From AVweb.......
Runway Holds Banned?
Taxi-into-position-and-hold (TIPH) (scroll down to 3-9-4) clearances can
speed up operations but they can also put aircraft in direct conflict if
things go awry and recent stirrings suggest the FAA may be moving toward a
nationwide ban on the practice. According to numerous e-mails received by
AVweb, the practice will officially end March 20, but FAA sources weren't
able to confirm that for AVweb prior to this publication. Already
commenting, however, the National Air Traffic Controllers Association says
the ban will have something opposite of the desired effect on safety. NATCA
spokesman Doug Fralick said eliminating TIPH will make it much more
difficult for controllers to judge how much time is needed to ensure the
runway is clear for the next aircraft on approach, ultimately decreasing an
airport's flights-per-hour capacity while adding more variables to a
controller's equation. If the plane taking off is already on the runway and
ready to go, the departure time is easy to predict, but if the next plane in
line has to maneuver onto the runway, perhaps backtrack and get turned
around, seconds can easily turn to minutes and the chance for conflict
grows. "Therefore the likelihood is that spacing on finals will have to be
increased, once again decreasing capacity while at the same time the FAA is
doing all they can to increase capacity," Fralick noted. He also said the
FAA is using a blanket approach to the issue when there are many airports
that have never had a problem caused by TIPH. "The bottom line is that the
loss of TIPH will make the airport environment a more dangerous place than
it was before," Fralick said. "I couldn't imagine not being able to use this
time proven tool."
http://www.avweb.com/eletter/archive.../588-full.html