Yes, according to Bendix/King Service Memo 347, periodic testing of a gyro is required to keep the unit in an airworthy state. The testing consists of running the gyro for a minimum of 6 hours on a Scorsby table. This periodic testing applies to the following King gyro instruments along with the maximum storage time:

	KG-102A		12 Months
	KG-107		12 Months
	KSG-105		12 Months
	KI-256		6 Months
	KG-258		6 Months
	KG-259		6 Months
	KG-253		6 Months
	KI-254		6 Months
	KVG-350		6 Months