Anti Collision Warning

"Dave Martin" wrote in message
...
This is what it boils down to EDUCATION/TRAINING

Training pilots how to look out.
How to concentrate,
What the dangers are, real and perceived and potential
and where these danger lurk in a particular phase of
flight.

We will never eliminate accidents but by education
we can reduce the opportunities. Train hard fly easy
as some one said!

Dave

At 17:00 30 April 2004, Rory O'Conor wrote:
Mid Air collisions are a problem. Maybe we need to
pull together more information about them.

There are a number of different phases of flight
during which they occur:

Climbing phase (high Angle of Attack)
(power planes only)
Circuit phase (all planes)
Aerobatics (all planes)
IFR & low visibility flight (all planes)
Normal flight (all planes)
Thermalling (soaring planes only)

We need to understand the proportion of collisions
occurring in the different phases and the potential
contributory factors. Road Traffic Accidents happen
more often in good weather than bad. It is not
entirely clear that thermal collisions happen more
often in competition gaggles than when there are only
two in a thermal, whatever our instincts.

For the different flight phases, different factors
will be more or less important and the solutions and
devices to prevent collisions may be different.

Personnally I would be surprised if TCAS devices could
cope with resolving the trajectories of thermalling
gliders other than the basic level of identifying
another nearby plane. Thus I suspect that the main
detection instrument in thermals remains the eyeball.
In which case, every effort should be made to ensure
the best use of the eyeball in thermals.

There may be a role for such devices in other phases
eg normal flight and IFR.

The only power planes that regularly fly close
together are the military and aerobatic display teams.
I am sure that the Red Arrows are fitted with the
instruments that they best require, but I would be
most surprised if they have any electronic device
warning them that they are about to hit a team-mate.
I expect that they do a lot of training, have superb
lookout and excellent communications.

I would assume that a TCAS/GPS device will be making
noises at 1 mile and probably very loud noises at 1/4
mile (1500 ft). With a typical thermalling diameter
of 200-600 feet and circling period of less than 20
seconds, any normal TCAS would be screaming fit to
be
turned off!

We are also entering the area where the margin of
error for a GPS (30 ft horizontally, 100 ft
vertically) is a significant issue. GPS is not
accurate enough to tell which side of the highway you
are driving on, nor probably to determine the correct
seperation of two thermalling gliders when the pilots
using their eyeballs consider that they are adequately
seperated.

I cannot envisage an electronic GPS device for
avoiding intra-thermal collisions, assuming that the
planes are going to remain in the same thermal.

Rory





We've trained and trained for 100 years and yet we still have collisions.
The 'Mark 20 eyeball' is a good tool but it isn't the total solution.
Humans just can't maintain the vigilance required. We have plenty of
evidence of that both clinical and anecdotal.

Bill Daniels

We've tried "look out the window." We still have collisions. Since
human capabilities change only over evolutionary time, and training
programs that encourage good use of existing capabilities have been in
place for some time, we should assume that training and exhortations
have achieved as much improvement as they ever will. The remaining
collision risk must be reduced through some other means.

The traffic pattern and thermals are two high-density traffic
environments where aircraft maneuvering renders collision prediction
difficult. It's not just difficult for machines, it's also difficult
for pilots. During pilot training the task must be taught in several
steps: 1) be aware of how many other aircraft are nearby 2) locate
them 3) avoid getting close to those aircraft unless necessary 4) if
proximity is necessary, watch (i.e., try to predict) the path of the
other aircraft and avoid going toward the place where it is going 5)
learn to anticipate possible unpredictable variations in the path of
the other aircraft also and avoid going toward those areas. Level 5)
is probably only required in thermals and in formation flying. When
we begin thermaling, most of us have to use 3) because we're not good
enough at 4) or 5).

However, at the moment pilots are much better than machines at 4) and
5), while machines are much better than pilots at 1) and 2). Yet, if
1) fails, the rest is useless.

The fact that machines can't do the whole job does NOT mean they can't
be helpful. A machine that could inform a pilot that there are 5
other aircraft in the thermal within +/- 500 ft would be valuable to a
very alert contest pilot who could account for only 4 of them. The
tasks of finding the 5th, and avoiding all 5, might still have to rely
on the Mark I Eyeball.

Of course, pilots in gaggles know that they are in a high
collision-risk situation, and they devote significant attention to
seeing and avoiding other aircraft. Pilots who think they are alone
in the sky devote much less mental capacity to those tasks. Insisting
on "always" maintaining lookout vigilance is ill-advised: many of us
have a pretty high cognitive load a high percentage of the time in
flight, and if we devote too much attention to lookout we may well
lose navigational or meteorological situational awareness, or even
just tire ourselves out mentally, leaving ourselves vulnerable when
attention is important later. This is where a machine could help, by
maintaining a scan and verifying that, indeed, the collision risk is
low. If that changes, the machine can alert the pilot, allowing the
pilot to properly switch mental capacity to "see and avoid." In fact,
this is the primary benefit of flight following during powered VFR
flight, and it's no small benefit.

Insisting that a technology is useless unless it can solve the whole
problem makes perfection the enemy of the good. It's also, in this
case, blind to the imperfection of the current technology - the Mark I
Eyeball - which plenty of science has shown is, in most near-miss
scenarios, far less valuable than the sheer size of the sky.

On 30 Apr 2004 15:16:05 -0700, (Finbar) wrote:

We've tried "look out the window." We still have collisions. Since
human capabilities change only over evolutionary time, and training
programs that encourage good use of existing capabilities have been in
place for some time, we should assume that training and exhortations
have achieved as much improvement as they ever will. The remaining
collision risk must be reduced through some other means.
efl

Insisting that a technology is useless unless it can solve the whole
problem makes perfection the enemy of the good. It's also, in this
case, blind to the imperfection of the current technology - the Mark I
Eyeball - which plenty of science has shown is, in most near-miss
scenarios, far less valuable than the sheer size of the sky.


Finbar, I think that post sums it up nicely. The Swiss FLARM would
appear to be a good start.

Having something say " traffic, 5 miles. closing, level" would give
you something to look for and would essentially be an automated and
autonomous flight following service.

Unfortunately we won't get sensible ADS-B anytime soon at any
reasonable price for the rest of aviation. Take a look at the system
specifications and you'll soon see it is over specified by about 3
orders of magnitude. Politics again.

A simple GPS/VHF based system was demonstrated in Australia a few
years ago but the authorities didn't follow through because there were
no ICAO standards for such a system. Even now ADS-B looks like
operating on different frequencies in different countries.

Mike Borgelt

Mike,

The FLARM concept has been painfully obvious, from a technology point
of view, since the introduction of low-cost GPS. In fact, it could
even have been partially implemented with LORAN, but those receivers
were expensive and were never widely deployed.

Unfortunately, FLARM-type collision avoidance is only going to work if
it's deployed to virtually all aircraft, which would require the
authorities to insist on it. This won't happen: ADS-B is the chosen
approach.

It seems to me that TIS-B is most likely what will first begin to
provide us with the functionality we need - and actually get deployed.
TIS-B (Traffic Information Service - Broadcast) is a portion of
ADS-B, essentially a broadcast of the radar returns seen by ATC. At
the moment it has limited coverage in the US but you can receive it -
however you need to spend about $15,000 on avionics including a Mode S
transponder plus a display unit designed for bigger panels than we
have. Still, no doubt it will soon occur to some entrepreneur that a
TIS-B receiver without all the Mode S baggage, designed for display on
a PDA might well find a market (lots of Cezzna drivers think $15k is a
lot of money too).

In article ,
Mike,

The FLARM concept has been painfully obvious, from a technology point
of view, since the introduction of low-cost GPS. In fact, it could
even have been partially implemented with LORAN, but those receivers
were expensive and were never widely deployed.

Unfortunately, FLARM-type collision avoidance is only going to work if
it's deployed to virtually all aircraft, which would require the
authorities to insist on it. This won't happen: ADS-B is the chosen
approach.

Sort of important to this approach is "is it worth it?" and
"does the solution cause more death than the problem?"

Kind of like parachutes. If the added weight increases the
marginal stall speed to the point it causes .001% more
fatal accidents, but only saves .0092% more pilots
in breakups, then it was a bad idea. Of course it's
extremely unlikely anyone can prove the extra 15 pounds was
the cause of fatality, right?

How many added fatalities will there be because the pilot
is distracted by the bleepy noise, even though the aircraft
would have missed by six inches if neither pilot was aware?
How many will die because of the distraction itself?

This is just too hard to calculate. Huge numbers (hours
of flight)multiplied by tiny estimated numbers (risk of midair)
makes for a tough comparison. Now instead of risk
use cost in $$$$s to implement, and the true cost vs. benefit is
very difficult to estimate correctly...

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Mark Boyd
Avenal, California, USA