"Steven P. McNicoll" wrote:

"Jeff Saylor" wrote in message
...

I believe airports with weather reporting capability also qualify;
many airports that do not meet the qualifications above received
all letters after their new ASOS/AWOS was comissioned.


Yes, I meant to include that. I didn't copy far enough.


On a related note, a bunch of VORs that had the same 3 letter
ID as airports that they were near had their IDs changed a
number of years ago. For example the Williamsport (Pa) VOR
had its ID changed from IPT to FQM. I've wondered if the
letters FQM stand for anything but as far as I can tell it's just a
random identifier. The VOR is a distance away from IPT (KIPT)
the airport, and sits atop a mountain ridge. Apparently some
pilots flew to the mountain instead of the airport.

On the other hand MHT VOR is 4.8 miles away from KMHT
(Manchester NH) airport and they share the same identifier.

This appears to violate 7350.7N 1-2-5
1-2-5 Duplication
a. At the same location, the same identifier may be assigned to
one navigational aid (which must be located within the airport
boundary), to the airport, to a manned air traffic control facility,
and to an aviation weather station on the airport. With certain
restrictions, variations of the airport identifier may be assigned
also to landing systems.


The location identifier criteria obviously changed over time. About twenty
years ago navaids that shared their identifiers with airports but weren't
located on the field began having their identifiers changed. But not all of
them were changed, those that were fairly close were left alone. The cutoff
seemed to be about five miles.


7350.7N 1-2-4 doesn't make it clear that this is ground for
changing the identifier that has been assigned, although it is probably
safe to assume that if the VOR could no longer share its ID with the
airport than this airport was less important.

1-2-4 Permanence.
Established three-letter identifiers are considered permanent and will
not be changed without strong and documented justification, primarily
concerning air safety. Other than three-letter identifiers may be
changed when the status of a landing facility changes, e.g. private-use
to public-use, etc.


FAAO 7350.7 doesn't say anything about what conditions constitute grounds
for changing a 3-letter identifier, but quite a few have changed over the
years nonetheless. DRU is different than any other I've seen change. All
the rest were VORs, which qualify for 3-letter identifiers on their own,
they were just changed to some other 3-letter identifier because they shared
the identifier with an airport some distance away, an airport which also
qualified for a 3-letter identifier on it's own.

The strange thing is that they bothered removing the identifier that had already
been issued; there must have been a compelling reason to make a change beyond
the fact it didn't meet the criteria for a new 3 letter. I wouldn't be
surprised if KDRU shows up somewhere else in the next few years.




But Drummond Airport doesn't qualify for a 3-letter identifier on it's own,
it's not even close. It's just a single short turf strip, 2400 feet, with
no services or lighting. One wonders why it ever had a 3-letter identifier.
One wonders so much that one is compelled to dig out some old publications
that explain it.

Drummond Airport is a former CAA Intermediate Field, it was Site 44B on the
Seattle-Helena airway, part of Green 2. In 1945 the runway was 3600 feet
long, it had runway and obstruction lights, a rotating beacon with course
lights, and an Airway Communication Station (FSS). There was a rotating
airway beacon with course lights, Site 44A on the airway, about three miles
northwest of the field, Drummond Radio Range was about a mile and a half
northeast of the field. The range identifier was DR.

By 1947 an Airport Approach Zone had been added.

By 1954 Drummond VOR/DME was in operation, located immediately south of the
radio range. The range and VOR shared the identifier DRU. Victor 2 had
been established coincident with Green 2. The runway had been reduced to
2600 feet.

By 1962 Green 2 had been disestablished. The radio range was still there
but the identifier had been changed to DU. The VOR, instead of showing DME,
now shows NSME-Non Standard Measuring Equipment. I haven't a clue what that
was.

By 1967 the radio range was gone, the airway beacon was gone, the FSS was
gone, and the VOR had no measuring equipment at all.

In 1972 the airport beacon and course lights were still in operation, as was
the field lighting.

By 1987 the course lights and field lighting were gone, but the airport
beacon was still in operation. The runway was down to it's present 2400
feet.

By 2001 the airport beacon was gone.

The chart segment available on AeroPlanner.com still shows the airport
identifier to be DRU, so the change was very recent.

Interesting history. I wonder why the runway was shortened over the years.