Monday, October 31, 2011

Glow man

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Sunday, October 30, 2011

Ti chart for sunday october 30

There was lift, but not a lot. Lee and Osaki had to go twice to find any. They and Hugh and Bob  and Steve eventually got good flights. Herb was up a long time, but was "hugging the airport."
I got in three flights, pattern practice. Gary flew solo in the 2-33 and in another glider.

Saturday, October 29, 2011

Thermal Index (How To)


To figure out the thermal index, use Foreflight:
Airport: KBRY –> Weather –> Winds Aloft.
It usually makes sense for us to use the 2 pm (1800Z) prediction.
In two columns, jot down Altitude and Forecast temperature in Cº.
Alt: Temp: 
9,000     -7ºC       
6,000     -4ºC
3,000     +2ºC
surface    -----
Then add a third column by writing down the maximum temperature expected that day at the surface 
(in this example, 58ºF = 14ºC)
Alt: Temp:
9,000     -7ºC       
6,000     -4ºC     
3,000     +2ºC     
surface    ------      14ºC
Then use the Dry Adiabatic Lapse Rate of 3ºC per 1000 feet (9ºC per 3000 ft) to figure the theoretical temperature that a 58ºF parcel of air will attain as it rises thru the atmosphere, cooling as it goes.   
Since our airport is 700ft MSL, not sea level, the first calculation will be 14ºC -  (2.3 * 3º) to make the 3000ft prediction.  
2.3*3º = about 7º that will be subtracted from the max temperature for the day.
So for the 3000 ft TI, 14º - 7º = 7º.)
Alt: Temp:       Parcel
                         temp:
9,000 -7ºC      
6,000 -4ºC      
3,000 +2ºC       7ºC
surface ----- 14ºC
For the rest of the layers, just subtract 9º from each lower level temperature.
Alt: Temp: Parcel
temp:
9,000   -7ºC        -11ºC
6,000 -4ºC       -2ºC
3,000 +2ºC         7ºC
surface ------      14ºC
Now, we make the fourth column, the "Thermal Index," by computing the difference between columns 3 and 4.
Alt: Temp Parcel TI:
temp
9,000 -7ºC      -11ºC     +4
6,000 -4ºC       -2ºC                 -2
3,000 +2ºC        7ºC              -5
surface ------      14ºC
A thermal index of  between -2 and -4 is necessary to get enough lift to carry a glider.  Any larger negative number is even better. So, the index indicates good lift at 3000ft, and perhaps up to 6000ft, but not higher.

Sunday, October 16, 2011

Thinking about cursive writing

If schools are permitted to teach a pre-cursive alphabet from the outset, this conversation is happily re-directed into one about quality time. Look at the DeNelian alphabet, which many educators prefer. It starts students with fluid adult movements. It completely avoids the difficulty of those b's and d's, p's & q's that were introduced artificially a century ago (remember making letters with ball and bat?). It then becomes cursive at a natural pace, with only a little prompting from the teacher, and sufficient time to write in either stage.

Parents, teach this to your children yourself, and encourage the schools do it as well.