AWB 34-3 Issue 1, 25 July 2001
King Radar Altimeter incompatibility
Applicability
All KRA 405 and 405B installations.
Purpose
The purpose of this AWB is to highlight difference installation requirements between KRA 405 and KRA 405B Radar Altimeters.
Background
There have been recent reports of ground proximity warning system installations using the above equipment generating spurious warnings. The matter was referred to Honeywell for investigation. The initial installation details were for a KRA 405 Rad Alt. As these were no longer available the KRA 405B was utilised as a replacement. A direct interchange is not possible.
Advice
The equipment manufacturer has produced a Installation Bulletin Number 454 which is required to be read when retrofitting the later KRA 405B, which states:
- The KRA 405 and 405B have different connectors and therefore are not direct plug in replacements; and
- The newer KRA 405B requires a different minimum length Co-axial cable runs.
Persons approving the use of a KRA 405B in lieu of a KRA 405 should consider the different installation requirements and the affects on the Radar Altimeter installation on other systems that derive data from them before giving the approval.
Operators experiencing problems with this equipment/installation should submit an SDR to CASA and notify the STC holder or CAR 35 Instrument of Appointment Holder who approved the installation.