NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Aircraft Sextants
From: Andrés Ruiz
Date: 1999 Jul 29, 12:23 AM
From: Andrés Ruiz
Date: 1999 Jul 29, 12:23 AM
I'm wondering how good is an aircraft sextant for use on the sea. Has anybody used one? � In Celestaire catalog I've found: � NAVY MARK V SEXTANT (AN 5851-1) An extremely versatile sextant. It is particularly suitable for marine use, can be used in aircraft; and is perfect for back yard practice. Its great versatility lies in the fact that it is a combination marine and aircraft sextant. As such, it utilizes both an artificial (bubble) horizon, and a visible (sea) horizon. � The bubble horizon is most useful during periods of sea fog or darkness when the sea horizon is obscured. Otherwise, the sextant functions exactly like an accurate marine sextant. � The Mark V includes: a 2x telescopic optical path, a selectable astigmatizing lens, and 4 sun filters. The elevation scale reads from -10� to +100�. A fine scale micrometer drum indicates to 2 minutes of arc with interpolation easily possible to within less than one minute. The sextant is made mainly of brass and aluminum. � The MARK V was manufactured with some models incorporating a chronometric averager. The averager records 60 different readings over a two minute period and supplies an average reading. It was designed for use aboard aircraft where accelerations produce erroneous bubble positions. Sextant weight with the averager installed is 6 lbs., and without the averager is 4 1/2 lbs. Because of the weight penalty, we recommend the non-averaging model for marine use. The Sextant comes in freshly, overhauled condition, with comprehensive instruction manual, and calibration report. It does not, however, come with a carrying case. � Navy Mark V with Averager #1502 $900 Navy Mark V without Averager #1503 $750 � Andr�s http://www.geocities.com/CapeCanaveral/Runway/3568/index.html e-mail: aruiz@orona.es
