Summary
We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, Model A300 C4-605R Variant F airplanes (collectively called Model A300-600 series airplanes), and Model A310 series airplanes. This proposed AD was prompted by reports of unreliable airspeed indications that were caused by pitot heater resistance shorted to ground. This proposed AD would require replacement of certain parts. We are proposing this AD to address the unsafe condition on these products.