-----Original Message-----
From: Jose ]
Posted At: Wednesday, October 04, 2006 9:13 AM
Posted To: rec.aviation.ifr
Conversation: How can we "fix" LEX to prevent wrong runway selection
everywhere?
Subject: How can we "fix" LEX to prevent wrong runway selection
everywhere?

I find myself wondering what the cost of a low-power ground radar
capable of interpreting transponder codes, coupled to a small (not
much
horsepower) computer capable of matching the geo-coords of the txpdr
to
the assigned runway (or taxiway) and triggering an alarm if the
variance
is too great

It would not help in the case of intersecting runways when the
aircraft
is =at= (or close to) the intersection and lined up for the wrong one.
It would not know that the pilot is intending to take off, rather than
simply pausing for traffic. (this means that there could be many
false
alarms or many misses, depending on how the software is set up).


Good point - the system would have to monitor the aircraft after it was
in position and during the start of the takeoff roll to determine which
intersecting runway was being used.

This should all be off-the-shelf technology, shouldn't be considered
a
"flight critical" or "safety-of-flight" system (so if it goes down for
a
few hours only the local information would change)

... and it may well be down when it's needed. One of the issues with
the LEX incident was that lights were not working properly, and there
was construction on the runway. It shouldn't have mattered (as your
proposed system's down time shouldn't matter) but if the system is
there, and it's relied upon, and it's down, then even though people
may
know it's down, it provides a hole in which to bury oneself.

Another good point - The alarm would have to be in both tower cab and
the cockpit and have to be audible to be effective.

I'm not sure how we can ever reduce the possibility to zero regardless
of the technology we implement. Short of erecting a barrier net on the
inactive runway, there may be no way of keeping humans from making a
mistake and attempting to depart on the wrong runway.

As it is now however, the only checks and balances are all human. I'm
not sure it shouldn't remain that way, but at the same time if some
technical solution isn't developed by the industry then the politicians
and lawyers will develop one for us. We all know how well those work...


That's why we practice partial panel and such, and why there is a
reaction against all the gee-whiz (moving map, glass) in the cockpit
with some pilots thinking it reduces general pilot competency.

Jose
--
"Never trust anything that can think for itself, if you can't see
where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.