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Old 22nd Mar 2014, 19:23
  #7307 (permalink)  
Pom Pax
 
Join Date: Oct 1998
Location: Kalgoorlie, W.A. , Australia
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First Light

Originally Posted by multycpl
I take it that the search planes can fly in the dark !......So why take off at first light. If it takes 2 hrs to get onsite couldn't they leave 2 hours earlier ??
Yes I believe most modern aircraft can fly in the dark but can you effectively conduct a visual search in the dark?
When is first light? Well there is civil twilight, nautical twilight and astronomical twilight, take your pick.
Today's time for Perth are
Astronomical twilight 5.00 a.m. local (GMT +8)
Nautical twilight 5.29 a.m.
Civil twilight 5.57 a.m.
Sunrise 6.21 a.m.
Now the search zone is at least 20 degrees West of Perth so Sunrise will 80 minutes later, however the search area is also further South than Perth and being Autumn in the Southern Hemisphere Sunrise will be even later.
So an aircraft leaving Perth at 5.00 a.m will be in the search area shortly after Dawn.
oxo
If you are using mk1 eyeballs to look for the debris, you don't want to be starting at dawn when there will be long shadows.
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