When the aircrew straps into the aircraft to execute their plan, the information on
the jet log is nothing more than their best estimate as to what will happen.
Aviation is a dynamic environment. Conditions or situations change rapidly and
unexpectedly requiring the aircrew to adapt and rethink/recompute their plan
To the greatest extent possible, aircrew should strive to maintain their course as
published or planned in order to maintain a safe and orderly flying environment.
However, in this course, if the aircrew find themselves off course, merely
compute a NEW course and heading to the turn point/destination using updated
winds, and update the ETA and EFR.
FLIGHT CONDUCT (UPDATING) STEPS
Basic in-flight navigation follows four basic updating steps:
Plot fix and measure track/distance.
Measure updated true course/distance to next turn point.
Determine actual in-flight winds.
Apply new winds to remaining legs and update ETA and EFR.
FLIGHT CONDUCT EXAMPLE
Continuing with the flight planning example from Tyndall AFB to Marianna
Municipal, enroute to Blountstown at an elapsed time of 5+05, the aircrew find
themselves on the 205° radial from Marianna VORTAC (30° 47.2'N 085° 07.5'W)
at a distance of 39NM. Fuel flow remains 240pph. Compute a new ETA and EFR
STEP 1: PLOT FIX AND MEASURE TRACK/DISTANCE
The first step in this problem is to plot the given fix and measure the resulting
track and distance flown. Plotting 205º/39 on the chart (don't forget to convert
mag to true) and then measuring the line from Tyndall to this point yields a track
of 045° TRUE and a distance of 11NM (Figure 4.7-15).