Transponder Landing System ???

Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TDS
N2997Y

AIM 1-1-23. Special training is required.

Bob Gardner

"Trent D. Sanders" wrote in message
om...
Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TDS
N2997Y

I have flown the demonstrator that was set up at Madras. A couple of
corporate operators were going to get together and buy one for Sun Valley.

I don't think that ever happened. It takes a controller on the ground with
the equipment and you get a special squawk and just fly it like any other
ILS.

Curved approaches are possible. There was military application as well. The
unit could be parachuted out and set up in 30 minutes to a remote location.

Karl




"Trent D. Sanders" wrote in message
om...
Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TDS
N2997Y

kage wrote:
I have flown the demonstrator that was set up at Madras. A couple of
corporate operators were going to get together and buy one for Sun Valley.

There was also a demonstrator set up at The Dalles airport (DLS) for a
while. The company working on this is Advanced Navigation Positioning
Systems (www.anpc.com) of Hood River, OR. According to their web site,
they have 4 sites where it is installed and a dozen or so planned. I'm
not sure what installed means as the DLS one is considered "installed",
but it certainly not an approved approach. Ditto for Pullman, WA.

I flew the approach DLS approach under VFR. Seemed to work ok. I'm not
sure what special training would be required. You have to talk to a
controller on the ground and get a transponder code. After that, tune
your radio to the right frequency and follow the needles. The Dalles
approach was an normal dme arc that put you onto the TLS straight-in
approach course. A curving TLS approach could be interesting.


--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

TLS is a substitute for an ILS where an ILS can't be installed due to
terrain or other factors. It's also a whole lot cheaper than an ILS so it's
useful for smaller airports. That's good, because it's capacity limited
(more later) so it's not a good solution for busy airports.
It works by using a Mode A interrogator and multiple receivers around the
periphery of the airport. By measuring the time difference of arrival
(TDOA) of your transponder replies, it calculates your position relative to
the airport and the approach path. It then broadcasts thru an omni antenna
an "ILS" signal modulating the 90 and 150 Hz tones to drive your CDI to
indicate the proper guidance to the approach path.
To fly it, you have to set your transponder to the squawk code on the
approach plate (so it knows who is flying the approach) and tune your ILS
receiver to the "ILS" freq. The you fly it just like an ILS approach. No
special endorsements or training.
The capacity limitation I mentioned above comes about because only one a/c
can have the approach squawk code set at any one time or the system will get
confused and flag.
I haven't flown one. Most are in the pacific northwest at small airports in
the mountains.
Try the following link:
http://anpc.com/

Gerry


"Trent D. Sanders" wrote in message
om...
Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TDS
N2997Y

Lousy website!
You have to use MSIE to access it!

Gerry Caron wrote:
Try the following link:
http://anpc.com/

TLS is a system that was originally conceived as a system with ILS CAT I
minima, but that didn't need the expensive siting and grading required
by a normal ILS system.
Right now it appears that the original 200' HAT that was hoped for is
being limited to a 350 HAT, at least temporarily. It is also considered
"special" so you won't see them on the approach plates and will need to
have special training and permission to fly it. FEDEX is using one in
the Phillipines, and FAA has one set up in Atlantic City.
The system still requires ILS equipment on board the aircraft, but also
requires an operator on the ground to acquire the transponder code and
operate the ground equipment.
Rather than try to explain it in my own words, check this website out
that has a good description;
http://avnwww.jccbi.gov/icasc/docs/1...essibility.doc

or;
http://www.gaavionics.com/tls.htm

JPH

Trent D. Sanders wrote:
Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TDS
N2997Y

It isn't cheaper when you consider that it requires an operator.

Mike
MU-2


"Gerry Caron" wrote in message
. ..
TLS is a substitute for an ILS where an ILS can't be installed due to
terrain or other factors. It's also a whole lot cheaper than an ILS so
it's
useful for smaller airports. That's good, because it's capacity limited
(more later) so it's not a good solution for busy airports.
It works by using a Mode A interrogator and multiple receivers around the
periphery of the airport. By measuring the time difference of arrival
(TDOA) of your transponder replies, it calculates your position relative
to
the airport and the approach path. It then broadcasts thru an omni
antenna
an "ILS" signal modulating the 90 and 150 Hz tones to drive your CDI to
indicate the proper guidance to the approach path.
To fly it, you have to set your transponder to the squawk code on the
approach plate (so it knows who is flying the approach) and tune your ILS
receiver to the "ILS" freq. The you fly it just like an ILS approach. No
special endorsements or training.
The capacity limitation I mentioned above comes about because only one a/c
can have the approach squawk code set at any one time or the system will
get
confused and flag.
I haven't flown one. Most are in the pacific northwest at small airports
in
the mountains.
Try the following link:
http://anpc.com/

Gerry


"Trent D. Sanders" wrote in message
om...
Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TDS
N2997Y

"Mike Rapoport" writes:
"Gerry Caron" wrote
"Trent D. Sanders" wrote

Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TLS is a substitute for an ILS where an ILS can't be installed due to
terrain or other factors. It's also a whole lot cheaper than an ILS so
it's useful for smaller airports. That's good, because it's capacity
limited (more later) so it's not a good solution for busy airports.

It works by using a Mode A interrogator and multiple receivers around the
periphery of the airport. By measuring the time difference of arrival
(TDOA) of your transponder replies, it calculates your position relative
to the airport and the approach path. It then broadcasts thru an omni
antenna an "ILS" signal modulating the 90 and 150 Hz tones to drive your
CDI to indicate the proper guidance to the approach path.

To fly it, you have to set your transponder to the squawk code on the
approach plate (so it knows who is flying the approach) and tune your ILS
receiver to the "ILS" freq. The you fly it just like an ILS approach. No
special endorsements or training.

The capacity limitation I mentioned above comes about because only one a/c
can have the approach squawk code set at any one time or the system will
get confused and flag.

I haven't flown one. Most are in the pacific northwest at small airports
in the mountains.

Try the following link: http://anpc.com/

It isn't cheaper when you consider that it requires an operator.

The descriptions given above and other followups don't make it
clear: What's the function of the operator?

You need an operator to asign codes to inbound aircraft (ATC was not going
to do this). Presumably the machine also need to get the code input. There
was talk about putting one in here at SZT but the operator issue killed it
along with comments by the FAA that the localizer would have to be removed.
The TLS was also only going to be approved for a limited number of users
(certainly not part 91 piston airplanes, after all they only comprise 90% of
the airplanes using the airport). It was also only going to be in use for a
limited number of hours per day (when the operator was present)

I think that the solution is precision GPS approaches.

Mike
MU-2


"Everett M. Greene" wrote in message
...
"Mike Rapoport" writes:
"Gerry Caron" wrote
"Trent D. Sanders" wrote

Have you ever heard of, or have any experience with a thing called the
"Transponder Landing System", a form of IFR approach using a
transponder? What is it, how does it work, does it work, do you have
to have a special "endorsement" to fly it, etc?

TLS is a substitute for an ILS where an ILS can't be installed due to
terrain or other factors. It's also a whole lot cheaper than an ILS so
it's useful for smaller airports. That's good, because it's capacity
limited (more later) so it's not a good solution for busy airports.

It works by using a Mode A interrogator and multiple receivers around
the
periphery of the airport. By measuring the time difference of arrival
(TDOA) of your transponder replies, it calculates your position
relative
to the airport and the approach path. It then broadcasts thru an omni
antenna an "ILS" signal modulating the 90 and 150 Hz tones to drive
your
CDI to indicate the proper guidance to the approach path.

To fly it, you have to set your transponder to the squawk code on the
approach plate (so it knows who is flying the approach) and tune your
ILS
receiver to the "ILS" freq. The you fly it just like an ILS approach.
No
special endorsements or training.

The capacity limitation I mentioned above comes about because only one
a/c
can have the approach squawk code set at any one time or the system
will
get confused and flag.

I haven't flown one. Most are in the pacific northwest at small
airports
in the mountains.

Try the following link: http://anpc.com/

It isn't cheaper when you consider that it requires an operator.

The descriptions given above and other followups don't make it
clear: What's the function of the operator?