PowerFlarm and ADS-B solution, can we find one?

I'm with you, T8.

I read this exact strategy back in the 80s; I think it was in
Reichmann's book. I couldn't wait to perform a Split-S through a
thermal. I was a new guy and thought that would be cool. The "come to
Jesus" meeting at the end of the day with the other occupants of the
thermal was, shall we say, enlightening.

So here's my take on this whole Flarm "stealth" thing:

Those who want stealth mode, don't want others to be able to identify
them and become remoras. That seems a nicer word than leeches. They
state the reasons for their opposition in clear terms.

Those who don't want stealth mode want to be remoras but don't want to
admit it. In an attempt to push their view, they fall back on Mom,
apple pie, children, lawyers, and safety. We see the same arguments all
the time in other activities and they become more unlikely and extreme
with each round.

On 1/8/2016 3:59 AM, Tango Eight wrote:
On Thursday, January 7, 2016 at 10:24:34 PM UTC-5, jfitch wrote:
a correct strategy is to turn sharply 180 degrees from the intended departure direction and dive through the core so that you have maximum speed gain with minimum loss to traverse the sink.
No.

T8

--
Dan, 5J

On Friday, January 8, 2016 at 8:03:36 PM UTC-8, Dan Marotta wrote:
I'm with you, T8.



I read this exact strategy back in the 80s; I think it was in
Reichmann's book.* I couldn't wait to perform a Split-S through a
thermal.* I was a new guy and thought that would be cool.* The "come
to Jesus" meeting at the end of the day with the other occupants of
the thermal was, shall we say, enlightening.



So here's my take on this whole Flarm "stealth" thing:



Those who want stealth mode, don't want others to be able to
identify them and become remoras.* That seems a nicer word than
leeches.* They state the reasons for their opposition in clear
terms.



Those who don't want stealth mode want to be remoras but don't want
to admit it.* In an attempt to push their view, they fall back on
Mom, apple pie, children, lawyers, and safety.* We see the same
arguments all the time in other activities and they become more
unlikely and extreme with each round.




On 1/8/2016 3:59 AM, Tango Eight wrote:



On Thursday, January 7, 2016 at 10:24:34 PM UTC-5, jfitch wrote:


a correct strategy is to turn sharply 180 degrees from the intended departure direction and dive through the core so that you have maximum speed gain with minimum loss to traverse the sink.


No.

T8





--

Dan, 5J

Hahaaaaa!
New subject.
Jim

On Friday, January 8, 2016 at 10:03:36 PM UTC-6, Dan Marotta wrote:

So here's my take on this whole Flarm "stealth" thing:

Those who want stealth mode, don't want others to be able to
identify them and become remoras.* That seems a nicer word than
leeches.* They state the reasons for their opposition in clear
terms.

Those who don't want stealth mode want to be remoras but don't want
to admit it.* In an attempt to push their view, they fall back on
Mom, apple pie, children, lawyers, and safety.* We see the same
arguments all the time in other activities and they become more
unlikely and extreme with each round.

Dan, considering you don't fly with a PowerFlarm and don't currently race, your comments are somewhat simplistic.

I've had PF since the day it came out, and have raced with it (in your stomping grounds, by the way). I love the situational awareness it provides, and think it makes racing a lot more fun, as well as safer. If you carefully read all the threads on this subject, you find a few hard core "IT WILL RUIN RACING AS WE KNOW IT!!!" proponents of stealth, a few hard core "MANDATE STEALTH AND ILL NEVER RACE AGAIN", and a lot of "I really like full flarm SA and I worry about mid-airs, is there a way we can compromise? My personal take is that the leeching argument is way overblown with the attendance at US contests, otherwise everybody would be carrying binoculars and all the young guys with 20-10 eyes would be winning. And having picked up USAFA Duo's(all USAFA racing gliders have PF) head on co-altitude under a cloud street over 10 km on the nose, I REALLY dont want to give up that capability.

All this knashing of teeth about how to tweek "stealth" to "competition" that will please everybody seems pointless to me. As others have pointed out, ADS-B out is coming, and if a cheap 1090ES system for UAVs comes out soon, I bet you will see it explode in gliders, and with PF you will see all those guys regardless of stealth or competition modes.

Instead of whining, we should all embrace the new technology and the capability it brings, and find new ways to use it. Despite what many nay-sayers are claiming, for the average racing pilot full up flarm makes a contest more enjoyable and safer - and isn't that really the point of it?

You should borrow a portable PF and try it - you may find that opens your eyes on what is really flying around in your airspace - you'll be able to see those airliners deviate around you!

Cheers from cold, wet, dreary St Louis.

Kirk
66

Well said Kirk.

The premise of this thread, that there should be some acceptable way to degrade the behavior of a safety device is just off base. We should only be looking to Flarm folks for ways to improve safety performance. That is their mission - no nonsense, no confusion about goals please.

Hi Kirk,

Yes, I've towed you during at least one contest at Moriarty and I've
admired your LS-6.

Please understand that I don't "poo-poo" Flarm in my comments, I only
respond to the comments of some, which I believe are unreasonable or
downright wrong. I always welcome logical proofs like the math-based
analysis of the pull-up (in a previous thread).

And yes, I think Flarm is a great tool for situational awareness but I
don't think that knowing a blip's ID is a requirement for safety. And
I'm neither for nor against "stealth" mode - I don't care either way.
The idea of coordinating an escape plan with another aircraft 5 miles
away by radio is simply ludicrous. Remember when contests were fully
manned and there was no Flarm or GPS? I'm not against either, as a lot
of the folks here think, but I think a lot of the fun has gone and
that's the main reason I don't fly contests any more.

So why do I keep posting? It's out of a genuine concern that false
perceptions, unchallenged, will eventually become policy, and I don't
want any more policies.

On 1/9/2016 8:09 AM, kirk.stant wrote:
On Friday, January 8, 2016 at 10:03:36 PM UTC-6, Dan Marotta wrote:

So here's my take on this whole Flarm "stealth" thing:
Those who want stealth mode, don't want others to be able to
identify them and become remoras. That seems a nicer word than
leeches. They state the reasons for their opposition in clear
terms.
Those who don't want stealth mode want to be remoras but don't want
to admit it. In an attempt to push their view, they fall back on
Mom, apple pie, children, lawyers, and safety. We see the same
arguments all the time in other activities and they become more
unlikely and extreme with each round.
Dan, considering you don't fly with a PowerFlarm and don't currently race, your comments are somewhat simplistic.

I've had PF since the day it came out, and have raced with it (in your stomping grounds, by the way). I love the situational awareness it provides, and think it makes racing a lot more fun, as well as safer. If you carefully read all the threads on this subject, you find a few hard core "IT WILL RUIN RACING AS WE KNOW IT!!!" proponents of stealth, a few hard core "MANDATE STEALTH AND ILL NEVER RACE AGAIN", and a lot of "I really like full flarm SA and I worry about mid-airs, is there a way we can compromise? My personal take is that the leeching argument is way overblown with the attendance at US contests, otherwise everybody would be carrying binoculars and all the young guys with 20-10 eyes would be winning. And having picked up USAFA Duo's(all USAFA racing gliders have PF) head on co-altitude under a cloud street over 10 km on the nose, I REALLY dont want to give up that capability.

All this knashing of teeth about how to tweek "stealth" to "competition" that will please everybody seems pointless to me. As others have pointed out, ADS-B out is coming, and if a cheap 1090ES system for UAVs comes out soon, I bet you will see it explode in gliders, and with PF you will see all those guys regardless of stealth or competition modes.

Instead of whining, we should all embrace the new technology and the capability it brings, and find new ways to use it. Despite what many nay-sayers are claiming, for the average racing pilot full up flarm makes a contest more enjoyable and safer - and isn't that really the point of it?

You should borrow a portable PF and try it - you may find that opens your eyes on what is really flying around in your airspace - you'll be able to see those airliners deviate around you!

Cheers from cold, wet, dreary St Louis.

Kirk
66

--
Dan, 5J

On Friday, January 8, 2016 at 11:03:36 PM UTC-5, Dan Marotta wrote:
I'm with you, T8.



I read this exact strategy back in the 80s; I think it was in
Reichmann's book.* I couldn't wait to perform a Split-S through a
thermal.* I was a new guy and thought that would be cool.* The "come
to Jesus" meeting at the end of the day with the other occupants of
the thermal was, shall we say, enlightening.



So here's my take on this whole Flarm "stealth" thing:



Those who want stealth mode, don't want others to be able to
identify them and become remoras.* That seems a nicer word than
leeches.* They state the reasons for their opposition in clear
terms.



Those who don't want stealth mode want to be remoras but don't want
to admit it.* In an attempt to push their view, they fall back on
Mom, apple pie, children, lawyers, and safety.* We see the same
arguments all the time in other activities and they become more
unlikely and extreme with each round.




On 1/8/2016 3:59 AM, Tango Eight wrote:



On Thursday, January 7, 2016 at 10:24:34 PM UTC-5, jfitch wrote:


a correct strategy is to turn sharply 180 degrees from the intended departure direction and dive through the core so that you have maximum speed gain with minimum loss to traverse the sink.


No.

T8





--

Dan, 5J

Dan, I specifically asked to keep this thread clean from any comments not related to finding a solution. Please take your comments to another thread and argue there. These comments bring no value towards finding a solution. This thread was intended to bring people together to find a solution not to create another divide.

To all, let's not get engaged in questioning each other motives.

Regards,
Andrzej

On Thursday, January 7, 2016 at 10:24:34 PM UTC-5, jfitch wrote:


Some people do push over in lift, and nearly everybody pulls up in lift. If you are near cloud base in a thermal and you expect sink in the ring around it (very common), a correct strategy is to turn sharply 180 degrees from the intended departure direction and dive through the core so that you have maximum speed gain with minimum loss to traverse the sink. This is exactly when a glider entering is pulling up. 1000 ft is nothing in this scenario.

That is so George Moffat 70's right out of Winning on the Wind.
There is very rarely an improvement in speed made good by some very dynamic exit of a thermal. The case that would favor it is very strong lift surrounded by strong sink.
A better technique is to use the lift at the end of the climb to smoothly accelerate the glider to the desired speed before hitting the sink. Rarely would this require more than a few hundred feet at most. Modern gliders get up to speed with very little loss of altitude.
What you are describing may be fun but it is not very efficient.
Pull ups obviously can and are more dynamic but even there smoothness pays off. UH

On Friday, January 8, 2016 at 5:36:33 AM UTC-8, wrote:
SNIPThe case that would favor it is very strong lift surrounded by strong sink.

There ya go: +10 followed by -10 not that uncommon here. The tradeoff between altitude and speed is mathematically fixed by classical physics: 1st law of thermo which I think everybody believes. It hasn't changed since the 70s (or even the 1770s). Drag of sailplanes has reduced very slightly in 45 years, which affects it very slightly. 90 knots speed reduction (from 140 - 50) is around 700 ft. (minus energy lost due to inefficiency, but plus gain due to 10 knot thermal). Pushover form 50 - 140 is the same, reversed.

No, I would not do that on a day with 2 knot thermals topping at 2500 ft. But I assume we want a Flarm stealth solution that works in all conditions?

On Friday, January 8, 2016 at 5:36:33 AM UTC-8, wrote:
Rarely would this require more than a few hundred feet at most. Modern gliders get up to speed with very little loss of altitude.
What you are describing may be fun but it is not very efficient.
Pull ups obviously can and are more dynamic but even there smoothness pays off. UH

A little math would help - but this seems roughly right.

Any decending air outside a thermal would likely be more gentle than the rising air at the core. I have certainly found I could gain more than 1,000 feet within 15 or 20 seconds with a smooth pull-up into a strong thermal.

We are talking about having adequate closing time (of around 45 seconds) from first being put on the traffic screen until potential collision - and not being . A glider running in say 3 knots of sink at 110 kts will lose around 500 feet in 45 seconds and a glider pulling up into lift might gain 7-800 from the pull-up and another 3-500 from the lift over that time period for a total of 1500-1800 feet net change (assuming the run into the thermal didn't also have some lift). Anything less creates a scenario where you can sneak in outside of the altitude filter for stealth and come into view with less than the requisite 45 seconds. Less than 1200 or so and the surprise can be quite sudden - maybe 8-10 seconds.

Of course getting into lines of lift can yield many different scenarios - running storm shelves is a common tactic, but so is convergence and occasionally wave - all have pairings of strong lift and some level of sink and pairings of gliders maneuvering. The fact that sink tends to generate push-overs and lift tends to generate pull-ups means that the effects are amplified, rather than canceling, so you need to look at both together.

9B

On Thursday, January 7, 2016 at 10:24:34 PM UTC-5, jfitch wrote:
On Thursday, January 7, 2016 at 6:20:32 PM UTC-8, Andy Blackburn wrote:
On Wednesday, January 6, 2016 at 7:36:27 AM UTC-8, Dan Marotta wrote:
In the spirit of technical discussion I must point out what seems to
me to be a basic flaw in logic.



The statement that you can gain or lose altitude at 10 m/s (~20 kt)
is certainly valid in the US southwest.* However the supposition
that two gliders traveling in opposite directions with 200 meter
vertical separation would be at risk of collision due to one
suddenly dropping and the other suddenly climbing in the same
airmass does not appear to be a serious risk.*

I think the idea is that they'd be in *different*, adjacent airmasses. Where you have strong lift you tend to have similar sink adjacent to the lift, this is true for wave, convergence and thermals. It's one reason why it's common to push over when exiting a thermal, so you can quickly traverse the sinking air surrounding the thermal (what goes up comes down somewhere nearby - that way all the air doesn't end up above the boundary layer). I've gained 1,000' pulling up in strong lift and I've seen similar opposite situations thunderstorm shelf-running. The climbing and descending gliders would not be maneuvering in the same thermal to be sure as it's hard to imagine in that case the pushing over into sink glider and the pulling up in lift glider doing anything other than diverging, but one glider pushing over to get through a veil of rain and sink while another glider is just pulling up into the strong lift under the shelf just beyond. You'd like to see that guy coming rather then letting him sneak in below the Stealth invisibility cloak and pop up into a conflict. Maybe it's just me, but I don't like surprises.

Part of the challenge with selectively degrading a device like Flarm is making sure you haven't made an assumption about the scenarios that can (or can't) come up.

9B

Some people do push over in lift, and nearly everybody pulls up in lift. If you are near cloud base in a thermal and you expect sink in the ring around it (very common), a correct strategy is to turn sharply 180 degrees from the intended departure direction and dive through the core so that you have maximum speed gain with minimum loss to traverse the sink. This is exactly when a glider entering is pulling up. 1000 ft is nothing in this scenario.

i know thats what moffat says to do.... but that's not a good maneuver if you are sharing the thermal.