Chapter A.8, Problem 61AYU

To determine

To find: Find the tail wind.

Answer to Problem 61AYU

$137.06$ knots

Explanation of Solution

Given:

On a recent flight from Phoenix to Kansas City, a distance of $919$ nautical miles, the plane arrived $20$ minutes early. On leaving the aircraft, I asked the captain, “What was our tail wind?” He replied, “I don’t know, but our ground speed was $550$ knots”.

Calculation:

On a flight from Phoenix to Kansas City, the plane arrived $20$ minutes or $\frac{1}{3}$ hour.

The distance concerned is $919$ nautical miles.

The ground speed (GS) was $550$ knots.

$1$ knot $=1$ nautical mile per hour

Actual flight time $=\frac{919}{550}$.

True Air Speed (TAS) $=\frac{919}{550+w}$.

$\frac{919}{550}-\frac{919}{550+w}=\frac{1}{3}$

$\frac{919\left(550+w\right)-919\left(550\right)}{550\left(550+w\right)}=\frac{1}{3}$

Therefore $=137.06$ knots.