PowerFLARM questions

[Greg Arnold[_2_]]

Will the PowerFLARM logger record pressure altitude, or only GPS
altitude? Will it record engine noise level?

[Darryl Ramm]

On Oct 31, 12:33*pm, Greg Arnold > wrote:
> Will the PowerFLARM logger record pressure altitude, or only GPS
> altitude? *Will it record engine noise level?

It *has* to record (cockpit ambient) pressure altitude to be an IGC
approved recorder, and it also has to record the GPS altitude as well
(if it has a GPS fix).

There is an ENL option for the PowerFLARM.


Darryl

[Darryl Ramm]

On Oct 31, 12:33*pm, Greg Arnold > wrote:
> Will the PowerFLARM logger record pressure altitude, or only GPS
> altitude? *Will it record engine noise level?

It *has* to record (cockpit ambient) pressure altitude to be an IGC
approved recorder, and it also has to record the GPS altitude as well
(if it has a GPS fix).

There is an ENL option for the PowerFLARM.


Darryl

[Andy[_1_]]

On Oct 31, 12:44*pm, Darryl Ramm > wrote:
>
> It *has* to record (cockpit ambient) pressure altitude to be an IGC
> approved recorder, and it also has to record the GPS altitude as well
> (if it has a GPS fix).

I thought new flight recorders were allowed, even required, to be
connected to a static port. This eliminates the differences between
the logger and the altimeter due to speed changes. Not sure when the
requirement changed but it has been discussed here before.

So the real question is will the blind PowerFLARM have a static
connection.

Andy

[Darryl Ramm]

On Nov 1, 7:13*pm, Andy > wrote:
> On Oct 31, 12:44*pm, Darryl Ramm > wrote:
>
>
>
> > It *has* to record (cockpit ambient) pressure altitude to be an IGC
> > approved recorder, and it also has to record the GPS altitude as well
> > (if it has a GPS fix).
>
> I thought new flight recorders were allowed, even required, to be
> connected to a static port. *This eliminates the differences between
> the logger and the altimeter due to speed changes. *Not sure when the
> requirement changed but it has been discussed here before.
>
> So the real question is will the blind PowerFLARM have a static
> connection.
>
> Andy

Andy

Opps you are right (my C302 bias showing) thanks for catching that -
the current IGC standards allow either. I'm not aware if any of the
other more recent flight recorder implementations do this - the C302
static port is not used for its flight recorder.

Personally I'm happy having cockpit ambient but it would be nice for a
PowerFLARM brick to come with a port suitable to connect with a static
line (even if that might not pass FAA muster...). You don't need to
connect it if you don't want to.

And so the original question's answer is yes still yes it has one but
the question has changed.

Urs....?

Darryl

[Wayne Paul]

Andy,

I know the EWMicro doesn't attach to the static port. I think it would be considered a "new" logger. So, it must not be "required."

Wayne
http://www.soaridaho.com/


"Andy" > wrote in message ...
On Oct 31, 12:44 pm, Darryl Ramm > wrote:

I thought new flight recorders were allowed, even required, to be
connected to a static port. This eliminates the differences between
the logger and the altimeter due to speed changes. Not sure when the
requirement changed but it has been discussed here before.

So the real question is will the blind PowerFLARM have a static
connection.

Andy

[Darryl Ramm]

On Nov 1, 10:08*pm, "Wayne Paul" > wrote:
> Andy,
>
> I know the EWMicro doesn't attach to the static port. *I think it would be considered a "new" logger. *So, it must not be "required."
>
> Waynehttp://www.soaridaho.com/
>
> "Andy" > wrote in ...
>
> On Oct 31, 12:44 pm, Darryl Ramm > wrote:
>
> I thought new flight recorders were allowed, even required, to be
> connected to a static port. *This eliminates the differences between
> the logger and the altimeter due to speed changes. *Not sure when the
> requirement changed but it has been discussed here before.
>
> So the real question is will the blind PowerFLARM have a static
> connection.
>
> Andy

I should have typed my last reply more carefully as well. It is
currently optional for a IGC flight recorder to use either cockpit
ambient or static if the flight recoder is for a fixed install. If it
a portable flight recorder it must use cockpit ambient. The EWMicro is
a portable so would not qualify anyhow.

So to be clear here is the current IGC flight recorder technical
specification language...

"Pressure Altitude - In a GNSS FR, this is a five numeric group
indicating the pressure altitude in metres with respect the
International Standard Atmosphere (ISA) used in aviation, to a sea
level datum of 1013.25 HPa. The pressure recorded in the *.IGC file
may either be "cockpit static" (vented within the FR box), or use a
tube connection to the pressure from glider instrument system static
tubing. If the pressure altitude signal within the FR is used for
other purposes such as cockpit instrument readings which can be set to
other datums such as QNH or QFE, a one-way transmission system must be
used from the sensor so that the IGC file always records the required
ISA to the 1013 sea level datum irrespective of other settings used
for flight instruments. The permitted use of instrument-static is
intended for a GNSS FR mounted in the instrument panel. With such an
installation, an OO as part of the inspection of the FR installation
must check the tubing and the pressure connection to the FR to ensure
that they will be out-of-reach of the aircrew in flight. This is to
prevent alteration to the IGC-file pressure altitude record by any
method. (AL4)"

The OO would also have to check for and seal any alt-static switches/
valves so they can't be used in flight.


Darryl

[Chris Nicholas[_2_]]

All this seems to be a very demanding requirement for official
observers.

Chris N

[Darryl Ramm]

On Nov 2, 4:09*am, Chris Nicholas > wrote:
> *All this seems to be a very demanding requirement for official
> observers.
>
> Chris N

Yes this does increase the work for OO and contest CD in principle.
There are demanding requirements for the OO now depending on the
individual flight recorder approval--like possibly sealing the
recorder to the aircraft in some circumstances. How often do you think
OOs are 1. aware of these requirements for a particular flight
recorder approval and 2. follow them?

The trade-off is do you want to provide pilots with the option or an
IGC flight recorder pressure altitude that is sourced from the static
line (and therefore should line up after QNH calibration better with
their altimeter) or is the extra choice(=possible confusion)/
complexity/hassle not with it?

I'm not aware of any other vendor offeing this - does anybody know of
any. The LX 8000/9000 do not and the C302 does not - they all record
ambient pressure altitude. I just did a quick check and it looks like
the ability to use static line pressure altitude was introduced in the
GNSS Flight Recorder Technical Specifications AL4 ~2001 (not sure of
the exact adoption date - but it was *not* recent).

Darryl

[Greg Arnold[_2_]]

On 11/2/2010 12:52 PM, Grider Pirate wrote:
> I don't have FLARM, but I have a TT21 transponder. I WILL be talking
> on 123.5 on the Whites!
> Let me get this straight. FLARM uses GPS altitude. My transponder
> uses Pressure altitude.
> FLARM will see my transponder (assuming I'm interrogated) much as a
> PCAS.
> FLARM will look at its GPS altitude, and maybe not worry about me
> because it thinks we have 1000' vertical separation. Too bad for us
> if it's a smokin' day, and the tranponder pressure altitude show
> 16,800 when the GPS altitude shows 18,000!
>
> B2016373615714N11540384WA 05179 05561 000076000000
> B2016413615718N11540296WA 05202 05585 000072000000
> (just an example of a 1,256 difference between pressure and GPS alt,
> spaces added for clarity)
>
> The difference between cabin and static is trivial compared to the
> difference between pressure and GPS.


Also, we just learned that the altitude of other gliders displayed by
SeeYou for Flarm purposes is absolute, not relative. So we will be
comparing the GPS altitude of other gliders with the pressure altitude
on our altimeter. This seems like a problem.

[Ramy]

On Nov 2, 1:05*pm, Greg Arnold > wrote:
> On 11/2/2010 12:52 PM, Grider Pirate wrote:
>
>
>
>
>
> > I don't have FLARM, but I have a TT21 transponder. I WILL be talking
> > on 123.5 on the Whites!
> > Let me get this straight. *FLARM uses GPS altitude. My transponder
> > uses Pressure altitude.
> > FLARM will see my transponder (assuming I'm interrogated) much as a
> > PCAS.
> > FLARM will look at its GPS altitude, and maybe not worry about me
> > because it thinks we have 1000' vertical separation. *Too bad for us
> > if it's a smokin' day, and the tranponder pressure altitude show
> > 16,800 when the GPS altitude shows 18,000!
>
> > B2016373615714N11540384WA *05179 *05561 *000076000000
> > B2016413615718N11540296WA *05202 *05585 *000072000000
> > (just an example of a 1,256 difference between pressure and GPS alt,
> > spaces added for clarity)
>
> > The difference between cabin and static is trivial compared to the
> > difference between pressure and GPS.
>
> Also, we just learned that the altitude of other gliders displayed by
> SeeYou for Flarm purposes is absolute, not relative. *So we will be
> comparing the GPS altitude of other gliders with the pressure altitude
> on our altimeter. *This seems like a problem.- Hide quoted text -
>
> - Show quoted text -

My understanding from Urs's talk is that Flarm is using pressure
altitude, not GPS altitude. It does not make sense otherwise as other
pointed out. While GPS altitude is more accurate as an absolute
altitude (if you took a tape measure), the actual difference between
GPS altitude and pressure altitude can indeed be over 1000 feet, and
the accuracy of gps altitude relies heavily on reception and can
jitter a lot. Since all we need to know is relative altitude to
another aircraft carrying a flarm or transponder, pressure altitude
makes much more sense to me. Did I miss something?

Ramy

[Darryl Ramm]

On Nov 2, 12:52*pm, Grider Pirate > wrote:
> On Nov 2, 11:20*am, Darryl Ramm > wrote:
[snip]
>
> I don't have FLARM, but I have a TT21 transponder. I WILL be talking
> on 123.5 on the Whites!
> Let me get this straight. *FLARM uses GPS altitude. My transponder
> uses Pressure altitude.
> FLARM will see my transponder (assuming I'm interrogated) much as a
> PCAS.
> FLARM will look at its GPS altitude, and maybe not worry about me
> because it thinks we have 1000' vertical separation. *Too bad for us
> if it's a smokin' day, and the tranponder pressure altitude show
> 16,800 when the GPS altitude shows 18,000!
>
> B2016373615714N11540384WA *05179 *05561 *000076000000
> B2016413615718N11540296WA *05202 *05585 *000072000000
> (just an example of a 1,256 difference between pressure and GPS alt,
> spaces added for clarity)
>
> The difference between cabin and static is trivial compared to the
> difference between pressure and GPS.

James

Thanks for using a transponder!

You are asking a different question than I was talking about. flarm-
flarm collision avoidance radio links uses GPS altitude and does not
involve pressure. I did not say th PowerFLARM does not use pressure
information elsewhere.

PCAS systems today can suffer from altitide errors (esp if the PCAS
eqiupped glider does not have a local transponder to pick up an
accurate altitude). PCAS systems sniff the local transponder altitude
or use ambient cockpit pressure to sense their relative altitude to a
threat and I assume PowerFLARM will do similar. What exactly the PCAS
does I am not sure, then there are parts of the Zaon MRX that I don't
understand either. And I'm not losing any sleep over it given how
obviously the difference between encoder altitude and GPS altitude can
be (so pressure data is needed) and from conversation with these guys
over related issues where they clearly are smarter than your average
bear on this stuff.

I know you know this but the PCAS warning from a PowerFLARM or Zaon
MRX on the White Mountains to your Trig TT-21 will be a lot less
useful that the flarm-flarm link between two PowerFLARM units. I've
flown the whites with PCAS (and a Mode C) and on busy days you get too
many alerts with too little time to work out where the threat is. On
quiet days it is handy for letting you know somebody else is in the
area.

If you have a Trig TT21 in an experimental glider today you may want
to consider connecting a GPS and transmitting 1090ES data-out in
future. And before anybody asks - ADS-B data-out systems are required
to transmit GPS altitude _and_ pressure altitude.

Darryl

[Greg Arnold[_2_]]

On 11/2/2010 1:28 PM, Darryl Ramm wrote:

>
> You are asking a different question than I was talking about. flarm-
> flarm collision avoidance radio links uses GPS altitude and does not
> involve pressure. I did not say th PowerFLARM does not use pressure
> information elsewhere.


So PowerFLARM uses GPS altitude to avoid collisions, but also broadcasts
pressure altitude, and this is what shows up on the SeeYou screen next
to other gliders?

[Darryl Ramm]

On Nov 2, 1:39*pm, Greg Arnold > wrote:
> On 11/2/2010 1:28 PM, Darryl Ramm wrote:
>
>
>
> > You are asking a different question than I was talking about. flarm-
> > flarm collision avoidance radio links uses GPS altitude and does not
> > involve pressure. I did not say th PowerFLARM does not use pressure
> > information elsewhere.
>
> So PowerFLARM uses GPS altitude to avoid collisions, but also broadcasts
> pressure altitude, and this is what shows up on the SeeYou screen next
> to other gliders?

I was saying PowerFLARM is a PCAS *receiver* it just needs to know the
pressure altitude for that to work - it does not transmit anything.
Same for ADS-B since it is only a receiver.

Flarm and PowerFLARM have to be 100% compatible and Flarm does not use
pressure altitude in its collision avoidance protocol. And I want to
qualify that as far as I know PowerFLARM does not transmit pressure
altitude, but it might, I dont know. And if anybody ever wanted to use
that it might break things so I'm not sure it would ever be a good
idea. See my other post in this thread on how SeeYou Mobile does what
it does which I think will address these concerns.

Darryl

Darryl

[Greg Arnold[_2_]]

On 11/2/2010 2:02 PM, Darryl Ramm wrote:

>
> Flarm and PowerFLARM have to be 100% compatible and Flarm does not use
> pressure altitude in its collision avoidance protocol. And I want to
> qualify that as far as I know PowerFLARM does not transmit pressure
> altitude, but it might, I dont know.


It must transmit pressure altitude, as otherwise the altitude reading
displaying on SeeYou next to another glider is GPS altitude. I can't
compare that to the altitude on my altimeter.

[Darryl Ramm]

On Nov 2, 1:05*pm, Greg Arnold > wrote:
> On 11/2/2010 12:52 PM, Grider Pirate wrote:
>
>
>
> > I don't have FLARM, but I have a TT21 transponder. I WILL be talking
> > on 123.5 on the Whites!
> > Let me get this straight. *FLARM uses GPS altitude. My transponder
> > uses Pressure altitude.
> > FLARM will see my transponder (assuming I'm interrogated) much as a
> > PCAS.
> > FLARM will look at its GPS altitude, and maybe not worry about me
> > because it thinks we have 1000' vertical separation. *Too bad for us
> > if it's a smokin' day, and the tranponder pressure altitude show
> > 16,800 when the GPS altitude shows 18,000!
>
> > B2016373615714N11540384WA *05179 *05561 *000076000000
> > B2016413615718N11540296WA *05202 *05585 *000072000000
> > (just an example of a 1,256 difference between pressure and GPS alt,
> > spaces added for clarity)
>
> > The difference between cabin and static is trivial compared to the
> > difference between pressure and GPS.
>
> Also, we just learned that the altitude of other gliders displayed by
> SeeYou for Flarm purposes is absolute, not relative. *So we will be
> comparing the GPS altitude of other gliders with the pressure altitude
> on our altimeter. *This seems like a problem.

Having never flown with SeeYou Mobile and Flarm I'll admit to not
being sure exactly what is shows for altitude on the Flarm radar
screen. But that does not stop some reverse engineering...

Some other Flarm 3rd party display products only show relative height.
But lets assume SeeYou Mobile shows absolute altitude not differences.
But that does *not* automatically mean it is showing pressure altitude
(corrected for QNH) or GPS altitude of those other gliders?

The altitude data presented to SeeYou Mobile or any other application
that connects to a Flarm is only ever *relative* altitude between the
remote gliders flarm GPS and your flarm's GPS. The dataport interface
document is on Flarm's web site and is great quick bedtime read.
SeeYou Mobile would have to add your GPS altitude to the difference to
get the absolute GPS altitude of the other glider. Now if SeeYou
Mobile knows your pressure altitude I would hope it works with that
and all the other Flarm targets are show with pressure altitudes.
That would be consistent with the general handling of altitudes in
SeeYou Moble but I'll let Andrej or others confirm what they do.

BTW anybody else got an idea that Flarm folks working on this know
what they are doing? :-)

And to be clear to others in case they are worried about the absolute
altitude description - when you get a pop-up Flarm alert in SeeYou
Mobile the altitude displayed is always relative. The Flarm "radar"
display also has user settable color bands to show it the other
aircraft are near, above or below your altitude.

You know for a large map/radar display I'd personally rather see
absolute altitudes - especially as we eventually forward to ADS-B and
may see people over hundreds of miles. Ultimately having a choice of
relative/absolute would be best. Now somebody tell us that SeeYou
Mobile shows relative altitudes now and we can all go back to
sleep :-)


Darryl

[Darryl Ramm]

On Nov 2, 2:15*pm, Greg Arnold > wrote:
> On 11/2/2010 2:02 PM, Darryl Ramm wrote:
>
>
>
> > Flarm and PowerFLARM have to be 100% compatible and Flarm does not use
> > pressure altitude in its collision avoidance protocol. And I want to
> > qualify that as far as I know PowerFLARM does not transmit pressure
> > altitude, but it might, I dont know.
>
> It must transmit pressure altitude, as otherwise the altitude reading
> displaying on SeeYou next to another glider is GPS altitude. *I can't
> compare that to the altitude on my altimeter.

Greg,

O ye, of little faith. Wanna bet a case of good San Ynetz area wine?

Darryl

[Greg Arnold[_2_]]

On 11/2/2010 2:25 PM, Darryl Ramm wrote:

>
> You know for a large map/radar display I'd personally rather see
> absolute altitudes - especially as we eventually forward to ADS-B and
> may see people over hundreds of miles. Ultimately having a choice of
> relative/absolute would be best. Now somebody tell us that SeeYou
> Mobile shows relative altitudes now and we can all go back to
> sleep :-)

This morning Andrej told us it is absolute.

>
>
> Darryl

[Greg Arnold[_2_]]

On 11/2/2010 2:29 PM, Darryl Ramm wrote:
> On Nov 2, 2:15 pm, Greg > wrote:
>> On 11/2/2010 2:02 PM, Darryl Ramm wrote:
>>
>>
>>
>>> Flarm and PowerFLARM have to be 100% compatible and Flarm does not use
>>> pressure altitude in its collision avoidance protocol. And I want to
>>> qualify that as far as I know PowerFLARM does not transmit pressure
>>> altitude, but it might, I dont know.
>>
>> It must transmit pressure altitude, as otherwise the altitude reading
>> displaying on SeeYou next to another glider is GPS altitude. I can't
>> compare that to the altitude on my altimeter.
>
> Greg,
>
> O ye, of little faith. Wanna bet a case of good San Ynetz area wine?
>
> Darryl

No, I will decline that bet.

[playtimeover]

;753764']Will the PowerFLARM logger record pressure altitude, or only GPS
altitude? Will it record engine noise level?

Yes, I think. It will record it. :D

[Wayne Paul]

When reviewing the screens shown on http://www.gliderpilot.org/PowerFlarmDisplays it has been noted that the distances are in Km. Does the PowerFLARM system give the user the ability to change the defaults to statute, or nautical miles? (It would seem intuitive that an item being marketed to the US would have this ability.) How do you know the scale of the rings in the first sample photo with the eight in the upper left hand corner?

Wayne


"Greg Arnold" > wrote in message ...
> Will the PowerFLARM logger record pressure altitude, or only GPS
> altitude? Will it record engine noise level?

[Darryl Ramm]

On Nov 9, 7:36*pm, "Wayne Paul" > wrote:
> When reviewing the screens shown onhttp://www.gliderpilot.org/PowerFlarmDisplaysit has been noted that the distances are in Km. *Does the PowerFLARM system give the user the ability to change the defaults to statute, or nautical miles? *(It would seem intuitive that an item being marketed to the US would have this ability.) How do you know the scale of the rings in the first sample photo with the eight in the upper left hand corner?
>
> Wayne
>
> "Greg Arnold" > wrote in ...
> > Will the PowerFLARM logger record pressure altitude, or only GPS
> > altitude? *Will it record engine noise level?
>
>

The 8 in a circle is the standard Butterfly Flarm display way of
showing the range, in this case the 8 would mean the outer ring is 8km
and the inner ring is 4km.

If the PowerFLARM does not support imperial units I'll eat my hat (and
I have a big Stetson all ready to smother in ketchup). For example
Butterfly tell me that their iGlide software coming out soon for the
iPhone will support imperial units as well as km.

BTW it sobvious but I'll state it anyhow - if you are using an
external PDA etc. to also show traffic the units on that are selected
completely independently of the PowerFLARM or PowerFLARM brick's
dedicated external display.


Darryl