OPERATOR’S MANUAL
CMA-9000 FLIGHT MANAGEMENT SYSTEM
DME/DME NAVIGATION MODE
The assumptions used to support the accuracy requirements are:
Minimum three DME facilities are required to support the DME/DME navigation mode. It is assumed that the
DME transceiver is compliant with TSO-C66c.
A. ACCURACY
In the DME/DME navigation mode, a typical 95% position error is 0.5 nm in en-route and 0.4 nm in the
terminal area. The DME-DME navigation mode is not available for approach mode.
B. INTEGRITY
Based on typical MTBF values of the DME ground facilities and of the airborne DME transceivers, the FMS
has a probability of misdetection by hardware of a failure condition that would cause the DME-DME navigation
fix to be outside the containment limit of an order of magnitude of 10
-4
per flight hour.
This probability is improved by line of position reasonableness check internal to the FMS. Reasonableness
checks based on distance and ground stations geometry are applied during the DME facility selection
process and prior to use of the DME slant distance measurements to derive the navigation solution.
C. CONTINUITY
Based on typical values of the Mean Time Between Failures (MTBF) of the DME ground facilities and the
airborne DME transceiver, the FMS meets the 10
-4
per flight hour continuity requirement.
VOR/DME NAVIGATION MODE
The assumptions used to support the accuracy requirements are:
A minimum of one VOR and one DME facilities are required to compute a navigation solution. It is assumed
that the VOR receiver is compliant with TSO-C40a and the DME is compliant to TSO-C66c.
A. ACCURACY
In the VOR/DME navigation mode, a typical 95% position error is between 0.6 and 0.8 nm if the distance to
the tuned ground station is less than 7nm and 1.5nm greater distances. The VOR-DME navigation mode is
not available for approach mode.
B. INTEGRITY
Based on typical MTBF values of the VOR ground facilities and of the VOR receivers, the FMS has a
probability of misdetection by hardware of a failure condition that would cause the VOR-DME navigation fix
to be outside the containment limit of an order of magnitude of 10
-4
per flight hour.
This probability is improved by having an internal FMS line of position reasonableness check.
Reasonableness checks based on bearing and distance are applied prior to use of the VOR bearing
received and the DME distance received in the solution.
C. CONTINUITY
Based on typical values of the Mean Time Between Failures (MTBF) of the VOR ground facilities and the
airborne VOR receiver, the FMS meets the 10
-4
per flight hour continuity requirement.
Page 15-4
August 17, 2010
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