General

In the ATPL exam you will be presented with upper level wind forecasts. These detail the forecast winds and temperatures for the levels of FL185 to FL445, which covers most common commercial airliner cruise levels.
A typical flight may involve two or more RSWT forecast zones, and obtaining accurate wind/temp data in a short time is essential if you are to finish the flight planning examination in the allotted time.

Now attempt assignment RSWT 1.

The primary reasons for consulting the RSWT is to abtain the head or tail wind component, and ISA deviation effecting the flight. We will be using ERC charts exclusively in the ATPL exam (NOT WAC charts), and all tracks on ERC charts are in degrees magnetic. The RSWT information must first be converted to magnetic before the wind component can be found. This is especially important where the variation is large, such as East of Alice Springs, and in the Tasman sea or Pacific Ocean.
Refer example below.

Example 1.

ERC track between report points "BIDOG" and "TOPAZ" is 235M. Aircraft cruising level is FL350. Using the RSWT data block above, and an average variation of 8E, what is the forecast Head/Tail wind
component ?

Working:     Forecast wind by interpolation is 268T/103 kt. The magnetic wind is therefore 260M/103 kt.
                  Using the navigation computer, you should get a head wind component of 93 kt.

Now attempt assignment RSWT 2.

RSWT assignments

RSWT assignment 1.

Using the RSWT data block above, find the wind direction/speed expressed in magnetic, and ISA deviation.

1. FL445/Var 3E ?  Direction/speed_____________.              ISA deviation_________.

2. FL385/Var 3W ?  Direction/speed_____________.              ISA deviation_________.

3. FL340/Var 8E ?  Direction/speed_____________.              ISA deviation_________.

4. FL250/Var 6E ?  Direction/speed_____________.              ISA deviation_________.

5. FL310/Var 12E ?  Direction/speed_____________.              ISA deviation_________.

6. FL330/Var 6W ?  Direction/speed_____________.              ISA deviation_________.

RSWT assignment 2.

Using the RSWT data block above, calculate the Head/Tail wind component
and ISA deviation in the following, assuming Variation is 10E .

RSWT Suggested answers

RSWT assignment 1.

End of RSWT texts.