Digital Electronic AIP
How would you like your AIP, electronic or digital?
Much confusion exists on the various flavours of Aeronautical Information Publications. This article aims at clarifying the topic.
By Benoit Maisonny, Nilacandi Director and Senior AIM Consultant
Once upon a time, more precisely in 1960, ICAO introduced the concept of AIP, a compendium of permanent aeronautical information, organised in 7 parts, as defined by Annex 15 Amendment 8. For the first time, States were recommended a standard layout and content for this information. Of course, at that time, it was a paper document. There was a lot of repetition and clutter in the old structure. Therefore, the 3-parts AIP introduced by ICAO in 1994 was most welcome. Some AIS departments loved the old 7-parts AIP so much that they kept it until the early years of the 21st century.
What are ICAO Annex 15 requirements when it comes to paper AIP presentation and distribution?
Annex 15 §18.104.22.168: AIP, AIP Amendment, AIP Supplement and AIC shall be provided on paper and/or as an electronic document.
Annex 15 §22.214.171.124: Note.— A page pocket may be used in the AIP to include the Aerodrome Terrain and Obstacle Chart — ICAO (Electronic) on appropriate electronic media.
PANS-AIM §126.96.36.199 (abridged):
Only amended pages are re-printed ("loose-leaf")
Changes are marked by a vertical line or an arrow
Page numbers restart at each subsection
Maximum A4 paper format, but sheets may be folded to A4
AIP SUPs are printed on yellow paper
AICs come from a rainbow (white, yellow, pink, mauve, green)
Interestingly, paper AIPs may include an electronic media for providing some aeronautical information. Paper is not enough any more!
Annex 15 opens the door to electronic aeronautical information since the year 2000. ICAO refers to electronic AIP since 2009 and its Roadmap for the Transition from AIS to AIM. Since 2018, Annex 15 clearly offers the option of publishing the AIP only in electronic format. Several States didn't wait for this green light, actually.
Annex 15 §188.8.131.52: AIP, AIP Amendments, AIP Supplements and AIC shall be made available by the most expeditious means.
Most expeditious, really? But how about costs? Here is a quick survey on delivery services for a parcel of 2kg between Nilacandi's 3 offices:
Slowest: National post office, 10-20 days, 42€ (the cheapest)
Fast: Parcel delivery company, 10-11 days, 65€
Faster: Parcel delivery company, 6-7 days, 80€
Most expeditious: Personal delivery by an employee, 24 hours, 1000€ (economy flight)
AIS offices around the world use national postal service, which is not exactly the most expeditious mean.
Annex 15 §184.108.40.206 The aeronautical information publication (AIP) shall be amended or reissued at such regular intervals as may be necessary to keep it up to date.
As a matter of fact, AIP readers need to keep up-to-date with AIP Amendments as fast as possible. With paper AIP, some data users receive AIP AMDTs too late. We need electronic distribution to improve publication delays.
Now that we know the main benefit of an electronic AIP (immediate distribution), and considering that Annex 15 allows for it, what are the specific requirements related to an electronic AIP?
First of all, the reader will note that ICAO does not define what an electronic AIP is. Let's use common sense: an eAIP is an AIP document, made available electronically for consultation on a computer, for example. What are ICAO's requirements for an eAIP?
Annex 15 §220.127.116.11 (summarised) Recommendation.— The eAIP should allow for displaying on electronic devices and printing on paper.
Annex 15 §18.104.22.168 Recommendation.— Electronic aeronautical charts should be provided based on digital databases and the use of geographic information systems.
PANS-AIM has a little bit more on eAIP:
PANS-AIM §5.2.4 Electronic AIP (summarised):
22.214.171.124: AIP and eAIP contents shall be the same, with the same structure.
126.96.36.199 eAIP shall include printable files
188.8.131.52 Changes shall be annotated in the margin or by a comparison mechanism.
Interesting to note that the printability of the eAIP is a recommendation in Annex 15 but a "shall" in PANS-AIM. I would consider that Annex 15 takes precedence here. Annex 15 thus opens the door to the next generation of eAIP, which will be electronic only. More about this in a future article.
Strangely, ICAO uses Annex 15 rather than Annex 4 for recommending how to produce electronic charts. Moreover, ICAO does not make the same recommendation of using databases for producing AIP text and tables, but let me come back to this below.
PANS-AIM §184.108.40.206 The eAIP should be available on CD, DVD or other media and/or online on the Internet.
Note.— Guidance material on the use of the Internet is contained in Guidelines on the Use of the Public Internet for Aeronautical Applications (Doc 9855).
The eAIP does not need to be distributed physically, which would defeat the purpose of immediate distribution. An eAIP distributed on DVD by the post would still arrive late.
The reference to Doc 9855 is important: AIS should avoid using a generic Internet Service Provider (ISP) and rather use an Internet Aviation Service Provider (IASP).
As we can see, there are not many requirements specific to eAIP in Annex 15 and PANS-AIM. All we can conclude is that an eAIP according to ICAO is an AIP that can be read on screen. An AIP document distributed in PDF format is compliant. More compliance details are expected in the future version of ICAO Doc 8126, expected in 2021.
Eurocontrol trusted me to develop the eAIP toolbox and documentation from 2001 to 2012, under the supervision of Mr Eddy Porosnicu (the "father" of AIXM).
We released the first ever international standard for an electronic AIP in 2003. The same year, Belgocontrol (now Skeyes) was the first ANSP to publish a Eurocontrol-compliant eAIP for operational use, covering Belgium and Luxembourg.
In its extensive eAIP documentation, Eurocontrol proposed 2 clear definitions:
Electronic AIP: an AIP designed for the screen, with interactive, modern functionality.
Digital AIP: is an AIP converted to PDF or other common format suitable for on-screen display but not specially designed for it.
Features of the Eurocontrol eAIP
The Eurocontrol eAIP brings a number of advantages compared to a PDF AIP:
Most importantly, changes can be precisely marked.
On both paper and PDF AIP, with just a vertical bar along a data-rich line of text, one needs the previous revision of the page to find out what exactly has changed. Problem is, the user was instructed to remove that previous revision.
With the Eurocontrol eAIP, AIP editors can choose to show exactly what has changed. On the right, we see that the seconds of arc in STW DVOR/DME have changed, and nothing else on that line.
We can optionally display the previous revision of the text beside the new one ( with strike-through styling) by ticking the checkbox on the upper-right corner. We also have a precise and exhaustive list of changes in the AMDT tab on the left side.
Here's a short list of other useful features, among others:
The table of contents is always visible and includes hyperlinks, making it easy to navigate within the AIP
The checklists of AIP SUP and of AIC are just one click away and have links to the documents
Supplements offer a link to the supplemented AIP sections
Readers can search for text in the AIP: a tiny Google for AIP, SUP and AIC content
The latest version is the Eurocontrol eAIP 2.1, released in 2012. Until version 2.0, the specification was coming with extensive documentation and a toolbox. The eAIP toolbox is a set of Open Source software (free to use and modify, for fun and profit) for computer enthusiasts and of course the industry. This software can validate an eAIP document against a set of standard rules, publish it in HTML (the eAIP Web site) and PDF (for printing). While reading PANS-AIM, one can feel the scent of the Eurocontrol eAIP in between the lines. Well, at least I do. ☺
It is anticipated that the next release of ICAO Document 8126 describes the functionality of the Eurocontrol eAIP as a means of compliance to the concept of ICAO eAIP.
Annex 15 and PANS-AIM make no reference whatsoever to a digital AIP, but the terms have been used together in some ICAO documents, notably in AIS to AIM transition tables, where digital AIP is defined as an "electronic AIP generated from a digital database of aeronautical information". As we have seen, Annex 15 does not require an electronic AIP to be generated from a database. But in practice, it is highly recommended, and even for a paper AIP. Generating an AIP from an AIS database allows 50% to 90% of the AIP to be generated automatically, depending on the number of aerodromes and charts published.
Annex 15 and PANS-AIM go further as to let large pans of the AIP omitted, as long as a dataset is provided. Is this the beginning of the end for the AIP? It will shrink as datasets grow.
Electronic or Digital?
Electronic devices are different from digital ones: electronic devices are based on low voltage, transistors and integrated circuits while digital devices are simply using digits. A digital clock shows the time using digits and is not necessarily electronic even if most are.
What's the difference between an electronic AIP and a digital AIP? From an English point of view, there is none. An electronic document is a digital document and vice versa. When it comes to documents, the semantic difference doesn't matter: we understand digital as "being made of digits", referring to the digits used to encode the document on a computer system.
In fact, the difference between electronic and digital documents depends on conventions. For example, an electronic signature is defined as any kind of signature that can be processed by software, including an image of a hand-drawn signature. Digital signatures is defined by industry players as an electronic signature that uses cryptography to encode a signature. A digital signature is not the image of a drawing but a long number, hence digital. A counter-example is "digitalisation", the process of scanning a paper document to store, read and process it in a computer system. A digital document can just be an electronic image of a paper document.
We humans make our own conventions. Eurocontrol proposed one 15 years ago. ICAO proposed a different one 10 years ago. Let's follow ICAO's guidance. What matters at the end of the day, is that AIP readers get their fresh data as soon as it is published.
CreditsAIP Library at Eurocontrol © Benoit Maisonny
AIP Library in Yangon AIS office © Benoit Maisonny