TIS and What could have been

"David Cartwright" wrote in message
...

No offence, but wasn't this a VFR flight? If so, the primary way to find
out about traffic is to look out of the window. I agree that the
circumstances were such that the task of spotting the other guy was made
harder (your low wings and his high wings, for example) but there are ways
(e.g. weaving descents) to improve your chances.

While I agree that electronic assistance can be a very useful secondary
device for picking up the odd bit of traffic you've not eyeballed, it's
essential to remember that looking out of the window is rule number one,
and if you'd descended onto the top of this other aircraft, it'd have been
your fault. The other thing to remember, of course, is that TIS relies on
the other aircraft giving a correct altitude - which in the aircraft I fly
relies on the the pilot having the correct altimiter setting.


Isn't the altitude encoder the source of altitude used by TIS?

Why so?
I find it very useful and practical when it is available.

Boy, the installer for the mode S a year and a half ago didn't mention
that it was either impractical or obsolete!

Yes, I had been told to start decent to 3000. I was in DAYs class C
airspace. I know that in the sever clear of that day, I have the
obligation for seperation, but that doesnot change the controller
allowing decent and my TIS helping to correct the siruation.

Boy, isn't that true. With the TIS showing the distance at a mile or
so, I sometimes still can't see the plane. Big planes easy, but small
ones, not so.

In this case I did not have a visual on the 172. He was under me.

"Chuck" wrote in message
oups.com...

Yes, I had been told to start decent to 3000.


Was that before or after your request to start descent?



I was in DAYs class C
airspace. I know that in the sever clear of that day, I have the
obligation for seperation, but that doesnot change the controller
allowing decent and my TIS helping to correct the siruation.


What was the situation? Where was the other aircraft in relation to your
own?

Chuck wrote:

Why so?
I find it very useful and practical when it is available.

Boy, the installer for the mode S a year and a half ago didn't mention
that it was either impractical or obsolete!

It is impractical from a total systems perspective. It's not unlike TLS
and ILS.

I am sure it is a nice-to-have when you're in the limited service areas.
TCAS, on the other hand, works everywhere independently of the FAA's ATC
system.

It's a niche solution and competes for resources.

Steven P. McNicoll wrote:

Had you been assigned any altitude restriction prior to your descent
request? If not, then you were free to descend at any time. But it seems
odd that you weren't assigned an altitude restriction as you'd be pretty
much right over DAY.

DAY isn't very busy. My last flight through the DAY class C, they let
me fly right over the field at 4,500 using FF. I was expecting to be
vectored around but, all they did was give me notices of departing traffic.


-m
--
## Mark T. Dame
## VP, Product Development
## MFM Software, Inc. (http://www.mfm.com/)
"Never argue with an idiot. They drag you down to their level and
then beat you with experience"
-- Dilbert's Words Of Wisdom

On Mon, 31 Oct 2005 08:43:14 +0000 (UTC), "David Cartwright"
wrote:

. The other thing to remember, of course, is that TIS relies on the
other aircraft giving a correct altitude - which in the aircraft I fly
relies on the the pilot having the correct altimiter setting.

I am fairly certain the TIS is using the encoder from the transponder
system to send altitude info. The setting in the Kollsman window has
no affect on the output.

Chuck wrote On 10/29/05 14:31,:
Unnerveing thing happen to me today.
I have TIS displayed on the Garmin 430.
I was 15 or 20 miles north of Moraine (I73) in southern Ohio and
talking to Dayton Controller under Flight Following.
I'm at 4500 ft and landing at Moraine. I request (I'm in his air
space) the controller that I would like to start my decent and he says
cleared to decend. Shortly, the display squacks and says "traffic" and
I see a traffic indicated at 500 ft below. I tell controller that I
have traffic on my display 500 ft below and he says "Yes, it is a 172
going into Moraine also."

So now we have a low wing (my Archer) above a high wing (172) and I
have been cleared to decend. I tell the controller that I am stopping
my decent and turning left 30 deg (and speeding up). He did not
respond. The 430 display over the next minute shows seperation and I
turn back to course and see the 172. I continue to keep my speed
greater that his and we both land without further problem.

Welcome to the wonderful world of TIS. Now you can really see what the
controller sees, and be scared. I have seen some amazing things with TIS,
including a near collision between two other aircraft in front of me.

Now, I'm going to side, a little bit, with the controllers on this. I
was visiting the tower, and the controller said to me, some "some guys
have TCAS, because they don't trust us". That's exactly the way they
see it, that you are getting into *their* business.

Now take a typical situation. You are (apparently) closing on another
aircraft. You see the TIS, you make an evasive manuver. The problem
is, the controller, who is watching the entire picture, had it worked
out, and knew you were going to pass behind that aircraft. Now, you
are manuvering, and you have thrown all his cards in the air.

I'm not saying that in this situation you are definately wrong or
definately right, I am just saying that you can cause more harm than
good by second guessing the controller. He has a bigger picture than you
do with that TIS.


I think TIS may have saved my ( and others) life today and the FAA is
decomissioning the sites with the explination that ADS-B is going to be
better when they get it implemented in the next few years and an an
inexpensive plane electronic becomes available.

God, I wish I knew how to stop this decomissioning of TIS before ADS-B
is widely available. My life (and maybe yours) may depend on it.

Chuck


Its worse than that. ADS-B comes with dramatically greater equipment
requirements and expense. The UAT required with ADS-B is $8,000
(garmin). It dosen't stop there. the AIRLINE ARE NOT GOING TO USE
UAT, so you are going to spend all that money and STILL not see
the largest peices of metal in the sky. Oh, the FAA is going to
"cross link" you with the transponder based system that the
airliners are still going to use. Meaning that unless you are both
in radar contact, you won't see each other, neatly chopping off the
biggest advantage of the system, that it works outside radar
coverage.

So thats the FAA solution: More cost to you, less functionality,
less safety! Yea!

No, but I clear my flight path religiously. Most people I've flown with are
lucky to clear during turns, descents are the worst. Folks just assume
there's no one below them. I learned long ago to do a 'belly check' in low
wing aircraft to make sure I don't hit exactly the issue below.



"Ron Lee" wrote in message
...
"John Doe" wrote:

So you were overtaking the 172? Did you not see him prior to descending?

I assume that you see every aircraft near you. I wish I were that
good. Even when given aircraft advisories I often never see the
aircraft.

Ron Lee