– 9 –
Solution:
Press the key . Select the Airspeed
submenu and tap enter . Scroll to CAS, input and
tap enter for the planned CAS . Scroll to enter the
OAT:
and tap enter . Scroll to enter the PAlt:
and tap enter to enter 8,500 feet
PAlt .
The display will show 141 .03 KTS TAS, 28°F TAT,
and 0 .221 MACH .
Actual TAS
The Airspeed function can compute true airspeed
using information from instruments during an actual
flight . The inputs to this function are CAS, TAT, and
PAlt . The Airspeed function calculates TAS, OAT
(which can be used as an input to Plan TAS and Req
CAS functions), and Mach Number (MACH) .
Problem:
Compute the TAS at 6,500 feet PAlt,
+10°C TAT, at a CAS of 150 MPH .
Solution:
Press the key . Select the Airspeed
submenu . Convert from knots to miles per hour by
scrolling down to CAS and by pressing , (you
will also need to convert TAT from °F to °C) then
press:
and tap enter to input 150 MPH, then
and tap enter to input 10°C TAT, then
and tap enter again to enter
6,500 feet PAlt .
The display will show 166 .64 MPH TAS, 7°C OAT,
and 0 .222 MACH .
Required CAS
The Airspeed function can compute the calibrated
airspeed required to achieve a given true airspeed
with the inputs TAS, OAT, and PAlt . The Airspeed
function calculates CAS, TAT, and MACH .
Problem:
What is the required CAS or MACH to
obtain 150 knots TAS with 41°F OAT and 6,500
feet PAlt?
Solution:
Press the key . Select the Airspeed
submenu . Press:
and tap enter to input 150 knots
TAS, then
and tap enter to input 41°F OAT, and then
and tap enter to input 6,500 feet
PAlt .
The display will show 135 .58 KTS CAS, 46°F TAT,
and 0 .231 MACH .
FLT
0
1
0
1
5
0
0
5
6
FLT
1
4
0
1
5
0
0
5
6
FLT
2
3
0
0
5
8
◗
STANDARD ATMOSPHERE
Since air pressure and air density are specified by
an altitude in a standard atmosphere, you may want
to find the standard atmosphere for a given altitude .
The International Civil Aviation Organization (ICAO)
has established standard conditions for temperature
and pressure . You can enter an altitude (Alt) in
the StdAtmos function and obtain the outside air
temperature (OAT); pressure in inches of mercury (IN
Hg); and pressure in millibars (mb) for the standard
atmosphere . The StdAtmos function is valid up to
278,385 feet .
Problem:
What are the standard atmospheric
conditions at sea level?
Solution:
Press the key . Scroll to Standard
Atmosphere and tap enter . You are prompted for
the altitude . Press:
and tap enter to enter 0 feet, or sea level .
The display will show 29 .92 IN HG, 59°F OAT .
Problem:
What are the standard atmospheric
conditions at 20,000 feet?
Solution:
Select the Standard Atmosphere
function . You are prompted for the altitude . Press:
and tap enter to input
20,000 feet .
The display will show 13 .75 IN HG, -12°F OAT .
◗
AIRSPEED
Planned and Actual True Airspeed (TAS) and Mach
number can be calculated and are dependent on
the temperature input . Planned airspeeds require the
use of outside air temperature (OAT), obtainable from
the preflight weather briefing or from what you read
on a thermometer on the ground . Actual airspeeds
require the use of total air temperature (TAT), which is
obtained by a probe having velocity with respect to the
air (essentially, the thermometer in your aircraft) . TAT is
warmer than OAT, because of kinetic heating due to
compression on the upstream side of the probe .
Planned TAS
The Airspeed function can compute the true airspeed
(TAS) for a planned calibrated airspeed (CAS) with the
inputs Planned CAS, OAT, and PAlt . It is important to
use the OAT and PAlt at the planned flight altitude .
OAT may be obtained from winds aloft forecasts .
OAT can also be determined from the TAT during
flight . PAlt is normally obtained from the Altitude
function . The Airspeed function calculates TAS, TAT
(which can be used as a cross-check with the in-
flight TAT), and Mach Number (MACH) .
Problem:
You plan to fly 125 knots CAS, 8,500
feet PAlt, and 23°F OAT . Compute TAS and TAT .
FLT
0
0
0
0
0
2
CONV
UNIT
Содержание cx-3
Страница 1: ...CX3 USER S GUIDE CX 3 Flight Computer...