scope:

Description of Driving Event:

During the visual receiving inspection process of the fourth stage Altair IIIA motor for a 1984 launch from the Wallops Flight Facility, a delamination was found in the silica phenolic exit cone liner. A similar delamination was found in a nozzle being processed for a Vandenberg Air Force Base launch. An immediate visual, ultrasonic, and radiographic inspection of the remaining inventory of silica phenolic exit cone liner nozzles found one other nozzle that was suspect. The same inspections were completed concurrently for inventory nozzles that included graphite phenolic exit cone liners. No delamination indications were found in the carbon phenolic exit cone liners.

The delamination was determined to be a moisture related problem associated with silica phenolic. A monitoring program was established for the remaining silica phenolic nozzles and carbon phenolic nozzles. This monitoring consisted of storing the nozzle assemblies in the Dallas Scout Logistics Area, monitoring humidity, and attaching gages to one of the carbon phenolic nozzles and a dissected nozzle piece to measure strain on a periodic basis. Visual, ultrasonic, and radiographic inspections were completed at Dallas just prior to shipment to verify that a flightworthy nozzle would be shipped to the field site.