Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all GROB-WERKE (GROB) Model G120A airplanes. This proposed AD would require 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 proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. We are issuing this proposed 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.