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Re: do it yourself strobes . . .

Subject: Re: do it yourself strobes . . .
From: Robert L. Nuckolls III <nuckolls@aeroelectric.com>
Date: Tue, 11 Aug 1998 13:16:59
>Yes,
>        ... and old VWs with 6 volt lighting system and DIM headlights are
>still legal, but would you want to drive one on a windy, dark road at
>night???          I'm just surprised that the standard seems to be "boy,
>that's bright!" when observed inside the hangar.  These lights are designed
>for being seen from miles away, so at least do your eyeball checks from the
>other end of the runway.  Actually, older aircraft don't need any strobes,
>but try spotting them in the traffic pattern at night at any metropolitan
>airport.


  Yeeeaaahhhh BUT. The increase from 100 to 400 CP in light output
  is not all it's made up to be. Fortunately, the eye and supporting
  firmware is a very logarithmic sensing device - fortunate for us
  who use them or they'd be VERY hard to use over the range of 
  bright sunlight to starlight illumination levels. In a base 10
  logarithmic scale, the increase from 100 to 400 would result in
  only a few percent increase in perceived intensity . . . I forget what
  the average human eye was scaled at but I think it's response
  curve is steeper than a base 10 curve. Suffice it to say that
  standing side by side at a couple miles distance, you would be 
  able to pick out the 400 CP device over a 100 CP device.  
  However, the notion that it's 4x more likely to get somebody's 
  attenion is pure wishing.

  The annals of aviation tragedy are full of cases where airplanes
  come together simply beause two or more pilots had their heads
  down. Whether your strobes are 10, 100 or 400 CP, they won't be
  seen if nobody is looking for them.  This is one objection I have
  to things like moving maps, engine analyzers, etc.  Neat devices
  from a performance/technolgy perspective but they can intrude
  in dangerous ways upon a pilot's responsability to fly the airplane
  and avoid hitting things.

  IMHO, change to strobe rules was but another example of a group
  of rule makers sitting around the table saying, "okay guys,
  what shall we do THIS week?" On the face of it, they appear
  to be doing good things. In reality, airplanes will continue
  to hit things for reasons that regulation and punishment cannot
  affect.

  Heads up, enjoy the scenery, save systems diagnosis and repairs
  for the hangar, and watch for they guy with the strobes built
  from an article in a magazine . . . if you're looking for him,
  you WILL see him.


      Bob . . .
      AeroElectric Connection

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