What was found
INCOMING INSPECTION CHECKS ON ALTIMETER REVEALED JUMPS IN THE OPERATION OF 100 FEET TO 200 FEET. THE END-SHAKES ON THE MECHANISM SHAFTS WERE MEASURED. ONE END-SHAKE MEASURED ZERO. THE OH MANUAL CALLS OUT A MINIMUM END-SHAKE OF .0020 INCH ON ALL THREE CRITICAL ROTATING SHAFTS. BECAUSE OF THIS ZERO END-SHAKE CONDITION, FOUND THE JUMPY CONDITION AT ROOM TEMP, AND THE INSTRUMENT WOULD HANG UP THE POINTERS WHEN OPERATED IN A COLD ENVIRONMENT. THE MANUFACTURER INDICATED THAT A SHAFT END-SHAKE OF .0004 INCH OR LESS WILL CAUSE AN INSTRUMENT HANG-UP UNDER COLD OPERATING CONDITIONS ACCORDING TO THEIR TESTING.