New small transponder

On Mar 5, 8:44*am, John Smith wrote:
If you ever want to climb above 15,000 ft in an airspace where a
tansponder is mandatory (which I do regularly), then you are just plain
illegal with the TT21. This may be "fairly meaningless" for you, it's
not for me and should not be for any pilot.

Saying something is "illegal" is a fairly useless statement. A lot of
things are illegal, ranging from driving at 60 in a 55 zone and on up.

I think you need to explain:

- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".


- what is the penalty for being caught doing so? What is the chance of
being caught?

I don't know the answer to the first part but I think I can guess the
second.

In article Bruce Hoult writes:
On Mar 5, 8:44=A0am, John Smith wrote:
If you ever want to climb above 15,000 ft in an airspace where a
tansponder is mandatory (which I do regularly), then you are just plain
illegal with the TT21. This may be "fairly meaningless" for you, it's
not for me and should not be for any pilot.

Saying something is "illegal" is a fairly useless statement. A lot of
things are illegal, ranging from driving at 60 in a 55 zone and on up.

I think you need to explain:

- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".


Unless, of course, the encoder actually cannot encode significantly above
that altitude.

Or, if it encodes incorrect values, resulting in that airliner hitting you
and going down with all aboard. That will look about as bad as not having
had a transponder in the first place.


- what is the penalty for being caught doing so? What is the chance of
being caught?

The first part probably depends on how you are caught.

Alan

On Mar 4, 9:52*pm, (Alan) wrote:
In article Bruce Hoult writes:

On Mar 5, 8:44=A0am, John Smith wrote:
If you ever want to climb above 15,000 ft in an airspace where a
tansponder is mandatory (which I do regularly), then you are just plain
illegal with the TT21. This may be "fairly meaningless" for you, it's
not for me and should not be for any pilot.

Saying something is "illegal" is a fairly useless statement. A lot of
things are illegal, ranging from driving at 60 in a 55 zone and on up.

I think you need to explain:

- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".

* Unless, of course, the encoder actually cannot encode significantly above
that altitude.

* Or, if it encodes incorrect values, resulting in that airliner hitting you
and going down with all aboard. *That will look about as bad as not having
had a transponder in the first place.

- what is the penalty for being caught doing so? What is the chance of
being caught?

* The first part probably depends on how you are caught.

* * * * Alan

Nice fear theories but there is no reality here. The encoders in the
Trig transponders are not an issue. The TT21 and TT22 use the same
control head and that is where the encoder is.

Current Mode C/gray code (100' resolution) external encoders operate
to a minimum of 30k feet. More expensive expensive encoders get you to
higher altitudes. And to get into a Mode S/serial encoder (25'
resolution) style encoder typically gets you higher than 30k feet as
standard but most of the Mode S transponders we care about in gliders
come with built in encoders.

For all USA gliders after transponder installation a static system
check (Part 43 Appendix E) is required to ensure both altimeter and
encoder accuracy. Nothing in that static systems tests is specific to
type 1 or 2 transponders--just ask the person doing the test if they
can check to 18,000' or higher just to be sure. (and if a Trig encoder
needs adjusting to meet altimeter accuracy the test operator has to
drive it up to 20,000' anyhow to use the calibration adjustment).

What is important is to get people installing and properly using
transponders where we have high density airline and fast jet traffic.
Not only did Trig (and maybe some other products in Europe who are not
available in the USA) significantly lower the cost and power
requirements of installing Mode S but they also significantly reduced
the cost difference between the Class 2 and Class 1 versions of their
transponders. Other vendors had been using that class 1 vs class 2
requirement to create high artificial price differences between their
transponders (for what were basically the same electronics). Trig's
price difference seems only around $200, so pretty marginal, so there
is less reason to use the Class 2 TT21 if class 1 requirement worries
you. The TT22 will use slightly more power than the TT21. Almost all
glider installations of Trig transponders I am aware of are TT21 and
seem to be doing very well.

Darryl

On 3/4/2011 9:52 PM, Alan wrote:
In Bruce writes:
On Mar 5, 8:44=A0am, John wrote:
If you ever want to climb above 15,000 ft in an airspace where a
tansponder is mandatory (which I do regularly), then you are just plain
illegal with the TT21. This may be "fairly meaningless" for you, it's
not for me and should not be for any pilot.

Saying something is "illegal" is a fairly useless statement. A lot of
things are illegal, ranging from driving at 60 in a 55 zone and on up.

I think you need to explain:

- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".


Unless, of course, the encoder actually cannot encode significantly above
that altitude.

Or, if it encodes incorrect values, resulting in that airliner hitting you
and going down with all aboard. That will look about as bad as not having
had a transponder in the first place.

We need to be sure we are talking about the same regions (country and
altitude). For the USA, Class A airspace starts at 18,000', so for below
that altitude, there is no effective difference between the two classes
of transponders for pilots operating VFR.

If you intend to operate in USA Class A airspace without waiver, then
getting the higher altitude rated transponder makes sense. The extra
cost of the unit is small compared to the ongoing testing requirements
of your transponder, altimeter, and static system, so there is no point
in taking a chance the encoder might not be accurate enough at the high
end (30,000+?).

I am still curious about the differences between the two models, beyond
the obvious one of output power.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

On 3/5/2011 2:04 AM, Eric Greenwell wrote:
On 3/4/2011 9:52 PM, Alan wrote:
In

Bruce writes:
On Mar 5, 8:44=A0am, John wrote:
If you ever want to climb above 15,000 ft in an airspace where a
tansponder is mandatory (which I do regularly), then you are just plain
illegal with the TT21. This may be "fairly meaningless" for you, it's
not for me and should not be for any pilot.

Saying something is "illegal" is a fairly useless statement. A lot of
things are illegal, ranging from driving at 60 in a 55 zone and on up.

I think you need to explain:

- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".


Unless, of course, the encoder actually cannot encode significantly above
that altitude.

Or, if it encodes incorrect values, resulting in that airliner hitting
you
and going down with all aboard. That will look about as bad as not having
had a transponder in the first place.

We need to be sure we are talking about the same regions (country and
altitude). For the USA, Class A airspace starts at 18,000', so for below
that altitude, there is no effective difference between the two classes
of transponders for pilots operating VFR.

If you intend to operate in USA Class A airspace without waiver, then
getting the higher altitude rated transponder makes sense. The extra
cost of the unit is small compared to the ongoing testing requirements
of your transponder, altimeter, and static system, so there is no point
in taking a chance the encoder might not be accurate enough at the high
end (30,000+?).

I am still curious about the differences between the two models, beyond
the obvious one of output power.

If you are flying above 18K in the US without a waiver, don't you need
to be on an IFR flight plan, IFR qualified and current, and in an
aircraft properly equipped and certified for IFR operation? If so, I
suspect that almost all glider operations in the US above 18K require
some form of waiver.

--
Mike Schumann

On 3/5/2011 1:21 PM, Mike Schumann wrote:
On 3/5/2011 2:04 AM, Eric Greenwell wrote:


If you intend to operate in USA Class A airspace without a waiver, then
getting the higher altitude rated transponder makes sense. The extra
cost of the unit is small compared to the ongoing testing requirements
of your transponder, altimeter, and static system, so there is no point
in taking a chance the encoder might not be accurate enough at the high
end (30,000+?).

I am still curious about the differences between the two models, beyond
the obvious one of output power.

If you are flying above 18K in the US without a waiver, don't you need
to be on an IFR flight plan, IFR qualified and current, and in an
aircraft properly equipped and certified for IFR operation?

I'm sure you do need to be operating IFR, and I believe that would
include having the proper class of transponder (but I can't point to the
regulation that says that). That's what I meant by "getting the higher
altitude rated transponder"; i.e., not the up to 15,000' rated one.

If so, I
suspect that almost all glider operations in the US above 18K require
some form of waiver.

I believe that is true, and I also believe it's true you could use your
15,000' rated transponder without any safety impact when using a waiver
to operate over 18,000'. HOWEVER, I don't know what the regulations
require of your transponder installation when operating with a waiver in
Class A.

And, I am still curious about the differences between the two ratings
(above/below 15,000), beyond the obvious one of output power.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

Here's my summary on the topic...let me know where I am wrong....

In USA you can fly to 17,999' WITHOUT any transponder at all (class E
or G with some exceptions)

If you have a transponder rated only to 15,000", you must have the
transponder "on" and you can only fly to 15,000 (legally)

If you have the "high Power" transponder you can fly up to 17,999
legally

To fly a glider in class A you need "special permission" waiver etc or
whatever.

It is possible to get permission to above 18,000 without a transponder
at all. Wave camps, wave windows, etc.

It is probably more likely to get permission, with a transponder.

Why not just tell the nice man your transponder is only good to 15,000
when you ask permission to go into class A?

If you intend to fly above 15,000, why not just contact ATC and say
"I'm looking to fly above 15,000 but only have the low power
transponder?

If you fly above 15,000 regularly why not just buy the higher power
transponder in the first place?

If you have the old, low power transponder, I am sure it would be easy
to sell, or trade in for high power model!

We installed the trig TT21 in our club glider. One of our airline
pilot guys tried it out and contacted both NY approach, and
Philadelphia approach....both said the signal was very strong.
Probably with a proper install, and antenna the low watt transponder
may actually put out more power into the air than a poorly installed
high power transponder?? Also, we have an agreement to use 1201 code,
so they know it's a glider. Only trouble is, we seldom get that high
around here. State record is around 17,000......maybe somebody went
higher but never claimed..

Cookie

On 3/5/2011 5:47 PM, wrote:
Here's my summary on the topic...let me know where I am wrong....

In USA you can fly to 17,999' WITHOUT any transponder at all (class E
or G with some exceptions)

If you have a transponder rated only to 15,000", you must have the
transponder "on" and you can only fly to 15,000 (legally)

If you have the "high Power" transponder you can fly up to 17,999
legally

To fly a glider in class A you need "special permission" waiver etc or
whatever.

It is possible to get permission to above 18,000 without a transponder
at all. Wave camps, wave windows, etc.

It is probably more likely to get permission, with a transponder.

Why not just tell the nice man your transponder is only good to 15,000
when you ask permission to go into class A?

If you intend to fly above 15,000, why not just contact ATC and say
"I'm looking to fly above 15,000 but only have the low power
transponder?

If you fly above 15,000 regularly why not just buy the higher power
transponder in the first place?

If you have the old, low power transponder, I am sure it would be easy
to sell, or trade in for high power model!

We installed the trig TT21 in our club glider. One of our airline
pilot guys tried it out and contacted both NY approach, and
Philadelphia approach....both said the signal was very strong.
Probably with a proper install, and antenna the low watt transponder
may actually put out more power into the air than a poorly installed
high power transponder?? Also, we have an agreement to use 1201 code,
so they know it's a glider. Only trouble is, we seldom get that high
around here. State record is around 17,000......maybe somebody went
higher but never claimed..

I'm with Darryl on this one: if you think you need a transponder, put
one in your glider, ensure you have the batteries to run it for the
whole flight, and then _Turn_It_On_ when you fly. As long as you are in
the USA, flying VFR, there is no safety or operational reason for
choosing one transponder over the other. The most important thing is
having a transponder. All this fussing over whether it's a Class 1 or
Class 2 is a waste of time.

Buy the Trig 21 or 22, install it, and be happy (we'll all be safer).
ATC will be so pleased you did it that they won't ask you which one it
is, and you don't have to tell them. They don't care, as long as it
shows on their screen.

Or buy one of those old Beckers or Microaires that get traded in - they
are still fine units, and a used one is a lot cheaper than a new one.
Nine years and counting on my 175 watt Becker, so don't wait for mine!

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

Am 05.03.11 02:10, schrieb Bruce Hoult:
- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".

The word "suspect" says that you don't know. I don't know either, but I
suspect that there's a reason for the requirement.

Frankly, I simply don't understand this discussion. The price difference
between the TT21 and the TT22 is negligible (list price at Cumulus
Soaring $2195 vs $2395). How would any mentally sane pilot choose to go
illegal for a price difference of just 200 bucks?

On Mar 5, 2:44*am, John Smith wrote:
Am 05.03.11 02:10, schrieb Bruce Hoult:

- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".

The word "suspect" says that you don't know. I don't know either, but I
suspect that there's a reason for the requirement.

Frankly, I simply don't understand this discussion. The price difference
between the TT21 and the TT22 is negligible (list price at Cumulus
Soaring $2195 vs $2395). How would any mentally sane pilot choose to go
illegal for a price difference of just 200 bucks?

Perhaps because the TT21 is available from some sources for a lot less
than list price, but the TT22 is not.

Andy