Question About Turns > 90 Deg

Post Reply
luckyb52
Posts: 52
Joined: Fri Jun 06, 2014 9:18 pm

Question About Turns > 90 Deg

Post by luckyb52 »

:) Hello Fellow Simmers,

I'm approaching a fix. At the fix I am supposed to turn more than 90 deg onto a VOR track.

1.) Do I have to slow down, and if so by how much?

2.) Should I start turning early to a heading less than 90 deg from my current heading, then make another turn onto the VOR track? If so, how do I decide what the heading for the first turn is and when I should make the first turn?

I have researched the wazoo out of the Internet for the answers but to no avail.

Please help me out with wise counsel?

Thanks a ton in advance!

Best,

Lucky :)

///////////
hoser70
Posts: 169
Joined: Tue Jul 30, 2013 1:48 pm

Re: Question About Turns > 90 Deg

Post by hoser70 »

I wouldn't slow down. Just time it so you are on course after the turn/fix.
Thanks,
Lance

NDB Air
Scott Medeiros
Posts: 321
Joined: Sat Apr 12, 2014 8:49 am
Location: Atlanta, GA

Re: Question About Turns > 90 Deg

Post by Scott Medeiros »

The rule of thumb I always taught my students was GS/100=NM from the VOR to begin your turn. This alone works fine for low level flying. For higher altitudes the DME includes the slant range from the VOR. FL360=6NM of slant range distance. You must remember to add this distance to your calculated distance. Winds aloft will also affect your turn radius so this rule of thumb will simply get you close to the radial. You may still need to correct a few degrees to intercept the proper radial. 15* should be sufficient to get you on course.
gavink42
Posts: 171
Joined: Mon Apr 16, 2012 7:08 pm
Location: KMEM

Re: Question About Turns > 90 Deg

Post by gavink42 »

For VORs, I generally do what Scott said.

Just to dive into the topic a bit further... if you talk about waypoints and RNAV navigation, the AIM describes the important difference between fly-over and fly-by waypoints:

http://www.faa.gov/air_traffic/publicat ... m0102.html

- Gavin
- PP ASEL, instrument, complex, high performance
- Member AOPA, EAA, IMC Club, Piper Owner Society
- Cherokee 180C owner
Ryan B
Posts: 856
Joined: Mon Mar 05, 2012 2:37 pm

Re: Question About Turns > 90 Deg

Post by Ryan B »

I use what Scott does when flying...

In fact as a rw controller I use that rule of thumb for vectors to final approach course.... assuming you're being vectored on a course 90 degrees from final. I just add or subtract a percentage if it's different or if the wind will push pilots farther etc
PE ID: 29
FAA ATCS
FAA PPL ASEL
luckyb52
Posts: 52
Joined: Fri Jun 06, 2014 9:18 pm

Re: Question About Turns > 90 Deg

Post by luckyb52 »

:) hoser70, Scott, Gavin and Ryan,

Thanks so much for your tips. I will start the turn at GS/100 and add slant range for higher altitudes.

The AIM chapter of fly-by and fly-over VORs was fascinating.

Thanks again!

Best,

Lucky :)


//////////
Peter Grey
Posts: 5716
Joined: Tue Oct 12, 2010 3:21 pm

Re: Question About Turns > 90 Deg

Post by Peter Grey »

Here is another thread from a while ago that seeks to answer the same question.

It provides some good reading (and my take on it) to support the answers above.

viewtopic.php?f=3&t=1316&p=8365&hilit=turn+lead#p8365
Peter Grey
PilotEdge Director of Quality Assurance and Operations
peter@pilotedge.net
Post Reply