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» Online Classroom   »   » Public Discussion of Cel Nav   » Ex. 6.6 (Running Fixes) question

   
Author Topic: Ex. 6.6 (Running Fixes) question
Rich A


 - posted July 31, 2016 01:58 PM      Profile for Rich A           Edit/Delete Post 
Even though the exercises only really require you to advance the 1st LOP to the 3rd LOP in order to get the answer, would it be more accurate (and realistic) to advance LOP 1 > LOP 2, then LOP 2 > LOP 3?

Also, would it be more accurate to use an adjusted DR position from the RFIX you get from LOP 1 > LOP 2, then continue with your DR direction and speed?

Thanks

From: Lacey
Capt Steve Miller


 - posted July 31, 2016 04:11 PM      Profile for Capt Steve Miller           Edit/Delete Post 
Yes, it would be more accurate to advance 1st & 2nd to the 3rd LOP. But, you could advance the 1st to the 3rd and then the 2nd to the third using the appropriate times along the course line.
Advancing a LOP does not require a DR position, you just pick a point on the LOP and advance it along the course for the appropriate distance.
Advancing the two LOPs to the 3rd will very likely produce a 'cocked hat' from which you will have to pick the most likely FIX point.

From: Starpath
gschlos08


 - posted July 03, 2017 02:44 PM      Profile for gschlos08           Edit/Delete Post 
How long should it take for someone trained to calculate Hc and Zn for the three sightings and plot the course and LOPs and advanced LOPs on the plotting sheet to obtain the fix?
From: miami, fl
Capt Steve Miller


 - posted July 03, 2017 03:45 PM      Profile for Capt Steve Miller           Edit/Delete Post 
If you are using a computer or calculator solution, obtaining a Fix from 3 LOPs should take less than 5 minutes.
If you use The 249 or 229 Tables and a worksheet it should take about 30 minutes to do the same including doing the plot on a UPS.

Advancing the LOPs to a common time can add something to the process, depending on logbook records.

From: Starpath


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