T-45A UJPT & E2-C2 INAV08
Fuel, Weather, and Alternate Airfield Planning
83 KTS
Step 5
OPPOSITE
CROSSWIND COMPONENT
READ CRAB ANGLE (13)
Figure 5 (Part 2): COMPUTING GROUND SPEED WITH CRAB ANGLE 10 DEGREES OR GREATER
As previously stated, for wind problems where the crab angle is less than 10 degrees, the headwind or
tailwind component is simply applied to the true airspeed to obtain groundspeed. With small crab angles,
this is very close to being accurate, any inaccuracy being too small to be concerned about. With crab
angles of 10 degrees or more, however, the error is large enough to require the use of the EFFECTIVE
TRUE AIRSPEED (ETAS) (Cosign Scale) for obtaining more precise groundspeeds.
365 KTS
TS
Step 8
ETAS 365 KTS
MINUS
HEADWIND COMPONENT 35 KTS
= GROUNDSPEED 330 KTS
Figure 5 (Part 3): COMPUTING GROUND SPEED WITH CRAB ANGLE 10 DEGREES OR GREATER
(6-99) Original
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