Honeywell SPZ 8000 symbol generators in more than 90 Falcon 900s would have to be replaced if the FAA enacts a proposed AD. The FAA said that during approach, the quantity of data being processed may cause the EFIS display to flash or go blank. Until the symbol generators are replaced, the AD would require a temporary flight manual change advising the crew to avoid using certain display modes during approaches to decrease the load on the display processor.