Revised IGC-approvals for some types of legacy recorder

On Wed, 19 Nov 2003 11:57:02 -0500, Todd Pattist
wrote:

Tim Newport-Peace ] wrote:


It was suggested:

A: All Purposes including World Records.
B: Badges and Diplomas
D: Badges up to Diamond


What is the rationale for distinguishing between levels B
and D? If I understand correctly, D was initially separated
from everything else because of concerns about cheating,
then B was shown to be hackable (Wedekind). If that's
correct, why wasn't B moved into group D? Or, more
preferably, why isn't D given the same privileges as B?

Instead of ratcheting up costs, why can't we just use our
Official Observers to control cheating? We relied on them
for decades before RSA/DSA and public/private key
encryption. If I hack an A level recorder (with a GPS
transmitter simulator and a pressure chamber or by opening
the case and inserting GPS code between the off-the-shelf
GPS receiver and the custom circuitry), can we just agree
that no security is perfect and group them all as imperfect,
but usable for all levels with appropriate monitoring by an
OO?
Todd Pattist - "WH" Ventus C
(Remove DONTSPAMME from address to email reply.)


Far too sensible for GFAC , Todd and of course you, me and others like
Robert Danewid and Dave Starer pointed out all this in 1995-96.

Done a search for GPS simulators lately? Not only has PC technology
progressed in the last ten years but simulator technology has too. I
found several manufacturers quite easily in a few minutes.

Give the problem to a bunch of bright engineering students and I'll
bet in 12 months you not only have a nice GPS simulator that is driven
by a PDA but a nice commercial product too.

Knowing this I have doubts about many of the current crop of amazing
records which is a pity because they *might* even be real.

Engine noise level sensors are easy to fool. The technology is readily
available commercially from Headsets Inc.. Just organise your active
noise cancelling to put noise in during glides and noise cancelling
during climbs with engine running. I just put a kit in our headsets
for the BD4. Works great.

I heard a rumour yesterday that the IGC in fact have a motorglider
record they have doubts about because of vague engine noise levels.

The mickey mouse microswitch is also good for just the first time you
open a particular logger. I sell Volksloggers and have serviced two
and fooling the microswitch is truly child's play now. Any potential
World record or 1000 km diploma holders should contact me privately.
GFAC members need not apply.

I'm also told by some people who are actively seeking World Records
that some records have been set under some suspicious circumstances.
For records requiring declarations the trick is to carry multiple
loggers and choose the appropriate one after the fact with the
declaration for the flight you actually did. This is definitely
cheating so why should we be surprised at better efforts requiring
more organisation?

I believe that for World Records the following should apply:

At least 30 days notice to the IGC that records will be attempted.

Notice to include the serial numbers and type of logger being used
including spares and name of O.O being used and location.

No more than 2 loggers in the aircraft. Requires O.O. to be present
just before takeoff.

O.O to use his own PC to clear logger memory before takeoff then seal
the loggers in aircraft no more than 15 minutes before takeoff. O.O
notes takeoff and landing times.

O.O to take charge of loggers immediately after landing and download
them him or her self and send files to IGC. If landed at some other
place logger must stay sealed in aircraft until aircraft is brought to
O.O or O.O to aircraft. In this case any dataports must be sealed by
the O.O. and only unsealed by him.

IGC to reserve the right to substitute their own nominated O.O at any
time. Actually do this now and again.

Loggers used to be returned to manufacturer for examination as soon as
possible after record session ends before record is approved.

Yes it requires honest O.O's. If we don't have those then we don't
have anything do we?

Note none of the above requires any onerous electronic security on the
logger and the logger and GPS can be separate joined by a cable. As
Marc pointed out indirectly the RSA security drives the current
logger design.

We could also get real and eliminate the pressure sensor out of the
logger and start using geometric altitudes like the rest of aviation.
They are the same in an ISA standard atmosphere but near as I can tell
gliding assumes that pressure altitudes achieved were done in an ISA
atmosphere when this is most likely not the case. The differences are
quite serious for gold and diamond badges.

Mike Borgelt

"Mike Borgelt" wrote...
We could also get real and eliminate the pressure sensor out of the
logger and start using geometric altitudes like the rest of aviation.

Which would make it really easy to fake a flight using a GPS simulator. The
change to geometric altitude will happen soon, at least above the mean
altitude of the tropopause (32K feet or so). I personally believe the
pressure sensor requirement should be eliminated for badge/diploma level
approval.

Marc

On Wed, 19 Nov 2003 14:21:06 -0800, "Marc Ramsey"
wrote:

"Mike Borgelt" wrote...
We could also get real and eliminate the pressure sensor out of the
logger and start using geometric altitudes like the rest of aviation.

Which would make it really easy to fake a flight using a GPS simulator. The
change to geometric altitude will happen soon, at least above the mean
altitude of the tropopause (32K feet or so). I personally believe the
pressure sensor requirement should be eliminated for badge/diploma level
approval.

Marc


So you feed a pressure sensor to the computer controlling the GPS
pseudolites and it roughly matches with GPS altitudes with appropriate
corrections for reasonable guesses as to the mean temperature in the
atmosphere. Dead easy! And a trivial enhancement to your pseudolite
system. Given that some IFR aviation GPS systems already use pressure
altitude for GPS aiding it would not surprise me if test equipment
that can do all this isn't available off the shelf.

Why limit the change to geometric altitude to above 32K feet? Most
loggers are on cockpit static (an original adamantly insisted on
requirement by GFAC now changed I believe - why?). That is good for 50
to 100 feet of error, you get sea level pressure changes and huge
errors due to temperature in the atmosphere, let alone running the
pressure sensors at maybe -20 C or colder. The fully approved
Volkslogger only claims +/- 2hPa over temperature which is another
+/-100 feet at around 20,000. You are already over any reasonable GPS
error budget.

Mike Borgelt

Mike Borgelt wrote:
So you feed a pressure sensor to the computer controlling the GPS
pseudolites and it roughly matches with GPS altitudes with appropriate
corrections for reasonable guesses as to the mean temperature in the
atmosphere. Dead easy! And a trivial enhancement to your pseudolite
system. Given that some IFR aviation GPS systems already use pressure
altitude for GPS aiding it would not surprise me if test equipment
that can do all this isn't available off the shelf.

When is the demo going to be ready? 8^)

Why limit the change to geometric altitude to above 32K feet? Most
loggers are on cockpit static (an original adamantly insisted on
requirement by GFAC now changed I believe - why?). That is good for 50
to 100 feet of error, you get sea level pressure changes and huge
errors due to temperature in the atmosphere, let alone running the
pressure sensors at maybe -20 C or colder. The fully approved
Volkslogger only claims +/- 2hPa over temperature which is another
+/-100 feet at around 20,000. You are already over any reasonable GPS
error budget.

The IGC works in mysterious ways. It seems eminently sensible to me to
switch completely over to GPS measured geometric altitude, but I don't
get to make the rules. In any case, a number of people with expertise
in the area have argued rather convincingly that the relationship
between pressure altitudes measured above 32,000 feet or so and actual
elevation above the ground is tenuous, at best.

The reason for the change allowing panel mounted flight recorders to use
aircraft static as an alternative to cockpit static is very simple. An
instrument manufacturer requested the change, and persuaded us that the
original reasoning behind the requirement for cockpit static was no
longer relevant.

Marc

Marc Ramsey wrote:
In any case, a number of people with expertise
in the area have argued rather convincingly that the relationship
between pressure altitudes measured above 32,000 feet or so and actual
elevation above the ground is tenuous, at best.

Of course, I meant "actual elevation above sea level"...

Marc

On Thu, 20 Nov 2003 06:20:57 GMT, Marc Ramsey wrote:

Mike Borgelt wrote:
So you feed a pressure sensor to the computer controlling the GPS
pseudolites and it roughly matches with GPS altitudes with appropriate
corrections for reasonable guesses as to the mean temperature in the
atmosphere. Dead easy! And a trivial enhancement to your pseudolite
system. Given that some IFR aviation GPS systems already use pressure
altitude for GPS aiding it would not surprise me if test equipment
that can do all this isn't available off the shelf.

When is the demo going to be ready? 8^)

Easier to just break in to the logger and install the switchable IR
link. Trivial. Mickey mouse microswitches just don't do it. The
professionals use thermite.


Why limit the change to geometric altitude to above 32K feet? Most
loggers are on cockpit static (an original adamantly insisted on
requirement by GFAC now changed I believe - why?). That is good for 50
to 100 feet of error, you get sea level pressure changes and huge
errors due to temperature in the atmosphere, let alone running the
pressure sensors at maybe -20 C or colder. The fully approved
Volkslogger only claims +/- 2hPa over temperature which is another
+/-100 feet at around 20,000. You are already over any reasonable GPS
error budget.

The IGC works in mysterious ways. It seems eminently sensible to me to
switch completely over to GPS measured geometric altitude, but I don't
get to make the rules. In any case, a number of people with expertise
in the area have argued rather convincingly that the relationship
between pressure altitudes measured above 32,000 feet or so and actual
elevation above the ground is tenuous, at best.

I believe that was calculated before SA was turned off. As I pointed
out above I doubt very much that any cockpit static can be better
than 50 to 100 feet.Static ports on gliders are sometimes pretty
terrible too so may not be any better. Try a good side slip and see
what happens also.
Add in the other error sources and you are worse than GPS altitude at
any altitude much above 1000 feet AGL.


ISA day sea level 1000 feet pressure altitude, geometric altitude 1000
feet
Try sea level 45 degrees C with DALR and a pressure altitude of 1000
feet. Mean temperature of layer is 43.5 geometric altitude 1102 feet

102 feet error! GPS is at least as good as this most of the time.


The reason for the change allowing panel mounted flight recorders to use
aircraft static as an alternative to cockpit static is very simple. An
instrument manufacturer requested the change, and persuaded us that the
original reasoning behind the requirement for cockpit static was no
longer relevant.

Then again neither the original reasoning nor the persuasion seems to
have seen the light of day.

Do you realise that the original requirement drove some serious system
architecture considerations for manufacturers? As I said the GFAC were
originally adamant about no static connections - what changed their
minds?
How does anyone trust the rules when they may change next week?
Nothing I've seen written here convinces me that anyone on GFAC has a
clue.

Mike Borgelt

Mike Borgelt wrote:
I believe that was calculated before SA was turned off. As I pointed
out above I doubt very much that any cockpit static can be better
than 50 to 100 feet.Static ports on gliders are sometimes pretty
terrible too so may not be any better. Try a good side slip and see
what happens also.
Add in the other error sources and you are worse than GPS altitude at
any altitude much above 1000 feet AGL.

It isn't a question of accuracy, it's a question of what is being
measured. Some believe we should continue to measure pressure altitude,
simply because that's what we've always done. I think it safe to say
that is now recognized by the IGC that once you get into the tropopause,
the magnitude of the error goes up rapidly. The current world altitude
records can't really be said to measure altitude, they simply measure
record low pressures.

Then again neither the original reasoning nor the persuasion seems to
have seen the light of day.

Frankly, GFAC is pretty much like every other committee I've been
involved with. Decisions aren't necessarily made by reason or
persuasion, they often are made by something approximating the consensus
when everyone gets tired of discussing it. After a few years, it's
often difficult to figure out exactly why a particular decision was made.

Keep in mind, there is no secretary, no meeting notes. Just a few
people spread out over a couple of time zones, many of whom have never
met any of the others face to face. 95% of the communication that goes
on is over email, and there's is no central archive. Perhaps if there
was a more sizable budget and actual salaries, we could communicate to
all with the level of detail and consistency you seem to be expecting.
But, for the moment you are stuck with a bunch of volunteers, some of
whom have been putting up with this sort of grief for 10 years now.

Do you realise that the original requirement drove some serious system
architecture considerations for manufacturers? As I said the GFAC were
originally adamant about no static connections - what changed their
minds?

Yes I do realize that. Just as I'm sure you realize that the concept of
flight recorders was very new in 1995, and that there has been a steep
learning curve for all involved. You also realize that the makeup of
GFAC now is quite different than it was in 1995. And, of course you are
fully aware that people can change their attitudes about issues over time.

How does anyone trust the rules when they may change next week?

The rules don't change every week. Rule changes are proposed at the IGC
meeting each March. Those rule changes that are accepted at the meeting
go into effect the following October. The manufacturers of approved
flight recorders (and those who have notified us that they intend to
submit a recorder for approval) are nearly always given advanced
notification (nobody is perfect, except you apparently) of proposed
changes, and asked for their input.

Nothing I've seen written here convinces me that anyone on GFAC has a
clue.

Well, at least we don't sit around badmouthing you on r.a.s.

Marc

Mike Borgelt wrote:


At least 30 days notice to the IGC that records will be attempted.

Either you are joking, either you have a very good weather forecaster...

--
Denis
Private replies: remove "moncourrielest" from my e-mail address
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On Thu, 20 Nov 2003 00:38:22 +0100, Denis Flament
wrote:

Mike Borgelt wrote:


At least 30 days notice to the IGC that records will be attempted.

Either you are joking, either you have a very good weather forecaster...


Not at all. Are you seriously suggesting that you can break a World
Record at essentially no notice on Sunday afternoon at your local
gliding club? Lots of luck.

Take a look at the effort that Steve Fossett and others are going to.

Nowadays it takes much preparation and planning which will take you
much longer than 30 days. It isn't at all unreasonable to require
prior notice of intention.

It has nothing whatever to do with weather forecasters (and I am one
-or used to be).

Mike Borgelt

Mike Borgelt wrote:

Not at all. Are you seriously suggesting that you can break a World
Record at essentially no notice on Sunday afternoon at your local
gliding club? Lots of luck.

yes I do ! Look at this one :

FAI has received the following Class D (Gliders) record claim :
================================================== ==============
Claim number : 7983
Sub-class DO (Open Class Gliders)
General Category
Type of record : Speed over a triangular course of 100 km
Course/location : Fremont County Airport, Canon City, CO (USA)
Performance : 243.41 km/h
Pilot : Tom K. SERKOWSKI (USA)
Glider : Schleicher ASH 26E
Date: 09.11.2003
Current record : 234.95 km/h (07.05.2000 - James M. PAYNE, USA)
================================================== =============

Tom had been doing his annual inspection on Saturday, his rigged on
Sunday morning and took off for a check flight, which happenned to be a
world record !


Nowadays it takes much preparation and planning which will take you
much longer than 30 days. It isn't at all unreasonable to require
prior notice of intention.

I don't say that he did not prepare this flight for a long time, but he
certainly could not have noticed FAI 30 days before than he would be
attempting a record that particular day. And I say again that you cannot
forcast a wave situation 30 days in advance.

I you just suggest that any pilot willing to attempt a record make a
notice without mentioning the exact date, it's like doing nothing... or
you can notice FAI each day for the following 30th day that you will
attempt a record, by some sort of automatic mailer, not to miss THE good
day, but I don't see any interest neither.


--
Denis
Private replies: remove "moncourrielest" from my e-mail address
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