DC-3 Astrodome

Astrodome for C-47 found at Oshkosh

For me, the highlight of our trip to EAA Airventure was finding this part for our plane. Unless you are a DC-3 "Nut" as are some of us, you may not know that all C-47's had an astrodome, which is a transparent (Plexiglas) dome intended primarily to permit taking celestial observations for navigation. (Also known as an astral dome or navigation dome).

On the C-47 it is located on the upper fuselage, just aft of the cockpit. Technically it only belongs on the military C-47, not a civil DC-3, but since we intend to continue to display our plane as a C-47, it is appropriate and authentic on a C-47.

We have wanted a navigator's dome ever since Massey acquired the DC-3 in 2006. In 2007, while in Oshkosh, we picked up a radial engine firewall which Basler Turbo Conversions was kind enough to donate to the museum (they can't utilize radial engine parts). While talking with them I asked about the availability of astrodomes. Oh yeah, they had some NOS (new old stock) but there was no way they were going to part with them since there was still a demand for them from their customers, some of which are foreign military. From that, I suspected a dome would be very expensive if one could even be located.

On Tuesday, I was looking for a pitot tube for the Corsair in the Aeromart ("Flymarket") at Airventure when I saw it on a low shelf. Unbelieving of my luck, I reached down to read the attached description on the card: "astral dome - C-47". Not only was the Plexiglas clear but it was attached to the circular aluminum mounting ring (contoured to fit the fuselage diameter). In the top center of the dome was a black rubber disc with what appears to be a flat aluminum grounding wire running to the mounting piece. The Aeromart was very helpful providing transportation to Jim's van in the campground so that we didn't have to carry it around.

It looked right but at 19" diameter it seemed a little small, so we walked to Warbirds to check out the other C-47s. That confirmed it, one of them even had the black center piece - which, being difficult to see from the ground, I had never noticed before. There is a lot of satisfaction in making "finds" like this - if one is a little obsessed with airplanes.

Navigator's astral dome or astrodome.  We think this is for grounding static electricity.

Left: Plexiglas is in good shape, we were surprised to find grounding device.

Right: Jim Sypherd & Bill Dougherty marveling at their good luck in finding the dome.

In addition to the dome's primary function, allowing the navigator to shoot stars for celestial navigation, it was used for communicating with towed gliders or other planes in flight.

Aldis Lamp: During a combat mission, because of radio silence, a crew member standing on a small stool in a lead plane, would flash the Aldis Lamp through the Astrodome. With four minutes before the paradrop, the Lamp, covered with a red filter, would be flashed at formation pilots who in turn alerted the paratroopers to stand and hook up. At the drop moment, the Lamp, now covered with a green filter, was flashed again to inform the pilots [and the paratroopers] that they were over the drop zone.

Following is the (partial) reminiscence of a C-47 crew member on D-Day June 6, 1944:

Navigators, crew chiefs and radio operators could not resist seeing the view. First up forward through the pilot's front windows, then through the overhead astrodome, and also by way of the large opening in the rear of the aircraft where the jump door had been removed. The full moon shone brightly, reflecting off the skins of the "goonies". Damn near like daylight. [HALL] "I was scared and anxious, but that was one of the most beautiful scenes I have ever seen. My job was to go up in the bubble (astrodome) and scan the skies for enemy airplanes, but I could also take in the view. Out across the English Channel were airplanes as far as you could see, all headed for the coast of France.

Re: 29th Troop Carrier Squadron in England http://www.patriotfiles.com/index.php?name=News&file=article&sid=499

The Aldis signal lamp has a sighting scope for pointing directly at "target" plane.

WW II Era photo taken from the astrodome of a C-47

http://www.506infantry.org/his2ndbnwwiiarticle08.html

View of Astral Dome on a C-47

http://www.microworks.net/PACIFIC/aviation/r4d_gooneybird.htm

View of Astral Dome on a C-47

This outstanding close formation air-to-air photograph was taken by 1st Lt. John M. Jones. It is one of many photographs in Lt. Jones' autobiography of his experiences with the 71st TCS during WW II. Visit the 'In their Own Words' page for Lt. Jones' autobiography. http://www.71stsos.com/71st%20C-47%20Air-to-Air.html

Massey Air Museum