help in (Manipulation)

[crew_scheduler]

Hi,
i need someone help in this scenario :

FL300=270/114kt -45C
FL240=280/100kt -30C

Need to find out FL 290=?

Wind Direction = 280-270 = 10 Degree different
10/6000ft = 1.6
1.6 * 5000ft = 8000
wind Direction = 272 Degree

Speed = 114-100= 14 kts Different
14kt / 6000ft = 2.3 * 5000ft = 11.6kt which is 12 kt

Temp = 15 C different / 6000 = 2.5 * 5000 = 12.5 which is 13 C
so 13 + 30 = 43 which is -43
FL 290= 272/112 Kts - 43 C
:D
now my question is:
when we got wind direction we we done 280-8 to get 272
when we got the speed we done 100kt + 12kt = 112 kt
when we got the Temp. we done 13 +30 to get 43

when we use the minus and when we use add + ???:confused::ugh:
can some one help me ?
thank you
:8

[crew_scheduler]

thats what happen to yo uwhen you dont practice for 2 or 3 month. you forget the simple things ....
STUDY STUDY STUDY !!!!
waiting your help guys and girlz

thanks

[ubaid123]

u are trying to find 290 which is between 240 and 300

so u are trying to find something that is higher than 240 and lower than 300.. which is 290

its called interpolation

see brother for example

at FL 240 the wind is 114kt and at FL300 wind is 110 Kt

Look at it , as u are going up the wind is decreasing .. at FL240 it is 114 and at 300 it is 110 So FL 290 is between them , meaning the value should be less than 114 and greater than 110 , so that is why u subtract(-) from 114 , as u go up the wind is decreasing so it wil be -2 ,

So when u look at the problem u can see when to subtract and when to add ,

U could also solve it in another way

At FL300 wind is 110 and at FL 240 it is 114

Here u can look at it like this , As u go Down the wind Increases ,

so when u interpolate between 114 and 110 u get 2

This two u will add to 110 and u will get 112 , It depends where u are starting from , u will get the same answer,

Look at it like this , It cannot be 114 + 2 coz then it will not make sense , ur answe should be between 114 and 110 , so it cannot be 116 , so obvioulsy it has to be 112 coz 112 is between 110 and 114 just like FL 290 is between FL 240 and FL 300

[crew_scheduler]

hey ,
thanks bro but still im getting confused
by the way in my example its not 110 its 100 kts
let me answer the question in another different way :
regarding speed the answer should be like this :
Speed = 114-100= 14 kts Different
14kt / 6000ft = 2.3 * 5000ft = 11.6kt which is 12 kt
so 100 + 12 = 112kts

why its not 114 - 12 = 102 kts
and still 102 is between 114 and 100
also in Temp.
Temp = 15 C different / 6000 = 2.5 * 5000 = 12.5 which is 13 C
so 13 + 30 = 43 which is -43
why its not 13- 45 = - 32
which is -32 is between -30 and - 45
im getting confuse when to subtract or when to add :{

[boredcounter]

To use the - is pefectly acceptable, however, the - is taken off the FL300 figures. Therefore to find FL290 it is 1x not 5x. Using your example of the -, you are calculating FL250?

(Hope I have understood you correctly)


Bored

[crew_scheduler]

no im finding out FL290
but trying to figure out when i subtract and when i do add
how come did you multiply by 1 ? i think you are counting form FL290 to FL300
im counting it from FL240 to FL290 which is 5000ft Different 5x
:)
is there other ways to solve it ? any tricks ...etc

[boredcounter]

Think ambient lapse rate........

By your math, work out FL250. Then work out FL290.

i.e. take the top FL and use the -ve. or use the bottom FL and use the +ve.

[crew_scheduler]

thanks bored
now i got t :ok: