Re: McDonnel Douglas warns against carry-on electronic devices

From:         barr@ash.mmm.ucar.EDU (Keith Barr)
Date:         08 Jan 93 12:59:12 PST
References:   1 2
Followups:    1 2 3
Next article
View raw article
  or MIME structure

In article <airliners.1993.34@ohare.Chicago.COM> Kevin Driscoll writes:

> Current opinions vary about how much EMI an avionics system is protected
> against, but 200 v/m is a typical number.  One would not expect the
> above devices to produce such levels.  RF getting into the radio nav aids
> is another matter, but that wouldn't cause a transient change in aircraft
> attitude anyway.  Unless there is more to this story, this looks like a
> case of the ignorant pulling a demon out of their hat.

Wouldn't there be a change in attitude if the autopilot was engaged,
which it obviously was, and if the navigation equipment was disturbed by RF?
For example, if you are flying a heading of 090 to hold the 270 degree
radial to the station, and someone in back turns on their super-powered
Sony Nav-Mess 1000 CD player, the nav equipment, may sense that the
aircraft is now on the 280 degree radial, and the autopilot would command
a turn to the right to correct the situation.  I am not saying this is
what happened, but it is possible.  I don't remember how much bank was
introduced, but I would think, however, that the amount of bank the
autopilot is allowed would be limited to 30 degrees or so.
 _____________________________           _____
| Keith Barr                  \           \ K \__      _____                  
|           \___________\   \/_______\___\_____________    
| Comm/AS&MEL/Inst/IGI         /           < /_/   .....................  `-.
|_____________________________/             `-----------,----,--------------'
When you think how well basic appliances work, it's   _/____/               
hard to believe anyone ever gets on an airplane.--Calvin