Airworthiness Directives; Shadin ADC-2000 Air Data Computers

The FAA adopts a new airworthiness directive (AD) for certain Shadin ADC-2000 air data computers (ADC) installed on airplanes. This AD requires you to replace affected ADC-2000 units with a modified unit. This AD results from reports that certain ADC-2000 units display incorrect altitude information on the Electronic Flight Information System (EFIS) to the pilot. We are issuing this AD to prevent ADC-2000 units, part numbers (P/Ns) 962830A-1-S-8, 962830A-2-S-8, and 962830A-3- S-8, configurations B, C, and D, from displaying incorrect altitude information. This could cause the flight crew to react to this incorrect flight information and possibly result in an unsafe operating condition.