timing holds

"arthur mcallister" wrote in message
...
Why would anyone time a hold in this day and age?


June 14, 1998

Pelican's Perch #5:
Don't Time That ILS Approach!

http://www.avweb.com/news/columns/182042-1.html


"...if you start a NON-precision approach (including a LOC-only) and fail to
start the timer (or note the time), it's a major boo-boo. Your only recourse
is to immediately go missed and start it over. If you perform an approach
where timing is required, and you do not time it, it's a good bust on a
checkride, for that is compounding an error with stupidity."

--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

"Roy Smith" wrote in message
...
I actually prefer a plain sweep second hand clock in the panel (one of
those good-old 8-day windup things work just fine). Glance at the
thing when you start outbound, when the second hand gets back to the
same place, turn inbound. Correct as required for wind.

Same here. In our old club PA-28 the clock was never, ever right because the
knob you set it with had long since fallen off. The second hand worked fine,
though, so when you went overhead the beacon you simply remembered what
number the second hand was pointing at and waited for it to point that way
again.

In our current aircraft, the clock is generally right. Same principle holds,
though :-)

D.

wrote in message
...
My handheld GPS is far more accurate and reliable than your Radio
Shack stopwatch.

Are you sure? I've got 20-year old watches that still work fine, and I've
had plenty of electronic gadgets that didn't make it past a couple of years.
Simple (Radio Shack stopwatch) is often better.

And cost doesn't imply accuracy, either. My 70-quid Accurist watch keeps
better time than my Breitling Navitimer!

D.

Now (while you are outbound in the procedure turn) mentally calculate
the time adjustment required by the headwind component of a variable
23-knot wind from 32 degrees off the nose which shears twice
somewhere between the time you start the approach and the time you
finish it, add the errror introduced by the fact that you don't start
the timer EXACTLY over the FAF, further include the error you made
in the mental interpolation of the time required for the approach
because your airspeed is somewhere between 90 and 120 knots, now throw
in the the fact that said airspeed will probably will change 4 or 5
times along the way, and we'll discuss the accuracy part.

Oops, I nearly forgot.

Don't forget all the times that after you make all these calculations,
that you forget what it was halfway down the final approach course.


On Wed, 16 Feb 2005 10:27:57 +0000 (UTC), "David Cartwright"
wrote:

wrote in message
.. .
My handheld GPS is far more accurate and reliable than your Radio
Shack stopwatch.

Are you sure? I've got 20-year old watches that still work fine, and I've
had plenty of electronic gadgets that didn't make it past a couple of years.
Simple (Radio Shack stopwatch) is often better.

And cost doesn't imply accuracy, either. My 70-quid Accurist watch keeps
better time than my Breitling Navitimer!

D.

wrote in message
...
On Tue, 15 Feb 2005 18:51:15 -0700, "Matt Barrow"
wrote:

"...if you start a NON-precision approach (including a LOC-only) and fail
to
start the timer (or note the time), it's a major boo-boo. Your only
recourse
is to immediately go missed and start it over. If you perform an approach
where timing is required, and you do not time it, it's a good bust on a
checkride, for that is compounding an error with stupidity."


First of all, we were talking about holds, not approaches.

Secondly, given the prevalence of DME and GPS, you have to be an idiot
to rely on timing when more accurate measurements are available,

My handheld GPS is far more accurate and reliable than your Radio
Shack stopwatch.

Agreed. The article only addresses _timing_ anything.

Many folks are still flying via the 1930's technology/mindset.

"David Cartwright" wrote in message
...
wrote in message
...
My handheld GPS is far more accurate and reliable than your Radio
Shack stopwatch.

Are you sure? I've got 20-year old watches that still work fine, and I've
had plenty of electronic gadgets that didn't make it past a couple of
years.
Simple (Radio Shack stopwatch) is often better.

You're conflating "accuracy" and "reliability".

And cost doesn't imply accuracy, either. My 70-quid Accurist watch keeps
better time than my Breitling Navitimer!
Unless it's off appreciably, you can't fly as accurately as either
timepiece.

"David Cartwright" wrote in
:

Are you sure? I've got 20-year old watches that still work fine, and
I've had plenty of electronic gadgets that didn't make it past a
couple of years. Simple (Radio Shack stopwatch) is often better.

And cost doesn't imply accuracy, either. My 70-quid Accurist watch
keeps better time than my Breitling Navitimer!

GPS is accurate to nanoseconds. Time difference is how it determines
position, and the time has to be so precise that relativistic effects
caused by the satellite's velocity and lack of gravity have to be
accounted for. GPS is more accurate than any conventional timepiece
you'll ever own. The display is less precise than the actual
timekeeping, though, because displaying the time is far down the list of
priorities. The display is certainly accurate to the second, though, and
it is always accurate, because it is controlled by multiple atomic
clocks.

--
Regards,

Stan

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." B. Franklin