Airworthiness Directives; GROB-WERKE Model G120A Airplanes

The FAA adopts a new airworthiness directive (AD) for all GROB-WERKE (GROB) Model G120A airplanes. This AD requires you to repetitively inspect visually the area between the vertical stabilizer main spar and the nearby vertical stabilizer skin for any disbonding/ crack; repair any disbonding/crack found; and calculate weight and balance after any repair. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. We are issuing this AD to detect and correct any disbonding/crack in the area between the vertical stabilizer main spar and nearby stabilizer skin, which could result in possible structural failure. This failure could lead to difficulty in airplane flight control.