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Old July 3rd 10, 03:47 AM posted to rec.aviation.piloting,rec.aviation.student
Mxsmanic
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Posts: 9,169
Default Navigation strategy on a short flight

FlyCherokee writes:

I would've climbed a bit higher, for safety, in that terrain.


I considered that, but it was a daylight flight and the C152 is rather anemic,
and a review of the maximum elevation figures in the quadrants I planned to
cross revealed nothing higher than 2900. I think I might have filed for 5500
and then changed my mind once in the air.

You can exclude pilotage, but it doesn't sound like you created a
navigation log before your flight.


No, I did not. I had forgotten that navigation log is a widespread aviation
misnomer for a navigation plan. I didn't have a written plan, nor did I log my
progress. In general I eschew anything that might require writing, because
there is no space on the table for writing things by hand, and because the
room is generally dark except for the monitor, making writing difficult.

Even when following the VORs, airways, etc, you need a basic nav
log to predict and keep track of your position throughout the flight.


I have a mental plan of sorts, but I don't write it down. I often plot things
on SkyVector and use that to derive points that I must verify during flight.

I think Flight Simulator has
this function(?), but you should make it by hand, if you've never done
it, to help understand how it works. With the Nav log, you wouldn't
try to "...judge my distance from the VOR..." by looking for it; you'd
know approximately when you were going to cross it by looking at your
clock.


Thus far I've made virtually no attempt to do anything by the clock, although
I suppose I should. The inability to determine my actual ground speed
discourages me from trying to calculate anything involving speed vs. time. In
order to determine my position through dead reckoning, I need to know my
ground speed. But in order to determine my ground speed, I need to know my
position. If I know neither ground speed nor position, it's not immediately
obvious to me how I'm going to solve for either of them.

I don't think I would have followed V105 in this case, I would've just
followed the appropriate radial outbound from PXR VOR, followed my
position using the clock and my nav log, checked my position about
midway by switching my VOR momentarily to either of the neighboring
VORs, then watched the clock again to make sure I didn't fly past the
airport.


How would you determine your ground speed?

But the key to all that is the nav log you make before your flight.
All the times and positions of the key points, including the midway
waypoint is on the log, then you just follow along. If your planned
waypoint doesn't appear at the proper time, then you take measures to
reestablish your position.


But here again, I need an accurate ground speed to make these kinds of
calculations, which is problematic if I don't have an accurate position.

A possibility might be accurate knowledge of winds aloft, but how accurate is
this information going to be?

By the way, Flight Simulator is perfect for this kind of practice.


It works well for me. My failure or success in the sim should accurately
mirror what my result in real life would be.