Ed Rasimus wrote:
(ArtKramr) wrote:

GPS was something we could only dream of.Think of the thousands of lost planes
and lives and ruined missions that could have been saved if we only had GPS.

A lot of guys had the same wistful thought about INS. Simply enter the
coordinates and follow the bearing pointer to the target. I can't
begin to tell you the long series of stories of guys blindly following
the needle while totally ignoring the landmarks, the TACAN, the radar
presentation and good ol' fashioned ded reckoning until they are
totally lost, busted the TAC check and missed the target.

GPS is simply one of a series of tools that must, repeat MUST, be used
in concert and with common sense.

Even the vaunted E-6B (I taught flight planning and navigation in
pilot training academics) was only as good as the common sense of the
user. I would patiently tell the students repeatedly to first estimate
what they think an appropriate answer might be, then do the "whiz
wheel" calculation. For example, my airspeed is 300 knots and I'm
going 120 miles on the leg, how long should it take me? If you guess
24 minutes before you pick up your E-6B, you've got a good chance of
coming up with the right answer.

I recall an ORI out of Torrejon Spain that sent us to a tanker in the
N. Atlantic on a track we seldom used. The "planning cell" in the
command post prepared our flight data cards and transposed two digits
in a Lat/Long for INS coordinates. I was leading with the wing DO on
my wing. When we coasted out from Spain, the bearing point showed 40
degrees left of where the TACAN radial was and where ded reckoning
said we should head. I went to the tanker track while the DO told me I
was wrong and should follow the INS. I told him he was #2 and to
maintain radio silence. We went to the tanker.

Garbage in--garbage out. It never changes.

Another great story Ed, thanks. As I tried to explain to Art, despite
its vaunted capabilities, we are just now beginning to understand the
downsides of GPS navigation. The USAF began using GPS as far
back as Dec. 1973, but the civilian pilot community is still wrestling
with GPS issues such as accuracy, availability, redundancy, and
integrity to this day. AOPA conducted a study that indicated flying on
GPS w/o autopilot actually resulted in two to four times *greater*
cockpit workload. Other issues such as reduced accuracy of
maneuvering because the pilot is staring at the GPS and is all
over the sky, lack of standardization (unlike VOR's for example,
every GPS make/model is different), pilots using handheld GPS
units to shoot IFR approaches not realizing that handheld GPS
units lack integrity or RAIM (receiver autonomous intergrity
monitoring), and the threat of terrorism (e.g: GPS jammers currently
available that can jam GPS signals within 45 kilometers) which
would absolutely ruin your day if you happen to be approaching
the FAF and the GPS goes tango uniform, lack of positional
awareness (more airspace incursions), pilots flying via GPS with
out-of-date databases (they're supposed to be updated every
28 days for IFR use), and the list goes on and on...

Don't get me wrong, I navigate with GPS almost every day and
my trusty GPS unit has literally saved my life on more than one
occasion when flying in Can't-See-**** conditions. The worldwide
coverage, free flight off airways on any desired course, and
dead-nuts-on accuracy of GPS's ensures that GPS navigation is
definitely here to stay well into the future.

The point I was trying to get across to our friend Art was simply
that GPS's are not the panacea that he seems to think they are.
Like you said, "garbage in -- garbage out" never changes and
I've had several students get lost on cross-countrys after plugging
in the wrong coordinates.

-Mike Marron