An Idea

Sat Sep 15 04:14:47 UTC 2001

On Fri, Sep 14, 2001 at 11:06:59PM -0400, Grace, Terry wrote:
> 
>    With  all  of  the  difficulties piecing together what occurred on the
>    aircraft,  a  friend  and  I were throwing around some wild ideas. One
>    that  I thought had some merit was to have all instrumentation output,
>    voice  and  even  possibly  video  (flight deck and cabin) continuosly
>    downlinked  to ground stations or uplinked to satellites enroute.

Yes, I've had a similar idea:

1) In addition to traditional "black boxes" there would be
transmitters in planes that would transmit flight data to a network of
ground stations that would record the data.  The storage problems
would not be too bad as recordings would be recycled after N days.

2) The transmitted data would be sent encrypted and only the
ciphertext would be recorded by the ground stations.  Encryption would
be done using symmetric ciphers.  The encryption key would be set
before every flight by a NTSB technician, and known only by the NTSB
(or the equivalent agency if the flight originates overseas).

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.

4) The transmitters should be designed and installed so that they
would be difficult to disable while a plane is in flight.

5) Decryptions and correlation of data from multiple ground stations
need only be done if needed, after the fact.

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.

Jeff