reply to post by nh_ee
I truly don't wish to rain on your parade, nh_ee
, but your account (of LORAN) and the navigation for instrument approaches (it is a
"localizer", nowadays. Not sure when that was invented, will research).
Anyway, the guy flying the bomber was doing the (unthinkable, to most of us) and just dropping down and HOPING to see the ground, and find his way to
the airport. (It is now named "La Guardia", or course...back then it was just the "Queens Airport", because that's where it's located).
The plane was only minutes from LaGuardia but lost in a dense fog that limited visibility. Flight rules of the time required aircraft to maintain
an altitude of at least 2,000 ft (610 m) over the city, but Smith dropped to less than half that height hoping to regain sight of the ground. That he
surely did, but the pilot had misjudged his location and soon found his plane bounding through the concrete canyons of the city's skyscrapers. The
bomber soon attracted attention from alarmed citizens as its roaring engines echoed off the facades of buildings below. Those working in the upper
stories of office buildings raced to windows to watch in amazement as a plane flew beneath them, turning and banking rapidly as its wingtips barely
missed some structures. One observer was Army Air Force Lt. Frank Covey who spotted the doomed B-25 from his room in the Biltmore Hotel. Covey watched
in disbelief as the plane barely missed the New York Central Office Building and was no higher than its 22nd floor.
Further research on the history of the localizer. (It is a component, usually, of the full ILS**)
(**)ILS = Instrument Landing System, which includes, as mentioned, the Localizer -- along with a Glide Slope transmitter, marker beacons (^^) along
the final approach portion and, in modern era, the Approach Light System (ALS). However, the Localizer alone can be used as a navigatigonal aid in
certain Insturment Approach Procedures.
(^^)Marker beacons a bit superfluous, nowadays. They are still there, but really are unnecessary in reality. Especially in a "precision approach"
procedure (when there's a glideslope) we know our lateral location, along the final approach course, by our altitude. WHEN "on glideslope", of
course. Also, modern era, there's usually DME associated as well. DME = Distance Measuring Equipment. All of this info is on the proper Approach
Plate (or chart) that is referenced for the procedure. Example links below.......
I found that in 1945 (no specific month given, will keep digging) there were only NINE facilites in the U.S. that had ILS installed. And, the source
I just found did not specify the locations. Except, one was mentioned...Pittsburgh. Mentioned as the FIRST place a full ILS approach was conducted
with a passenger flight, in 1938. In a snowstorm.
Also, in that era (1938-1945) different forms of technology and systems were being tested, until finally they settled on what is still in use today.
Of course, on-board equipment is far superior to that of the earlier era, as well as how it's represented to the pilots. Ground equipment no doubt,
Approach Plate examples:
Washington National Airport ILS Runway 01
(You can read, near the bottom, that if the G/S ----glideslope---- is INOP, then it becomes a non-precision Localizer only procedure....that is in the
box labeled "S-LOC 1". It merely shows the different weather "minima" requirements. Also, arranged by aircraft 'category'. Basically, 'category' in
this sense refers to the minimum/normal speeds able for an airplane, on approach. Go faster, less time to react, so 'higher' minimums).
So, the Localizer can stand alone (in some cases, when there is no glideslope transmitter installed) or, in the case when G/S transmitter is broken,
the procedure is "downgraded" and used appropriately.
Also, there exist (becoming increasingly obsolete, though) the LDA, or "Localizer Directional Aid" approach procedure, still in use at National
Washington National Airport Runway 19 LDA
The "LDA" is a localizer sgnal that is offset, or not aligned, with the runway. It is a more precise form of guidance than, say, a
or NDB (##)....and it helps for unique situations like DCA. (Where,
because of the Prohibited Areas over the city, a straight-in to Runway 19 cannot be conducted).
(##)NDB approaches are all but obsolete for sure, nowadays. With the increasing use of GPS, they are designated "RNAV" approaches now....when relying
on GPS for lateral navigation in approach scenarios. "NDB" is aka "ADF", for those old-timers out there.
edit on 25 September 2010 by weedwhacker because: Text and links.