High Vis Markings

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/more...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/phocado...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.