body and the drill knob to shorten the delay to an intermediate value (i.e., shortening the delay by 2 or 6 seconds).
As is always the case with drilled RMS delays, the delay element should be installed in the motor with the drilled end facing the propellant grains (or away from the ejection charge) for
best delay accuracy. Also, no delay should be shortened to less than 4 seconds.
AeroTech is planning to eventually sell most 54mm RMS reloads in only the longest certified delay, so the RMS Delay Drilling Tool will be essential for the future use of the 54mm RMS
line of products.