[Laser] Laser injures Delta pilot's eye

TWOSIG at aol.com TWOSIG at aol.com
Mon Oct 4 21:47:42 EDT 2004


I have been following the comments on the news story.  A few comments from my 
perspective.  I have no conclusions, just some thoughts to put a few 
boundarises on the discussion.

>From various news reports the aircraft was a 737 about 5 miles from the 
airport.  Typical landing pattern is at an angle of about 3 degrees.  At a range of 
about 30,000 feet, the aircraft's altitude would be 1500 feet, probably less. 
 Approach speed of a 737 is between 100 and 160 knots depending on weight and 
flap setting.  The aircraft would have been less than 3 miniutes from 
landing, which would put the flight crew very busy, looking both in and out of the 
cockpit.

The reported event involved a green laser.  Green is a fact, which I can only 
assume was accurately reported.  That would rule out any red laser pointers.  
If it was a laser might be questioned, but to the general public only a laser 
is bright enough to cause eye damage at night in an airliner.

Some supposition, that the pilot would have been injured in the time before 
he could blink, which is reported to be about 0.25 seconds, during which time 
the aircraft would have traveled about 42 feet.  The cockpit window would 
provide good visibility from straight ahead to each side, but not down.   On the 
assumption that the beam came from the ground, the possible "footprint" is 
bounded, though large.

The beam would have to have been bright enough to cause damage to the pilot's 
eye and large enough, or controled enough to follow the aircraft's path.  The 
higher the energy density, the faster the eye damage, the smaller the beam 
had to be, or the less time it had to "track" the aircraft.

If it is a terrorist tactic, it will not be an isolated incident.  Nor will 
future incidents be isolated to Salt Lake City.  The less press this gets, the 
less likely it will be attractive as a weapon.   And the less likely some 
Washington Bureau-idiot will make experimenting with, or even possession of lasers 
into a federal crime.


James
N5GUI


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