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ACARS (was Re: An Idea)

  • From: richb
  • Date: Sat Sep 15 16:00:48 2001

>From earlier postings:
>> ... have all instrumentation output, voice  and  even  possibly  video
>>  (flight deck and cabin) continuosly downlinked  to ground stations
>>  or uplinked to satellites enroute.

> 1) In addition to traditional "black boxes" there would be
> transmitters in planes that would transmit flight data to a network of
> ground stations
> 3) Since the transmitters don't have to survive an impact they
> wouldn't have to be terribly expensive so you'd be able to intall them
> even on relatively small aircraft.
> 6) Overseas flights might need to switch to some sort of satellite
> system.  This would probably be more expensive so would probably be
> limited to larger aircraft.

This capability has existed since the early 1980s.  It is called
ACARS, which stands for Aircraft Communications Addressing and
Reporting System.  I developed firmware for the Bendix system
purchased by Delta, Piedmont and Northwest Orient in 1985.  Those same
systems (which sold for, if I recall correctly, about US$18,000) are
in use today.  Little, if any, of my other career work has had similar
longevity: it is a (sobering) reminder of how long it takes to make
improvements in commercial aviation.

You can learn more about modernization efforts, including satellite,
overseas, and encryption capabilities, by surfing over to
and searching on the keyword ACARS.

I do not know whether the airlines are interested in using this to augment
the cockpit voice recorder but it would make sense.  Twenty years ago, the
system was limited to 2400 baud and it was essentially used as a "time clock"
for automating the process of tracking hourly air crew wages.  The other
two primary uses were to provide rapid turnaround on jet engine performance
parameters (which reduced service costs), and to expedite bi-directional
weather reporting (pilots could retrieve or file weather reports into an
automated system).

The aviation industry was fun to work in back then but more recently it
has been no joy at all (the last project that I participated in was ETMS,
which is a USA radar tracking network whose control room is in Kendall
Square, Cambridge, MA):  too much bureaucracy and too much money to get far
too little done.  It just doesn't seem hard to me to come up with a snazzy
database system to keep track of 10,000 airplanes in real-time with data,
audio, and video feeds.  A dot-com could've done the equivalent task on
a few tens of millions of VC money in the space of 3 years, whereas the
US government manages to plunder $billions and waste decades.

Pardon me for venting.  But if someone wants to give it a try, perhaps for
some country other than the USA, then I'll come join you on building a
"real" aviation network.