With all the posts regarding collision avoidance electronics, I was wondering about high vis markings.

Seems like many of us put thousands of dollars into electronics and nothing into high vis markings.

Kinda hard to believe the infinite wisdom master has not mandated it, and especially since a transposer is not required.

On Friday, January 22, 2016 at 9:23:37 AM UTC-5, Casey wrote:
> With all the posts regarding collision avoidance electronics, I was wondering about high vis markings.
>
> Seems like many of us put thousands of dollars into electronics and nothing into high vis markings.
>
>

Kinda hard to believe the infinite wisdom master has not mandated it, and especially since a transponder is not required.

On Friday, January 22, 2016 at 6:30:10 AM UTC-8, Casey wrote:
> On Friday, January 22, 2016 at 9:23:37 AM UTC-5, Casey wrote:
> > With all the posts regarding collision avoidance electronics, I was wondering about high vis markings.
> >
> > Seems like many of us put thousands of dollars into electronics and nothing into high vis markings.
> >
> >
>
> Kinda hard to believe the infinite wisdom master has not mandated it, and especially since a transponder is not required.

Actually, kind of hard to believe it is not illegal under US contest rules, because it makes leeching easier :).

There could be vis paint applied that changes color for stealth mode. May have to apply current to the paint, otherwise it would be just changing all the time.

https://www.youtube.com/watch?v=Tl8LWTX9Guo

>
> Actually, kind of hard to believe it is not illegal under US contest rules, because it makes leeching easier :).

On Friday, January 22, 2016 at 9:23:37 AM UTC-5, >
I was wondering about high vis markings.
> ...the infinite wisdom master has not mandated it

High vis marking is mandated in some parts of the world (French Alps?). But it is controversial whether they help or hurt in all contexts. Some people conclude that the markings work as camouflage because they erode the edge of the plane's outline/silhouette.

There was someone in the UK that got good results with putting mirror tape on ailerons that flashed sun glint to overtaking planes when the glider was on final.

Sun glint is promising. I will someday get around to experimenting with Bird Scare Ribbon streamers on my wing tips or perhaps on the tips of my horizontal stabilizer.
http://www.amazon.com/100-Foot-2-Inch-Repellent-Holographic-Deterrent/dp/B00GNLS8WC/ref=sr_1_3?ie=UTF8&qid=1453478826&sr=8-3&keywords=bird+tape

On Friday, January 22, 2016 at 10:13:43 AM UTC-6, son_of_flubber wrote:
> On Friday, January 22, 2016 at 9:23:37 AM UTC-5, >
> I was wondering about high vis markings.
> > ...the infinite wisdom master has not mandated it
>
> High vis marking is mandated in some parts of the world (French Alps?). But it is controversial whether they help or hurt in all contexts. Some people conclude that the markings work as camouflage because they erode the edge of the plane's outline/silhouette.
>
> There was someone in the UK that got good results with putting mirror tape on ailerons that flashed sun glint to overtaking planes when the glider was on final.
>
> Sun glint is promising. I will someday get around to experimenting with Bird Scare Ribbon streamers on my wing tips or perhaps on the tips of my horizontal stabilizer.
> http://www.amazon.com/100-Foot-2-Inch-Repellent-Holographic-Deterrent/dp/B00GNLS8WC/ref=sr_1_3?ie=UTF8&qid=1453478826&sr=8-3&keywords=bird+tape

You might want to do some testing on how draggy those streamers would be - a simple test using a car might be instructional.

My gut feeling is that any length long enough to be useful would be pretty draggy!

Let us know.

Kirk

On Friday, January 22, 2016 at 12:19:47 PM UTC-5, kirk.stant wrote:

> My gut feeling is that any length long enough to be useful would be pretty draggy!

I figure the wing tip is already very draggy. How much worse could it get? I'm thinking about 12" would work as the tape acts like a signal mirror picking up the sun glint. The wing tip turbulence means it passes through a lot of different angles.

As stated above the anti-collision markings are mandated in France, and they have been proven to work! Fluorescent orange is not a color in nature and it stands out against a snowy or cloudy background. There are called High Visability marking for a reason. There is an article somewhere on-line about the effectiveness of these markings. France has mandated Flarm now and had a significant reduction in collisions.

Take a look at the Schleicher web site, they offer a LED strobe strip in the vertical fin (it is part of leading edge so no aerodynamic penalties). With an LX ACL controller the strobe fires when there is a Flarm alert! I am surprised all manufactures do not just include this unit is the base price and not even make it optional.

The big sky theory is as valid as cold fusion.

Alisport has been offering LED strobe on fin of the Silent 2 Electro for several yrs.

On Friday, January 22, 2016 at 2:22:53 PM UTC-5, Jonathan St. Cloud wrote:
> As stated above the anti-collision markings are mandated in France, and they have been proven to work! Fluorescent orange is not a color in nature and it stands out against a snowy or cloudy background. There are called High Visability marking for a reason. There is an article somewhere on-line about the effectiveness of these markings. France has mandated Flarm now and had a significant reduction in collisions.
>
> Take a look at the Schleicher web site, they offer a LED strobe strip in the vertical fin (it is part of leading edge so no aerodynamic penalties). With an LX ACL controller the strobe fires when there is a Flarm alert! I am surprised all manufactures do not just include this unit is the base price and not even make it optional.
>
> The big sky theory is as valid as cold fusion.

On Friday, January 22, 2016 at 1:17:50 PM UTC-6, son_of_flubber wrote:
> On Friday, January 22, 2016 at 12:19:47 PM UTC-5, kirk.stant wrote:
>
> > My gut feeling is that any length long enough to be useful would be pretty draggy!
>
> I figure the wing tip is already very draggy. How much worse could it get? I'm thinking about 12" would work as the tape acts like a signal mirror picking up the sun glint. The wing tip turbulence means it passes through a lot of different angles.

Like I said, try it out first, you may be surprised. Think of the hardware needed to attach the ribbon, or are you going to just tape it to the trailing edge? So now you have 12 inches of tape flapping in the wind - It can get a LOT worse! Or you may have come up with the best thing since sliced bread ;^)

So please, give it a try and report back!

I have orange wingtips and rudder, and other pilots have commented on how visible they make me - especially against a white background. Wouldn't fly without them...

Kirk

Kirk

Funny you should ask that question. After determining the transponder/ADS-b out-in and whatever else it takes to "see" was too expensive I looked in the the "be seen" part of the saying.
And I just returned from my local bike shop with a Bontrager Flare RT Tail light with remote control in my possession. It was not cheap, at $80 but is very bright, small and rechargeable. They claim a 2k range in daylight. The remote control was $70 and I could have done without it. All I have to do is figure out where to mount it, yea, I know cant put anything on the aircraft as per the FAR's, but maybe near the wheel well facing rearward? Also, I checked into DOT tape truckers are required to have all over their trucks. Again not cheap at $30 per 25'x1" roll, but very bright in the daylight sun. Maybe the underside of the fuselage for this tape? And lastly if I really want to be seen, I might have the auto body shop near me paint a hunter orange stripe (12'x1.5') on the underside of my wings. I have a few quotes of $500-$650. Not sure about this one, I'll have to think about it, since my wings are carbon, painting them is no big deal.
Thank God for the off season so we can get stuff like this done.
Cheers.

On Friday, January 22, 2016 at 3:15:58 PM UTC-5, kirk.stant wrote:
> On Friday, January 22, 2016 at 1:17:50 PM UTC-6, son_of_flubber wrote:
> > On Friday, January 22, 2016 at 12:19:47 PM UTC-5, kirk.stant wrote:
> >
> > > My gut feeling is that any length long enough to be useful would be pretty draggy!
> >
> > I figure the wing tip is already very draggy. How much worse could it get? I'm thinking about 12" would work as the tape acts like a signal mirror picking up the sun glint. The wing tip turbulence means it passes through a lot of different angles.
>
> Like I said, try it out first, you may be surprised. Think of the hardware needed to attach the ribbon, or are you going to just tape it to the trailing edge? So now you have 12 inches of tape flapping in the wind - It can get a LOT worse! Or you may have come up with the best thing since sliced bread ;^)
>
> So please, give it a try and report back!
>
> I have orange wingtips and rudder, and other pilots have commented on how visible they make me - especially against a white background. Wouldn't fly without them...
>
> Kirk
>
> Kirk

Reflective tape study - Oct 2002 - at www.dg-flugzeugbau.de/Data/glider-conspicuity-study.pdf

And LED light mounted on front lip of canopy: http://www.how2soar.de/index.php/led-blitzer-und-rechenknecht

Facing rearward, you are flying too slow :))

On Friday, January 22, 2016 at 1:02:27 PM UTC-8, wrote:
>All I have to do is figure out where to mount it, yea, I know cant put anything on the aircraft as per the FAR's, but maybe near the wheel well facing rearward?

In a head-on near miss at cloud base some years ago, I first caught sight of the orange wingtips of the oncoming glider and barely had time to slow a little and initiate a turn. The other pilot passed 50 feet under me and never saw my glider. Our igc files showed an impressive closing speed leaving little time to react. No doubt markings are helpful, but not always enough!

Mike

On Friday, January 22, 2016 at 1:02:27 PM UTC-8, wrote:
> Funny you should ask that question. After determining the transponder/ADS-b out-in and whatever else it takes to "see" was too expensive I looked in the the "be seen" part of the saying.
> And I just returned from my local bike shop with a Bontrager Flare RT Tail light with remote control in my possession. It was not cheap, at $80 but is very bright, small and rechargeable. They claim a 2k range in daylight.. The remote control was $70 and I could have done without it. All I have to do is figure out where to mount it, yea, I know cant put anything on the aircraft as per the FAR's, but maybe near the wheel well facing rearward? Also, I checked into DOT tape truckers are required to have all over their trucks. Again not cheap at $30 per 25'x1" roll, but very bright in the daylight sun. Maybe the underside of the fuselage for this tape? And lastly if I really want to be seen, I might have the auto body shop near me paint a hunter orange stripe (12'x1.5') on the underside of my wings. I have a few quotes of $500-$650. Not sure about this one, I'll have to think about it, since my wings are carbon, painting them is no big deal.
> Thank God for the off season so we can get stuff like this done.
> Cheers.

If these lights are really that effective and small enough, perhaps they could be molded into wingtip wheels and/or tail wheel fairings facing front and back. Ideally as a kit which can be retrofitted relatively easy at your local shop.

When I flew hang gliders many years ago I used to have a small (1-2") "party ball" tied to my kingpost which was quiet effective. Nowadays I use high vis and reflective tape on my wingtips and winglets.

Ramy

Ramy, I saw you on PowerFlarm way out but never saw the tape up in Idaho :)

http://soaringxx.com/index.php?route=product/product&product_id=91

Seen this in Namibia. Very flashy up to 3 km.

On Fri, 22 Jan 2016 13:02:25 -0800, mikeatwork2 wrote:

> Again not cheap at $30 per
> 25'x1" roll, but very bright in the daylight sun. Maybe the underside
> of the fuselage for this tape?
>
May not be much use under the fuselage or flying surfaces due to a lack
of direct sunlight on the tape.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Martin,
Dark under wing shows up better (my opinion and article I just read). Large contest numbers or European registration numbers under side of wing stand out well.


On Saturday, January 23, 2016 at 6:34:32 AM UTC-5, Martin Gregorie wrote:
> On Fri, 22 Jan 2016 13:02:25 -0800, mikeatwork2 wrote:
>
> > Again not cheap at $30 per
> > 25'x1" roll, but very bright in the daylight sun. Maybe the underside
> > of the fuselage for this tape?
> >
> May not be much use under the fuselage or flying surfaces due to a lack
> of direct sunlight on the tape.
>
>
> --
> martin@ | Martin Gregorie
> gregorie. | Essex, UK
> org |

On Sat, 23 Jan 2016 05:15:08 -0800, Casey wrote:

> Martin,
> Dark under wing shows up better (my opinion and article I just read).
> Large contest numbers or European registration numbers under side of
> wing stand out well.
>
Well, big dark registration would certainly show up better than unlit
reflectors. That was my point: that reflectors mounted where the sun
never shines on them aren't a lot of use.

However, while large, dark registration or comp ID is readable on a
glider that is within a fairly narrow overhead cone and probably not a
lot more than 1000ft above you, its unlikely that they are even visible
if the glider is more than a kilometer away or 2-3000 ft higher.

IOW, I don't think the reg etc. make any difference to the visibility of
gliders that are over 1 km away and in any case a glider should be easy
to see at that distance if its above or below you.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

2 Yrs ago I saw a Silent2 FES with the LED on fin. I understand AS is offering as an option too. Just wondering why manufactures are not offering LED on underside or if they actually are. Or maybe the LED on fin can been seen some from forward/below.

On Saturday, January 23, 2016 at 9:32:00 AM UTC-5, Martin Gregorie wrote:
> On Sat, 23 Jan 2016 05:15:08 -0800, Casey wrote:
>
> > Martin,
> > Dark under wing shows up better (my opinion and article I just read).
> > Large contest numbers or European registration numbers under side of
> > wing stand out well.
> >
> Well, big dark registration would certainly show up better than unlit
> reflectors. That was my point: that reflectors mounted where the sun
> never shines on them aren't a lot of use.
>
> However, while large, dark registration or comp ID is readable on a
> glider that is within a fairly narrow overhead cone and probably not a
> lot more than 1000ft above you, its unlikely that they are even visible
> if the glider is more than a kilometer away or 2-3000 ft higher.
>
> IOW, I don't think the reg etc. make any difference to the visibility of
> gliders that are over 1 km away and in any case a glider should be easy
> to see at that distance if its above or below you.
>
>
> --
> martin@ | Martin Gregorie
> gregorie. | Essex, UK
> org |

In my ASG-29 the LED strobe is maybe 14 inches long and is the leading edge of the vertical fin. Yes it projects forward.

On Saturday, January 23, 2016 at 9:04:20 AM UTC-8, Casey wrote:
> 2 Yrs ago I saw a Silent2 FES with the LED on fin. I understand AS is offering as an option too. Just wondering why manufactures are not offering LED on underside or if they actually are. Or maybe the LED on fin can been seen some from forward/below.
>
> On Saturday, January 23, 2016 at 9:32:00 AM UTC-5, Martin Gregorie wrote:
> > On Sat, 23 Jan 2016 05:15:08 -0800, Casey wrote:
> >
> > > Martin,
> > > Dark under wing shows up better (my opinion and article I just read).
> > > Large contest numbers or European registration numbers under side of
> > > wing stand out well.
> > >
> > Well, big dark registration would certainly show up better than unlit
> > reflectors. That was my point: that reflectors mounted where the sun
> > never shines on them aren't a lot of use.
> >
> > However, while large, dark registration or comp ID is readable on a
> > glider that is within a fairly narrow overhead cone and probably not a
> > lot more than 1000ft above you, its unlikely that they are even visible
> > if the glider is more than a kilometer away or 2-3000 ft higher.
> >
> > IOW, I don't think the reg etc. make any difference to the visibility of
> > gliders that are over 1 km away and in any case a glider should be easy
> > to see at that distance if its above or below you.
> >
> >
> > --
> > martin@ | Martin Gregorie
> > gregorie. | Essex, UK
> > org |

On Fri, 22 Jan 2016 06:23:34 -0800 (PST), Casey
> wrote:

>With all the posts regarding collision avoidance electronics, I was wondering about high vis markings.
>
>Seems like many of us put thousands of dollars into electronics and nothing into high vis markings.
>
>Kinda hard to believe the infinite wisdom master has not mandated it, and especially since a transposer is not required.

USAF airplanes had Day-Glo markings in the Fifties, but it went away.
IIRC they concluded it just wasn't getting results, even with all
their formation flying.

rj

The cross country model glider guys have found that the best color for visibility at distance is flat black. This applies both in the blue and under cloud. Black anti collision marking would be awesome.
Darth.

On Sunday, January 24, 2016 at 10:34:26 PM UTC+3, wrote:
> The cross country model glider guys have found that the best color for visibility at distance is flat black. This applies both in the blue and under cloud. Black anti collision marking would be awesome.

Conversely, in WW2 the British discovered that the best camo paint job for low level bombers was actually bright lights along the leading edges, to make them as bright as the sky. Even white paint is much darker than the background.

Well, certain sunglasses also help objects standing out. Wouldn't be cool to have a high vis paint the shows up with special sun glasses that does not show up without them. Someone could make a mint with the paint and sunglasses.

I had a hard time finding sunglasses that I like that were not too dark or polarized.

Seems to me the best is to have LEB strobe. Otherwise it would not be offered on new gliders.

On Sunday, January 24, 2016 at 6:33:11 PM UTC-5, Casey wrote:
> Well, certain sunglasses also help objects standing out. Wouldn't be cool to have a high vis paint the shows up with special sun glasses that does not show up without them. Someone could make a mint with the paint and sunglasses.
>
> I had a hard time finding sunglasses that I like that were not too dark or polarized.
>
> Seems to me the best is to have LEB strobe. Otherwise it would not be offered on new gliders.

....or everyone be required to fly with FLARM or ADS-B connected to google glass! (with a maximum range in comp mode of course...

Sorry, i couldn't resist.

As the referenced article reminds me, there were some controlled experiments in the U.K. years back that empirically debunked the popular wisdom that Day-Glo tips and tail significantly enhanced visibility at a distance. This followed the movement in the mid to late 1970s when German gliders started arriving in the U.S. with orange/red tips and checkerboard tails. This trend seem to die out later as the evidence mounted that the high-viz paints didn't always help and, in fact, could hurt. I recall reading about experiments with mirrored coatings and black underside paints, two things that did seem to help in some circumstances. But it's dangerous to assume that what looks highly visible on the launch grid or close by in a thermal will work equally well at a distance, in particular on a collision course.

I'd argue the "big sky theory" (however one defines it) is still valid. What's undeniable is the probability that however remote, the odds of an encounter with another aircraft in that big sky are not zero and the consequences of that tiny probability are so devastating that it's worth seeking ways to reduce the risk.

I'm not current on the origins of FLARM but I seem to recall one of the drivers was the concentration of gliders along certain mountain ranges and ridgelines in the Alps, coupled with myriad cables and towers that posed a danger to low-flying gliders (I believe that was the reason for the obstruction database provided for in FLARM).

I suspect the only time we see that kind of concentrated traffic here in the U.S. is around major airports/airways/navigational features (where we either can't fly anyway or most pilots fly with heightened awareness and concern) and at large soaring contests, the size of which has diminished over the past 30 years. Nephi--which will almost certainly be oversubscribed--looks to be the exception to that.

One final not-quite-apocryphal story: back in the days of 65-glider national contests, I recall one attended by a pilot in a brightly colored Finnish glider. The pilot was thought by many to be particularly aggressive in thermals, so much so that a sighting of the "yellow PIK inbound" was often enough to prod even the most quavering, unapologetic leech to roll out on course in alarm. I don't know if yellow is the best color for visibility but against the background of Midwestern farm fields, it stood out pretty well. :)

Chip Bearden

On Tue, 26 Jan 2016 15:46:55 -0800 (PST),
wrote:

.... text deleted
>>I suspect the only time we see that kind of concentrated traffic
>>here in the U.S. is around major airports/airways/navigational features
>>(where we either can't fly anyway or most pilots fly with heightened
>>awareness and concern) and at large soaring contests, the size of which
>>has diminished over the past 30 years. Nephi--which will almost certainly
>>be oversubscribed--looks to be the exception to that.
>
.... text deleted

Unfortuantely a mid-air collision only requires 2 aircraft. Recall the
very tragic accident at Crazy Creek on Nov 28, 2009 (NTSB Docket.
WPR10FA068A and WPR10FA068B). We lost 2 good pilots.

At Texas Soaring Association this accident was one of the prime
drivers for equipping our entire club glider fleet (10), including our
Pawnee towplanes (3), with PowerFlarm when the units were first
released to the US in 2011.

Not saying Flarm would have prevented the Crazy Creek accident, but
"see and avoid" is clearly not 100% effective.

On a busy day TSA can have two towplanes and upwards of two dozen
gliders all within a few miles of the gliderport. Flarm is cheap
insurance.

Bob

I searched this thread and did not see an actual study referenced, only urban legend, that bright colors not found in nature somehow act to "work as camouflage because they erode the edge of the plane's outline/silhouette". Is this not the same ilk as "we only use 10% of our brain" or "it is improper English in end a sentence in a preposition"? BTW, all three urban legends have no basis in science, fact, or English structure. If you think so, you do not have a leg to stand on. Perhaps you do not know what you speak of. What are you talking about? Just three examples of one urban legend mentioned above. Autonomous processes of the body take more than 10% of brain function alone. Military uses high visibility paint on training aircraft, because it works. If you travel Russia you will also find most Russians do not wear seatbelts because they all know someone, who knew someone that was friends with someone that was saved because they were thrown free in an auto accident. Of course no one knows anyone first hand that was so saved, but they all believe the BS legends. Hmm... I wonder why hunters wear high visibility clothing? Is it to be seen so they are not shot... no I am sure the orange would just blur they edges so it would be difficult for a center shot.

France mandated high vis markings for a reason, they saw a statistically significate difference. France mandated Flarm for the same reason, it works.

I am not a fan of the big sky theory, have had way too many close calls, from the airport environment, to the middle of nowhere, thus the only possible conclusion is the theory is bunk. Sure, most aircraft do not collide, but the theory that only works 98% of the time is not really a theorem, is it.. Then it just becomes probability, fate, vicissitudes of life, karma... Imagine if the theory of relativity only worked 98% of the time. What if the laws of physics only worked 99% of the time.

Four times in the airport environment, under tower control, I have been place directly in the path of another aircraft, and this is by trained professionals. Too many times to count out in "the Big Sky", I have only had time to flench as another aircraft streaked by, once so close I did not even see an aircraft, just a grey blur filling the entire windscreen as I heard the roar of jet engines. And this was over the roar of my own jet engine and through noise cancelling headset.

Not intending to offend anyone, just to solicit thought, not rote acceptance. Show me the beef. (by way of full disclosure, I not not eat beef).

On Wednesday, 27 January 2016 09:29:58 UTC+2, Jonathan St. Cloud wrote:
> I searched this thread and did not see an actual study referenced, only urban legend, that bright colors not found in nature somehow act to "work as camouflage because they erode the edge of the plane's outline/silhouette".

The fact that this topic re-appears every couple of years and generates a lot of debate suggests that not enough scientific research has been done to validate or invalidate the argument for or against anti-collision markings.

In certain situations such as a glider against a snow covered mountain, high visibility orange DayGlo certainly does help but it may also camouflage the glider in other conditions.

The RAF held glider conspicuity trials at Bicester in June and October 2002..
It evaluated 3M Mirror Film and DayGlo markings.
The summary was "We conclude that the DayGlo patches did not improve conspicuity." while the mirror film greatly increased sighting range if sunlight was present.
Source: http://www.dg-flugzeugbau.de/Data/glider-conspicuity-study.pdf

A German flavoured study: https://www.streckenflug.at/index.php?p=technikwarn
Summary: "The use of colour markings as an anti-collision aid is questionable. In particular when two aircraft are on a constant-bearing (collision) course, it is the size and shape of the other aircraft which is seen first, not any colour pattern. The use of colour seems obvious at short range and on the ground but this is often not the critical case in the air in a collision situation." Position reporting, pilot scan technique and strobe lights were deemed to be far more effective than colour markings.

As a glider owner who is planning to repaint his glider this year in a country that doesn't mandate anti-collision markings and doesn't experience snow fall (where I fly), I am very interested in what the best solution is.
My personal conclusion is that FLARM, mirror film and strobe lights facing all directions would be a much better solution than just DayGlo markings. Unfortunately the power requirements and drag created by multiple strobe light housings retro-fitted to a glider prevents me going this route so mirror film and FLARM is probably the best bet?

"France mandated high vis markings for a reason, they saw a statistically
significate difference. France mandated Flarm for the same reason, it
works."


FRANCE mandated hi viz marking to help see gliders in the snowy backdrop of
the alps.

They also mandated FLARM for the alps as FLARM can see round corners in the
mountains and the eye can not.


Bright colour markings do nothing. If you wish to improve visibility put
silver reflective tape on each of your control surfaces.

On Wednesday, January 27, 2016 at 2:29:58 AM UTC-5, Jonathan St. Cloud wrote:
> I searched this thread and did not see an actual study referenced, only urban legend, that bright colors not found in nature somehow act to "work as camouflage because they erode the edge of the plane's outline/silhouette". ..

The study you mention that disputed the effectiveness of day-glo patches on the wings was reported in Sailplane and Gliding Magazine for December, 2000. The tests conducted for the report were conducted during June, 2000 at RAF Bicester.

Another study, on mirrored surfaces, was "Glider Conspicuity Trials Held at RAF Bicester in June and October 2002", carried out under the direction of Dr. Tony Head, then of the Human Factors Group, School of Engineering, College of Aeronautics, Cranfield University. It as this study that, to some degree, suggested that mirrored control surfaces did improve conspicuity. although the report does include several dislaimers, based on weathser conditions during the testing. I have a copy of THAT report (but not the 2000 study) if anyone's interested (jim at kellett cot com)

At 09:01 27 January 2016, Justin Craig wrote:
>
>"France mandated high vis markings for a reason, they saw a
statisticall
>significate difference. France mandated Flarm for the same
reason, i
>works."
>
>
>FRANCE mandated hi viz marking to help see gliders in the snowy
backdrop o
>the alps.
>
>They also mandated FLARM for the alps as FLARM can see round
corners in th
>mountains and the eye can not.
>
>
>Bright colour markings do nothing. If you wish to improve visibility
pu
>silver reflective tape on each of your control surfaces.
>
The "Big Sky" theory only works if all aircraft are evenly distributed
over the airspace. The restrictions and requirements of gliding
means that they are far from evenly distributed.

High vis markings (dayglo) do work with gliders against some
backgrounds if they are above or below. In the most dangerous
area, the same level they do not work too well at all as the area is so
small that the "benefit" is cancelled out.

Silver reflective tape, or mirror tape only works in sunshine. Gliders
spent a lot of time in shade, under clouds, and again at the same
level the effect is minimal. Something that requires the sun to shine
is not likely to be too effective for most of the time in the UK.

The Royal Air Force did a study which concluded that the best
colour to provide the best chance of being seen was black, which is
why all RAF training aircraft, except the GRP ones, are painted
black. From my limited experience in seeing these aircraft in the air
they certainly seem to be more easily picked out from most
backgrounds.

It would seem that what is needed is a colouring that absorbs
visible light but reflects ultra violet and infra red. So there is the
challenge.

I'm pretty sure FLARM cannot see round Alpine corners.

Adding mirror foil to control surfaces certainly works if it's
sunny but your friendly engineer or glider manufacturer might
view adding weight to the control surfaces in a different light?
I've seen it suggested that this might affect flutter?

David Walsh

> The Royal Air Force did a study which concluded that the best
> colour to provide the best chance of being seen was black, which is
> why all RAF training aircraft, except the GRP ones, are painted
> black. From my limited experience in seeing these aircraft in the air
> they certainly seem to be more easily picked out from most
> backgrounds.

Canadian Air Force trainers are also painted black. Best contrast against sky, clouds, snow, and prairie. Unfortunately, not possible for most gliders, and rather warm to the touch for ground handling.

Well, I stand corrected. However, if you google military high visibility markings you will find formations of aircraft with and without high vis markings. One can really see the high vis aircraft better. Ever noted how all the roadside workers wear orange vests, certainly improves their visibility, same for hunters, crosswalk monitors, school buses, fire trucks, bicycle riders...etc. Out west I have only see two gliders with high visibility markings, one in blue, which did not improve my ability to spot it in the sky, but another glider had fluorescent orange markings and it stood out like a sore thumb! Not a statistically significant sample size, nor a controlled experiment, but I could spot that glider against any background even out of the corner of my eye. Vanity kept me from using the same color scheme as I thought it was too "in your face" and on the ground the color appeared to hurt my eyes it was so bright.

Thanks for the studies, glad I have an LED strobe, Flarm and good eyes!

On Wednesday, January 27, 2016 at 6:51:28 AM UTC-5, Jim Kellett wrote:

> Another study, on mirrored surfaces, was "Glider Conspicuity Trials Held at RAF Bicester in June and October 2002"

This study also tested orange and found no benefit.

Here is the .pdf

http://www.dg-flugzeugbau.de/Data/glider-conspicuity-study.pdf

On Wednesday, January 27, 2016 at 7:00:07 AM UTC-5, Don Johnstone wrote:

> Silver reflective tape, or mirror tape only works in sunshine. Gliders
> spent a lot of time in shade, under clouds, and again at the same
> level the effect is minimal.

Nothing is going to work from all directions and under all conditions. But some combination would improve the odds.

LED lights for the shade and mirror for sunlight would be complementary.

A forward facing LED strobe is a big payback even though it works on only one axis.

How about something like this on top of the fuselage and another on the bottom? If mounted from the inside through a hole it would be less than 20mm tall and I'm guessing a streamlined bubble to cover it wouldn't add any significant drag.

https://www.superbrightleds.com/moreinfo/1905/#/tab/Specifications

This appears to be the same as used on emergency vehicles and with a draw of over an amp at 12v, it sure seems like it should be bright. I'm sure a much slower flash rate would reduce the current draw.

I've seen a bicycle headlight strobe while looking into the rising sun from more than 4 miles. I was sure it was a police car flashing headlight with someone in front of him covering one of the lights. But when I got closer it was a bike!

5Z

On Wednesday, January 27, 2016 at 12:11:48 PM UTC-8, son_of_flubber wrote:
> LED lights for the shade and mirror for sunlight would be complementary.
>
> A forward facing LED strobe is a big payback even though it works on only one axis.

On Tuesday, January 26, 2016 at 11:29:58 PM UTC-8, Jonathan St. Cloud wrote:
> I searched this thread and did not see an actual study referenced, only urban legend, that bright colors not found in nature somehow act to "work as camouflage because they erode the edge of the plane's outline/silhouette". Is this not the same ilk as "we only use 10% of our brain" or "it is improper English in end a sentence in a preposition"? BTW, all three urban legends have no basis in science, fact, or English structure. If you think so, you do not have a leg to stand on. Perhaps you do not know what you speak of. What are you talking about? Just three examples of one urban legend mentioned above. Autonomous processes of the body take more than 10% of brain function alone. Military uses high visibility paint on training aircraft, because it works. If you travel Russia you will also find most Russians do not wear seatbelts because they all know someone, who knew someone that was friends with someone that was saved because they were thrown free in an auto accident. Of course no one knows anyone first hand that was so saved, but they all believe the BS legends. Hmm... I wonder why hunters wear high visibility clothing? Is it to be seen so they are not shot... no I am sure the orange would just blur they edges so it would be difficult for a center shot.
>
> France mandated high vis markings for a reason, they saw a statistically significate difference. France mandated Flarm for the same reason, it works.
>
> I am not a fan of the big sky theory, have had way too many close calls, from the airport environment, to the middle of nowhere, thus the only possible conclusion is the theory is bunk. Sure, most aircraft do not collide, but the theory that only works 98% of the time is not really a theorem, is it. Then it just becomes probability, fate, vicissitudes of life, karma.... Imagine if the theory of relativity only worked 98% of the time. What if the laws of physics only worked 99% of the time.
>
> Four times in the airport environment, under tower control, I have been place directly in the path of another aircraft, and this is by trained professionals. Too many times to count out in "the Big Sky", I have only had time to flench as another aircraft streaked by, once so close I did not even see an aircraft, just a grey blur filling the entire windscreen as I heard the roar of jet engines. And this was over the roar of my own jet engine and through noise cancelling headset.
>
> Not intending to offend anyone, just to solicit thought, not rote acceptance. Show me the beef. (by way of full disclosure, I not not eat beef).

Assuming no one is considering wrapping their whole glider in orange glow, only the wing tips, part of the rudder and maybe part of the nose. How could this possibly act as camouflage?? By reducing the visible wing span by less than 5%? This sounds like a myth. Worst case scenario it will have no impact, base case scenario the small orange surface will catch your attention and save your life. So instead of debating it to death, best is to just purchase a stripe of orange vinyl (less than $50) and stick it to your wing tip/winglets/rudder. It will make your glider look prettier, more unique, and maybe even safer. And if you dont like it - remove it...

Ramy

At 05:03 28 January 2016, Ramy wrote:

>> Not intending to offend anyone, just to solicit thought, not rote
>acceptance. Show me the beef. (by way of full disclosure, I not
not eat beef).
>
>Assuming no one is considering wrapping their whole glider in
orange glow,
>=
>only the wing tips, part of the rudder and maybe part of the nose.
How
>coul=
>d this possibly act as camouflage?? By reducing the visible wing
span by
>le=
>ss than 5%? This sounds like a myth. Worst case scenario it will
have no
>im=
>pact, base case scenario the small orange surface will catch your
>attention=
> and save your life. So instead of debating it to death, best is to
just
>pu=
>rchase a stripe of orange vinyl (less than $50) and stick it to your
wing
>t=
>ip/winglets/rudder. It will make your glider look prettier, more
unique,
>an=
>d maybe even safer. And if you dont like it - remove it...
>
>Ramy

Camouflage works by breaking up the outline of a familiar object so
that the eye/brain does not recognise it, or alternatively confuses
the eye/brain.
British soldiers in your war of independence wore red coats,
because red made it difficult for the enemy to count the number of
soldiers, to camouflage the size of their force . Ships in WW1 were
painted in garish zig-zag patterns which broke up the outline so
they were less likely to be recognised as ships and made range
estimation difficult. It is not as simple as it seems.
Sticking it to your rudder is a bad idea, as has been pointed out
earlier. Altering the mass balance of a control surface, even by a
small amount, without comprehensive testing, is unlikely to end
well.

I was at a Nationals at Caesar Creek, OH one summer and was running in the mornings. Like everyone else, I knew bright orange was highly visible (duh) so that's the color of the shirt I wore. One morning at the pilots meeting, a competitor commented that he hadn't seen me alongside the road that morning until he was almost on top of me. "Wear white," he suggested, "it's more visible against the trees and vegetation in this area." So I did, and he confirmed my greater visibility the next day.

The trouble with conventional wisdom is that so many people assume it's true because it seems logical--but without ever checking. There's another category of experts who continue on with, in essence, "don't confuse me with the facts; I know what I know," evidence from experimental studies to the contrary.

For the record, the Big Sky theory works very well. 99%+ (probably high 9s) of aircraft in flight don't collide. But it's not perfect. That's why we keep our eyes open, look for ways to make our gliders more visible in the environments in which we usually fly, and rely increasingly on electronic anti-collision technology to improve the odds still further.

The studies on glider conspicuity I've seen were all performed in Europe. It would be interesting to see the results of a similar study in an area like Nephi, or Hobbs, or Uvalde, or Minden on a typical summer soaring day. I've flown at the latter three sites but not at Nephi.

Chip Bearden

I would like to see the experiment method described in detail. While I have not conducted any tests on high visibility colors, I can tell you they work on my eyes for roadside workers, construction crews, hunters, and they single glider I have seen with the day-glo orange, all the above were highly visible. I also know from merging and formation flying the aircraft with red really stood out.

As a former engineer I will gladly accept well designed test results. But if you do not publish the experiment method, in detail, then the conclusion is suspect as it has not undergone peer review. Having said that, I am depending on eyes, Flarm and LED strobe in my bird.


> The studies on glider conspicuity I've seen were all performed in Europe. It would be interesting to see the results of a similar study in an area like Nephi, or Hobbs, or Uvalde, or Minden on a typical summer soaring day. I've flown at the latter three sites but not at Nephi.
>

On Friday, January 22, 2016 at 9:23:37 AM UTC-5, Casey wrote:
> With all the posts regarding collision avoidance electronics, I was wondering about high vis markings.


At Uvalde 2012, from the ground, I saw the European gliders with fluorescent orange significantly sooner than the pure white US and Candian gliders

On Friday, January 29, 2016 at 2:31:47 PM UTC-5, Jonathan St. Cloud wrote:
> I would like to see the experiment method described in detail.

Below are some snipped relevant paragraphs from the most recent conspicuity study I could find online. I recall reading several others, including one that was referenced in this thread recently, but the conclusions were the same, IIRC.

Speaking as a former engineer, the methodology designed and employed by Dr. Head and his associates for the important "head-on-converging" scenario seems reasonable. It's likely a worst case "no relative movement" converging tracks situation. I agree that red/orange tips and tail are pretty visible on the grid, across a thermal, looking up at the sky, or even looking down against a contrasting background. But the scenarios most of us worry about are those where two aircraft are converging at similar altitudes with little relative motion for the eye to pick up. There are variations of this, of course, involving another aircraft approaching from the side (as when several gliders converge on an already established thermal from different directions at the same level--one where I've almost been clobbered a few times) or a power plane overtaking from directly behind (another personal near miss). But the one that seems to get the most attention is head on under a cloud street (a la the Uvalde incident some years ago).

The full Bicester report includes details on other trials involving simulated thermaling, mirror film, and black underside paint. I'm sure there are other ways to run these tests but this team seems to have made a competent, good-faith effort to experimentally determine the effectiveness of different types of markings/colors on glider visibility.

Unlike at least one other test I've heard about, this group stopped short of saying that the Day-Glo markings made a glider less likely to be visible. So I guess there's no harm pimping your ride if it makes you feel better. But keep those eyes open.

From "See and avoid?"
Dr Tony Head, from the College
of Aeronautics at Cranfield
University, reports on the
outcome of recent conspicuity
research conducted at Bicester
(from "Sailplane & Gliding", Aug-Sep 2003)
http://uvs-international.org/phocadownload/03_5ba_Discussion_papers/See%20and%20avoid%20testing%20at%20Bicester%20sail plane%20and%20gliding%20aug-sep%202003.pdf

Trial Four: Air Cadets' DayGlo© pattern
during constant-bearing converging paths
The randomisation and the direction of
runs was as for Trial One and Figure 1 (p29).
Weather was excellent with scattered cloud
and visibility in excess of 25km.

[excerpt follows from p29 describing Trial 1 methodology]
Crews flew toward a central point at
2,000ft AGL and 70kts ground speed (as
indicated by GPS). Each pair of crew was
given a set of headings to fly for both outward
and inward tracks. When crews sighted the
other MG, they called "Mark" on the radio
and noted their distance from the central
point as indicated by GPS. Once both MG
had been sighted, crews reversed track and
began the next run. An example of the
randomisation and the direction of runs is
shown in Figure 1, below.

The distance between the aircraft was
calculated by simple trigonometry, the
distances of both MG from the central point
being noted and recorded at the time of
visual contact.
[end of excerpt]

Results: There were no significant
differences in detection distances between
the clean (2.67nm) or DayGlo© MG
(2.82nm). The mean detection distance for
all of the runs was 2.75nm, with ranges
from 0.88 to 5.3nm.

The weather for these trials was ideal,
with sunlight and scattered cloud.
The overall mean detection distance of
2.7Snm was considerably better than in trial
1 (1.69nm) reported here, when the weather
was less than ideal.

In the previous trials carried out in 2000,
where similar DayGlo© patches were
applied to the MG, the overall mean detection
distance was a comparable 2.54nm.
As the crews were different for the 2000
and 2002 trials, there can be no meaningful
statistical comparison. However, the mean
detection distance, in good conditions, with
hyper-vigilant crews, for all MG with or
without DayGlo©, is only 2.64nm. The
crews, who were initially very enthusiastic
about the larger DayGlo© patches,
confirmed that they did not appear to aid
conspicuity.

The two studies, in 2000 and 2002,
that examined conspicuity of MG during
constant-bearing convergence, failed to
demonstrate a significant increase in
detection distance with the use of the
DayGlo© patches. There appeared to be no
measurable negative effect upon conspicuity
either. Any detection was consistently reported
to be due to the silhauette of the MG or
to a glint, and not to the DayGlo©.

Two personal experiences:

In one of my clubs, an ASK-13 was painted completely in bright orange. The only situation where this was really visible was in bright sunlight when flying slightly higher. In all other situations it just looked gray/black, just like any other sailplane.

During one alpine flight, with a green/brown backdrop (no snow) and with the sun in the back, I was surprised at seeing a series of white dots coming in my direction. It was a glider with a series of hi-vis stripes, approximately 50 cm wide, taped chordwise every meter or so on the leading edge. The white was decidedly more visible than the stripes...

With a snowy backdrop, bright orange markings are a welcome plus, but I prefer large markings at the wingtips rather than numerous small strips all over the sailplane.

I used to fly in a Janus with two classic white strobe lights, one under the nose in front of the nosewheel, the other on the back just behind the canopy. No improvement in visibility in full sunlight, but very visible when flying in the shadow of the clouds (cloudstreet, convergence). Not sure the new "LED" strobes would be as efficient, but certainly worth a try.

At 21:03 30 January 2016, wrote:
>Two personal experiences:=20
>
>In one of my clubs, an ASK-13 was painted completely in bright
orange. The
>=
>only situation where this was really visible was in bright sunlight
when
>fl=
>ying slightly higher. In all other situations it just looked
gray/black,
>ju=
>st like any other sailplane.
>
>During one alpine flight, with a green/brown backdrop (no snow)
and with
>th=
>e sun in the back, I was surprised at seeing a series of white dots
coming
>=
>in my direction. It was a glider with a series of hi-vis stripes,
>approxima=
>tely 50 cm wide, taped chordwise every meter or so on the leading
edge.
>The=
> white was decidedly more visible than the stripes...=20
>
>With a snowy backdrop, bright orange markings are a welcome
plus, but I
>pre=
>fer large markings at the wingtips rather than numerous small
strips all
>ov=
>er the sailplane.
>
>I used to fly in a Janus with two classic white strobe lights, one
under
>th=
>e nose in front of the nosewheel, the other on the back just
behind the
>can=
>opy. No improvement in visibility in full sunlight, but very visible
when
>f=
>lying in the shadow of the clouds (cloudstreet, convergence). Not
sure the
>=
>new "LED" strobes would be as efficient, but certainly worth a try.
>
I think it is a common finding in this thread that almost nothing
increases the visibility of a glider approaching head on, in fact some
markings may reduce visibility. The frontal area of a modern glider
is so small so with no relative lateral or vertical movement they are
very hard to spot.
There is a way of mitigating the risk and that is to make regular
course changes to induce relative movement, the question then
arises if performance should be sacrificed for safety, I can already
hear howls of anguish at that thought.

On Saturday, January 30, 2016 at 5:45:06 PM UTC-5, Don Johnstone wrote:

> I think it is a common finding in this thread that almost nothing
> increases the visibility of a glider approaching head on, in fact some
> markings may reduce visibility. The frontal area of a modern glider
> is so small so with no relative lateral or vertical movement they are
> very hard to spot.

The exception to that might be a forward facing narrow beam white LED strobe. Say a 15 degree cone.