Flarm Target direction

Earlier in the year I had a close call, the Flarm was going off with multiple targets most of which I could visually identify. One I did not see, we both had to turn sharply left to avoid a straight on collision.
Apparently Flarm calculates the potential collision taking into account all directions of movement including turn radius. If I had the Flarm view on the S100 set to the correct zoom I most likely would have picked up the circling glider heading my way. Same possibly goes for the other glider.
Accepting the Flarm view may have shown the exact position of the target, when it switches to the warning mode is it still pointing to the target or the potential collision point?
To clarify I was flying straight and level the target was in a thermal, probably banked 30deg turning left.
Cheers
Anton L

On Tuesday, June 1, 2021 at 1:15:57 AM UTC-4, wrote:
Earlier in the year I had a close call, the Flarm was going off with multiple targets most of which I could visually identify. One I did not see, we both had to turn sharply left to avoid a straight on collision.
Apparently Flarm calculates the potential collision taking into account all directions of movement including turn radius. If I had the Flarm view on the S100 set to the correct zoom I most likely would have picked up the circling glider heading my way. Same possibly goes for the other glider.
Accepting the Flarm view may have shown the exact position of the target, when it switches to the warning mode is it still pointing to the target or the potential collision point?
To clarify I was flying straight and level the target was in a thermal, probably banked 30deg turning left.
Cheers
Anton L

I can't speak to the FLARMview (you might try reading the manual), but from the Butterfly Display, it says in "Traffic Warnings":
"The warning-screen shows the viewing angle to the most dangerous collision threat. A
compass-style indicator gives information about the horizontal viewing angle to the threat."

In addition, the FTD-012 Interface Control Document (version 7.12, July 2019), page 20, speaking on PFLAA sentence (data on other proximate aircraft), says it delivers " Relative position in meters true north from own position... Relative position in meters true east from own position... Relative vertical separation in meters above own position. Negative values indicate that the other aircraft is lower.")

So, it points to where the threat currently is, which makes sense, because it gives a direction for you to look in. If it pointed to where the threat will be, there will be nothing there.

I am interested why you both turned left. I was taught that aircraft approaching head-on both were required to alter course to the right. Perhaps it's different where you fly.

I believe flarm is more effective for situational awareness than for last second collision avoidance since it does not give a resolution and as such once you get the alarm there is very little time to interpret the information correctly, locate the target and react correctly, especially if you didn’t already have visual contact.
As such make sure your flarm display, zoom level, audio alerts and even flarmnet are all configured and set in an effective way to provide situational awareness and avoid the situation of collision avoidance to start with.

Ramy

On Tuesday, June 1, 2021 at 5:22:39 AM UTC-7, Dan Daly wrote:
On Tuesday, June 1, 2021 at 1:15:57 AM UTC-4, wrote:
Earlier in the year I had a close call, the Flarm was going off with multiple targets most of which I could visually identify. One I did not see, we both had to turn sharply left to avoid a straight on collision.
Apparently Flarm calculates the potential collision taking into account all directions of movement including turn radius. If I had the Flarm view on the S100 set to the correct zoom I most likely would have picked up the circling glider heading my way. Same possibly goes for the other glider.
Accepting the Flarm view may have shown the exact position of the target, when it switches to the warning mode is it still pointing to the target or the potential collision point?
To clarify I was flying straight and level the target was in a thermal, probably banked 30deg turning left.
Cheers
Anton L
I can't speak to the FLARMview (you might try reading the manual), but from the Butterfly Display, it says in "Traffic Warnings":
"The warning-screen shows the viewing angle to the most dangerous collision threat. A
compass-style indicator gives information about the horizontal viewing angle to the threat."

In addition, the FTD-012 Interface Control Document (version 7.12, July 2019), page 20, speaking on PFLAA sentence (data on other proximate aircraft), says it delivers " Relative position in meters true north from own position... Relative position in meters true east from own position... Relative vertical separation in meters above own position. Negative values indicate that the other aircraft is lower.")

So, it points to where the threat currently is, which makes sense, because it gives a direction for you to look in. If it pointed to where the threat will be, there will be nothing there.

I am interested why you both turned left. I was taught that aircraft approaching head-on both were required to alter course to the right. Perhaps it's different where you fly.

On Tuesday, June 1, 2021 at 12:26:36 PM UTC-4, Ramy wrote:
I believe flarm is more effective for situational awareness than for last second collision avoidance since it does not give a resolution and as such once you get the alarm there is very little time to interpret the information correctly, locate the target and react correctly, especially if you didn’t already have visual contact.
As such make sure your flarm display, zoom level, audio alerts and even flarmnet are all configured and set in an effective way to provide situational awareness and avoid the situation of collision avoidance to start with.

Ramy

Hi Ramy. I guess my problem with that is that you spend a lot of time with head in cockpit gaining this SA, and less with eyes out, doing see and avoid for traffic that isn't FLARM (or in the case of the U.S., ADS-B) equipped (and properly functioning). I agree if you do not practice and work it into your motor memory, it might be a problem. For me - alarm; look at display, up to the correct o'clock to acquire visually, then if not, what vertical - above/below, angle again. If still alarming, and in front, turn right to avoid. You have 19 seconds. If you continue to get alarms, you'll collide if you don't do something. If you don't practice this drill, you don't get better.

Of course, all bets are off if one of the flarms is shut off or broken, not updated, or with a poor installation.

One key to situational awareness is knowing what information to essentially discard. If you're approaching 3 targets and visually acquire 2 of them and can rule them out as a risk, don't focus on them. All too often people focus on the glider circling 600ft above/below them and ignore the fact that the glider they are going to not see and hit is the one at the same altitude.

I try not to lose track of the other gliders, but once they are determined to not be an immediate threat, I'm back to looking for the "invisible" target that could be a threat. Especially important in areas where you have a mix of FLARM and no-FLARM traffic and it is easy to fixate on a known FLARM target.

Morgan


On Tuesday, June 1, 2021 at 10:25:29 AM UTC-7, Dan Daly wrote:
On Tuesday, June 1, 2021 at 12:26:36 PM UTC-4, Ramy wrote:
I believe flarm is more effective for situational awareness than for last second collision avoidance since it does not give a resolution and as such once you get the alarm there is very little time to interpret the information correctly, locate the target and react correctly, especially if you didn’t already have visual contact.
As such make sure your flarm display, zoom level, audio alerts and even flarmnet are all configured and set in an effective way to provide situational awareness and avoid the situation of collision avoidance to start with..

Ramy
Hi Ramy. I guess my problem with that is that you spend a lot of time with head in cockpit gaining this SA, and less with eyes out, doing see and avoid for traffic that isn't FLARM (or in the case of the U.S., ADS-B) equipped (and properly functioning). I agree if you do not practice and work it into your motor memory, it might be a problem. For me - alarm; look at display, up to the correct o'clock to acquire visually, then if not, what vertical - above/below, angle again. If still alarming, and in front, turn right to avoid. You have 19 seconds. If you continue to get alarms, you'll collide if you don't do something. If you don't practice this drill, you don't get better.

Of course, all bets are off if one of the flarms is shut off or broken, not updated, or with a poor installation.

The situational awareness can be done with little head in if you set your display to give you audio traffic alerts (not just collision alarms) , and set the ranges such that you only get alerts for relevant traffic, eg no more than 5 miles and 2000 feet altitude range (although for buddy flying you may want flarm range set to max).
Some displays doing better job with audio alerts than others. I am working with LXNAv to improve traffic advisory alerts on LX9000. In most displays as soon as you hear alert you can determine if the traffic can be a threat with a quick glimpse. In most cases you wouldn’t need to make visual contacts.

Ramy

On Tuesday, June 1, 2021 at 11:06:36 AM UTC-7, wrote:
One key to situational awareness is knowing what information to essentially discard. If you're approaching 3 targets and visually acquire 2 of them and can rule them out as a risk, don't focus on them. All too often people focus on the glider circling 600ft above/below them and ignore the fact that the glider they are going to not see and hit is the one at the same altitude.

I try not to lose track of the other gliders, but once they are determined to not be an immediate threat, I'm back to looking for the "invisible" target that could be a threat. Especially important in areas where you have a mix of FLARM and no-FLARM traffic and it is easy to fixate on a known FLARM target.

Morgan
On Tuesday, June 1, 2021 at 10:25:29 AM UTC-7, Dan Daly wrote:
On Tuesday, June 1, 2021 at 12:26:36 PM UTC-4, Ramy wrote:
I believe flarm is more effective for situational awareness than for last second collision avoidance since it does not give a resolution and as such once you get the alarm there is very little time to interpret the information correctly, locate the target and react correctly, especially if you didn’t already have visual contact.
As such make sure your flarm display, zoom level, audio alerts and even flarmnet are all configured and set in an effective way to provide situational awareness and avoid the situation of collision avoidance to start with.

Ramy
Hi Ramy. I guess my problem with that is that you spend a lot of time with head in cockpit gaining this SA, and less with eyes out, doing see and avoid for traffic that isn't FLARM (or in the case of the U.S., ADS-B) equipped (and properly functioning). I agree if you do not practice and work it into your motor memory, it might be a problem. For me - alarm; look at display, up to the correct o'clock to acquire visually, then if not, what vertical - above/below, angle again. If still alarming, and in front, turn right to avoid. You have 19 seconds. If you continue to get alarms, you'll collide if you don't do something. If you don't practice this drill, you don't get better.

Of course, all bets are off if one of the flarms is shut off or broken, not updated, or with a poor installation.

On Wednesday, 2 June 2021 at 00:22:39 UTC+12, Dan Daly wrote:
On Tuesday, June 1, 2021 at 1:15:57 AM UTC-4, wrote:
Earlier in the year I had a close call, the Flarm was going off with multiple targets most of which I could visually identify. One I did not see, we both had to turn sharply left to avoid a straight on collision.
Apparently Flarm calculates the potential collision taking into account all directions of movement including turn radius. If I had the Flarm view on the S100 set to the correct zoom I most likely would have picked up the circling glider heading my way. Same possibly goes for the other glider.
Accepting the Flarm view may have shown the exact position of the target, when it switches to the warning mode is it still pointing to the target or the potential collision point?
To clarify I was flying straight and level the target was in a thermal, probably banked 30deg turning left.
Cheers
Anton L
I can't speak to the FLARMview (you might try reading the manual), but from the Butterfly Display, it says in "Traffic Warnings":
"The warning-screen shows the viewing angle to the most dangerous collision threat. A
compass-style indicator gives information about the horizontal viewing angle to the threat."

In addition, the FTD-012 Interface Control Document (version 7.12, July 2019), page 20, speaking on PFLAA sentence (data on other proximate aircraft), says it delivers " Relative position in meters true north from own position... Relative position in meters true east from own position... Relative vertical separation in meters above own position. Negative values indicate that the other aircraft is lower.")

So, it points to where the threat currently is, which makes sense, because it gives a direction for you to look in. If it pointed to where the threat will be, there will be nothing there.

I am interested why you both turned left. I was taught that aircraft approaching head-on both were required to alter course to the right. Perhaps it's different where you fly.
Yes in retrospect it's obvious that it points to the target not the collision point, what slightly complicated the situation was the opposing glider was circling to the left and I was going straight, hence the initial question of where does the warning point.
The fact the opposing glider was already in a left hand turn is why he went more left and I left the opposite way.
Unlike TCAS, Flarm doesn't tell you how to avoid the collision, that is left to the pilot to decide, if you haven't sighted the opposing aircraft its hard to know what to do, that was my dilemma. In future I'll get out of there if I have any doubt.

The rule of thumb is that if you can’t quickly locate the other aircraft and not sure what to do, it is better to do something than nothing since the collision algorithm detected that if both gliders will continue in their predicted pass they may collide. As such, if you change your path you will reduce the risk of collision. And it is faster to push the nose down or pull the nose up and quickly change altitude, then initiate a bank. Bank away (normally to the right) if you see the target and determine you have enough time to maneuver.

Ramy


On Wednesday, June 2, 2021 at 12:57:15 PM UTC-7, wrote:
On Wednesday, 2 June 2021 at 00:22:39 UTC+12, Dan Daly wrote:
On Tuesday, June 1, 2021 at 1:15:57 AM UTC-4, wrote:
Earlier in the year I had a close call, the Flarm was going off with multiple targets most of which I could visually identify. One I did not see, we both had to turn sharply left to avoid a straight on collision.
Apparently Flarm calculates the potential collision taking into account all directions of movement including turn radius. If I had the Flarm view on the S100 set to the correct zoom I most likely would have picked up the circling glider heading my way. Same possibly goes for the other glider.
Accepting the Flarm view may have shown the exact position of the target, when it switches to the warning mode is it still pointing to the target or the potential collision point?
To clarify I was flying straight and level the target was in a thermal, probably banked 30deg turning left.
Cheers
Anton L
I can't speak to the FLARMview (you might try reading the manual), but from the Butterfly Display, it says in "Traffic Warnings":
"The warning-screen shows the viewing angle to the most dangerous collision threat. A
compass-style indicator gives information about the horizontal viewing angle to the threat."

In addition, the FTD-012 Interface Control Document (version 7.12, July 2019), page 20, speaking on PFLAA sentence (data on other proximate aircraft), says it delivers " Relative position in meters true north from own position... Relative position in meters true east from own position... Relative vertical separation in meters above own position. Negative values indicate that the other aircraft is lower.")

So, it points to where the threat currently is, which makes sense, because it gives a direction for you to look in. If it pointed to where the threat will be, there will be nothing there.

I am interested why you both turned left. I was taught that aircraft approaching head-on both were required to alter course to the right. Perhaps it's different where you fly.
Yes in retrospect it's obvious that it points to the target not the collision point, what slightly complicated the situation was the opposing glider was circling to the left and I was going straight, hence the initial question of where does the warning point.
The fact the opposing glider was already in a left hand turn is why he went more left and I left the opposite way.
Unlike TCAS, Flarm doesn't tell you how to avoid the collision, that is left to the pilot to decide, if you haven't sighted the opposing aircraft its hard to know what to do, that was my dilemma. In future I'll get out of there if I have any doubt.

The FlarmLED offers minimal information. With other displays you can adjust the range to allow yourself to see what other aircraft are up to as well as relative altitude, azimuth, range, vario, FlarmNet ID...

You can use that information to keep clear (or leech) and generally avoid alarms.

Flight computers connected to a Flarm can also show Flarm targets and give audible and visual notifications well ahead of time.

I was the other pilot in this near miss. Just to give more context it was a pre-start in a competition day, there were a significant number of sailplanes in this thermal, a number of which were at or about my altitude, not to far under cloud-base in rather murky shady visibility.
In this situation where Anton was approaching a thermal with many sailplanes Flarm is of limited use. Yes it will warn of predicted collision danger which should be heeded, but that is an adjunct to "Mark 1 eyeball". Anton and I saw each-other at the same time and he did everything right from that point and the situation was sorted.
I think it is one of those situations which will statistically arise from time to time and it is training and airmanship which will save the day, not the reliance on Flarm.