Airworthiness Directives; Bombardier, Inc. Airplanes

We are revising an existing airworthiness directive (AD) for certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes; all Model CL-600-2C10 (Regional Jet Series 700, 701, & 702) airplanes; all Model CL-600-2D15 (Regional Jet Series 705) airplanes; and all Model CL-600-2D24 (Regional Jet Series 900) airplanes. That AD currently requires replacing certain water accumulator assemblies having a certain part installed on the pitot and static lines of the air data computer (ADC). This new AD corrects an erroneous service document number and removes the other erroneously cited service document from that AD. This new AD was prompted by an error that was discovered in one service document number, and a determination that credit for accomplishing actions in another erroneously cited service document should be removed from that AD. We are issuing this AD to prevent pitot-static tubing from becoming partially or completely blocked by water, which could result in erroneous airspeed and altitude indications and consequent loss of control of the airplane.