The Technical Adak

Well, this is kind of a "surprise" post on a previous subject, Adak, because of a few old pictures I recently came across. Some of you may find it interesting, but the rest of you won't hurt my feelings if you're bored to tears and decide to skip it.

AN/CPN-4 GCA Unit built by Gilfillen. Air transportable, it consists of a prime mover, a parts/electronics workshop trailer, and an operations trailer. On the roof of the ops trailer is the air surveillance radar (ASR) antenna. Just below and to the right of the ASR antenna are a horizontal window and the double-decked vertical window containing the azimuth and elevation precision approach radar (PAR) antennae. There are also various UHF and VHF radio antennas on the "doghouse".

I had been doing some research on Navy air traffic control, and searched high and low on the Internet for a decent picture of a CPN-4 GCA unit and I was hoping against hope that I might even find one of the unit assigned to Adak. A lot of work with little to show for it - not any good photos of a CPN-4. Then I got sidetracked, looking on my computer for a picture of something else and Eureka! I found the picture above - surely the quintessential photograph of a CPN-4, and on Adak to boot! I took this picture shortly after purchasing my Minolta, and it could well have been on the very first roll of film I shot. I scanned it at some point during the last couple years and didn't get around to "cleaning up" the scan, so I had not transferred it to any of my several gallery directories. It's amazing what you find when you keep looking. Housekeeping / bookkeeping. . . pshaw!. . . a waste of time. The pile of snow in the background is Mount Moffitt, the highest peak on Adak at 3924 '.

The picture above is from Google maps. For orientation, the satellite photo is aligned more or less with north at the top. I marked the runways, the ops building/tower, and the location of the GCA unit, which has long since been removed. With the unit aligned perpendicular to runway 5/23, the PAR antennae are immediately adjacent to the runway and point out the final approach course. The patch in the upper left corner of the picture is one I designed on the island. Someone traveling to Japan for R&R took my drawing and had patches made for us. I cannot explain what possessed me to put a checkerboard background on the diagonal separator. On the diagonal, are the three rating badges associated with air traffic control facilities (L to R): engineman, electronics technician, and air controlman.

There's one additional X on the map, north of the runway near the approach end. The day I flew onto the island aboard a Reeve Aleutian Airways L-188 (my 1st Lockheed plane), as we passed over the runway threshold, all the passengers on the starboard side of the plane were treated to the disconcerting vision of a burned out hulk - a memorial the the ones who didn't make it? It was left there undisturbed as long as I was on the island but has certainly been removed since. The X is about where I remember it. Also, my memory is fuzzy on occasion. I remember it as a C-118, the Navy version of the DC-6. But the only records I've found online suggest it was a Navy P-3 Orion that had crashed on takeoff on June 3, 1969, six months before my arrival.

The pair of pictures below was taken inside of the ops trailer, the first one shows the typical layout with a writing desk below the ASR and PAR scopes, a clipboard with "run sheets" to keep track of what little traffic we had, and a small desk lamp. The second focuses on the radar scopes, ASR on top and PAR on the bottom. The PAR scope combines two displays, elevation on top and asimuth on the bottom.

Above, the ASR scope is set up with 2 nm range rings, offset 6 nm north to show more of the final approach (an arrival would typically be shown moving from the bottom of the scope towards the top (Heading 230). You might note the large reflection between 6 and 7 miles from the center, slightly right of the final approach corridor. That return is Mount Adagdak on the northeast corner of the island with an elevation of 2115'.

Above, the ASR scope is set up with 5 nm range rings and centered. The target of interest here is directly under the final approach at 23 miles. That return is Great Sitkin Island, at 5710'. Because of its location, it's been the site of several aircraft wrecks over the years. Note that the compass rose is aligned with the runway; North is NOT at the top of the scope.

In both pictures the PAR display is the same. The vertical ticks are range marks, 1 mile apart and logarithmically spaced (larger spaces closer to the airport). At the vertex of both displays you see "clutter" or "ground return" reflecting the airport. Then, below the 3 nm range mark on the elevation scope and underlying the 3 nm range mark on the azimuth scope is a large reflection that corresponds to Zeto Point, a peninsula that extends out below the final approach course and creates a windshear that always antagonizes controllers, sometimes discombobulates pilots, and regularly terrifies passengers. You can read about my introduction to Zeto Point here. The picture below, taken on one of the two best days on Adak in 1970, looks out over Zeto Point and across Kuluk Bay toward Scabbard Bay.

This excellent picture (found on the internet) is taken from the area of zeto point, looking north at Mount Adagdak. With two small lakes in the foreground the land narrows to an isthmus as it approaches Adagdak. The larger body of water on the left is Clam Lagoon and the one on the right is Sitkin Sound. The scattered buildings in the middle ground are abandoned shacks and Quonset huts, remaining from World War II.

It's hard to do a photo post on Adak without including at least one photograph of Great Sitkin Island. The picture was taken from the approach end of runway 23 with a 135 mm lens and both a 2X and a 3X extender. That's steam from the volcano, not your ordinary everyday cloud. In the middle ground you see Zeto Point (again) with a lot more of the abandoned Quonsets. In the foreground is a low bank of tundra and sea oats between the runway and the water.

Pop Quiz:

- Sitkin's elevation is _____'. It lies ___ nm northeast of the airport.

- Zeto Point lies ____ nm off the end of the runway.

- Adagdak is off to your right as you approach to land on runway 23, ____ nm from the airport.