Operational Navigation Flight Training Instruction
Flying the Route
Course/Time Corrections at Checkpoints
If you see a checkpoint ahead and slightly off course and you know you are supposed to pass directly
over it, maneuver to fly over it. If it is too close or you see it late, maneuver to put it on your tail as you turn
to the outbound heading. Try to reach it on the planned inbound heading, if you can pass over it, you can
turn directly to the correct outbound heading. Check your time and adjust power and airspeed as neces-
sary to correct for being early or late at the turnpoint.
Timing is very important in operational navigation, both in locating yourself along your course line and in
correcting your position. You must consistently check your time and correct any time you find your timing
off by more than five seconds. You may be fast or slow, so be sure to correct in the right direction. If you
are suppose to be at a bridge at 10+00 but you fly over it at 9+50 then you are fast, ahead of your clock.
Adjust speed to slow down and let your clock catch up.
Add or subtract 1 knot airspeed for each second slow or fast; hold the corrected airspeed for 6 minutes at
360 knot. For example, if you are 20 seconds late on a 360 knot low-level, add 20 KTAS for 6 minutes.
If distance to the initial point is short, use a larger correction and hold it for less time. Increase or
decrease TAS by 30 knots for 2 minutes to correct for 10 seconds on a 360-knot route. If timing is
significantly off, a 60-knot correction may be made for one minute to adjust for 12 seconds off. The 60-
knot correction should only be made if there is insufficient time or distance to make a smaller correction.
Small speed changes provide smoother , more controlled and predictable corrections.
Once you are back on time, return to your planned airspeed, with any required adjustment. Analyze the
recent correction. Why were you off time? Consider wind, course corrections, your own airspeed control,
and take them into account. If you are flying into a headwind, you will need to account for it with your
indicated airspeed. How strong is it? Which direction? Which way will it blow you on your next leg? If
you corrected your course, you probably used up some time. Are you flying the correct IAS for the
temperature? You should be flying 360 knots true airspeed in a no-wind, standard-day condition. Check
the HUD for true airspeed, then fly the IAS required to maintain that TAS. The key to accurate timing is
precise heading and airspeed control!
Course corrections may be rapid or gradual, depending on the situation. If you see your checkpoint
straight off to one side when it should be directly underneath, you have to maneuver to get on course after
the checkpoint. If you see your turnpoint ahead and a bit to one side, just fly to it and turn on top to pick
up your outbound heading. If you have enough room prior to the checkpoint, you can make an S-turn to
cross the point on planned inbound heading. You can also apply a calculated correction: 10 degrees for
one minute for each mile off course (360 KTAS). You have to estimate accurately how far off course you
are, but you can do that by reference to such items as section lines, known landmarks, and experience.
Be careful of large heading changes; like timing corrections, smaller corrections are better. A large
heading change of 30 degrees for one minute will move the track three miles, but changes the view that
you planned to have. Do you know what to look for? You can become disoriented easier. Use
10 degrees for three minutes instead, provided you have sufficient leg time. As always, turn on time.