Mto at over 8000 feet

[Texasautogyro]

I was flying up to Bridgeport Texas on Tuesday and tried to get away from a 20kt headwind. So I took the MTO over broken clouds at over 8000 feet and 95kts.

[scandtours]

How small/narrow gets the seat at this hight, Texasautogyro?

[Gyro28866]

I took my Bensen to 5000agl once. It felt mighty small, and it was a really lonely feeling.

[willisbr]

I am confused at how conditions change with altitude. With 20 mph headwind, how would you know to look for calmer conditions when climbing? Doesn't winds aloft increase with altitude or does getting above the clouds change things? I would like to learn how to make more effective cross countries and work with weather better. Or work against it I should say. Thanks for your advice.

[perbgyro]

Originally Posted by willisbr

I am confused at how conditions change with altitude.

Get the winds aloft conditions and forecast. Sometimes, there is no wind at some altitudes. That's why Airlines will pick altitudes during their route to reduce the travel time and that is the secret sauce for hot air balloners and how they change directions by changing altitudes.

[Mike484]

Desmon and I were flying my RAF one day and the wind was rough and choppy, we took it up to 3,000, just above the clouds, and it was unbelievably smooth.

[thomasant]

The winds aloft forecast would give a lot of useful info at different altitudes. If the machine has the capability of climbing, it is great to find an altitude with tail winds based on the charts.

[All_In]

@Brian
Hi Buddy!!!

Here is a detailed answer:

The wind changes direction as you increase or decrease in altitude. With hot air balloons you drop bird seed to see where the wind is blowing below you to find the air current going in the direction you wish to fly.

When flying fixed wing aircraft the winds aloft forecast can a big difference in the time required to make the flight. I have had a 100+ tail wind on several occasions - now that a fast/short flight.

Here is an example of today’s winds aloft forecast for San Diego.

FT 3000 6000 9000 12000 18000 24000 30000 34000 39000

SAN 9900 1715+20 1520+13 1325+06 1525-12 1823-24 233138 244046 243954


The FT = the altitude of the wind/ Flight level. 3000= 3000 feet, 18000 = 18000 feet, etc.

At 3000 feet it say’s 9900 = the wind direction is 99° and the wind speed is 0 K.
At 6000 feet is says 1715+20 = 17 add a 0 = 170° wind direction, the 15 is the speed in knots and the +20 is the temperature.
The temperature is provided so I can calculate TRUE air speed at that altitude.

How we use it:
So, I need to plan a flight to El Mirage and must fly at an even attitude +500 feet for my VFR required heading of 329°.
.
I also must fly at 8,500 feet or above to fly over the controlled airspace of Los Angles controlled airspace.

I wish to find an altitude with the best tail-wind = the one coming closes to my heading of 329°.

So for my flight what altitude should I fly at for the best ground speed possible?
====
Here is one more piece of the puzzle:
Because all values are not listed on the tables or graphs, interpolation is often required to determine intermediate values for a particular flight condition or performance situation.
Interpolation

To interpolate means to compute intermediate values between a series of given values. In many instances when performance is critical, an accurate determination of the performance values is the only acceptable means to enhance safe flight. Guessing to determine these values should be avoided.

Interpolation is simple to perform if the method is understood. The following are examples of how to interpolate or accurately determine the intermediate values between a series of given values.

The numbers in column A range from 10 to 30 and the numbers in column B range from 50 to 100. Determine the intermediate numerical value in column B that would correspond with an intermediate value of 20 placed in column A.

A B
10 50
20 X = Unknown
30 100

It can be visualized that 20 is halfway between 10 and 30; therefore, the corresponding value of the unknown number in column B would be halfway between 50 and 100, or 75.

[ckurz7000]

Originally Posted by All_In

At 3000 feet it say’s 9900 = the wind direction is 99° and the wind speed is 0 K.

I believe the code 9900 stands vor "light and variable" instead of 99° at zero knots.

-- Chris.

[Graeme Monro]

Wasn't 99 86's partner?

Graeme.

[willisbr]

Thanks so much for that John. I read winds aloft completely wrong then. I thought that the +20 was wind speed and that it was a constant direction all the way up. Now I understand that the direction changes as you change altitude. I need a course in what you are talking about. Some good CC training.

[SpyderMike]

Use can a free website like www.navmonster.com to confirm your interpretation. They reformat the code to be very understandable.


Here is another nice site:

http://www.usairnet.com/cgi-bin/Wind...course=azimuth

[cleatus99]

If you were west bound low altitude then ~2000 ft would be a good altitude to choose..

Forecast high taken from DFW
  23-SEP-2011 12 UTC  Soaring report from FWD upper air data.
   Forecast high: 82 F; est. base of any clouds: 5500 feet AGL.

                    === Raw Upper-Air Data ===
Feet MSL:    643   1063   1780   2661   2900   2931   3662   3942   4226   5093
Pres mb:     998    983    958    928    920    919    895    886    877    850
Temp C:     12.8   14.6   14.4   12.6   12.8   13.4   13.2   14.8   15.4   14.8
VirT C:     14.4   16.5   16.3   14.3   14.4   15.0   14.4   15.5   15.8   15.1
DewPt C:    12.2   14.6   14.4   12.2   11.6   11.2    7.2   -1.2   -7.6  -13.2
Wdir@kts:                              30  7                             330  7

       === Interpolations (temps in deg. F, altitudes in feet MSL) ===
  MSL  *TI* Wdir@kts trig  VirT  2.3 degrees/division ("`": Dry Adiabatic)
-----  ---- -------- ---- . ---- -----------------------------------------
18000  13.8           107 | 17.3 `         :
17500  13.3           106 | 19.1  `         :
17000  12.9           105 | 21.0   `         :
16500  12.4           104 | 22.8    `         :
16000  11.7  360  23  103 | 24.2     `        :
15500  10.8           101 | 25.3      `        :
15000  10.4           101 | 27.2        `       :
14500  10.3           100 | 29.7         `       :
14000  10.2  340  14  100 | 32.2          `       :
13500  10.1           100 | 34.6           `       :
13000  10.0           100 | 37.1            `       :
12500   9.7            99 | 39.2             `       :
12000   9.1  340  18   98 | 40.8               `      :
11500   8.4            97 | 42.3                `     :
11000   7.7            96 | 43.8                 `     :
10500   7.1  310  11   95 | 45.3                  `     :
10000   6.3            93 | 46.6                   `    :
 9500   5.5            92 | 47.8                     `   :
 9000   4.7  295  12   90 | 49.0                      `  :
 8500   3.8            89 | 50.2                       `  :
 8000   3.0  305  19   87 | 51.4                        ` :
 7500   2.2            86 | 52.6                         ` :
 7000   1.4  310  15   84 | 53.8                          `:
 6500   0.6            83 | 55.0                            :
 6000  -0.1  305  13   82 | 56.5                             :
 5500  -0.3            82 | 58.7                              :
 5000  -1.5  330   7   80 | 59.3                              :`
 4500  -2.5            78 | 60.1                              : `
 4000  -4.0  355   6   76 | 60.0                              :  `
 3500  -6.5            71 | 58.2                             :     `
 3000  -7.6   10   8   69 | 58.9                              :     `
 2500  -9.4            66 | 58.4                             :       `
 2000  -9.8   80   7   65 | 60.4                              :       `
 1500 -10.7            64 | 61.4                               :       `
 1000 -12.4            61 | 61.1                               :         `


   === Complete Upper Air Data ===

   P(mb)     H(ft)    Tv(C)    T(C)    DP(C)   wind dir  wind spd

    998.0      643     14.4     12.8     12.2
    983.0     1063     16.5     14.6     14.6
    958.0     1780     16.3     14.4     14.4
    928.0     2661     14.3     12.6     12.2
    920.0     2900     14.4     12.8     11.6       30        7
    919.0     2931     15.0     13.4     11.2
    895.0     3662     14.4     13.2      7.2
    886.0     3942     15.5     14.8     -1.2
    877.0     4226     15.8     15.4     -7.6
    850.0     5093     15.1     14.8    -13.2      330        7
    843.0     5322     15.3     15.0    -15.0
    817.0     6187     13.2     13.0    -20.0
    700.0    10397      7.6      7.4    -22.6      310       11
    657.0    12098      4.8      4.6    -23.4
    642.0    12714      3.6      3.4    -18.6
    582.0    15289     -3.5     -3.7    -19.7
    559.0    16332     -4.7     -4.9    -23.9
    500.0    19177    -10.6    -10.7    -34.7      350       26
    492.0    19583    -11.4    -11.5    -35.5
    400.0    24666    -23.7    -23.7    -50.7      320       19
    300.0    31326    -40.5    -40.5    -64.5      305       24
    275.0    33249    -45.7    -45.7    -65.7
    250.0    35314    -49.7    -49.7    -67.7      285       31
    231.0    36996    -53.7    -53.7    -69.7
    220.0    38022    -54.9    -54.9    -69.9
    216.0    38406    -54.9    -54.9    -69.9
    213.0    38701    -53.7    -53.7    -69.7
    200.0    40022    -55.7    -55.7    -70.7      280       45
    196.0    40444    -56.5    -56.5    -71.5      280       46
    189.0    41202    -55.5    -55.5    -70.5
    181.0    42104    -57.1    -57.1    -71.1
    174.0    42925    -55.9    -55.9    -70.9
    155.0    45326    -58.1    -58.1    -72.1
    152.0    45730    -57.7    -57.7    -71.7
    150.0    46004    -58.1    -58.1    -72.1      280       52
    122.0    50224    -63.1    -63.1    -75.1
    113.0    51773    -62.3    -62.3    -75.3
    102.0    53829    -66.1    -66.1    -78.1      270       38
Additional wind data:

  H(ft)   dir   spd
 ------   ---   ---
  2000     80     7
  3000     10     8
  4000    355     6
  6000    305    13
  7000    310    15
  8000    305    19
  9000    295    12
 12000    340    18
 14000    340    14
 16000    360    23
 20000    345    30
 24000    320    20
 25000    320    18
 27000    325    14
 29000    325    22
 30000    315    23
 31000    305    22
 34000    310    29
 35000    285    33
 38000    290    44
 39000    275    41
 44000    270    58
 49000    275    54
 50000    270    45
 52000    265    32

[cleatus99]

Here is something else glider pilots use, it's called Soar forecast....
http://www.soarforecast.com/ti.cgi?S...Altitude=18000

It has winds aloft and the altitudes where you can expect lift (thermal Turbulence)
the bigger the negative TI # the more lift you should find.