Retro Review: ASA CX-1 Pathfinder
Quick Facts
Type: Aviation, Flight Calculator
Original
Cost: unknown, but ASA’s current
version, the CX-3 sells for $99.95, my guess would the CX-1 originally sold for
that amount
Year
that the CX-1 was produced: The late
1980s
Batters
for the CX-1: 2 CR 2032 batteries (the
CX-3 has 4 AAA batteries)
How I Acquired the CX-1
I
picked up the CX-1 at a yard sale for $1.
It needed new batteries, thankfully the battery compartment was still
good. Replacing the batteries on the
CX-1 required me to remove two plates on the back. Thank goodness for the small screwdriver
sets.
Features
The
CX-1 (and subsequently the CX-2 and CX-3) is a unique type of calculator, which
focuses on solving problems in aviation, as well as a timer, stopwatch, work
with time (hours-minutes-seconds), and conversions. The keys are soft, so presses have to be
deliberate.
Solvers: Aviation
The
CX-1 had a vertical screen separated into two parts: the above portion has the calculator and the
solver and its prompts. The CX-1 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 CX-1
online but was able to find one for the CX-2 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/H-Wind
|
Calculates
head wind (head wind is negative (in your face), tail wind is positive (wind
at your back)), and X-Wind (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
Hours-Minutes-Seconds
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 CX-1 does not have a beep.
Conversions
The
CX-1 features a handful of conversions, all accessed by pressing the [CONV] key
first.
Conversions
available:
*
Hours/Hours-Minutes-Seconds (HMS)
*
Gallons/Liters
*
Feet/Meters
*
°F/°C
*
Kilograms/Pounds
*
Statue (regular) Miles (SM)/Nautical Miles (NM)
*
Kilometers/Nautical Miles (NM)
The Updated CX-3
The
current version, the CX-3 has a backlit, color screen, and can be flash
updated. Added in the second version are
density altitude and rhumb-line 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 CX-1 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