1. xNOTAM Project Overview
xNOTAM Workshop #2
Brussels, November 2007
Item 2
European Organisation for the Safety of Air Navigation

2. Presentation objectives
Set the scene
The need for digital NOTAM
What is digital NOTAM
Benefits
AIXM 5 Specification
Implementation plans – xNOTAM Project

3. Tendency in NOTAM world
ICAO region
2006
2000
Change in numbers
Change in %
E+L+B
200,384
117,560
82,824
70%
A+N+Y
27,642
16,919
10,723
63%
R+V+W+Z
47,624
30,452
17,172
56% U
3,817
10,220
6,403
168%
D+F+G+H
17,981
12,242
5,739
47% O
12,998
5,571
7,427
133%
C+K+P
120,441
78,897
41,544
53%
M+S+T
41,518
25,614
15,904
62%
Total
478,808
291,073
187,735
65%
Information source: European AIS Database (EAD)

4. Tendency in ECAC area north
Slide source: European AIS Database (EAD)

5. Tendency in ECAC area south
Slide source: European AIS Database (EAD)

6. Static Data Why Digital NOTAM Increasing risk of information overload!
Dynamic/temporary data
Static Data
PIB
Increasing risk of information overload!

7. NOTAM information is safety critical
Sometimes, the availability of the dynamic/temporary data in digital format could make the difference between a safe journey and a disaster…

8. Closed runway example Singapore Airlines Flight SQ006
“On October 31, 2000, at 15:17 UTC, 23:17 Taipei local time, 9V-SPK, a Boeing , attempted to take off from the wrong runway at Chiang Kai-Shek International Airport during heavy rain caused by Typhoon Xangsane. The crew attempted takeoff on runway 05R, which had been closed for repairs, instead of the assigned runway 05L (which runs parallel to 05R). Due to poor visibility in the heavy rain, the flight crew did not see that construction equipment had been parked on runway 05R. The aircraft collided with the machinery and broke up into pieces. A massive fire followed. 79 of 159 passengers and 4 of 20 crew members died in the accident.
Source:
See also:
05R

9. !?! Work on the runway TWR ATIS PIB
The Excel Airways incident at Manchester, UK, in 2006 is one such example, where digital NOTAM could enable safety improvements. Extracted from the incident investigation report (AAIB Report No: 3/2006. Report on the serious incident to Boeing N, G-XLAG, at Manchester Airport on 16 July,
“Runway 06L was in use but the flight crew were not aware that this runway was being operated at reduced length. This was due to work-in-progress to remove rubber deposits at the far end of the runway, which was out of sight from the 06L threshold end as the runway is built over a slight rise in the ground. Due to a difference in interpretation of information passed between Air Traffic Control (ATC) and the flight crew, the aircraft entered the runway from holding point AG, rather than the expected holding point A, and the takeoff was conducted using a reduced thrust setting calculated for the assumed normal runway length. As the aircraft passed the crest of the
runway, the flight crew became aware of vehicles at its far end but, as they were now close to their rotation speed, they continued and carried out a normal takeoff.”
“The crew of G-XLAG did not realise that Runway 06L was operating at reduced length due to work-in-progress at its far end, until their aircraft had accelerated to a speed approaching the rotate speed (VR), despite:
Being in possession of a NOTAM concerning the work-in-progress
The ATIS broadcast relating to the work-in-progress
ATC passing information on the takeoff distance available
At this point, the aircraft was approaching seven vehicles on the runway and was at a position which precluded an abort within the useable runway length remaining.”

10. Work on the runway
56 feet
The aircraft passed within 56 ft of a 14 ft high vehicle.
A similar incident took place recently in Singapore.

11. Developments/Projects that could prevent such events
On-board moving maps
airport layout
own ship position
Graphically displayed taxi route/clearance
Also needed
actual operational status of airport movement area elements
requires “digital NOTAM”
© TUD

12. What is a “digital NOTAM”
Example - TWY closure
Today, published as NOTAM
A0874/03 NOTAMN
Q) EBBU/QMXLC/IV/M/A/000/999/5054N00429E005
A) EBBR
B) C)
E) TAXIWAYS OUTER 7 AND E6 CLSD
Digital NOTAM = Fully data modelled NOTAM
intended for computers
using the Aeronautical Information Exchange Model (AIXM) version 5
<OK for computers>
<not OK for computers>
To explain what is meant by “digital NOTAM”, let’s take as example a current NOTAM message, announcing TWY closures at an airport.
Reading the E field, which is free text, it is not possible for a computer to identify automatically which TWY is closed
NOTAM is intended to be read and understood by humans, not by machines;
It’s unreliable to ask a computer to interpret the free text field - it is likely to work for 80% of the ‘simple’ NOTAM, but not for all!
By digital NOTAM we mean a fully data modelled NOTAM, where all information is stored in a computer model that can be interpreted by computers. Basically, a digital NOTAM eliminates the free form text contained within a NOTAM and replaces the text with a series of structured facts about the affected aeronautical facility concerned. This is no longer presented as a “NOTAM message”. Instead, the information is exchanged in a format (text or even binary), which can be understood and used by computers. This new encoding is based on the Aeronautical Information Exchange Model (AIXM) - version 5.

13. What is a “digital NOTAM”
Instead of
<text>TAXIWAYS OUTER 7 AND E6 CLSD</text>
Use explicit feature properties
For example…
<taxiway>
<name>OUTER 7</name>
<status>CLOSED</status>
</taxiway>
<name>E6</name>
This is a much more closer to a truly digital NOTAM
… and the goal of AIXM 5
In a digital NOTAM, the current NOTAM fields do no longer exist. Instead, the information is structured using the Extensible Markup Language (XML), according to a schema pre-defined by AIXM. Every feature, every property and every possible situation needs to be identified by specific codes.
The challenge for AIXM version 5 is to model all these features and situations, knowing that the potential scope of NOTAM information is very wide

14. What is a “digital NOTAM”
Real-time computer interpretable aeronautical information
Operational concept
AIXM 5 encoding

15. What digital NOTAM could change
Improved Pre-flight Information
Current
text PIB
AIXM Tempdelta
Reduced TORA
WIP
If the NOTAM containing information about work in progress and reduced take-off run available (TORA) was a “digital” one, thus enabling computers to understand it, then it would be perfectly feasible:
to structure the Pre-Flight Information Bulletin (PIB) by the criticality of the information, and use a structure, fonts and colours that facilitate the reading and give a better chance to the pilot to identify a NOTAM affecting his flight;
to present the PIB graphically, showing on the airport map the location of the works and the reduced TORA;

16. PIB improvements More efficient information filtering
Based on detailed information model
Based on flight plan parameters not currently exploited by PIB
aircraft type or category
reduce the amount of retrieved information

17. AI Service benefits
Data processes based on “change impact” rules

18. Digital NOTAM benefits
eliminate manual re-typing of information
avoid misunderstandings
Efficiency
… I assume "before" the threshold rather than "beyond“ ?!…
… a crane 520 m in front of THR 24 …
AIP
AIP
NOTAM
NOTAM
In addition to safety benefits, another important outcome of digital NOTAMs would be efficiency gains.
Currently, the most important part of the NOTAM information is provided in free text, which requires human reading and interpretation. This can significantly slow down the information flow.
It can also trigger misunderstandings, as shown by a recent discussion on AIS Agora (“Crane at Rotterdam”), where a native English speaker was asking for clarification with regard to the exact meaning of the words "520m in front of THR 24...". If the NOTAM information was available in digital format, this would enable, for example, the graphical depiction of the obstacle location, therefore eliminating any doubts
<AIXM/XML>

19. Digital NOTAM benefits
“Hello Agorians!
Can one explain, how the ARC part of this restricted area should be built […]”
“Draw a circle with 75Km radius, on appropriate transparent paper and same scale as chart used.
Fit the circle on the chart in such a way as both points B and C (previously plotted on the chart) become part of the circle.
The geodesic (WGS84) distance between B and C is 94497,25m, this geodesic being a chord of the circle.”
Another recent example of non-efficiency due to free text and manual processing
(A0350/07 NOTAMN Q)VECF/QRDCA/IV/NBO/W /000/220/ A) VECF B) C) D) BTN DLY E) ARMY AIR DEFENCE COLLEGE WILL
CARRYOUT SEAWARD FRNG WI AREA BOUNDED BY COORDS:
A:191436N E B: N E
C: N E D: AN ARC OF 75KM RADIUS JOINING POINT B AND C
DURING THE PERIOD OF EXER ATS ROUTES A465 AND W90 ARE REALIGNED AS FLWS.
1. ATS ROUTE A465 NOT AVBL BTN KAKID AND VVZ VOR ALTN ROUTE KAKID- TRACK 251/071NM-BBS VOR-TRACK 242/062 DEG 072NM -MEPOL-TRACK 215/035 DEG 145NM-VVZ VOR (BIDIRECTIONAL)
2. ATS ROUTE W90 NOT AVBL BTN BBS VOR-VVZ VOR.
ALTN ROUTE BBS VOR-TRACK 242/062 DEG 072NM-MEPOL-TRACK 215/035 DEG 145NM-VVZ VOR (BIDIRECTIONAL) F) SFC G) F220)
“... there's an ambiguity: must I draw it convex (I think so!) or concave?”
“I think the times are over where we have to construct restricted areas geometrically on transparent paper, but being able to put it into some piece of software. So I think it is absolutely not practical to define an area like that […] you can interpret this in two different ways. This definition definitely misses the centre of the arc.
In such cases I would draw a huge circle around all points. If nobody can say for sure how this area is built, why should the guys firing the rockets be able to tell ;-)”
This is another example of an ambiguous NOTAM that triggered some discussions on AIS Agora (
Quoting Mr. Felix HACKL (FLUGWERKZEUGE AVIATION SOFTWARE, Austria) on AIS Agora: “[…] I think the times are over where we have to construct restricted areas geometrically on transparent paper, but being able to put it into some piece of software. So I think it is absolutely not practical to define an area like that. Furthermore, as Melani already wrote, you can interpret this in two different ways. This definition definitely misses the centre of the arc. In such cases I would draw a huge circle around all points. If nobody can say for sure how this area is built, why should the guys firing the rockets be able to tell. ;-)”

20. Digital NOTAM benefits
Support “ATC safety nets”
AIXM Tempdelta
Reduced TORA
WIP
Coming back to the incident presented before, another - more sophisticated - possibility offered by digital NOTAMs would be to:
enable the computers assisting the controller to corroborate the NOTAM information about the reduced TORA: with the aircraft type from the Flight Plan and warn the controller that the aircraft is likely to not have sufficient take-off run available;

21. Digital NOTAM benefits
Improve crew awareness / on-board “safety nets”
AIXM Tempdelta
Reduced TORA
WIP
Or the avionics could play the safety guard role:
enable the on-board avionics to corroborate the reduced TORA information with a digital take-off clearance sent by data-link and warn the pilot that the runway selected is too short, etc.
Taxiway closures, runway closures and restricted area activations are the most frequent kind of information issued on short notice, through NOTAM. If ignored, such situations can lead to serious incidents or even accidents. Digital NOTAM will enable temporary and last minute information to be rapidly accessible and usable by the computers, therefore increasing the safety of the ATM system.
As mentioned before, this is enabled by AIXM version 5.
Screenshot from digital NOTAM trial using AIXM 5 (by TUD)

22. AMDB/xNOTAM Study
Gap Analysis ED-99A – AIXM and Prototype AIXM 5 schema
Validation of AIXM temporal model (xNOTAM)
Validation of results in real scenario in flight simulator
Use AIXM 5 message to announce temporary change
Visualise change information on cockpit display
“static” database
Digital NOTAM
Digital NOTAM Decoder

23. Procedure-xNOTAM Study
Objective:
To demonstrate the technical possibilities of digital NOTAM for updating Terminal Procedure data in an onboard database
From: T12:00:00Z Until: T23:59:00Z
Due to temporary obstacles, minimum altitude raised to 4500 ft between RID and DF271.
<AIXMMessage> …
<gml:TimePeriod>
<gml:beginPosition> T12:00:00Z </gml:beginPosition>
<gml:endPosition> T23:59:00Z </gml:endPosition>
</gml:TimePeriod>
<aixm:interpretation>TEMPDELTA</aixm:interpretation>
<aixm:lowerLimitAltitude uom="FT">4500</aixm:lowerLimitAltitude> …
</aixm:AIXMMessage>
Operational Change
digital NOTAM
Procedure DB 23

24. Navigation Display (ND) Primary Flight Display (PFD)
Prototype application
Procedure xNOTAM Processor (PxP)
Reads procedure data from DB including temporary changes
Features an UI to interact with the displays
Checks effectivity of procedure change
Displays
ND: plan view of approach channel
PFD: 3D view of approach channel
Procedure DB
PxP
Navigation Display (ND)
Primary Flight Display (PFD) 24

25. Scenario 1
Procedure transition temporarily unavailable due to temporary restricted airspace 25

26. Scenario 2
Segment leg minimum altitude raised 26

27. Scenario 3
Temporarily Restricted Area affects RNAV procedure; different fixes are used 27

28. In summary Digital NOTAM can provide
Increased safety - enable temporary and last minute information to be rapidly accessible and usable by the computers, therefore increasing the safety of the ATM system
Increased efficiency – eliminate human interpretation and translation
Increased capacity (enabler) – poor information quality (in its broadest sense) often results in the extension of protection volumes and surfaces, with the consequent loss of capacity

29. The challenge Implementation requires
Specifications
Technical - AIXM 5
Operational
Resources
Budgets
Tools
People
Training
Coordination
Regional
Global
Etc.
The EUROCONTROL answer: “xNOTAM Project”

30. xNOTAM Project Objectives
for people
for machines
EAD (2007)
DATA
AIP

31. xNOTAM Project Objectives
[1] “States (AIS) to maintain and make available their aeronautical information as individual data items, in accordance with AIXM version 5. This includes both permanent and temporary changes”
[2] “To achieve a common production and distribution chain for both permanent and temporary changes”
[3] “To achieve a fully digital production and distribution chain for all AIS data products (AIP, charts, NOTAM, data sets)”
Supported by AI Team and previous xNOTAM Workshop

32. Implementation Plans
AIXM 3.3

33. 2008: Digital NOTAM Trial
It will involve test ‘digital NOTAM providers’ from the participating NOTAM offices of the ECAC States, who will use the test system in order to generate test “digital NOTAM”, such as:
closure or limited use of airport, runway, taxiway
activation of restricted airspace, ad-hoc restrictions, etc.
closure/opening of conditional routes
North-Atlantic tracks
temporary obstacles
etc.
It will also involve test ‘digital NOTAM users’ – organisations who will try to exploit the AIXM 5 messages (digital NOTAM), which contain structured encodings about temporary situations affecting aeronautical facilities and are suitable for intelligent machine use.

34. 2008: Digital NOTAM Trial

35. xNOTAM Trial Home Page

36. xNOTAM Trials

37. US Digital NOTAM Project
Activity
Date
Result
Industry Day
May ’07
Commitment by U.S. Government to Modify NOTAM System
Initial Policy Change
Oct ‘07
NOTICE: D NOTAMs redefined consistent with ICAO definition (reclassify civil L NOTAMs)
System and Additional Policy Changes
Aug ‘09
One Federal NOTAM System (FNS) with Full ICAO Implementation
System Enhancements
2010+
Aeronautical Information eXchange Model (AIXM) NOTAM Capabilities

38. US Digital NOTAM System Near-term capability demonstration
AIXM
Quality Control
AIXM
Common Web Services (AIXM, RSS, WMS)
Publishing
Candidate temporary aeronautical data
AIM Database
Legacy Systems
(Preserve legacy investments at status quo functionality)

39. US Digital NOTAM System Near-term capability demonstration
Screenshot of a draft version, courtesy of FAA

40. US Digital NOTAM System Near-term capability demonstration
Screenshot of a draft version, courtesy of FAA

41. Digital NOTAM Implementation
Conclusion
Digital NOTAM Implementation
The European approach
Digital NOTAM are technically feasible
Improved safety
Improved efficiency
Support increased capacity
Digital NOTAM requires a global approach
ICAO standardization
Global commitment

42. Questions?