[MT-ALES] Always Make Your Time - RC Groups

[CURTIS SUTER]

Have you seen this?
From Bob McGowen who is currently competing in the Worlds USA F3J team in Romania.


https://www.rcgroups.com/forums/

Always Make Your Time
Finding the lift

Let’s first talk about how to find the lift. First and foremost you look for obvious signs (planes, birds, spider webs, dust devils) as these can all be signs of rising air. Keep your home field advantage knowledge in mind as you consider most likely places and plan a search pattern. I find this especially key in selecting what part of the field I want to be over for my last ditch effort as I am getting low. Plan ahead for that, your emergency exit. For me that place is usually slightly down wind of me so I can read wind shifts. If available, it will also be an area that takes advantage of the terrain or a tree line which may kick off thermals like a slope. If a thermal trip is not available, be over or down wind of a surface or area more likely to generate thermals. Before you launch always have a plan-A search area in mind and then a backup plan-B if that does not work. If neither work you need be at that last ditch effort place before you hit the ground.

Knowing where the sink is by watching the various signs is almost as valuable as knowing where it is because you will obviously be avoiding those areas as you search. Your timer should be telling you about any clues he detects as well as the obvious things such as where people are going up and where people are sinking. It may be wise to adjust your search plan in flight based on what he is telling you. Most importantly, never cover the same ground twice and keep your plane moving at a good pace to cover as much ground as possible. Don’t hesitate to reflex and push to get through areas of sink at high speed.

Thermal Feeds

Observing and interpreting the changes in wind speed and direction for several minutes prior to your launch is a huge advantage as you decide where to search. As thermal air rises it must be displaced by surround air near ground level. The ground level air rushes into the bottom of the thermal from all directions. So, on a calm day if you suddenly feel the wind come up this is actually air feeding the thermal, and if you follow that wind, it will lead you directly into the thermal.

It’s easy on a calm day, but gets a bit trickier to interpret on a windy day. Let’s say it is a windy day and you are at the winch and the wind seems to die down. This means that there is a thermal upwind because from your perspective it is sucking air into itself directly upwind and this is partially cancelling out the prevailing headwind. If it is a huge thermal and the prevailing wind was not that strong, it may make the wind actually reverse from your perspective. As the thermal drifts closer and closer to where you are standing at the winch the wind will die down more and then become calm. When calm the thermal is either still a bit up wind of you or right over you. When the wind starts back up and hits you in the face the thermal has just past you. It is drifting down wind now and what you feel from your perspective is an increase in the prevailing wind speed. Launch now and go catch it just a little ways down wind. If you can’t launch immediately, the thermal will be getting further and further down wind. How far is too far? You’ve been watching gliders drift with the thermals all day and have observed the normal prevailing wind speed so you need to imagine how far you think it has drifted. Don’t be psyched out by the intense wind you are feeling now, remember the normal drift speed is the same as it always was but you are feeling the sum of the prevailing wind speed and the extra wind speed created by the thermal sucking in from all sides. If it is sucking real hard making you terrified to go down wind because the wind has gotten so strong, just remember it is an indication of a monster thermal, not a huge wind that will strand you off field. Go for it and get there as quick as you can with a turn and burn launch and a fast run.

The last paragraph talked about thermals directly upwind or downwind and our clue was the wind intensity changing, but direction remained constant to the prevailing wind of the day. Now let’s consider when the wind shifts off to one side or the other. If you knew the exact strength of the thermal and its distance from you, you might be able to do a vector analysis and have an exact intercept path to take. We don’t know those things, nor can I do math in my head, so a general heading and search area is the best I can do. We can narrow our guess into quadrants pretty easily. If the wind has shifted left and intensified, the thermal is in the downwind left quadrant. If the wind has shifted left but calmed down a little, the thermal is in the upwind left quadrant. If the wind is pulling right and just got stronger, search in the downwind right quadrant. If the wind just got lighter and is pulling off to the right, search the upwind right quadrant.

Let’s think a bit more about a thermal that is down wind and off to the side. As the wind intensified it also pulled off to the right somewhat. The thermal will be even further to the right than the wind is pointing to because the prevailing wind must be factored in. When reading the wind shifts from prevailing, the thermal will always be outside of the direction the wind has shifted to. This is a key point.

The best way to master reading these wind shifts is with a discus launch glider because you can predict, throw, and confirm over and over, many tests in a short amount of time. You can learn it with a big plane flying around at ½ or less of normal launch height, but it takes more time. Don’t rely on just a snapshot but observe the changes taking place over time and try to map what is happening on the field in your mind. This will tell you both where to search and were you need not bother searching. We can have a pretty good idea of what is down wind of us, but upwind is always a bit more of a mystery. If I have not felt anything go past me in a long while and it is my time to launch, I will tend to search upwind or way off to the side because I already know downwind there is nothing.

Riding the Thermals

I try to ride the downwind side of lift. I’m not going to get into a long explanation on how to center the lift as that is pretty basic stuff (move to the side of the circle that is rising more). I will say that as you center, error on the side of being too far downwind. When circling in lift, probe downwind slightly elongating your turn downwind and see if the lift is still there and keep moving that way. It seems to me that I locate the strongest part of the lift as I probe further downwind. The real reason I like to error on the side of being too far downwind is that if I lose my thermal by accident, I will re-acquire it when I get panicked and head for home. When you are already way down wind and lose touch with the thermal the last thing you are naturally inclined to do is search even further down wind. If you lose the thermal, it is a better scenario if you had out drifted it by accident because you’ll hit it again coming home. If you fall out the front side of the thermal by not drifting fast enough, chances are you won’t have the guts to go down wind even further trying to re-acquire it.

The last tip relates to riding those really tight dust devil like thermals found near the ground. I flip a switch to engage Elevator to Camber mixing for this type of tight and highly banked circling. I personally do not use snap camber for riding lighter and wider thermals or cruising, but many do. I’m a believer in keeping my airfoil steady and working in its optimum shape as much as possible and that also means minimal aileron control inputs.

Ballast

“How much ballast are you carrying” is always a favorite question as we wait for our turn to launch. At minimum you should make your plane heavy enough that you have the ability to move slowly forward into the wind without adding down stick, down trim, or reflex. Whether you should add any more than that depends on strategy. If your strategy is to just “poke and float”, you should not go heavier. That is never my strategy. If your strategy is to catch a thermal, ride it back, and then penetrate home into the wind, then you want to be a bit heavier. You should be heavy enough that you can make into the wind progress at a good speed and get home with just a little down trim (not needing to resort to reflex). Don’t ballast so light that you must use reflex and speed trim to get home, reflex should be reserved for punching through sink at very high speed, not for cruising back upwind in OK air. Another strategy that might call for extra ballast is trying to run upwind after launch to get to some type of terrain that is reliably kicking off thermals or wave lift. Factor in the typical thermal strength of the day when selecting your ballast. Ballast on the heavier side if thermals have a great rate of climb. These are conditions where you know you’ll go up at any weight if you can only get to that lift and then get back home after riding it. Ballast a little lighter than you otherwise would if you see thermals are yielding a very weak rate of climb. Weak thermals in the wind is the toughest of conditions.

A bonus for carrying ballast in the wind will be seen when you come in to land. The extra weight will help your plane stay stable and on course in turbulent wind conditions. Because you are landing into the wind, your ground speed will not be excessive even with some extra air speed. The extra air speed will make your controls more effective so you can guide her to the hundred even as the wind is gusting.

We need your help

I am on the 2018 USA F3J Soaring Team. We will be traveling to Romania soon and our fundraising efforts will continue for a while even after we return. If you got anything out of the above and think the read was worth a couple bucks, please go to our website and buy a couple raffle tickets. Thanks. Here is the link: https://www.teamusaf3j.com/


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