Airmanship - Inflight Decisions

by A. J. Smith

Previously we've talked about general, almost textbook aspects of competition soaring. Now we'll consider one specific aspect to illustrate what it's like in reality.

The decisions a competition pilot makes inflight are important. Inflight decisions are important because most preflight strategy is based on weather observations, reports and analyses which seldom are complete or accurate enough for our purposes. Weather observations made later inflight provide more and better information. Really critical decisions are going to be made or confirmed on the basis of what we see and observe after we're airborne. If we examine just one aspect of the process of inflight decisions, we begin to see a philosophy for dealing with other problems.

Anticipation of need for inflight observation and examination well ahead of time, (now!) should help us develop systematic inflight observation and evaluation and facilitate quick and good decisions during competition flights when we don't have much time. We can and should gain experience and develop an approach to competition flying before we are actually involved in it.

I choose to examine the simple aspect of course deviations during a contest flight.

Competition flight paths seldom look like the classic soaring textbook climb and glide profiles. There's so little relationship between the paths or profiles we produce in the air and those we read about in the textbook, that we might consider reviewing our entire approach. The textbook deserves only credit for pointing out the general philosophy of soaring; very general, rare and classic but seldom the way it really is. Perhaps on some occasions when you're at the right exotic site--there aren't many--you might produce a flight that resembles the textbook soaring flight . This is indeed rare. You might even have the possibility of putting together several classic flights in one competition. If you are able to do that, you are quite likely to win the competition and have a tremendous sense of your good luck. It doesn't happen often.

We can consider the many factors in the problem of deviations from course and draw classic solutions for the problem. It's important that we understand all the factors but it seems more important to realize that the classic solutions provide only general guidelines.

Nick Goodhart, in Sailplane and Gliding about a year ago, discussed the problem of dealing with crosswind as we progress to a goal. His solution was beautifully accurate and practically done, but in the category of Sunday night fun around the bar. What are most such flights really like? Most commonly the flights wander off in random patterns well away from the course and well away from the idealized vertical profile of a soaring flight. We're concerned here that we wander randomly away from the perfect course line. We know the reasons. The weather forces or entices us away from the course line.

The problem is to accommodate to this enticement. To accommodate profitably we've got to be competent in evaluating weather influenced alternate courses available to us. Getting competent requires practice.

In simple terms, we might begin practicing systematic evaluation in three parts.

The first part could be observation; and this is a part for constant consideration during flight. The question? Are there any significant weather induced alternate courses to our goal? Constant consideration? We can ask that question every few minutes. We've got to learn to constantly observe weather inflight; we've got to observe its changing results and influences. It's important to know, too, that we should observe the weather at all altitudes and from all altitudes. This simply because the weather we're looking at--the air mass--its results and influences, are three-dimensional. The three-dimensional masses are composed of visual solids, clouds, dust, haze, and of voids. We can't accurately assess these three-dimensional masses--these solids and voids-unless we look at them from as many angles as possible and then estimate their sections. We can't have a good understanding of three-dimensional masses with just one view of them.

Our vantage points for viewing air masses are many because we're going up and down in thermals and moving horizontally.

We can practice weather observation during all our soaring flights. We can sharpen our ability to observe. Because some of us, in our daily work, are oriented to activities that don't involve visual observation, we need to improve our ability in this activity.

We can practice expanding our field of visual consciousness. For the most part, we look at things not more than a few hundred feet away. This is poor utilization of our consciousness. We should exercise our ability to observe at maximum distance. In soaring, if we don't expand our field of vision, we miss a lot.

How far can we see? This question is just as important at Marfa where sometimes we're observing weather at 200 miles or thereabouts; it is just as important there as it is where our field of vision is limited to a few miles by air masses, terrain and whatever. This simple question is the foundation for a practice exercise. Practice looking out as far as possible.

What do we see? How many different conditions do we see? Again, the farther we see, the more we see, and the more facets we observe and consider in the air mass, the better the decisions we make.

When we're at the top of a thermal we are provided with an excellent vantage point to assess the air mass and make long range plans. Each time, as we anticipate the top of the thermal and we consider the decision to leave, we should look around, really look around. At this moment our view of cloud shadows is superb. We Bee the patterns of the clouds better or, if there is no particular orderly pattern of the clouds, we see sequences of clouds, perhaps irrational patterns, that would be good to use to continue our flight. We see greater distances, at this moment; our visual penetration through haze is better. Perhaps more importantly, we can assess the top of the air mass. We can compare cloud masses over a wide range and clearly see what is happening at some distance and the varying depth of convection. In the structure of distant clouds we can see developments that tend to indicate an alternate to our perfect course to the goal.

The second part of our practice of a systematic evaluation of alternate courses might be comparison practice. The question, after observing weather variations; what relative values might we expect on the weather influenced alternate courses? What changes in the rate of climb? What changes in the frequency of the thermals? What patterns or distributions of lift might be available on the alternate courses? More frequent thermals give us the opportunity for selectivity in addition to the possibility that we might simply use more of them in straight flight. The advantage of some pattern of lift could easily obviate the need to use one thermal. We must be able to evaluate differences which might be experienced in alternate micro air masses. There is a way to practice this.

On every flight and particularly during the period prior to our start on a competition flight we should sample each of the different air masses which might be available to us. There are often several micro air masses available for sampling before starting. Instead of picking the best one, soaring easily and comfortably until the time is right for starting, we might sample the worst ones and determine the full range of conditions. Surprisingly, we find many times that an air mass which might be judged poor from visual inspection will provide better soaring than anticipated. We've gained valuable experience if we determine this. It is particularly pertinent if we determine this in the few minutes before a start of a competition flight; it is almost as valuable if we determine this during a flight around our home base. We gain valuable experience for future comparisons thus.

The game is to accumulate experience through sampling air masses.

This builds backward to part one; we've observed that there are differences in micro air masses, and now, because we've a lot of experience, we can accurately estimate the values in different air masses. We're gaining experience so that estimates made in future competition will be better estimates. With experience, we're not frightened of the classic blue holes and that sort of thing. We know that we have examined many of them and some provide quite good soaring.

The last part of the examination of alternate courses might be the final calculation. We've observed that there are alternates available to us. We've compared the different values we might expect in these alternate courses. The calculation involves only simple arithmetic. We realize we're going to fly some extra distance to deviate from the textbook courseline. We must accurately measure this added mileage. This probably is one of the few things in this whole process that we can do accurately. We need a map. Using cloud shadows, landmarks, and whatever, we should do an accurate plot of the alternate courses. Don't try to judge distances. Use a scale. Since it is wise to keep the number of tools in the cockpit at a minimum, it is fortunate that most calculators have scales along the side and we can quickly measure the extra distance to fly if we choose an alternate course.

Measure the cost. For a rule of thumb, an added mile will require an added minute. Our average speeds are on the order of 60 mph, so an added mile is an added minute. An added minute on the average task, it's reasonably fair to say, is probably one-half mile per hour and is approximately a one percent decrease in speed for the average task. It's really worth worrying about. In the final standings a one percent difference might cover several top places. That is the cost. What are the advantages of going the alternate course? We've observed the alternate course and we've got to calculate the return if we go that way. Again, to establish a simple rule of thumb, 100 fpm better climb in one thermal on the alternate course could, in the average thermal, save approximately two minutes. One such thermal-increase the rate of climb 100 fpm--saves two minutes and, might on the average speed task increase our achieved speed by one mph. The net return, if we added a mile to our course as we deviated for that slightly better thermal, is minus a minute and plus one-half mph. That's worth going after.

The lesson in this simple example is to look a bit to the sides for better thermals. I questioned this lesson systematically for a year because I felt I was tending to go too far from the perfect courselines. I found I was at worst coming up even and at best with slight changes in course I was overtaking other pilots.

After evaluating course deviations for a season and realizing they weren't costing much, I've concluded I needn't worry about minor angular wanderings. I simply invest in minor wanderings to better conditions and an confident of gaining considerable chances for savings in time. However, it still seems necessary to do accurate measuring and simple but accurate arithmetic to determine whether moderate or major angular wanderings are profitable.

Several times in recent Internationals, major deviations from course may not have been forced, may not have been absolutely necessary, but the enticements were fantastic in terms of both cost and advantage. The cost sometimes in terms of flying as much as 30 extra miles on one 70 mile leg. Coming ahead of a great clot of sailplanes that vent direct, after flying fifty percent farther proved the worth of systematic evaluation of alternate courses. Some precompetition study of our sailplane's Achieved cross country speed with thermal strengths would facilitate evaluation of these large deviations.

There is a good point to keep in mind in this discussion. We might be tempted, if we are inclined to conservatism, laziness, or whatever, to continue straight down the perfect course. If we were to go through an evaluation and determine that a deviation generated a net return of zero, we might be tempted to take the easy way and stay on course. However, we shouldn't neglect the fact that any deviation to better soaring conditions, most particularly in marginal weather, is going to decrease your chances of complete failure. The big game in competition soaring is in completing all the tasks. If we go through an evaluation and come up with a zero net return, we ought not to lay it aside. We should first ask, "is the weather sufficiently marginal to make me want to deviate simply to increase my chances of completing the task"?

Just as good as a better thermal would be a better pattern of lift along possible alternate courses. Thirty miles of cruise, with altitude loss for example, using various patterns, could obviate one climb in a thermal and allow perhaps five or six miles added mileage and still net a one mph increase in ground speed. That's a lot.

Examine available alternate weather influenced courses in the simplest terms--30 miles out and six miles across generates a moderate angle. This one to five ratio doesn't appear great as we look at it from its acute apex in the sky. It doesn't tend to make us anxious. What sometimes frightens though is the measurement of that last six mile correction going into the turn. However, if the evaluation looks favorable, we should start out on the alternate course and continue our evaluation. If it works well, proceed. If it doesn't, we've still an opportunity to revert to near courseline with little time invested.

Keep in mind as we go through these wanderings, contrary to what the textbook says about idealized sawtooth courses with crosswinds and this sort of thing, the object is to get to the turnpoint at the most advantageous Altitude in the fastest way from where we are at any particular moment.

In the simplest of terms, we've examined one facet and one kind of decision out of the many we must make inflight. We study this one example in order to develop a philosophy of dealing with other tactical soaring problems. Once we practice breaking the operation down into observation, comparison and calculation we can apply the same approach to other problems which confront us in competition.

We can practice solving problems by sketching typical course deviations. We can sketch the example of the slight deviation to a better thermal and get a feeling for distances involved, the scale and values of the problem. We can sketch the example of a pattern of lift which deviates from our perfect course and sense the mileage involved.

Since we have moved quickly into high performance sailplanes, a feeling for the scale of these problems in relation to the performance of our machines is important. Very few of us appreciate the scale of glides in high performance ships. With the machinery we've got, we should be looking out as far as possible, perhaps using our calculators a bit more and studying usable lift patterns 20, 30 or 40 miles away.

We might tend to complain at this point that we've taken all the fun out of soaring again; that we haven't allowed for the appreciation of the beauty of it or whatever; and we've made work of it. In reaction we could say that for the flower lovers there's a simple version of our evaluation.

They could go through the same sequence. They could look far out and appreciate the beauty of the structure of the clouds as they change and the difference in patterns and shadows. In the event of overwhelming beauty they could go and taste the joys of better soaring and experience the relevancy of doing that. The rest of us who practice and work diligently, plan and measure accurately, and calculate precisely will probably be waiting back at the finish line for them.

All the above refers generally to speed tasks. Some comment should be made to relate the above to distance tasks.

Gross deviations from the planned course and strategy on a distance day early in the flight don't cost much. We can compensate for these early deviations. As a distance flight progresses, major deviations can tend to become more costly and more difficult to compensate. The justification for early deviations may be one of simply having to stay up. Staying up with some gross deviation from course, perhaps even coming back a bit, might give the weather a chance to improve and provide overall opportunity. However, the justification may simply be in selection of the best of relatively good alternatives.

Paul Bikle made an outstanding competition distance flight to the west out of Marfa when almost all others went to the northeast. He made the decision to go west after he was airborne, and he did much better than the others. The others were probably equally good observers but Paul was a better evaluator that day. They experienced the same conditions at the same moments but he wasn't bound by previous strategy or by previous weather information. He elected to make a major deviation from the more obvious course and to go with the favorable conditions observed inflight. It was a wise decision made early enough in the flight. The flight illustrates the point.

We can build on our preflight strategy through the process of the inflight evaluations. We should build by making large scale plans just as we should in our preflight strategy. We should anticipate all the consequences of a deviation and project the results of that deviation as far as we can into the future. In that fashion, we will either complement our preflight strategy or have a realistic foundation to challenge that strategy.

Questions And Answers

Question: (Tom Page) You've really talked about a cost/benefit analysis almost, as analyzing conditions inflight and making decisions to change them. What about the cost of acquiring this information? You don't say anything about that. if you're going to have to be sitting there writing and calculating and figuring all the time, that is going to cut into your perception. What kind of criterion do you have for balancing the cost of acquiring, or in a sense, remembering information against the time spent in collecting it?

Answer: Well, I'm not doing any-thing more important up there. The cost is high. Constant attention is difficult. Memory training is important. But the calculations are easy. They detract little from observation activity.

A year ago I said that unless you are working every minute, even late in a seven or eight hour flight when you're tired, you're not getting the job done. I suppose in overall terms that the cost is extremely high. But, that's the game. I'm convinced you can do this observation, comparison and calculation, and keep doing it constantly during a long flight. Precontest practice will make it easier.

Our problem is that we drift away mentally from any one subject quickly. If we can pay better attention we tend to stop worrying about the cost, we use our time more effectively and perform better in competition. The answer is the cost in effort is high; it's hard work. That's why I presented the flower lovers' version. The cost to them would be much less. Probably the return in competition less also.

Comment: (Ed Byars) I believe you said you usually make two decisions of a major proportion every minute. Is that right?

Answer: Perhaps a major decision or a review of a major decision. Frequently reviewing a previously made decision is valuable business too. I make a lot of decisions that need to be reviewed!

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