RC madness

On Tuesday, December 22, 2015 at 1:26:07 PM UTC-5, jfitch wrote:

Ok now think about the glider going your direction you think might be just above to your left, and the one you think might be just below to your right (they are not threats and are invisible on your tactical display due to stealth).
SNIP
With (non-stealth) Flarm, this scenario doesn't even raise your heart rate, you knew where everyone was 7 miles out,

Not trying to be difficult but I must be missing something. If they're that close to you (i.e., within 2 km), they're visible even with Stealth.

That's for the standard (Portable) FLARM display I use, of course. I can't say how the glide computer tactical displays might present the information in an "improved" fashion.

If, on the other hand, they don't have FLARM at all, then you don't know where everyone is 7 miles out.

Chip Bearden
ASW 24 "JB"
U.S.A.

On Tuesday, December 22, 2015 at 2:15:16 PM UTC-8, wrote:
SNIP Not trying to be difficult but I must be missing something. If they're that close to you (i.e., within 2 km), they're visible even with Stealth..


From the Flarm documents, V6.0 page 19 (maybe this has changed?):

"Targets with enabled “Stealth Mode� are only displayed.... if they meet at least one of the following requirements:

- target is a threat

- target is within 100m horizontal and 50m vertical
- target is within 2000m horizontal and 300m vertical and within ±45° of own flight track."

So the guys going your way - the ones ND is going to pull up sharply into - you don't even know are there. They aren't a threat because they are paralleling your course. Even if they are close enough to appear, their relative altitude is intentionally wrong.

Now I am going to repeat for the 20th time or so, I don't believe Flarm is a huge increase in safety. It is a big sky and most accidents are spin/stall, not head on. I don't even call my Flarm an anti-collision device, I call it an in-flight entertainment system. But certainly beyond a doubt, it improves situational awareness always, and particularly in the scenario described. On The White Mountains and the Sierra convergence lines, I don't think there have been any head-ons than I can recall. Its a big sky. But plenty of people have had to change their underwear at the end of the day, I can assure you. It was enough of a concern that a rather elaborate procedure was devised in the area, reserving a radio frequency and involving reporting points etc., all of which seemed pretty ineffective, while non-stealth FLARM pretty much solves the problem completely and with no distraction.

On Tuesday, December 22, 2015 at 7:50:19 PM UTC-5, jfitch wrote:
On Tuesday, December 22, 2015 at 2:15:16 PM UTC-8, wrote:
SNIP Not trying to be difficult but I must be missing something. If they're that close to you (i.e., within 2 km), they're visible even with Stealth.


From the Flarm documents, V6.0 page 19 (maybe this has changed?):

"Targets with enabled “Stealth Mode� are only displayed..... if they meet at least one of the following requirements:

- target is a threat

- target is within 100m horizontal and 50m vertical
- target is within 2000m horizontal and 300m vertical and within ±45° of own flight track."

So the guys going your way - the ones ND is going to pull up sharply into - you don't even know are there. They aren't a threat because they are paralleling your course. Even if they are close enough to appear, their relative altitude is intentionally wrong.

Now I am going to repeat for the 20th time or so, I don't believe Flarm is a huge increase in safety. It is a big sky and most accidents are spin/stall, not head on. I don't even call my Flarm an anti-collision device, I call it an in-flight entertainment system. But certainly beyond a doubt, it improves situational awareness always, and particularly in the scenario described. On The White Mountains and the Sierra convergence lines, I don't think there have been any head-ons than I can recall. Its a big sky. But plenty of people have had to change their underwear at the end of the day, I can assure you. It was enough of a concern that a rather elaborate procedure was devised in the area, reserving a radio frequency and involving reporting points etc., all of which seemed pretty ineffective, while non-stealth FLARM pretty much solves the problem completely and with no distraction.

i'm not sure.... but think i could miss a glider as i pull if i'm looking right at him dude... you said one glider high left, one low right, so how am i in a position to hit someone if i go high right? especially if i look up in the direction of my pull?? you can't win at hypthetics, because the antagonist can always say, "ok that's fine, but what if..." i'm gonna bow out of this stupid debate now. have the last word if you like. see you dudes! (hopefully)

On Tuesday, December 22, 2015 at 7:50:19 PM UTC-5, jfitch wrote:
On Tuesday, December 22, 2015 at 2:15:16 PM UTC-8, wrote:
SNIP Not trying to be difficult but I must be missing something. If they're that close to you (i.e., within 2 km), they're visible even with Stealth.


From the Flarm documents, V6.0 page 19 (maybe this has changed?):

"Targets with enabled “Stealth Mode� are only displayed..... if they meet at least one of the following requirements:

- target is a threat

- target is within 100m horizontal and 50m vertical
- target is within 2000m horizontal and 300m vertical and within ±45° of own flight track."

So the guys going your way - the ones ND is going to pull up sharply into - you don't even know are there. They aren't a threat because they are paralleling your course. Even if they are close enough to appear, their relative altitude is intentionally wrong.

Now I am going to repeat for the 20th time or so, I don't believe Flarm is a huge increase in safety. It is a big sky and most accidents are spin/stall, not head on. I don't even call my Flarm an anti-collision device, I call it an in-flight entertainment system. But certainly beyond a doubt, it improves situational awareness always, and particularly in the scenario described. On The White Mountains and the Sierra convergence lines, I don't think there have been any head-ons than I can recall. Its a big sky. But plenty of people have had to change their underwear at the end of the day, I can assure you. It was enough of a concern that a rather elaborate procedure was devised in the area, reserving a radio frequency and involving reporting points etc., all of which seemed pretty ineffective, while non-stealth FLARM pretty much solves the problem completely and with no distraction.

From your experience, at about what distance does Flarm give conflict alert in a high speed head on situation? I understand that some gliders show on display at "long" range, presumably before alarms go off by some amount. I'm trying to get a practical understanding of the best case sensing and how it compares with alarming.
Anyone with real world experience, please ring in.
Thanks
UH

From your experience, at about what distance does Flarm give conflict alert in a high speed head on situation? I understand that some gliders show on display at "long" range, presumably before alarms go off by some amount. I'm trying to get a practical understanding of the best case sensing and how it compares with alarming.
Anyone with real world experience, please ring in.
Thanks
UH

UH this is pretty easy to go back and look at using the Flarm range analysis tool. Just use the IGC file for a good ridge day where everyone is doing laps back and forth on the same ridge. My Flarm range is usually around 10km directly out front. I will say it is very nice to get a short beep alert and have the time to look at the target's direction and relative altitude well before getting surprised by a radar warning and having much less time to visually acquire the glider if you don't have them yet (which also happens regularly even while attempting to maintain a good visual scan) Ridge days are where I see a possible issue with the stealth rule here in the east.

On Wednesday, December 23, 2015 at 12:28:10 PM UTC-8, wrote:
On Tuesday, December 22, 2015 at 7:50:19 PM UTC-5, jfitch wrote:
On Tuesday, December 22, 2015 at 2:15:16 PM UTC-8, wrote:
SNIP Not trying to be difficult but I must be missing something. If they're that close to you (i.e., within 2 km), they're visible even with Stealth.


From the Flarm documents, V6.0 page 19 (maybe this has changed?):

"Targets with enabled “Stealth Mode� are only displayed..... if they meet at least one of the following requirements:

- target is a threat

- target is within 100m horizontal and 50m vertical
- target is within 2000m horizontal and 300m vertical and within ±45° of own flight track."

So the guys going your way - the ones ND is going to pull up sharply into - you don't even know are there. They aren't a threat because they are paralleling your course. Even if they are close enough to appear, their relative altitude is intentionally wrong.

Now I am going to repeat for the 20th time or so, I don't believe Flarm is a huge increase in safety. It is a big sky and most accidents are spin/stall, not head on. I don't even call my Flarm an anti-collision device, I call it an in-flight entertainment system. But certainly beyond a doubt, it improves situational awareness always, and particularly in the scenario described. On The White Mountains and the Sierra convergence lines, I don't think there have been any head-ons than I can recall. Its a big sky. But plenty of people have had to change their underwear at the end of the day, I can assure you. It was enough of a concern that a rather elaborate procedure was devised in the area, reserving a radio frequency and involving reporting points etc., all of which seemed pretty ineffective, while non-stealth FLARM pretty much solves the problem completely and with no distraction.

From your experience, at about what distance does Flarm give conflict alert in a high speed head on situation? I understand that some gliders show on display at "long" range, presumably before alarms go off by some amount. I'm trying to get a practical understanding of the best case sensing and how it compares with alarming.
Anyone with real world experience, please ring in.
Thanks
UH

I have never had an unexpected head on warning. The expected ones seem to happen about as claimed, around 12 - 15 seconds prior to impact. The reason I have never had an unexpected warning is that any glider with non-stealth Flarm shows up on the tactical display many miles out - at least 5 and often 10 or more. Most gliders flying in this area fly with non-stealth Flarm. I consider unexpected warnings to be a direct result of loss of situational awareness, after which one should evaluate what he/she is doing wrong.

Prior to Flarm, flying a very fast narrow street like the White Mountains, it was not at all uncommon to have a glider flash by going the other way maybe a few wing spans apart, with 2 - 3 seconds from visual recognition to passing. You are looking for a nose-on white glider against a white cloud background. No doubt there were others that I never saw. With Flarm, you see MANY more gliders that you never would have seen, and close crossings are easily avoided.

Now I will pre-empt the responses about head down time. I consider the Butterfly and other dedicated Flarm displays to be quite deficient for tactical, situational, and collision avoidance use. I don't have one. Flarm targets appear on the moving map tactical display at all times, and are emphasized on that display if the get close. A one second glance is more than enough to evaluate the whole fleet. The vario has voice warnings for collision threats of both gliders and GA aircraft. It does not add to heads down time.

On Wednesday, December 23, 2015 at 1:19:41 PM UTC-8, jfitch wrote:


Now I will pre-empt the responses about head down time. I consider the Butterfly and other dedicated Flarm displays to be quite deficient for tactical, situational, and collision avoidance use. I don't have one. Flarm targets appear on the moving map tactical display at all times, and are emphasized on that display if the get close. A one second glance is more than enough to evaluate the whole fleet. The vario has voice warnings for collision threats of both gliders and GA aircraft. It does not add to heads down time.

What map display and vario are you using?

On Wednesday, December 23, 2015 at 1:32:09 PM UTC-8, wrote:
On Wednesday, December 23, 2015 at 1:19:41 PM UTC-8, jfitch wrote:


Now I will pre-empt the responses about head down time. I consider the Butterfly and other dedicated Flarm displays to be quite deficient for tactical, situational, and collision avoidance use. I don't have one. Flarm targets appear on the moving map tactical display at all times, and are emphasized on that display if the get close. A one second glance is more than enough to evaluate the whole fleet. The vario has voice warnings for collision threats of both gliders and GA aircraft. It does not add to heads down time.

What map display and vario are you using?

I am using an Air Avionics (Butterfly) vario which does very nice, clear voice warnings for Flarm (also gear, spoilers, and other warnings). I have used Winpilot and XCSoar (which also show targets) but for the last year or two I have been using iGlide. It shows Flarm targets with on-screen emphasis when they turn into warnings. It has some other nice features which will no doubt add to the paranoia: any target can be marked with a color, it retains that color throughout the flight whenever contacted. So my primary leach target can be red, secondary yellow, third blue, etc. Nearly zero head down time IDing them. One target can be set up so all of his/her data shows up in nav boxes (these are very easily navigated in iGlide) so constant large display of altitude, heading, climb rate, etc. Further, you can display the tracks of all Flarm targets, for example to match your thermalling circle with a leeching target.

Despite all that - at least here in the west - this will not allow you to stick to a better pilot. The climb rate reported for your target is wildly off. If you match his circle from below you will not be in the best lift. If you deviate more than a few hundred yards to a perceived better climb more likely than not you will not find it. It is just as Andy says. Don't know east coast flying so maybe it would work better there.

The main speed advantage I get from it is that you can see pilots pass you and get further and further ahead. This reminds me to push a little harder - but do my own thing.

On Wednesday, December 23, 2015 at 1:19:41 PM UTC-8, jfitch wrote:

Now I will pre-empt the responses about head down time. I consider the Butterfly and other dedicated Flarm displays to be quite deficient for tactical, situational, and collision avoidance use. I don't have one. Flarm targets appear on the moving map tactical display at all times, and are emphasized on that display if the get close. A one second glance is more than enough to evaluate the whole fleet. The vario has voice warnings for collision threats of both gliders and GA aircraft. It does not add to heads down time.


I'll add to that point.

The modern moving-map displays like Oudie, LX Nav and I'm sure many, many others put down very easy to scan "snail trails" of traffic that give a ton of information at a glance - position, track and, with a little extra focus, relative altitude (sometimes it's a numerical label, sometimes it's color coding). I put this information in a clearly contrasting color so I can scan easily. That is a nearly sure-fire way to avoid conflicts - especially now that almost everyone in contests is carrying Flarm. The longer range the target information is made available, the less frequently my gaze has to return to the display.

It is a fallacy in this new world that you are going to pick up more targets looking out the window - especially the conflicting ones you really care about (no I'm not arguing for 100% heads down - a good scan is part of aviating). Just try flying around looking for targets with your Mark I eyeballs on a reasonably busy day, then look at your Flarm display. I bet you find surprises - particularly if they are on a course without angular movement - like collision courses are by definition.

9B