Feb 052013
Astro Compass
The Navigator’s Information File has a description of the Astro Compass (or Astrocompass) . This device was used by navigators to determine the true heading of the airplane, to steer a true heading, to identify a star, or as a pelorus, a device without magnetic needles used to read bearings.
It is unclear to me if, or how often, this device was actually used. I ran across an Astro Compass while visiting the United States Air Force Armament Museum at Eglin Air Force Base, near Fort Walton Beach, Florida.
Pages 122 and 123 of the Navigator’s Information File describe how to adjust and use the Astro Compass.
In the 1960’s to the 80’s, we used an astro compass to get a true heading while in the area of compass unreliability in Norhern Canada. at that time, we flew a B-737-200 combi, usually in a split cargo/ passenger configuration. This was our primary heading information to go to the Dewline and to Resolute Bay. If I remember correctly, we tried for a clear shot every twenty minutes, to avoid too much precession of the gyro compass.
Now, my Grandson uses the astro compass in the same region. He flies an ATR 42.
My brother, an ex KLM captain, gave me recently an old astrocompass Mk2. It is not completely in good nick, so I’m looking for a manual to see if it is restorable to good working condition.
He told me that it is supposedly from the Constellation days, when they used it for flying the arctic routes.
By the way, in his training days, end of 60’s, he was trained in celestial navigation and he reportedly used that during ocean crossing in the old DC8’s