OPERATOR’S
MANUAL
CMA-9000 FLIGHT MANAGEMENT SYSTEM
Page 17-5
November 19, 2009
NAVIGATION IN DEAD RECKONING (DR) MODE
CAUTION:
IFR operation in dead reckoning mode may not be permitted in certain classes of airspace.
When reversion to DR mode occurs (due to unavailability of all other navigation modes), the CMA-9000 FMS
must rely solely on heading, true airspeed and the last computed value of wind, for navigation. This results in a
position accuracy which degrades continuously during prolonged intervals of DR operation. The rate at which
accuracy degrades depends on the quality of the source of the heading and speed inputs. The CMA-9000 FMS
may therefore only maintain its normal accuracy if DR operation does not exceed three to five minutes duration
(at typical speeds; it will be longer at lower speeds).
Navigation accuracy during prolonged DR operation may be improved by manual updating of present position
and/or the actual track and ground speed and/or the wind speed and wind direction based on external
information. This is particularly necessary during periods of changing winds, since the CMA-9000 FMS
providing navigation data assumes constant wind during DR operation. In an installation where digital True
Airspeed (TAS) is not provided, the CMA-9000 FMS assumes constant ground speed during DR operation,
therefore the latter must be updated manually at regular intervals.
Manual update of the CMA-9000 FMS track and ground speed is accomplished as follows:
1. Display the PROGRESS 1/4 page by pressing [PROG] when the 4-page set of PROGRESS pages is
configured (the PROGRESS 3/3 page when the 3-page set of PROGRESS pages is configured).
2. Enter the track angle in True (T)/Magnetic (
o
)and ground speed in knots into the scratchpad, e.g. 281/228.
3. Move the track angle and ground speed to the TK/GS field by pressing LSK 3R.
NOTE: Track angle and ground speed will automatically be updated as soon as the CMA-9000 FMS resumes
normal navigation operation.
1 R
2 R
3 R
4 R
5 R
6 R
ACT PROGRESS 1/4
2 8 0
T
D T G
N M
E T E
ARRIE
3 5 . 2 0 0 + 2 0 . 2
<
2 8 0
o
TOU
8 8 . 3 0 0 + 3 2 . 2
TRUE
W I N D T K / G S
>
020
T
/ 45
K T
2 8 1
T
/ 2 2 8
K T
T K E / X T K
R 0 0 0
T
/ L 0 . 0 0
N M
R N P / A N P
1 . 0 0 / 0 . 0 5
N M
N A V M O D E
<
G P S
1 L
2 L
3 L
4 L
5 L
6 L
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