# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Message:αβγ
Message:abc
 Add Images & Files Posting Code: Name: Email:
Re: Open Cockpit Sun Sights Exercise
From: Ken Gebhart
Date: 2013 Mar 6, 15:01 -0600
Paolo, It sounds like you had the back seat person hold the plane steady while you averaged readings over a period of time. Averaging would be necessary because the control inputs necessary to hold the plane steady impart accelerations to the bubble.  You might try next time to take a single sight while the plane is trimmed hands off. Between the beginning and end of the sight, if the plane did not change heading or speed, the sight should be accurate. Of course I don't know if you CAN trim a Stearman hands off!

Ken
On Mar 6, 2013, at 2:14 AM, Paolo Borchetta wrote:

This morning I took a pilot friend and we went flying to take a series of sun' sights and see the results. The plane, a Boeing Stearman, is an open cockpit biplane of the late 30's, I sat in the front cockpit which is a bit more spacious and allows me to be able to get shots looking on one side thus clearing the upper wing.
The session was rough one in terms of just taking a series of sights, mathematically averaging them, the same for the time, start of series UT and end of series UT, averaged. Few calculation on a knee board piece of paper to get a single LOP. Not much use but later the data have been verified against the USNO results for same position and time. Here are results:
Ho 46 09.4' against a Hc 46 15.8' with an intercept of 6.3'A.
bubble octant A-12 Link, bubble size 2.5 sun' dia.,pressure altitude 5,000 feet, speed 75 Knots and OAT 16C. Pos. Lat 24 28.2'N; Lon 054 22.8'E.
Paolo

----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------

View and reply to this message: http://fer3.com/arc/m2.aspx?i=122655

Browse Files

Drop Files

### Join NavList

 Name: (please, no nicknames or handles) Email:
 Do you want to receive all group messages by email? Yes No
You can also join by posting. Your first on-topic post automatically makes you a member.

### Posting Code

Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
 Email:

### Email Settings

 Posting Code:

### Custom Index

 Subject: Author: Start date: (yyyymm dd) End date: (yyyymm dd)