Aeroflex today introduced the ALT-8000, the
world’s first RF-based portable radio altimeter flightline test set. The ALT-8000 is a
lightweight universal test set for 4.3 GHz FMCW (frequency modulated continuous
carrier wave) radio altimeters and pulse radio altimeters with a large 12-inch color touch
screen for ease of use.
The ALT-8000 is the first flightline test system of its kind. A breakthrough in
avionics test technology, the ALT-8000 is an inexpensive, portable simulator for testing
radio altimeters installed in aircraft and UAV (unmanned aerial vehicles). Until now,
flightline test sets have not been RF-based and have only tested the analog or digital
back-end of the receiver via test port signal injection. Existing RF based test systems
have been confined to bench test applications and rely upon heavy, bulky and
expensive delay lines to check altitude indications at one or two fixed points.
By contrast, the ALT-8000 is easy to use and can be carried to the flightline. The
ALT-8000 may be directly coupled to the radio altimeter transmitter/receiver (TX/RX)
ports or may be connected via supplied TX/RX antenna couplers, which accommodate
most aircraft antenna variants. As a result, faulty radio altimeter system elements can
Aeroflex ALT-8000 FMCW/Pulse Radio Altimeter Flightline Test Set
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be identified faster. Problems are identified with a positive diagnosis and a confirmed
resolution, reducing NFF (no fault found) occurrences and reducing the airline LRUs
(line replaceable units) inventory.
About the ALT-8000 radio altimeter flightline test set
RF simulation of radio altitude from -100 feet to +50,000 feet (+/- 1.5 foot
accuracy) is provided and altitude rate may be set to provide a smooth ramping altitude
simulation to verify decision heights and altitude trips, for auto-land systems and altitude
data feed to EGPWS (enhanced ground proximity warning systems). Up to three ALT-
8000 test sets may be linked via an altitude sync line for executing 2- or 3-channel
coordinated altitude simulation for dual or triple installation auto-land system testing.
The supplied antenna couplers allow the radio altitude system to be quickly verified,
without access being required to test ports on the UUT (unit under test). The RF looped
test verifies TX frequency, power, sweep rate; the RF level control provides the means
to test the UUT sensitivity.
Features of the unique ALT-8000 include:
- Testing capability for 4.3 GHz FMCW radio altimeters, including CDF (Constant
Difference Frequency) types, a universal test set for all system variants, ARINC-
552 or ARINC-707, or custom;
-  Testing capability for 4.3 GHz (non-pulse compression) pulse radio altimeters;
-  Full RF loop test allows TX antenna or feeder faults to be identified by measuring
TX power and frequency and sweep rate;
-  Programmable multi-leg climb and descend profiles to test auto-land systems
with programmable, repeatable approach flare profile;
- Altitude path loss simulation to ensure that the test environment replicates actual
airborne conditions, allowing antenna bonding issues to be verified and test
RX sensitivity