Beschreibung
BendixKing KA 54A, P/N 071-01501-0000, is the microstrip antenna of the KRA 405 and KRA 405B radar altimeters. Each system uses two KA 54A antennas, one transmitting and one receiving, both pointing straight down. The antenna covers 4240–4360 MHz with a VSWR of 1.5:1 maximum, 10 dBi gain, linear polarization and 50 Ω impedance; the beamwidth is at least 45° (E-plane) and 40° (H-plane).
The KA 54A complies with TSO-C87 and ETSO-2C87 and is rated to 60,000 ft and −54 to +85 °C. Honeywell lists the white version as 071-1501-00 and a black version as 071-01501-0100. New antennas come with sealing gaskets; the antenna installation kit 050-02960-0000 with TNC connectors and the RG393 cable are separate items.
The installation manual requires the two antennas to be at least 20 in (508 mm) apart, within ±6° of vertical, with each RF cable no longer than 17 ft (5.2 m). Replacing an antenna on a certified aircraft follows the approved data for the aircraft and ends with a release to service. Fit depends on the radar altimeter model and the aircraft type.
