Airworthiness Directive · Amendment 39-11420 · AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, - 200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes
AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, - 200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes
RIA-32A instrument landing system (ILS) navigation receivers having part numbers (P/N) 2070724-3201 and 3203; as installed in, but not limited to, Airbus Model A300 series airplanes and Boeing Model 747-100, -100B, -100B SUD, -200B, -200F, -200C, -300, 747SR, and 747SP series airplanes; certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to certain instrument landing system (ILS) navigation receivers manufactured by AlliedSignal. This action requires replacement of certain resistors in the ILS navigation receiver with higher ohm resistors and replacement of the nameplate on the receiver with a new nameplate. This amendment is prompted by reports of ILS navigation receivers incorrectly indicating signals from the glideslope ground station during final approach. The actions specified in this AD are intended to ensure the ILS receiver provides the flight crew with accurate glideslope data. Inaccurate glideslope data could result in an approach off the glideslope, and, consequently, a landing short of the runway or a runway overrun.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
