Refer to figure.
CRP-5 Flight Computer:
True Airspeed Calculation: (convert 140 kt CAS to TAS)

1) Align the pressure altitude of 9 000 ft window with the OAT of -7ºC;
2) Once the wheel is aligned, find the CAS of 140 kt on the inner most scale. Read the corresponding TAS of approx. 159 kt on the outer scale.

Determine the Ground Speed:

• GS = 159 kt - 15 kt = 144 kt

Follow the steps detailed below in order to find unknown wind (CRP-5):

Course/Track and GS are the references related to the path of the aircraft over the ground, and we will start with them.
(1) Place the track (316º) under the true index.
(2) Place the centre of the rotating disk on the value representing the ground speed (144 kt).
(3) The Course/Track and heading difference will determine the Wind Correction Angle.

• Heading with lower angular value then the Course, WCA mark left of the center line.
• Heading with higher angular value than the Course, WCA mark right of the center line.

(4) Maintaining the central grommet over the GS line, find the point where WCA crosses the TAS and make a pencil mark.
(5) Rotate the azimuth disk until the pencil mark is on the centerline between the grommet and the true index.
(6) Determine the wind velocity by counting the lines between the grommet and the pencil mark: 35 kt.
(7) Read the true wind direction under the true index: 245º.

E6-B Flight Computer:

True Airspeed Calculation:

1) Find the small window labeled either "FOR TRUE AIRSPEED AND DENSITY ALTITUDE" or the one below the "DENSITY ALTITUDE" window, depending on your E6-B model.
2) Set the pressure altitude to 9 000 ft and match it with the OAT of -7°C.
3) Without moving the scales, look for the True Airspeed (TAS) on the outer scale, aligned with the Calibrated Airspeed (CAS) of 140 kt on the inner scale. In this case, the TAS reads approximately 159 kt.

True Wind Direction and Velocity Calculation:

(1) Move the slide so the ring lines up with the speed arc corresponding to your Ground Speed, which is 144 kt.
(2) Rotate the transparent azimuth disk until the True Track of 316° is under the TRUE INDEX.
(3) Determine the wind correction angle (WCA). With a True Heading of 304° and a True Track of 316°, the True Heading is 12° to the left of the True Track, meaning the WCA is -12° (or 12° left).
(4) With the ring on the 144 kt Ground Speed arc, find where the -12° WCA crosses the 159 kt TAS speed arc and mark it with a pencil.
(5) Rotate the azimuth disk until the pencil mark aligns with the centreline above the ring, between the ring and the TRUE INDEX.
(6) To find the wind velocity, count the lines between the ring and the pencil mark. In this case, the pencil mark falls on the 179 kt speed arc while the ring is on the 144 kt speed arc. This gives a wind velocity of 35 kt (179 - 144 = 35).
(7) Finally, read the True Wind Direction under the TRUE INDEX, which in this case is 245°. Therefore, the True Wind Direction is 245°.