Collision Avoidance Systems
jcarlyle
Systems with the intent of putting one in my transponder-less ASW-19. I
was interested in such a system because my glider club lies inside the
Mode C veil of PHL, because an active military air base is 5 miles
away, and because there are several airways that lie within several
miles of us. Here's the result of my research; I hope it might be of
help to others.
Zaon MRX - This was the one I bought. Pros - shows threat distance
and height; receives civilian signals A, C, S and 3/A, as well as
military signals X, Y and 2; alerts are visual and aural (high pitched
beeps); uses internal power (but can use aircraft power); is the
smallest system available; can be panel mounted with remote antenna.
Cons - does not show threat direction; doesn't output threats via
RS232 to PocketPC type devices. List price $499
Zaon XRX - This is the one I really liked. Pros - shows threat
direction as well as distance and height; receives civilian signals A,
C, S and 3/A, and also military signals X, Y and 2; alerts are visual
and aural (synthesized voice); outputs threats via RS232 to PocketPC
type devices. Cons - needs aircraft power; fairly large and tall, and
must be mounted on the glare shield. Supposedly Zaon will offer a panel
mount version with remote antenna in the future. List price $1795
Proxalert R5 - I rejected this one. Pros - shows threat distance
and height; shows squawk code of three threats (but threats combined if
same squawk); alerts are visual and aural (high pitched beeps); outputs
threats via RS232 to PocketPC type devices; can be panel mounted with
remote antenna. Cons - Combines threats with same squawk code on same
line showing closest threat distance, and flip-flops threat altitude;
needs aircraft power; only receives civilian A, C and S signals; fairly
large and hangs over glare shield lip. I also was turned off by the web
site, when I see poor English in sales literature I can't help but
wonder if the engineering was also done carelessly. List price $795
Monroy ADT-300 - I rejected this one. Pros - shows threat distance
and height (but only if you have an altitude encoding transponder);
alerts are visual and aural (synthesized voice); second smallest
available; can be panel mounted with remote antenna. Cons - Needs
altitude encoding transponder to show threat height; needs aircraft
power; only receives civilian A, C and S signals; doesn't output
threats via RS232 to PocketPC type devices. List price $795
Please note that this list is biased towards my own needs, in a quiet
glider with no transponder, operating with civilian and military
aircraft. You might have different requirements, so do check out the
manufacturer's sites for fuller specs and manuals:
http://www.zaonflight.com/
http://www.monroyaero.com/
http://www.proxalert.com/
A good single reference page to many Collision Avoidance Systems is
here: http://www.avionix.com/collis.html
There are also some (fairly old) threads on RAS on this subject; you
might wish to search for them.
Be careful up there!
-John
(I have absolutely no connection or financial interest with any of the
companies named in this message).
flying_monkey
Hello, haven't heard from you in a while. I'm curious as to why your
research didn't include one whole class of CAS - transponders, both
Mode C and Mode S. I know that they are more expensive, but, knowing
you, I imagine you have a better reason than that.
Ed
jcarlyle wrote:
> Last week, before the Minden midair, I reviewed Collision Avoidance
> Systems with the intent of putting one in my transponder-less ASW-19. I
> was interested in such a system because my glider club lies inside the
> Mode C veil of PHL, because an active military air base is 5 miles
> away, and because there are several airways that lie within several
> miles of us. Here's the result of my research; I hope it might be of
> help to others.
. . . snip . . .
> Please note that this list is biased towards my own needs, in a quiet
> glider with no transponder, operating with civilian and military
> aircraft.
. . . snip . . .
jcarlyle
Hey, how's it going? Yes, I do have a good reason for not considering a
transponder at this time - no space for it in my panel, and not enough
useful load left to carry both it and the battery necessary to power it
(and I'm not about to steal operating time from the battery that powers
my radio, glide computer, GPS and iPAQ).
-John
Ian Cant
Thankyou for a really useful contribution.
Putting an alerting system in my glider gives ME useful
information that I can act on. Installing a transponder
alone gives me no such information, although it MIGHT
give second-hand info via FAA alerts to other traffic,
or MIGHT alert other traffic to my presence if they
have and use a CAS. And $500 is reasonably affordable,
whereas the total cost of an installed and legalized
transponder is much less so.
Part of the present confusion is the proliferation
of different technical partial solutions to the problem
- transponders [mode C or S], TCAS, ADS-B, FLARM etc
etc etc. Without standardization on one system, none
can reach their potential. Without wishing to decry
any of these systems, each one adds complexity and
to some extent increases heads-down cockpit workload
[even if only to note your battery drainage from time
to time]. Heads-out situation awareness is a desirable
state to aim for and should take preference over the
other interests of techies.
Who would like to use existing technology to come
up with one fit-and-forget unit that would act as a
flight recorder, GPS-enabled ELT, mainly-passive alert
and transmit-on-alert-only transponder ?
But at the end of the day, even with very good
warning of an impending collision, the limited maneuverability
of both a glider and a high-speed aircraft means that
you need to put an eyeball on the threat to have a
hope of avoiding it. We drive highways every day in
reasonable safety - but just think about doing that
with your eyes closed and your trusted passenger telling
you where the other traffic is.
Ian
jcarlyle
Thanks for your reply - you raise some very good points that need to be
emphasized. I especially love the analogy about driving with your eyes
closed, dependent upon your passenger to tell you about where the
traffic is - see and avoid is still the king!
I personally like the idea of ADS-B, but not at today's prices, size
and power requirements, and also the fact that it isn't mandated for
all aircraft flying in the US. Thus I think the aural alert with the
distance and height readouts on the Zaon MRX and most importantly
keeping my eyes out of the cockpit are, at the moment, the best
approach to try and stay safe.
-John
jb92563
121.5 ?
Just wondering if there is a way to alert the other traffic of the
possible conflict.
Ray
boer...@msn.com
Nice summary of the PCAS models available. Airliners and some corporate
jets have TCAS; they can "see" you without having to be told by ATC.
Smaller motorized traffic likely does not have TCAS; they need to be in
contact with ATC to know that your transponder-equipped glider is
nearby.
My choice was the tiny Zaon MRX. I use the rechargeable batteries
recommended. This model gives relative altitude, altitude trend, and
distance. Its beep beep is cheap cheap.
It does not give azimuth information, but it has forced me to improve
my good old-fashioned rubber-necking see-and-avoid procedure. One of
the advantages of the MRX is that the alerts are audible; we already
have too much heads-down technology in gliders to install more
equipment that requires visual monitoring.
When my MRX gives two beeps, I start looking everywhere (mine is set to
beep twice for traffic within 1NM and 1,000 feet). When it advances to
four beeps, I start looking everywhere with super motivation (mine is
set to beep four times when traffic is less than 1NM horizontal and 700
feet vertical).
Portability is an added advantage of the MRX. When doing introductory
rides for our club, I take my MRX unit with me.
The advantage of PCAS over the transponder is that you, the glider
pilot, is alerted to all traffic with transponders. This includes
Cessna 152s, corporate jets, commuters and large airliners. If all I
had was a transponder, I would have to be in communication with ATC and
under radar coverage to be available to be told about other traffic.
Airliners with TCAS are able to see and react to transponder-equipped
gliders. But the smaller powered aircraft cannot electronically see
those same gliders unless those small powered aircraft are
communicating with ATC (in a radar environment).
PCAS (portable collision avoidance system) gives me more peace of mind.
Given the choice between only some of them being able to see me, or me
being able to see most of them, is the main reason I chose the MRX over
a transponder.
Last week, I had a couple of "two beep" alerts. Both of these aircraft
came up from behind and below. But I was able to spot them sooner than
when I did not have the MRX.
Making transponders cheaper for gliders would be possible if the FAA
relaxed some of its technical specifications. Since Santa Claus didn't
show up with money, I can't have both a PCAS and a transponder, yet.
Raul Boerner
DM
LS6-B
Jack
> How would you communicate with the traffic on a collison course?
> 121.5 ?
We're not on rails, jb -- if you have time to talk, you have time to
fly. And limited reaction time for either crew is a major factor.
There is no requirement to monitor 121.5, nor is it practical.
Considering the poor radio discipline of many pilots, such a requirement
would be worse than useless, even if there were money/panel space for
two radios or just for an upgrade to a two-receiver-in-one box
configuration.
> Just wondering if there is a way to alert the other traffic of the
> possible conflict.
Affordable tech would certainly help if universally available. As it is,
full-time transponder operation is not practical for all sailplanes.
Though 121.5 may not be the answer, the radio can be a more useful tool
than we currently make of it. Sailplanes generally have radios and could
certainly use them more aggressively. Frequently alerting ATC to your
current position and altitude by voice contact, when transponder or
primary radar returns are not available to them, should become our
standard mode of operating. It's not like we cover ground by huge leaps.
Regular position updates may also serve the glider pilot well when he is
forced to land out, or bail out.
Nationally, it's not sailplane operations that are the problem. Are
there statistics to indicate there is an increase in sailplane activity
in recent years? In fact, we keep hearing concerns about the opposite trend.
The main problems are lack of crew awareness in a see-and-avoid
situation, speed differential, the minimal profile of the glider in some
attitudes (applies to different degrees to all aircraft), and --
related to speed differential -- the inability of even a maneuverable
craft to escape the threat when it has been identified.
Answers: training/crew discipline, and reduction of the speed
differential by extending the 250 KIAS speed restriction to FL 180.
See-and-avoid is far more effective when people have their heads out of
their...cockpits. And especially when their speed is appropriate.
Two-fifty below ten is no longer enough of a restriction, considering
the increase in the number of turbocharged light planes being sold, and
greater use of the mid-level airspace. Raising the 250 KIAS speed
limit to FL180 can easily reduce closing speeds by 50 kts or more at
those altitudes, will not affect Turbo Props much if at all, and gives
everybody a better chance to see and avoid in VMC, whether VFR or IFR.
Where the terrain out west is higher than we flat-landers have to deal
with, the "250 KIAS below FL180" restriction brings speeds into
alignment with what they are elsewhere in the country on an AGL basis,
giving low-speed operators out west the same protection we have in the
east at the altitudes at which the westerners are forced to operate.
Also, the existence of "G" airspace below 2000' AGL anywhere in the
contiguous states is an archaic holdover that ought to be ended. The
lack of radar coverage is a fact in most of the country at those levels
anyway, so that shouldn't be an issue.
Who ran into whom? Well, the jet crew took it on the nose, not in the
tail. The NTSB report could reverse that scenario for FAA enforcement
follow-up, especially considering right-of-way rules, but I'm not
betting the farm on it. The FAA is a political animal, too often driven
by the media-perceived problem, and the media, when not willfully
ignorant, more interested in the business advantages of emotional impact
from a sensational headline than in what is simply the truth.
Objectivity is boring for the average customer, so does not sell.
I hope AOPA will be front-and-center in this situation--shoulder to
shoulder with SSA--as AOPA's ox will be the very next one gored if
restrictions to glider ops are proposed and enacted.
Jack
kirk.stant
jcarlyle wrote:
> Last week, before the Minden midair, I reviewed Collision Avoidance
> Zaon MRX - This was the one I bought. Pros - shows threat distance
> and height; receives civilian signals A, C, S and 3/A, as well as
> military signals X, Y and 2 (snip)
WTF are military signals X and Y? Military uses IFF modes 1, 2, 3
(same as civilian mode A or 3/A), C (same as civilian mode C - gives
altitude only), 4 (secure), and S. I'm hoping "X" and "Y" are modes 1
and 4, since most military traffic have those on all the time-
especially mode 4.
Neat device, though, and definitely on my xmas list!
Kirk
66
Vaughn Simon
"jcarlyle" <jmca...@gmail.com> wrote in message
news:1156944317.5...@74g2000cwt.googlegroups.com...
>
> Zaon MRX - This was the one I bought. Pros - shows threat distance
> and height; receives civilian signals A, C, S and 3/A, as well as
> military signals X, Y and 2; alerts are visual and aural (high pitched
> beeps); uses internal power (but can use aircraft power); is the
> smallest system available; can be panel mounted with remote antenna.
> Cons - does not show threat direction; doesn't output threats via
> RS232 to PocketPC type devices. List price $499
>
Even after reading the web site and the manual, I am not clear about the
audio alert provided by this unit. Does it lack a method to hear the alert
through your headset? If so, it would be great for glider use, but perhaps
worse than useless in an airplane because the tiny speaker would be inaudible,
thus the gadget would just give you one more reason to keep your eyes focused
inside the cockpit.
Inquiring minds want to know.
Vaughn (a guy who goes both ways)
Ramy
any military aircraft?
jcarlyle
The easy one first - no, there is no headset output on the MRX. I
talked with our tow pilot today, and he, too, identified this as a
drawback for power planes. The XRX does have such an output, as does
the ADT-300 and the Proxalert R5.
As for military signals X and Y, the manual is no help. After a bit of
Googling, I'll take a guess, though - I think these refer to Tacan
signals. One of the frequencies Tacan can transmit on is 1090 MHz, like
a transponder. Unknown to me is whether a Tacan signal has altitude
encoded in it, but it appears that the output power of a Tacan unit is
the same as a transponder, so the distance measurement scheme these CAS
units use would work. Again, just a guess - what I don't know about
military flying would fill large books!
I flew today with the MRX, and I can report that in my ASW-19 it works
very well. I was amazed at how much traffic it picked up that I was
unaware of until the traffic got within 2 miles or so. The real
benefit, though, was the MRX alerting me to a helicopter that was at
500 feet, a half mile away, and was vectoring in on the tow plane and I
just after takeoff. To me, the $500 cost of the MRX has already been
repaid! On another note, in my ASW-19 I wouldn't want anything bigger
than the MRX on the glareshield. I know the XRX wouldn't fit, and I
don't think the Proxalert R5 would either (although the ADT-300 would).
-John
Vaughn Simon wrote:
> Even after reading the web site and the manual, I am not clear about the
> audio alert provided by this unit. Does it lack a method to hear the alert
> through your headset? If so, it would be great for glider use, but perhaps
> worse than useless in an airplane because the tiny speaker would be inaudible,
> thus the gadget would just give you one more reason to keep your eyes focused
> inside the cockpit.
Martin Gregorie
> Who would like to use existing technology to come
> up with one fit-and-forget unit that would act as a
> flight recorder, GPS-enabled ELT, mainly-passive alert
> and transmit-on-alert-only transponder ?
>
battery capacity of 2 x 7Ah, I'd settle for something like a combination
of the Zaon MRX and a Microair or Filser transponder in a single 57mm
package. I'd be happy to use one battery for transponder + radio and
reserve the other for varios, GPS and iPAQ.
Both these transponders fit a 57mm mount and are fairly light with low
power consumption. Adding the TPAS capability and using the same display
should make little difference to the package size while adding about 15%
to overall power consumption.
--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |
Rory O'Conor
How does the MRX perform when thermalling?
The manual suggests that the aerial should be vertical
for good reception and for the software calculations.
Does it give the right sort of readout, and beep at
the right time when you are thermalling?
Rory
At 13:30 30 August 2006, Jcarlyle wrote:
jcarlyle
I flew with my new MRX three times yesterday, but unfortunately each
flight was a sleigh ride - no thermals were found. As we've got Ernesto
moving in, I'm afraid I won't be able to answer your question for a
week or so.
Hopefully someone else can tell you sooner!
-John
sta...@gmail.com
>
> As for military signals X and Y, the manual is no help. After a bit of
> Googling, I'll take a guess, though - I think these refer to Tacan
> signals. One of the frequencies Tacan can transmit on is 1090 MHz, like
> a transponder. Unknown to me is whether a Tacan signal has altitude
> encoded in it, but it appears that the output power of a Tacan unit is
> the same as a transponder, so the distance measurement scheme these CAS
> units use would work. Again, just a guess - what I don't know about
> military flying would fill large books!
>
I thought of that, but think it's unlikely. TACAN is basically a UHF
"VOR"/DME equivalent, and is also used by civilians - airliners and
bizjets - and civilian DME is the distance measuring part of TACAN.
TACANs have both X and Y channels, Y being used for Air-to-Air distance
and bearing between cooperating aircraft (useless info: must set your
TACAN channels 63 apart to work: CH 29Y and CH 92Y are commonly used).
Anyway, only the DME portion transmits, the bearing portion is receive
only - like VOR. So it's unlikely that TACAN signals are being used,
in my opinion. If they are, then civilian DME should also trigger the
TPAS!
But I could be wrong...
Kirk
Kirk
jcarlyle
I called up Zaon, and they said that the X and Y signal modes they
receive are indeed DME.
-John
kirk.stant
jcarlyle wrote:
> Kirk,
>
> I called up Zaon, and they said that the X and Y signal modes they
> receive are indeed DME.
>
Interesting.
Then it should also see civilian DME. Too bad GPS is pretty much
replacing DME in military and civilian aircraft.
Thanks for the info - learned something new!
Kirk
66
kirk.stant
Ramy wrote:
> Kirk, will a TPAS which can only receive mode A,C, and S will detect
> any military aircraft?
>
Ramy,
In peacetime all military flights (caveat - my experience is AF, Navy
and Army may be different) are on IFR flightplans, so will be squawking
Mode 3/C (same as mode A/C). During certain phases of flight, they may
cancel and go VFR, but will still be squawking mode 3C/1200, just like
everyone else. Some newer jets may have mode S installed (C-17? F-22?)
in which case that would be on also.
It's possible during training in restricted airspace that mode 3 (and
S) may be turned off (so the other guy can't find you with his onboard
interrogator) but there shouldn't be any civilian traffic in that
airspace.
Other military modes (1, 2, and 4) are used as tactics and conditions
require, but are not required. More than likely they would be on
during routine flight to and from bombing ranges and restricted
airspace, and while using MOAs, so that other military planes equipped
with IFF interrogators can see and identify them.
Short answer - yes!
Hope this helps,
Kirk
66
rroz...@aol.com
is a small, passive system that only requires me to turn it on before
flight and turn it off after the flight is over. I bought it at Wings
and Wheels for approx $ 500.00 and I do feel that it a very valuable
safety device that folks should really consider purchasing, especially
for those operating in areas with a fair amount of commercial jet
and/or general aviation traffic. I operate out of Moriarty, NM (30 NM
East of Albuquerque, NM) and we have a fair amount of jet traffic
descending toward the Albuquerque International Sunport or climbing out
on departure. The MRX has really worked very well alerting me to
aircraft that get within 5 NM and 5,000 feet! - 3R
rroz...@aol.com
Flying level or turning in a thermal, the MRX seems to work just fine!
- 3R
boer...@msn.com
<< Rory wrote: How does the MRX perform when thermalling? >>
My observation so far is that it performs the same while thermalling
and cruising.
<< Rory wrote: Does it give the right sort of readout, and beep at the
right time when you are thermalling? >>
Yes.
Ron (RW)
I bought my MRX early this season, and I have been very pleased with
it's performance in both level and thermalling flight. The audio
warning could be louder, but is sufficient for sailplane use. The LED
displays are super bright even in bright sun; l catch display changes
in my peripheral vision pretty well as a result. Like the other
posters, I too have been surprised by how much more traffic I see,
especially coming up from behind. It would be the best of all worlds
to have heading info on traffic, but the MRX will at least allow you
to quickly concentrate either above or below the horizon when traffic
is closing. I found that the battery powered arrangement peters out
fast, as I like the display set for bright as it will go. So, I've
hard wired my unit on it's own fuse block, and also have an antenna
extension, that functions well beneath my DG's pedestal shroud. Very
tidy installation. Our Glider Club flies by written agreement within
a moderately busy Class D. It's not departing traffic in close that
worries me, but rather approaching heavy IFR traffic letting down
thru a nice cloud street about 25 miles out. Nothing gets your
attention like bouncing around 500 below cloudbase (of course :) and
seeing that display light up....... 5 miles, 1000' above..... and
descending. Worth the price of the unit right there :) Ron
N531RW
Jean
In Switzerland, Germany and France it looks like 75% of the ships are
equipped,
Jean
"jcarlyle" <jmca...@gmail.com> a écrit dans le message de news:
1156944317.5...@74g2000cwt.googlegroups.com...
jcarlyle
FLARM is a very nice concept, but it will never, ever be in the US (as
per the manufacturer's wishes). Even if it were, it wouldn't help with
the problem highlighted by the Minden mid-air, unless the manufacturer
embraces the Aussie design and allows it to interact with ADS-B. But,
ADS-B is going to take a number of years before it's in all aircraft.
So really your best bet right now to get a handle on what's in the air
with you is to get one of the collision avoidance systems mentioned at
the top of this thread, so you can keep track of the transponders most
of the powered aircraft carry.
-John
Yuliy Gerchikov
> FLARM ... wouldn't help with
> the problem highlighted by the Minden mid-air, unless the manufacturer
> embraces the Aussie design and allows it to interact with ADS-B. But,
> ADS-B is going to take a number of years before it's in all aircraft.
I was always curious: what are the principal differences between FLARM and
ADS-B? (Besides, that is, the fact that one of them is developed by a small
private corporation and the other by large governmental or international
agency(-ies), and therefore both the time-to-market and the total cost of
ownership will be an order or two of magnitude higher for the latter...)
If you excuse my ignorance for a second... Both seem to be doing basically
the same thing: broadcast their GPS coordinates and listen to other units
around them detecting potential conflicts. Ignoring for the moment the
differences in radio frequencies and transmission power levels, as well as
some details of collision detection algorithm that appears to be more tuned
for gliders in FLARM (knowing about thermalling etc.)... are they the same?
--
Yuliy