Airworthiness Directive · Amendment 39-11190 · AlliedSignal Inc. VN 411B Very High Frequency (VHF) Navigation Receivers
AlliedSignal Inc. VN 411B Very High Frequency (VHF) Navigation Receivers
The following very high frequency (VHF) navigation receivers that are installed on, but not limited to, Learjet Model 31A, Fokker Model F27-50, and British Aerospace Model ATP airplanes: --VN 411B, BPN 3614004-4101, all serial numbers, that are currently at Modification Status 18, 19, or 20; --VN 411B, BPN/KPN 3614004-4101/066-1101-00, all serial numbers, that are currently at Modification Status 18, 19, or 20; --VN 411B, P/N 066-1101-00, serial numbers up to and including 4229, that are currently at Modification Status 18, 19, or 20; and --VN 411B, P/N 066-1101-31/40/50, serial numbers up to and including 10799, that are currently at Modification Status 19 or 20.
This amendment adopts a new airworthiness directive (AD) that requires replacing certain AlliedSignal Inc. VN 411B VHF navigation receivers installed on aircraft if the receivers do not have Modification 21 incorporated. This AD is the result of a report of navigation receiver interference during landing operations. The actions specified by this AD are intended to prevent VHF navigation receiver interference from frequency modulation (FM) radio station broadcasts, which could cause distortion of the navigation audio and deflection of the desired flight path of the airplane during landing operations with possible loss of control of the airplane.
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.
Appliances and equipment
