Sigh... (USA)

I think that if Flarm were installed with 2 antennae, one high in the
cockpit or on top of the fuselage, and the other below, there would be
no Flarm blind spot and it would be as near perfect as possible. We
don’t do that because it is too much trouble and/or too expensive. It
is hard enough to persuade many pilots to have Flarm even in its most
basic available form.

Similarly, if we all had blind spot mirrors, the chance of seeing a
potential collision as the Finland one would be improved – but not
perfect still, as the human eye and attention is not capable of
perfection. Downward and rearward facing CCTV would be a further
enhancement of visual collision avoidance. (The latter is coming in on
road vehicles, so not technically impossible, just expensive to
develop and install.) Have we done it? No – “it isn’t worth it”.

As for PCAS – I have one of those too. I have only an aerial on top of
the glare shield. AIUI, transponders in gliders with only one antenna,
usually underneath, will have weak or non-existent signals upwards,
and my PCAS will only see at very shallow angles down, so would not
help in the Finland type accident if the lower glider had only a
transponder and only the upper one a PCAS.

As I have said before, the best is the enemy of the good. If everyone
waits for the best/perfection, we will have too many fatalities that
meanwhile the good – Flarm + PCAS – can help avoid some, or most,
times.

Chris N.

On 6/9/2012 4:16 PM, Chris Nicholas wrote:

As for PCAS – I have one of those too. I have only an aerial on top of
the glare shield. AIUI, transponders in gliders with only one antenna,
usually underneath, will have weak or non-existent signals upwards,
and my PCAS will only see at very shallow angles down, so would not
help in the Finland type accident if the lower glider had only a
transponder and only the upper one a PCAS.

As I have said before, the best is the enemy of the good. If everyone
waits for the best/perfection, we will have too many fatalities that
meanwhile the good – Flarm + PCAS – can help avoid some, or most,
times.

The transponder signal is so powerful (150+ watts) compared to a Flarm
signal (0.02 watts), a PCAS unit would be able to "see" a transponder
equipped glider, even in the situation in Finland. Also, the glider
above would almost certainly have it's transponder antenna on the
bottom, while the glider below would have it's PCAS antenna "on top"
(glare shield mounted) and have no trouble receiving it.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

PCAS is useless for gliders flying intentionally in proximity, e.g. in
thermals. Range is based on signal strength, altitude is based on
pressure altitude encoder and there's no directionality. Best that
PCAS would tell you is that there are "n" gliders close to you. It
certainly can't give collision warning.

-Evan Ludeman / T8

Also, the glider
above would almost certainly have it's transponder antenna on the
bottom, while the glider below would have it's PCAS antenna "on top"
(glare shield mounted) and have no trouble receiving it.

Eric, only if they both have both transponder and PCAS. Re the
stronger signal, you may well be right – I don’t know.

But PCAS of course does not distinguish between proximity but going to
miss, and proximity and going to hit. My unit also only knows in
1/10ths of a mile the approximate distance. Still, better than
nothing, of course.

Chris N

On Jun 9, 8:23*pm, Evan Ludeman wrote:
PCAS is useless for gliders flying intentionally in proximity, e.g. in
thermals. *Range is based on signal strength, altitude is based on
pressure altitude encoder and there's no directionality. *Best that
PCAS would tell you is that there are "n" gliders close to you. *It
certainly can't give collision warning.

-Evan Ludeman / T8

Sorry Evan but that is not completely correct. While I agree that
PCAS can only offer very limited collision avoidance it certainly does
help. Speak of the devil I have video to prove it! Check out the
following which is just one of many videos showing close sailplane
formation and PCAS proximity warnings. Note my PCAS warns me that I
am drifting too close to the other transponder equip ship. I am all
for Power Flarm and have one on order but please note that the PCAS
does offer at least a little bit of help. Better than nothing...that
is when it works. My Zaon PCAS has stopped working 3 times with no
warning other than it didn't alert me to a close aircraft giving me a
hint that it stopped working again. Grrrr!

http://www.youtube.com/watch?v=n2H4SQpjRxc

The PCAS warnings come at :18, :27 (note how the sailplane is drifting
towards me), :46, 1:14 and on and on throughout the video. Again,
I'll take Flarm any day of the week but I guess they have to start
shipping our brick units first. Another Grrr.

Take care,
Bruno - B4

On 6/9/2012 7:33 PM, Chris Nicholas wrote:
Eric, only if they both have both transponder and PCAS. Re the
stronger signal, you may well be right – I don’t know.

One could have the PCAS, the other could have the transponder, and the
PCAS glider would be alerted to the other glider. Better, of course, if
they both had PCAS and transponder.

Transponders do have very powerful transmitters, and it is one reason
they cost as much as they do. Look at the specifications at any website
selling them - the power ranges from about 130 to 250 watts (our
communication radios are typically 5 to 7 watts). That power is needed
to reach the ground radars that might be 30 to 150 miles away.

Flarm, including PowerFlarm, is designed for air to air ranges of a few
miles, and doesn't need very much power to do so.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

This unfortunate accident in Finland brings up 2 issues:
1- sharing the details of such accident is very important. This should be an example why a lower antenna should be strongly recommended.
2- we should never fly directly above or below another aircraft as we have huge blind spots at these directions.

Ramy

On Jun 9, 11:09*pm, Bruno wrote:
On Jun 9, 8:23*pm, Evan Ludeman wrote:

PCAS is useless for gliders flying intentionally in proximity, e.g. in
thermals. *Range is based on signal strength, altitude is based on
pressure altitude encoder and there's no directionality. *Best that
PCAS would tell you is that there are "n" gliders close to you. *It
certainly can't give collision warning.

-Evan Ludeman / T8

Sorry Evan but that is not completely correct. *While I agree that
PCAS can only offer very limited collision avoidance it certainly does
help.

Don't be at all sorry if it works for you!

Different environments.

In dense gaggles in crappy wx at 15s we got *frequent* flarm alerts...
because the flying was just that close. Was it annoying? Not
exactly. All the alerts were meaningful. Think of having a back
seater with omnidirectional vision calling out traffic (4 oclock
high.... 3 oclock level, etc), stuff you needed to know about, mostly
already knew about. Did it prevent a collision? We can't know.
Flarm tells you early enough that the corrections needed are small and
the conflicts never develop into scary situations. The most
interesting alert was when Flarm called out three targets at once, oy.

If we'd all been on TXPs and PCAS, a) half the time we'd have had no
coverage because were below the radar, b) other times we'd have had 30
contacts inside a half mile and 400 vertical feet. I don't see how
PCAS could have provided meaningful information in that environment
and that's the environment I was thinking of. Your mileage, and
collision avoidance requirements may vary!

-Evan Ludeman / T8

On Jun 10, 1:16*am, Chris Nicholas wrote:
I think that if Flarm were installed with 2 antennae, one high in the
cockpit or on top of the fuselage, and the other below, there would be
no Flarm blind spot and it would be as near perfect as possible. We
don’t do that because it is too much trouble and/or too expensive. It
is hard enough to persuade many pilots to have Flarm even in its most
basic available form.

Chris N.

That's what I decided on last winter., because the Flarm range
analysis on my carbon fuselage Flarm installation (Ventius cM) showed
that there were some blind spot (ranges 2km). I installed an antenna
splitter, the original Flarm antenna outside the fuselage near the
gear doors, and a stripe antenna behind my head inside the canopy.
"Blind spot" now means a range of 4 km ( a bit more than 2 nautical
miles for the colonials).
Investment was $200. My ass is worth more than that.

On Friday, June 8, 2012 10:47:31 AM UTC-7, Ramy wrote:
On Friday, June 8, 2012 9:56:30 AM UTC-7, BobW wrote:
Not a good past 2 weeks per FAA prelims...midair (no reported injuries, thank
heaven!) apparently yesterday, & a takeoff groundloop a week ago Monday..

Three "substantially damaged" gliders.

IDENTIFICATION
Regis#: 101LV Make/Model: CEN Description: CENTRAIR 101
Date: 06/07/2012 Time: 2145

Event Type: Accident Highest Injury: None Mid Air: Y Missing:
Damage: Substantial

LOCATION
City: SPARKS State: NV Country: US

DESCRIPTION
N943SB COLLIDED MID AIR WITH N101LV UNDER UNKNOWN CIRCUMSTANCES. SPARKS, NV

INJURY DATA Total Fatal: 0
# Crew: 1 Fat: 0 Ser: 0 Min: 0 Unk:
# Pass: 0 Fat: 0 Ser: 0 Min: 0 Unk:
# Grnd: Fat: 0 Ser: 0 Min: 0 Unk:

- - - - - -
IDENTIFICATION
Regis#: 943SB Make/Model: DISC Description: DISCUS BT/BM
Date: 06/07/2012 Time: 2145

Event Type: Accident Highest Injury: None Mid Air: Y Missing: N
Damage: Substantial

LOCATION
City: SPARKS State: NV Country: US

DESCRIPTION
N943SB COLLIDED MID AIR WITH N101LV UNDER UNKNOWN CIRCUMSTANCES. SPARKS, NV

INJURY DATA Total Fatal: 0
# Crew: 1 Fat: 0 Ser: 0 Min: 0 Unk:
# Pass: 0 Fat: 0 Ser: 0 Min: 0 Unk:
# Grnd: Fat: 0 Ser: 0 Min: 0 Unk:
- - - - - -
- - - - - -

IDENTIFICATION
Regis#: 817V Make/Model: EXP Description: SZD-55-1 GLIDER
Date: 05/28/2012 Time: 1800

Event Type: Accident Highest Injury: None Mid Air: N Missing: N
Damage: Substantial

LOCATION
City: FARMINGTON State: NC Country: US

DESCRIPTION
AIRCRAFT ON DEPARTURE GROUND LOOPED, FARMINGTON, NC

INJURY DATA Total Fatal: 0
# Crew: 1 Fat: 0 Ser: 0 Min: 0 Unk:
# Pass: 0 Fat: 0 Ser: 0 Min: 0 Unk:
# Grnd: Fat: 0 Ser: 0 Min: 0 Unk:
- - - - - -

Both pilots landed safely back at Airsailing after loosing a section of their wing and most of the aileron, according to preliminary reports and photos I've seen. Incredible luck. This was not a contest, just a small gathering. Apparently it did not happen in a gaggle or while thermaling and they never saw each other. So much for those who claim that powerflarms are only needed in contests...

Ramy

Below are the pilot reports with their permission:

From Walter:

"snip After reaching 10,700 feet over Tuly Peak I headed upwind to work the Dog Skins ridge, I was loosing some altitude and went back to the Red Rocks
where several other gliders were also searching for lift. There was
some turbulence but no good thermals to circle which caused most
gliders to manouver around in search of lift. I was keeping track of
the gliders in the area but suddenly at about 6,800 feet I felt a jolt
and a loud noise as another glider I hadn't seen colided with me. The
Cirrus immediately turned the nose down and at first it seemed I had
lost control of the glider. During impact I hit and slighly cut my
left leg against the instrument panel and my Oudie went flying. I
could see a damage on the left wing but being around 2,000 feet over
the ground and heading down with what seemed limited control I didn't
think there was much time to try seeing if I could regain control. I
decided to bail and was surprised I couldn't get the canopy to open
(may have turned out to be my saving grace). I then focused on
controlling the glider the best I could and head to a landing area.
After getting the glider to level flight, I headed back towards the
airport for a straight in landing on runway 21R since the main runway
had a glider getting ready to take off. I made a call on the radio
that I had an emergency and lowered and locked the landing gear. The
landing was normal without incidents but there wasn't much height
left. I had to wait for someone to come help me since I couldn't open
the canopy from the inside as the back hinge had released but not the
front part and it was stuck.

After talking to the other pilot Bill Johns (who used to be a fighter
pilot) from BASA flying a Pegasus and hearing his account of the
event, we hit pretty much head on, with him flying right over my
canopy and his right wing hitting my left wing (I was in a gentle
right bank and he was either flying straight or on a gentle right
bank). He saw me about 1 second before impact and thought he was going
to take my tail off, but fortunately he missed that. My wing was
somewhat damaged but other than loosing 80% of my left aileron and
having parts of the fiber glass torn (see first 2 pictures), it was
still flyable. After landing we noticed that the root of the Cirrus
wing had signs of stress and damage as well. The Pegaus lost about 3-4
feet of his right wing tip and half of his right aileron (see 3rd
picture). He didn't loose control of his glider and headed back to the
airport, landing after me on the dirt next to runway 21L.

If we had been flying thermals in a gaggle or if we were all flying
ridge it would have been simpler since we would be following a
protocol. The instructor Mark said the thing he might have done
differently was to leave the area since there were too many gliders
flying in different patterns (some trying to find thermals, and some
trying to fly the ridge). I understand that trying to see each other
would have required a careful and lucky scanning of the horizon, but
even so, I am not sure how easily we would have been able to see each
other. A FLARM device sounds really good to me right now, as any
indication of a likely collision, even if 3 or so seconds before
impact would have prevented the accident."

From Bill:

"snip All ASI gliders were to be on 122.9, ASI frequency, so there was a lot of chatter to do with airfield activities as well as airborne gliders. I made an initial call that I was climbing over the Red Rocks, then monitored and did not hear reports by other gliders in my area. As it turned out, I wish I had been more proactive in providing and asking for other position reports.

At 2:46PM, as I headed westerly, wings level, at about 7000', another glider suddenly appeared from under my nose on the right side, very close aboard, and complete opposite direction, too close for me to react prior to impact. The impact was charactarized by a loud "bang" and perception of parts flying in my right peripheral vision. The Pegasus was unphased by this, though she lost about 2 feet of right wingtip and the outboard half of the aileron. I experienced no loss of control, and made a shallow turn to the right to look back for the other glider. Ailerons and parts were fluttering in the distance and the Cirrus was well below, but continuing in stable flight to the east. I made a call to Air Sailing informing them of the mid air, that both gliders appeared to be OK and we would be returning for emergency landing. I continued at altitude, following the Cirrus as he made a low, wide circling turn and lined up for 21R. Once he was down, I proceeded over the field at 6500', lowered the gear, checked spoilers and verified again that I had good control at pattern airspeed. I landed 21L uneventfully.

I think short of something like FLARM, the only thing which could have prevented this would have been better situational awareness of which other giders were working in the same area. The conditions unknowingly put us each at the same altitude searching for lift, and nothing is harder to see than another glider head on. The other pilot reported he never saw me before, during or after the incident. Also, I learned after landing that he had lost control and attempted a bailout, had trouble opening his canopy release, so went to plan B and was able to recover the aircraft. We were no more than 1500' above the steep terrain at impact.

Both of us flew the next day and I had my best flight of the camp in the ASK-21 that Friday with Rob Stone. His comment...Bill's head was moving all the time...he sure was looking around!"


My conclusions after reviewing Walter's igc trace:

1 - Although the mid air happened at 2500 feet above the airport, they were only slightly more that 1000 feet above the hills below, probably too low to bailout successfully. the failure of the canopy release may have been indeed his saving grace.
2 - After the impact he dropped quickly and lost 2000 feet in one minute. Luckily the ground was dropping at the direction he was flying! He was only around 500 feet AGL after the first minute.
3 - The dive did not really slowed down much until the landing flare.
4 - The turn and the dive took him straight to the runway. He did not have time or altitude to land anywhere else. He was on the ground 2 min after impact.

None of them had flarm or pcas. Other then the obvious conclusion that flarm could have saved the day, another lesson is to check your canopy emergency release mechanism to make sure it works. Better scanning would have helped only if they knew exactly where to look at the right moment. Better radio communication as we often do in some places may have also helped preventing this accident.

I consider the results a miracle.

Ramy