Turnpoint list creation checklist

On Thursday, November 20, 2014 4:42:51 PM UTC-5, 2KA wrote:
(This reply is specific to the USA)

Chris,

Your list shows that you have put a lot of good thought into the topic. However, I've been creating turnpoint lists for contests and other uses for some years, and my process looks quite different. There are a couple of reasons for this:

- There are automated tools to do many of the things you mention, such as generating names, renumbering, composing airport lists, and so forth.

- The problem of keeping the airport data current is actually much more difficult than you might think. Most of the tunrpoint lists I see are materially stale. This happens because airports (especially private ones) close, frequencies and ID's change, and so forth. These kinds of changes are actually more frequent than many people realize.

So here is my process:

1. Concentrate on getting the control points established first, primarily using tasking considerations. These are the ones that would be numbered points in a contest, including the starts and finishes. Produce a list that contains ONLY the control points. Many people like to use SeeYou for this planning, and produce a .CUP file at the end.

2. Add to this list any unofficial airports or outlanding places you might want to include. These are the ones that would not appear in official databases. Designate these as "Outlanding Place" in SeeYou. This plus the control points from step #1 become your master list.

3. Compose a "black list" of airports that you want to exclude from your final database. These are ones that appear in the official sources, but for some reason should not be included. Perhaps the airport doesn't actually exist, or there is some reason you really wouldn't want to land there.

4. Use an automated tool such as my website (http://www.soaringdata.info) to fill the turnpoint list with airports. There are a couple of ways of doing this. One is to select a centerpoint and a radius. Another is to let the system to compute a bounding polygon for the turnpoints, and include all the airports within or near the boundaries. My system will produce a Soaring Turnpoint Exchange (STX) format file as well as CUP and a few other output formats. It will also automatically produce companion special use airspace files for the area covered by the turnpoints.

5. Make any hand edits you think necessary. You can choose to correct mistakes that might originate in official data here. There is also a way to make error reports to the FAA so that the official data gets fixed.

6. Submit the STX file to the Soaring Turnpoint Exchange. John Liebacher has automated tools to automatically translate it to literally dozens of different formats, complying with name and other restrictions unique to each.

7. When it comes time to update the database, you just start at step #4. You get fresh airport and airspace data painlessly.

I can provide detailed help with any of these steps if you would like to contact me separately. You can use the "Questions and Comments" link on my site.

Best of Luck

Lynn Alley
"2KA"

Lynn,
Thanks for the reply. In all practicality how often do you think we should update the official turnpoint lists for clubs and contest sites?

It is fair amount of work for the person doing it, as well as other volunteers [John L], but also pilots do seem absolutely resistant to going out and getting updated turnpoint files often. If I updated the local turnpoints list annually or even every 2-3 years I suspect I would get nastygrams from pilots. Nobody wants to find out they have the wrong TP file after they launch or get scored. Pilots don't seem to be in the habit of getting the latest data often.

Chris

For contest sites I definitely think they should be updated for each contest held or at least annually. If you follow the procedure I outlined above, it takes little time to update airport and airspace data -- certainly less than an hour. It makes John's life a little simpler also to have the input in an STX file. His tools handle things pretty automatically.

I update the local database (radius about 350 miles) in my glider a couple of times a year. There are material differences every time I do it. After frequency changes, the most common, unfortunately, is airport closures. New ones do open up from time-to-time.

Note also that simply updating airport information does not affect names, numbers, or locations of control points.

On Wednesday, November 19, 2014 9:15:10 PM UTC-5, wrote:
I am in the process of creating / editing a turnpoint list for another site in the US. I have created a few, this time I thought it might be good to gather input on what the best practices to do this as efficiently and accurately as is reasonable. Here the the notes I've written up so far on a check list. I would like to hear any helpful feedback.

* Establish a boundary based on possible best flights on best day ever, and remove all airstrips/airports "well outside" the boundary (items close to the boundary will probably be included for completeness).

* Remove all obviously abandoned/missing airports/airstrips.
Add in airports within the established boundary that are in the nearby databases, but not in the current database.

* Decide which are Turnpoints for contest and badges and what are additional landpoints, Plan points for 300+500km O&R & Triangles, plan to Accommodate the Best Pilot on the Strongest Day.

* Check to see if any TP are listed at 0ft MSL by error.

* Check each point in Google Earth, often the location is very wrong in official databases, do not change FAA data if its not off by more than about 750' in distance or 50'altitude. [bias toward offical data].

* Review special use airpace in task area.

* Separate turnpoints for Start and Finish?

* Verify Attributes, HSFTA, G

* Verify spelling

* Convert Metric Alt to feet if needed [or inverse]

* Renumber

* Sort all points alphabetically and see if any truncated names would be identical, such as a Turnpoint name Etowah, and a landable point called Etowah Bend.

* Names should not include special characters which are incompatible with 1 or more gps systems, examples: , ' * ! : ; & $

* Turnpoint names which start with numbers can be bad: number 2 which was 411X64 in the current database is a bad name for some software since it shows up as 02411X64 and computers think it is turnpoint number 2411 and put it at the bottom of lists.

* Names need to work (be differentiated) when truncated down to 6 and 8 characters, some navigation systems only display 6 characters, also some TP file formats have 2 numbers at the front of the name so that takes away 2 letters. Some systems such as SeeYou will abbreviate by eliminating vowels, this can make some names worthless and will need to be edited to have critical vowels.

* Regarding coordinate correction, Generally, John L's process "snaps" coordinates within a given radius of official airport coordinates to the airport coordinates. Of course this is not always appropriate (coordinates wrong etc). So give him a list of stuff not to snap and he will code it to be left alone."

* Recheck names and positions after getting back from Leibacher.

* Test import into scoring program, Winscore or SeeYou, and cockpit nav programs if possible.

* Review with other stakeholders.

* Approve for release.


---

On a side note the more I discuss with people which landout spots should be included the more I want to add more points. I hear comments like that "field could have a crop in it", or it might not be usable due to such and such. The same can be said of airports, I've see airports be closed due to accidents or maintenance, or to be converted into farm fields or housing developments. Perry last year had something like 2 gliders blocking 2 parts of the runway at the same time - a gear up and something else, pretty much made it hard to use for the people low in the pattern.

As far as I can tell there is no way to guarantee that ANY field, paved or grass runway will be available or useable when you want it. All points in a turnpoint file should be considered with suspicion until you get to inspect it from the landing pattern.


Chris

Also of interest (at least in our club's lists) have been the other glider
clubs in the region, out to a fair distance. We like hunting the BRSS Boomerang
Trophy, so it's nice to have its various homes at hand.