EGPWS and augmented reality
 

With respect to EGPWS and the incident reported in the Roumors section I would like to pose a naive computer scientist's question.
Why isn't a virtual image of the landscape outside represented
on one of the screens in the cockpit based on the GPS position?
My feeling is that the 3D data for our world shoud be pretty accurate already or could become sufficiently accurate at least for the
dangerous airports.
In an A320 you could essentially place your laptop on the table and
connect it to a GPS receiver and would probably get a pretty good
image of where you are and where the terrain is.
I just mean to illustrate how easy it would be, not that it should be done
in that way.
A system like this would clearly contribute to situational awareness and should not be very expensive.
My question is if something like that is in preparation and why it has not already been introduced during the last 5-10 years.

The further development of this is to have a 3D flightpath displayed, which would eg make approaches to Innsbruck much easier (I have seen some
research on that at my old University).

It has. There is a function called 'Terrain' on the Nav display that displays a map of terrain relative to the height of the aeroplane in relation to that terrain. So close terrain shows as amber, higher terrain as red, low terrain does not show at all. This must be pilot selected on.

Thanks Rainboe :ok: which aircraft have that kind of feature?

I was rather thinking about 3D graphics, what you probably refer to is
2D right?

I think to have seen that kind of display on the A380.

"3D" terrain representation is available to General Aviation on some new electronic ADI/PFD displays. For airliners, I suppose it is a matter of $$ and certification (that takes more $$)...

I think what greek-freak is referring to is the VSD (Vertical Situation Display) on the 737NG (available as a customer option):

Ie. :
http://www.b737.org.uk/vsd.jpg

:ok:

Thank you very much for the answers guys, I appreciate it :)

There are several issues that restrict the use of the EGPWS database as a 3D display.
1. Although the terrain/obstacle database in highly reliable, there are still problems with validation of the source information, e.g. mapping basis WSG84 or not. The high resolution available near runways may not be available elsewhere. Even with established maps there are still errors, e.g. Zurich RJ100 accident report (2000?) noted an approach obstacle omission on existing charts. In many other instances EGPWS (GPS) has identified that the runway co-ordinates are incorrect (Honeywell Operators Conferences 2001-2003).
2. Then there are the map lawyers !
3. The accuracy of an electronic terrain map depends on the navigation source. GPS is the best, but the receiver embedded in the EGPWS box is only a single channel and in order to satisfy certification regulations to use a terrain display as primary source of navigation, a dual/triple GPS would have to be used; these are just becoming standard in new aircraft. Note how many aircraft still suffer navigation map slips with the older standards of Nav equipment.
4. The existing EGPWS 2D terrain map display integrates with existing navigation or weather radar displays (ND, WXR), a 3D display requires use of either the attitude display or a new instrument. The latter is undesirable (cost / real estate) and the former requires that Attitude, Airspeed, and Altitude information shown in modern EFIS Primary Flight Displays (PFD) has to be incorporated with the terrain. This arrangement also has to meet the certification requirement of ‘never’ being hazardously misleading (certification term, < 1x10-9 failure).
5. Another major problem involves the human factors in depicting a 3D scene. Current PFD attitude formats are scaled in the pitch axis at approximately 5:1 against the real world, note that head up displays should be conformal – the 1:1 scaling enables an overlay with the real world. Head down 3D displays have been built, those which I assessed suffered from scaling problems – the terrain did not ‘look right’, a ‘letterbox’ format, or were so small that there was no meaningful detail in the picture. One particular issue was the lack of depth perception. Range estimation using 3D was poor, whereas in a 2D display different range scales can be selected. The one system which I assessed in-flight had a relatively large display format in comparison to most EFIS PFDs. This enabled improved pitch scaling and depicted the terrain with all of the colour coding enhancements of EGPWS. However, this system too suffered problems of depth perception and range estimation. In addition there were surprising indications that altitude assessment was degraded and hence terrain awareness reduced. Also the side scale displays of airspeed / altitude / ILS, etc required refinement so not to clutter the terrain display, but they still had to be prominent enough to enable instrument flight. The system was easy to use head down, but without any apparent benefit in displaying the threat of terrain and the indications of degraded instrument depiction, it warranted much more development.

The industry has to be cautious about using new technology – just because something can be done does not mean that it should be done. There should be many proven benefits of change, not at least reduced cost, workload, and training effort. A major problem emerging from the use of modern technology is the apparent lack of understanding that crews have; perhaps the designers are assuming too much about the availability of training time in the modern industry.

Many thanks for that most comprehensive answer safetypee.
Do you have any references (PDF or such) where I could read more about that?

This is one of the reasons why I stayed in basic research rather than in applied research.

One has much more freedeom to exploit novel ideas since there are neither economical (as long as you get funding for it) nor safety limitations.
Still even if you try to build a safe computer system for aviation you never know if your specification covers all possibilities (the LH A320 Warsaw
accident is my favorite example for this).
So the implementation of the specification might be 100% correct
but you never know about the specification itself, this is, in a sense, very similar to the axiomatic system of mathematics.

My very personal point of view is that this problem might represent one of the great threats for modern aviation.

greek-freak, sorry I overlooked your request. I doubt that any reports are public as most manufacturers (equipment and aircraft) treat such information as confidential.
For a ‘standard’ text, see “Information Visualization, C Ware, ISBN1558605118.
There is a good aviation perspective in cognitive capabilities of humans; this also has great value for CRM and human factors training.