Retro Review: ASA CX1 Pathfinder
Quick Facts
Type: Aviation, Flight Calculator
Original
Cost: unknown, but ASA’s current
version, the CX3 sells for $99.95, my guess would the CX1 originally sold for
that amount
Year
that the CX1 was produced: The late
1980s
Batters
for the CX1: 2 CR 2032 batteries (the
CX3 has 4 AAA batteries)
How I Acquired the CX1
I
picked up the CX1 at a yard sale for $1.
It needed new batteries, thankfully the battery compartment was still
good. Replacing the batteries on the
CX1 required me to remove two plates on the back. Thank goodness for the small screwdriver
sets.
Features
The
CX1 (and subsequently the CX2 and CX3) is a unique type of calculator, which
focuses on solving problems in aviation, as well as a timer, stopwatch, work
with time (hoursminutesseconds), and conversions. The keys are soft, so presses have to be
deliberate.
Solvers: Aviation
The
CX1 had a vertical screen separated into two parts: the above portion has the calculator and the
solver and its prompts. The CX1 is an
LCD calculator, hence the prompts for the solver were locked in place. When using one of the flight applications,
whatever prompt you are working with flashes.
The
bottom part of the screen contained all the solvers available. I wasn’t able to find a manual for the CX1
online but was able to find one for the CX2 and together with the help card
that came with the calculator to determine which solvers were included.
Units
used:
Temperature: Celsius (°C)
Speed:
Knots
Distance:
Nautical Miles (usually)
Volume: Gallons
Row
1 (from top to bottom):
Plan
CAS

Calculate
true air speed (TAS) given outside temperature and calibrated speed (CAS)

Act
CAS

Calculate
TAS given total temperature and CAS

Plan
M#

Calculate
TAS given outside temperature and mach #

Act
M#

Calculate
TAS given total temperature and mach #

Req
CAS

Calculate
TAS and heading (direction) given wind and course speed conditions

Row
2:
Hdg/GS

Calculate
true heading given TAS, course, wind conditions

X/HWind

Calculates
head wind (head wind is negative (in your face), tail wind is positive (wind
at your back)), and XWind (left wind is negative, right wind is positive)

Wind

Unknown
wind: calculates wind speed and direction given course direction and speed,
TAS, and flight direction

G
S

Calculate
GS given wind conditions and TAS

Req
TAS

Calculate
heading TAS given wind conditions and GS

Row
3:
Leg
Time

Calculate
time duration of a leg given distance and GS

Fuel
Burn

Calculate
the amount of fuel consumed give fuel burn rate and time

FPH

Calculate
fuel rate (burned per hour)

Endur

Calculate
how long a flight can endure given fuel capacity and burn rate

Dst
Fln

Calculate
distance flown given time and fuel burn rate

Row
4:
WT/Arm

Weight
– arms of an airplane (?)

%MAC

Mean
Aerodynamic Chord calculation

WT/Mom

Weight
 Momentum

Note CAS does not mean computer algebra system for the CX series.
In
regards to direction, direction is measured in degree angles 0° to 360°, with
respect to due north (I think), meaning at 90° wind goes west, 180° wind goes
south, and 270° goes east.
Navigating
the solvers takes a little bit getting used to, which is controlled by the
arrow keys ( [ ← ], [ → ]). The left key
also acts as down when you are at the first item in a row, while the right key
also acts as up when you at the last time in a row. The solver that is being selected will have
its prompt flashing.
Entering
HoursMinutesSeconds
Use
the [ T ] key after each component. For
example to enter 23 minutes 28 seconds, press 0 [ T ], 23 [ T ], 28 [ T ].
Timer
and Stopwatch
To
activate the stopwatch, press the [TIMER] key.
To stop the stop, press the [TIMER] again. Clear the stopwatch by pressing the [ C ]
key.
For
the timer, enter a time and press [CONV] [TIMER]. The CX1 does not have a beep.
Conversions
The
CX1 features a handful of conversions, all accessed by pressing the [CONV] key
first.
Conversions
available:
*
Hours/HoursMinutesSeconds (HMS)
*
Gallons/Liters
*
Feet/Meters
*
°F/°C
*
Kilograms/Pounds
*
Statue (regular) Miles (SM)/Nautical Miles (NM)
*
Kilometers/Nautical Miles (NM)
The Updated CX3
The
current version, the CX3 has a backlit, color screen, and can be flash
updated. Added in the second version are
density altitude and rhumbline navigation calculations. Also the weight calculations have been
streamlined. I think the square root
function is also added.
Final Verdict
For
a specialized calculator in aviation, the CX calculators (seemingly) fits the
bill. The keys on the CX1 are soft, but
are easy to use. To the key is to pay
attention to the prompts. The CX series
either enhances or replace the flight computer slide rules. If you are into aviation or a profession, the
CX is worth checking out.
Eddie
This
blog is property of Edward Shore, 2018