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Ten Tips To Get You There
By Bomber
INTRODUCTION
This article looks at some small things you can do that should increase your chances of
getting to where you plan to.
TIP ONE
The first tip is to estimate how long it will take you to fly your chosen course. Given
you know the thermal heights for the day, the strength of thermals and the wind speed (all
can be calculated from a temp trace) the table below provides the average cross country
speed at best L/D.
|
Wind Speed (Km/hr) |
|
|
|
Ther. Strength (ft/min) |
0 |
5 |
10 |
15 |
20 |
25 |
30 |
100 |
16 |
21 |
26 |
31 |
36 |
41 |
46 |
200 |
24 |
29 |
34 |
39 |
44 |
49 |
54 |
300 |
28 |
33 |
38 |
43 |
48 |
53 |
58 |
400 |
31 |
36 |
41 |
46 |
51 |
56 |
61 |
500 |
33 |
38 |
43 |
48 |
53 |
58 |
63 |
600 |
35 |
40 |
45 |
50 |
55 |
60 |
65 |
700 |
36 |
41 |
46 |
51 |
56 |
61 |
66 |
800 |
37 |
42 |
47 |
52 |
57 |
62 |
67 |
900 |
38 |
43 |
48 |
53 |
58 |
63 |
68 |
1000 |
39 |
44 |
49 |
54 |
59 |
64 |
69 |
Table for topless hang gliders - click here for king posted
Given you know your average Cross Country speed, you can work out how long
the flight will take.
Example: 400ft/min thermals to 7,000 feet with 10 km/hr tail winds. Average cross country
speed is 41 km/hr. If your flying a 160 Km course it should take about 4 hours.
TIP TWO
The second tip is knowing what time to take off. If you know how long the flight is going
to take and what time thermals will start (this can also be calculated from the temp
trace) you can figure out the best time to take off.
Example: The flight above will take 4 hours and thermals will start at 10am. The best part
of the day is 2pm till 4pm. So we want to fly during this time and an hour either side.
Therefore take off time is 1pm with ETA at 5pm. If you want to play safe you could take
off early. However, it would be risky till wait till 2 pm and fly from 2pm till 6pm.
TIP THREE
Fly with a digital watch with an alarm. This seems a bit odd but apart from knowing what
time it is you can do two useful things. The first is to set the watch to beep on the hour
- this provides a prompt to think about the following:
How far did I fly in the last hour?
Is this the average speed I expected?
Can I still get to goal at this speed?
The second is to set your alarm for 2 hours before sunset (sunset times can be gained from
your Garmin GPS). At about this time you should be thinking of getting as high as possible
as it is nearing the time for the last good thermal of the day. To get to goal or extend
your flight you want to be high at the end of the day and use the good air.
TIP FOUR
When leaving the paddock in your first thermal note the angle that you are climbing away
from the thermal source. This will provide you with a visual reference of how far down
wind to fly of any thermal sources to find the thermal.
TIP FIVE
Stay up wind of the course line. When you first start your flight you are fresh and
unstressed. By the time you finish your flight (depending on the length) you can be tired,
impatient, dehydrated and stressed. By being upwind of the course line you can afford to
dribble downwind into goal when the lift gets weaker and your decision making is less
efficient.
To plan to stay up wind of the course line you can do the following:
Draw a straight line on your map between goal and take-off
Figure out what the wind might do during the day (eg typical at Wylie an Easterly
swings to a South Easterly)
Plan to fly on the up wind of the course line (eg South of the course line). Check
out the roads you might follow
TIP SIX
Check your stress levels in flight. As you become more stressed your brain shuts out
external stimuli. If this occurs you might not notice those clues that often provide
indications of lift. To check your stress levels try the following:
Each hour (or more often) check your grip on the base bar - if your knuckles are
white your holding on too tight
Check the level of fatigue in your shoulder or legs from pushing out in the harness
To relax look around you and enjoy the view. The best way to stay relaxed is to
realise when you're not.
TIP SEVEN
Know roughly how far from goal you can glide in from. This is simple if you have a final
glide table (available on the club web site). During the flight you know what height
thermals are going to. If you have a GPS and wind speed indicator then the difference in
reading represents the wind speed at a given altitude. Knowing this allows you to
calculate how far from goal you need to be to glide in. This can be done way before you
get to goal.
| L/D |
|
25.26 |
22.45 |
19.65 |
16.88 |
14.15 |
11.49 |
8.93 |
6.57 |
4.56 |
|
| S.R.
(ft/min) |
|
-187 |
-188 |
-189 |
-191 |
-195 |
-201 |
-213 |
-238 |
-297 |
|
| Air
spd (km/hr) |
|
40 |
40 |
41 |
41 |
42 |
44 |
46 |
50 |
56 |
|
| C.R
(ft/min) |
|
|
|
|
|
|
|
100 |
300 |
500 |
|
| Wind
spd (km/hr) |
|
-50 |
-40 |
-30 |
-20 |
-10 |
0 |
10 |
20 |
30 |
|
| |
0 |
1000 |
1000 |
1000 |
1000 |
1000 |
1000 |
1000 |
1000 |
1000 |
0 |
| |
5 |
1700 |
1800 |
1900 |
2000 |
2200 |
2500 |
2900 |
3500 |
4600 |
5 |
| |
10 |
2300 |
2500 |
2700 |
3000 |
3400 |
3900 |
4700 |
6000 |
8200 |
10 |
| |
15 |
3000 |
3200 |
3600 |
4000 |
4500 |
5300 |
6600 |
8500 |
11800 |
15 |
| |
20 |
3600 |
4000 |
4400 |
4900 |
5700 |
6800 |
8400 |
11000 |
15400 |
20 |
| |
25 |
4300 |
4700 |
5200 |
5900 |
6800 |
8200 |
10200 |
13500 |
19000 |
25 |
| |
30 |
4900 |
5400 |
6100 |
6900 |
8000 |
9600 |
12100 |
16000 |
22600 |
30 |
| |
35 |
5600 |
6200 |
6900 |
7900 |
9200 |
11000 |
13900 |
18500 |
26200 |
35 |
| |
|
-50 |
-40 |
-30 |
-20 |
-10 |
0 |
10 |
20 |
30 |
|
King posted glider final glide table - more or click here for
topless table
By way of example we'll look at three scenarios.
Scenario 1: Thermals to 7,000 feet with 20 km/hr of tail wind. Glide in
distance with a safety margin of 1,000 feet at goal is 30 km.
Scenario 2: Thermals to 5,000 feet in nil wind. Glide in distance with a
safety margin of 1,000 feet at goal is just under 15 km.
Scenario 3: Thermals to 8,500 feet in 20 km/hr of head wind. Glide in
distance with a safety margin of 1,000 feet at goal is 15 km.
TIP EIGHT
Reduce parasitic drag.
Check out you're A-frame on the ground. When you have set up the glider and put all the
crap (eg GPS, Vario, Maps, Compass, etc.) on the A-frame walk to the front of the glider
and have a look at what the wind sees. You can reduce your drag by simply lining up your
instruments with your down tubes and making sure your maps are in a good streamline
position.
Check your angle of dangle during glides. If your feet are too low when gliding then you
are creating a heap of drag you can get rid of easily.
Pull up your tow bridle and store it out of the way.
TIP NINE
Always try to thermal with the smallest bank angle and as slow as you can. This will allow
you to reduce the sink rate of your glider. If your are thermalling with a bank angle of
45 degrees in 300 ft/min and you can decrease your bank angle to 30 degrees (given the
thermal is big enough and of the same strength) your rate of climb with increase to 380
ft/min. This means within 10 minutes of climbing you'll be 800 feet higher than the other
guy.
Also if your thermalling at 30 degrees in 300 ft/min at 46 km/hr and you slow down to 35
km/hr you'll increase you climb rate to 350 ft/min. Again 10 minutes of climbing and your
500 ft above the other guys.
This is one reason some pilots climb away from you in the same air. They are flying
flatter and slower. If you're climbing at a steady rate (given you're not too low trying
to save your butt or the thermal is tight) try and widen your turn and slow down. I know
that I don't do this and I'm often content to maintain the same bank angle if I'm getting
a good climb rate.
TIP TEN
Use other pilots as information sources rather than following them or letting them make
decisions for you. One example of this is seeing a gaggle downwind of the course line. No
point gliding to them (unless desperate) as when you finish climbing with them you have to
punch head wind back to where you came from.
Try to follow the pilots better than yourself. If you fly with someone who is slower than
you, you'll slow yourself down by waiting for them. This means you'll only be as fast as
they are.
Hope these help.
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