News Release by AeroTech Consumer Rocketry
Wednesday, May 21, 2008

As a result of field experience and customer feedback, AeroTech is now requiring the use of aluminum "forward seal disks" with current production reload kits intended for use with 54/1706, 75/5120 and all 98mm RMS™ hardware.

The specific kits affected are:

54/1706 Motor Hardware
K185W, K550W, K1100T, K695R, K513FJ, K805G

75/5120 Motor Hardware
L1420R, M1297W, M2030G

98/2560-15360 Motor Hardware
K458W, K650T, K680R, K1999N, L952W, L1300R, L1500T, M1419W, M1600R, M2100G, M2400T, M750W, M1939W, M2000R, M2500T, N2000W

The 54mm seal disk was announced last year (P/N 54FSD) and has been required for use with all 54/2560 and larger reload kits, the 75mm disk (P/N 75FSD) is currently being used with all 75/6400 and 75/7680 reloads, and the 98mm disk (P/N 98FSD) is a new machined aluminum part that will replace the phenolic disk currently shipping with 98mm reload kit production.

A small percentage of customers using some of these reload kits have reported a "blister" forming on the exterior of the forward end of the motor case. The blister is caused by excessive heating due to a small amount of hot gas passing between the case and liner during motor operation. In addition to weakening the casing, the blister can interfere with the proper fit of the case in the rocket's motor mount tube.

In the past, AeroTech has implemented the use of forward seal disks with its longest 29mm, 38mm and 75mm RMS motors. The seal disk is a narrow aluminum ring that seals to the inside of the phenolic liner with a circumferential o-ring. The motor's forward o-ring seals against the forward seal disk when the motor closures are tightened. With the use of the seal disk, the liner o-ring (54mm only) and phenolic or fiber forward insulator are no longer required and will not be included with new reload kits. An added benefit of using the seal disks is that motor cleanup is substantially easier; the disk prevents soot from being deposited on the forward end of the case.

The new 98mm aluminum forward seal disk will be available from AeroTech and its authorized dealers at a price of $20.00 each suggested retail. Three seal disk o-rings will be included with each disk for use with older reloads. Updated assembly drawings and instructions for the affected reloads will soon be available for download in PDF format from the Resource Library on the AeroTech website at: http://www.aerotechrocketry.com.

AeroTech Consumer Aerospace is a division of RCS Rocket Motor
Components, Inc., Cedar City, UT.