Berlin Airlift, IFR

KP wrote:



Well, "the pilot was expected to maintain separation from terrain" only in
the sense that like any other non-precision approach no glidepath info was
provided. If there was a step-down fix on final the aircraft was descended
to that altitude and only instructed to descend to the MDA after passing the
fix.


Exactly.

One other difference between a PAR approach and an ASR approach is
that in the PAR approach the distances as given are from touchdown,
and in the ASR approach distances are from the runway.

Unless it's a "Surveillance approach using PAR azimuth, mileages will be
from touchdown..."

Let's not confuse the aviators here. ;-)

The AN/TPN-8 (-18 with IFF) was an, ummm, interesting piece of gear. It was
pretty much a "one PAR at a time" set-up so the Arrival guy really had to
space them out in the pattern or get the turn to final right on the money to
get the second aircraft within coverage. Yeah, "interesting" that's the
word I was looking for ;-)

Been there, done that. Also seen on the TPN-18 where multiple PAR
approaches could be run simultaneously on two displays, with the
second final controller also acting as an arrival controller,
switching the radar from ASR mode to PAR mode long enough to sequence
traffic onto final and then switching back to PAR mode, handling PAR
on one freq and arrival on another freq, while the other controller
handles the other PAR on yet a third freq. Highly illegal but it's
been done, with one aircraft landing, one descending, and one
approaching to descend. Of course when the radar is switched from
PAR to ASR, the other controller also loses their PAR display, making
for some imaginative trending information to pilots.

The other "interesting" thing about the TPN-18/TPX-44 setup was having
the controllers read raw IFF blocks to decode.


John Hairell )