II. GPS

GPS is the most obvious change.

GPS made navigation much easier. There was a lot of grumbling, “real pilots know how to look at a map.” To this day, there’s lots of grumbling that “pilots will just stare at their GPS all day,” ignoring how much head-down time map navigation and glide planning took, and the fact that there has not yet been a midair collision ascribed to staring at GPS.  GPS was initially banned in contests, rules only giving in when costs got to the thousand dollar range, and most pilots were flying with GPS in their everyday flying.  It’s interesting that we loudly protest  $1000 instruments, but think nothing of each new generation of gliders that double costs. Now, of course, no student pilot leaves on a silver C attempt without two GPS and a moving map, and the immense controversy is hard to remember.

Interestingly, the vario got the same reception in the 1920s. “You’re losing the real skill of soaring by the seat of your pants.”  Both cases are worth remembering as we think how future technology will infuse to the world of soaring.

Easier navigation is only a small change. The secure flight recorder, developed by Dave Ellis at Cambridge brought the big change. Again, by itself the change from cameras to GPS documentation was a minor though very useful improvement. The Big Change is that the flight recorder opened the way to fundamental changes in how we run and fly contests. These are:

1. GPS allows the turn area task.

Unlike the traditional AST, the competition director (CD) assigns a sequence of areas; in the US circles between 1 and 30miles in diameter. Pilots must fly through these in order, but can choose to go deeper in one or shallower in another area.  A minimum time is announced, and if you finish undertime, your speed is calculated using the minimum time.

This task is slowly taking over as the default task. Many contests are now all turn area tasks, with one MAT (modified assigned task) and one pure assigned task (maybe) thrown in for variety.

The turn-are task is fundamentally different because it is defined by time rather than by distance. Where a new pilot faced a steady stream of landouts in the good old days, now new pilots can simply cut the task short and come back home.  Conversely, a CD who doesn’t want to discourage his newcomers can still call a task that fully challenges the top guns. If you have 4 hours of soarable day between start open and the end of the lift, you can call a 4 hour task; the winners can do hundreds of miles, and the newcomers can also fly a full day but end up at home around the bar.

The other time-limited task is the MAT, modified assigned task, in which pilots pick their own turnpoints. This has evolved steadily over the years. Its ancestors are the distance task, then the “cat’s cradle” distance. The rules and typical task layout have changed as well, with more emphasis on the assigned part, and less on the go where you want part.

However, pilots dislike MATs – they take a lot of in-cockpit head work, there is a lot of luck involved, in the sense that roll of the dice strategic decisions about which turnpoint to go to has a big influence on the results, and the optimal tactic is often to buzz around a few turnpoints in good lift or close to home. This isn’t real cross-country soaring. The MAT rules are flexible enough to accommodate more interesting variations – the ‘’Long MAT’’ with many assigned points in place of assigned tasks; the “OLC MAT” in which you can only use three turnpoints, and so forth – but these variations have not come in to widespread use yet.

The MAT is an important part of US contest soaring. It allows tasks in weather that even turn area tasks cannot accommodate, and situations such as very long ridge flights. But it isn’t as popular as the TAT in most cases.

The MAT does spread pilots all over the sky, which lessens start roulette and gaggling a lot. However, pilots like a certain amount of gaggling, the feeling of racing, and the sense that the race depends on what you do with a given sky, rather than clairvoyant turnpoint choices.

The TAT is so popular because it seems to arrive at just the right combination. Pilots are in roughly in the same sky, or at least parts of the sky that they can see and evaluate rather than guess.  (Sometimes a poorly set TAT leads to a big strategic decision about conditions in a far away turn area, which is less fun – but better than a MAT in the same weather.) You do see other gliders, and small gaggles form. But start time tactics and massive furballs are much less present.  The TAT is much more about the pilot, the glider, and the weather; not the start, the leech and the gaggle.

We are still adapting. I think some CDs call far too large circles – two 30 mile circles adds up to “just go where you want.” Often CDs call too short times. They seem to have mistaken the “minimum time” of 2.5  hours in regionals and 3 hours in nationals for the “target time,” ignoring clear directions in the rules to use the available soaring weather to its maximum.  They seem to forget that a short time is not necessary to bring newcomers home, unlike a short distance. We’re still fixing glitches in the rules: In 2009, we fixed a glitch involving  undercalled tasks; in 2010 I hope to fix a glitch involving the speed and distance points.

All of which emphazises my point. It was not GPS per se; or even GPS navigation or GPS flight recorders that made the big change. The big change is how GPS led to changes in how contests are run, flown, and won. And though GPS is 20 years old, that process is still underway.

2.  GPS-controlled start, finish.

In the good old days, there was a start line, visually controlled, with a limited altitude. You had to call the start gate, do an exciting VNE dive, and hear “good start.” The finish was a line in the airport, which you passed over, hopefully at high speed and 50 feet.

Now the start is (in the US) a cylinder, and is controlled by GPS. You simply pass a line in the sky, or thermal out the top. The cylinder is set up so VNE dives and other madness are not possible. The finish line is still available, but more and more contests are moving to a finish cylinder, also with a reasonably high floor of 500 to 1000 feet. You cross this line at normal flying speeds and enter a pattern to land.

It’s much less exciting.  But it’s a lot safer. We don’t have any flutter through the start gate anymore, and the appalling string of accidents at and near the finish line is sharply reduced.

3. Retrieves.

It goes without saying that GPS & cell phone change have dramatically changed the retrieve experience.

Series Navigation

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  2 comments for “II. GPS

  1. John Firth
    October 26, 2011 at 4:02 pm

    Though John Cochrane started gliding in 1972, he is perhaps not familiar with competition tactics of the period. Maybe the majority of pilots were just doing thermal and glide , but at the top of the group we were doing dolphin type flying even in 15m ships. The 19 to 22m ships with ballast allowed extended dolphining for many miles. Even in Ontario (1977)I was able to fly a 750km triangle, with the first 500km covered in 4 1/2 hrs, in a Kestrel 19 impossible with classic tactics in 5-6 kt lift .

    John Firth ( Cdn team pilot 1970-78)

    • John Featherstone
      November 5, 2011 at 7:26 am

      Sometime in that era John Firth talks about, I can remember reading a comment in Soaring magazine by or about AJ Smith of Chicago who stressed the importance of “climbing straight ahead.”

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