Unnecessary verbiage or sensible redundancy?

"Stefan" wrote in message
...

Likewise in the whole world that adheres to ICAO standards. Or in other
words, the in whole world except the USA.


Most nations use leading zeros, most pilots do not.

"G.R. Patterson III" wrote in message
...


Tony Cox wrote:

So what do instructors teach these days? Do you add the
extra zero or not?

The instructors I had in the late '80s and early '90s recommended using
the leading
zero in transmissions.

The instructors I had said just the opposite. No leading zero.


George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

"Peter Duniho" wrote in message
...
"Tony Cox" wrote in message
ink.net...
You're right, sorry. But extending to the general case (or 01/19 for
that
matter), my point is valid. Truncating the last number (or not) while
vocalizing the "zero" at least alerts others to a potential problem;
omitting the "zero" leads to potentially dangerous confusion.

You can't extend to the general case that way. You need 100% compliance
for
your theory to work, and there's no way to detect non-compliance.
Procedures like this only work if they allow people using them to not only
detect errors the procedures are designed to expose, AND they expose those
not using the procedure.

Oh I don't know about that. 100% compliance isn't necessary, since
the two methods of announcing intentions aren't contradictory and
no additional ambiguity is introduced.

And *in this particular case* (and no doubt in other scenarios
too) safety would have been enhanced had he used the "zero two"
phraseology. Even a mixed system with some using "zero two" and some
using just "two" is a more effective communicator of intent over an
imperfect
communication channel where the failure mode is truncation of the tail end
of the transmission. Heck, he could even have been saying "Cherokee
blah-blah, right base, two [zero right Jean traffic]" -- using perfectly
correct
phraseology -- but as he was truncated, I'd never have known now would I?


Any time you can't tell the difference between a legitimate communication
under the proposed procedure and an erroneous communication not using the
proposed procedure, the procedure is not capable of preventing erroneous
communication.

Indeed. But there is much one can do to maximize information transfer
over an imperfect channel. Sometimes asking a guy to retransmit isn't
an option (I'm reluctant to question solo students as to their intent as
they're
trying to land, for example. Sometimes the channel is just too busy). Look
at it this way...

Pilot calls "..left base, two". Could be either 2 or 20 & you know there
is an error. But you're none the wiser as to where he is. Worse case you
assume he's just being lazy with the "Jean traffic" bit & think he's on
base for 2.

Pilot calls "..left base, zero". Error detected, but a reasonable assumption
is that he is heading for 2.

Which is less likely to lead to problems? And safety is no worse because
some people are announcing the leading zero while some aren't, so you
don't need 100% compliance.

BTW, how does ATC call vectors? Don't they say things like "Cherokee
blah-blah turn right heading zero-two-zero", rather than just "two-zero" ?
Been a while & I can't remember.


It takes me about 3 seconds to repeat my home airport name. And
think of those poor sods at SJC when the tower is closed:- "Cherokee
blah-blah, left base 29, Norman Y. Mineta San Jose International
Airport traffic" ;-).

No one says you have to say the full name of the airport. You simply need
to include enough to uniquely identify the airport. IMHO, "Mineta" or
"San
Jose International" ought to be enough at either end of the transmission.

Missed the smiley, eh?


At what airport are you based, where it takes a full 3 seconds to say its
name? And why is an additional 3 seconds such a huge problem? And what
is
it about your home airport's name that prevents it from being shortened
while remaining unique?

Well, "Boulder City Traffic" takes me about 3 seconds & it's not an
issue unless there are 4 planes in the pattern, helicopters heading out
through the pattern & the jump pilots ordering sandwiches from their
base station all at the same time. Truncation leads to confusion with
"Bullhead", which although being on a different frequency, seems to
gets plenty of calls from pilots who forget to switch. Anyway, it isn't an
issue for us, since the only single-digit runway is 9, which cant be
confused
with anything.


What ASOS transmits on the traffic frequency?

Boulder City (61B) for one. Every 15 minutes or so even if not
prompted by three clicks.

According to the FAA data, 61B does not have an ASOS, and the nearest ASOS
is at KLAS, 16NM to the northwest (and that's phone-only anyway).

Perhaps you mean there's an automated unicom? That's very different from
an
ASOS. In any case, an automated transmission once every 15 minutes is a
non-issue with respect to determining radio procedures.

You're right. It's an automated unicom. No sign of it in the
AFD. Fancy that.

As I said before,
detecting conflicting transmissions is not a problem with aviation radio,
since the receiver gets a very clear indication of what happened.

It's not detecting conflicts. It's making use of degraded information.
Think of it as equivalent to a cyclic redundancy check, rather than
a parity check.

"Tony Cox" wrote in message
ink.net...

Pilot calls "..left base, two". Could be either 2 or 20 & you know there
is an error. But you're none the wiser as to where he is. Worse case you
assume he's just being lazy with the "Jean traffic" bit & think he's on
base for 2.

Pilot calls "..left base, zero". Error detected, but a reasonable
assumption
is that he is heading for 2.

Which is less likely to lead to problems? And safety is no worse because
some people are announcing the leading zero while some aren't, so you
don't need 100% compliance.


Using leading zeros creates the possibility of transposing numbers. A pilot
might say "zero two" when he means "two zero". With just "two" there's
nothing to transpose.



BTW, how does ATC call vectors? Don't they say things like "Cherokee
blah-blah turn right heading zero-two-zero", rather than just "two-zero" ?
Been a while & I can't remember.


Three numbers are used when issuing headings.

"Tony Cox" wrote in message
ink.net...
Oh I don't know about that. 100% compliance isn't necessary, since
the two methods of announcing intentions aren't contradictory and
no additional ambiguity is introduced.

For it to do any good, you need to be able to tell the difference between a
complete communication and an incomplete one. Without 100% compliance and
without some sort of built-in error detection, you can't. Your proposal
provides neither.

And *in this particular case* (and no doubt in other scenarios
too) safety would have been enhanced had he used the "zero two"
phraseology.

How do you know he wasn't?

[...] Heck, he could even have been saying "Cherokee
blah-blah, right base, two [zero right Jean traffic]" -- using perfectly
correct
phraseology -- but as he was truncated, I'd never have known now would I?

Which is why I said from the outset that the true solution is to NOT
TRUNCATE YOUR TRANSMISSION. It doesn't matter what you say, if you don't
hold that PTT switch down for the entire transmission, some information has
been lost.

Pilot calls "..left base, two". Could be either 2 or 20 & you know there
is an error. But you're none the wiser as to where he is. Worse case you
assume he's just being lazy with the "Jean traffic" bit & think he's on
base for 2.

How do you know there is an error? Perhaps he's landing on 2 and that was
the end of his transmission.

Pilot calls "..left base, zero". Error detected, but a reasonable
assumption
is that he is heading for 2.

How do you know he's heading for 2? Perhaps he's at a different airport,
landing on 1, 3, 4, 5, 6, 7, 8, or 9. Or even 2.

Which is less likely to lead to problems? And safety is no worse because
some people are announcing the leading zero while some aren't, so you
don't need 100% compliance.

It's not a question about whether safety is worse. I'm trying to explain to
you that safety is NO BETTER.

BTW, how does ATC call vectors? Don't they say things like "Cherokee
blah-blah turn right heading zero-two-zero", rather than just "two-zero" ?
Been a while & I can't remember.

As Steven said, three digit headings. But that has nothing to do with
calling runways, and they use single digits for single digit runways.

Well, "Boulder City Traffic" takes me about 3 seconds

I know you're closer to Texas than we are here in the Pacific Northwest, but
I had no idea you talked so slow in Nevada. "Boulder City Traffic" doesn't
take me nearly three seconds to say, and if it's that big of a problem you
could drop either or both the "City" and "Traffic".

& it's not an
issue unless there are 4 planes in the pattern, helicopters heading out
through the pattern & the jump pilots ordering sandwiches from their
base station all at the same time.

In that scenario, simply transmitting on the radio is an issue. Shortening
your transmission by a second, or even three, isn't going to make a
difference.

Truncation leads to confusion with
"Bullhead", which although being on a different frequency, seems to
gets plenty of calls from pilots who forget to switch.

Which is, again, why I said from the outset that the correct solution is to
NOT TRUNCATE YOUR TRANSMISSION.

It's not detecting conflicts. It's making use of degraded information.
Think of it as equivalent to a cyclic redundancy check, rather than
a parity check.

I'm afraid you need to read up on CRCs. They are simply a more reliable
error detection than a single bit parity check. They don't help you
reconstruct degraded information.

In any case, your proposal does not allow you to make use of degraded
information, as I have pointed out several times by now. There are plenty
of scenarios in which one does not even detect an error, which is a
prerequisite for reinterpreting the information in order to recover the lost
information.

Pete

But if you always use a leading zero, then you always know you have received
the entire number. If you're using a mix of single digit and two digit
numbers you can never be assured you received correct information on the
10 numbers.




"Steven P. McNicoll" wrote in message
link.net...

"Tony Cox" wrote in message
ink.net...

Pilot calls "..left base, two". Could be either 2 or 20 & you know there
is an error. But you're none the wiser as to where he is. Worse case you
assume he's just being lazy with the "Jean traffic" bit & think he's on
base for 2.

Pilot calls "..left base, zero". Error detected, but a reasonable
assumption
is that he is heading for 2.

Which is less likely to lead to problems? And safety is no worse because
some people are announcing the leading zero while some aren't, so you
don't need 100% compliance.


Using leading zeros creates the possibility of transposing numbers. A
pilot
might say "zero two" when he means "two zero". With just "two" there's
nothing to transpose.



BTW, how does ATC call vectors? Don't they say things like "Cherokee
blah-blah turn right heading zero-two-zero", rather than just "two-zero"
?
Been a while & I can't remember.


Three numbers are used when issuing headings.

"Bill Denton" wrote in message
...

But if you always use a leading zero, then you always know you
have received the entire number.


But not necessarily the correct number.



If you're using a mix of single digit
and two digit numbers you can never be assured you received
correct information on the 10 numbers.


If the guy says "...runway two Podunk.", I know he's referring to runway two
at Podunk. If he says "...runway zero two Podunk.", I know there's the
possibility that he transposed the numbers and actually meant runway two
zero. The leading zero does nothing to improve communications if the pilot
properly ends his transmission with the airport name.

On Wed, 01 Sep 2004 01:18:01 GMT, "Steven P. McNicoll"
wrote:

If the guy says "...runway two Podunk.", I know he's referring to runway two
at Podunk.


Unless he's making a reference "...TO podunk." Then the zero would
help.

No right answer with this one it seems.

z

I use the leading zero, so my students tend to do that, too. Quite honestly,
I think some people worry about excess verbiage a little too much. Yeah, I
don't want people writing "War and Peace" on the radio, but the guys who go
nuts whenever they hear what they think is even one extra word are just a
little bit touched, if you ask me.

In Canada we tend to use the leading zero.
So I would always say downwind zero five,
never downwind five

Tony


In article . net,
"Tony Cox" wrote:

I've had a smoldering dispute with a CFI friend of mine for
years about whether to announce (say) "zero-two" or just
"two" when operating at an uncontrolled field with runways
2-20. My friend is of the opinion that the extra "zero" is
superfluous, whereas I've always instinctively said "zero-two"
without really understanding why I do it. It has always "just
seemed right", with a blank in the orderly transmission of
information that cried out to be filled.

This weekend I felt vindicated. As I started to taxi out at
0L7 (two runways, 2-20R and 2-20L), I was not particularly
surprised to hear a Cherokee doing touch-and-gos on runway 2 (the
wind was 5 out of the north). Listening to several calls as I
prepared to depart, I finally caught a "two-zero" -- the fellow,
out of exuberance or lack of currency was letting his finger
slip off the transmit button to give an entirely erroneous and
completely believable false impression of what he was up to.
Turns out he was practicing downwind landings. Add to that
that the airport is right traffic for 20 and left for 02, the potential
for disaster is evident.

So what do instructors teach these days? Do you add the
extra zero or not?




--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE