Aviator Articles

March 12, 2025

Trusting the aviation data in the box: What you need to know

How more than half a million data changes get to your front panel every year

Ever wonder how all that navigation data gets into the avionics in your aircraft?

Pilots and planners punch in flight plans, enter routes, and select alternate airports, but probably don’t give much thought to what went into getting all those ones and zeros front and center on the flight deck. Aeronautical data is certainly not the most exciting part of piloting an aircraft at incredible speeds high above the earth, but it suddenly becomes your lifeline when you’re in the soup with low fuel and need to divert to an alternate airport. Nothing is more important than trusting the data in the box. So how can you trust the data is accurate? Who are all the people behind this?

 

Aviation data source providers

First, there are the source providers. These are all the civil and defense aeronautical authorities from around the world such as the Federal Aviation Administration (FAA) in the U.S. or European Union Aviation Safety Agency (EASA) in Europe. There’s a lot of them – 246 to be exact from 195 nations. Why are there more providers than nations? Because in some nations there are multiple agencies. For example, in the United States the FAA and the Department of Defense provide source data across the civil and military domains.

Aviation data processors

Second, there are data processors who take the raw source information and produce a formatted database file compliant with industry standards. Jeppesen is one company that has pioneered the navigation data production process over the last 50 years.

Aviation data OEM packers

Lastly, the avionics manufacturer, or Original Equipment Manufacturer (OEM), will take the standardized data and re-format it again into a binary file (called packing the data) for use in their proprietary software and avionics equipment. One quick go-back before taking a peek behind the curtain. While data processors is the term I used to describe the folks who turn raw source data into a formatted data set, it is a rather simplistic term that deserves some context. The resources, personnel, and tools required to process and produce formatted navigation data for a specific regional area demand a significant and monumental effort. But at a global level, it takes an entire village with decades of experience to process and maintain a database that contains over two million data records.

At Jeppesen, nearly 30% of the workforce, or almost 1,000 employees, are dedicated to global data management and support.

How aviation data is processed

So, how does all that data get from any one of 246 source providers around the world into your flight deck? I’d like to walk you through a day in the life of a piece of source data and how it gets transformed from its raw, state-published source into a finished data file ready to be loaded in your aircraft. A piece of source data can be a change in a single value such as a frequency change, or it can be an entire document with lots of changes. For our story, we’ll say this piece of source data is a revised localizer frequency that’s being changed to 110.50 MHz as a result of newly installed airport equipment.

The four phases in the data production process:

  1. Acquire
  2. Review
  3. Maintain
  4. Distribute

Seems like a simple concept. But like I mentioned before, it takes an entire village to accomplish this process and achieve the most critical component of any navigation data product – trust. Your trust that the largest and most accurate aeronautical database is available for your flight deck.

1. Acquire the source data

All new source data, whether it’s new or a revision to existing data, begins by being published in official state documentation in a variety of formats that are ultimately compiled into the Aeronautical Information Publication (AIP). The first step is it must be acquired. Someone at the data processor company has to acquire it, which typically happens through source subscriptions and reaching out to aeronautical authorities around the world.

There are 246 data source providers from 195 countries providing 47,000 pieces of data in 24 different languages every 28 days.

Source data comes in many different formats.

That’s a huge number of publications coming from 246 global providers. Imagine getting 246 magazine subscriptions at your door every 28 days but instead of magazines they are encyclopedia volumes filled with tens of thousands of changes that must be processed before every recurring 28-day deadline (standard update cycle for aeronautical data). Of course, most of the source publications are digital but it’s still a monumental amount of data typically to the tune of 47,000 pieces of source every month, or more than 500,000 pieces annually. Plus, all that source data isn’t published in a standard format, and it comes in 24 different languages. What happens if there are questions or discrepancies?

A healthy relationship with source providers and clear channels of communication to clarify any discrepancies is vital. This critical role is typically held by a team of experienced source liaisons. This team has long-standing relationships with aeronautical authorities around the world and they can quickly resolve any discrepancies found in the source documents.

2. Review the data

The source data will now go through a rigorous review and verification process because it first must earn the trust of the entire data processing and production department before it gets the final stamp of quality. Our example of a new terminal navaid frequency will be put under a microscope to be reviewed and evaluated not just once, but many times before it completes the process.

Once the new data is loaded into a source repository it’s then reviewed to make sure it’s valid or “fit for use”. This means the source documents are evaluated for completeness, i.e., if the source provider stated there are 100 pages for a particular update cycle but only 95 pages were received, then that’s a problem and it must be resolved. The source is also checked to ensure it’s visible and legible in the case of scanned documents. With so many source documents received in different formats and languages, this is a crucial step in the process.

 

Data specialists apply over 10,000 business rules when reviewing source data.

3. Maintain the data

After the source data is acquired and reviewed, the data revision is ready for the next phase where it will be added to the master aviation database. This is called the data maintenance phase. The first step the data maintenance team takes is, believe it or not, another in-depth review of the source changes.

A review is done to compare the new source data against the previous source data. This ensures all changes are captured with every new source publication. The source information for our example localizer frequency change may contain other changes such as location coordinates or a new bearing direction. It all must be captured, reviewed and processed.

A common sense, or sanity check is also performed on the source data. Let’s say the source for a revised localizer frequency is reviewed and the new frequency is shown in the source document as 101.50 MHz. Oops, that doesn’t work. That’s an FM radio station frequency probably broadcasting smooth jazz music.

While that might help lower your stress level in the terminal environment , it’s not going to help you execute the precision approach procedure. It was most likely a typo made by the source originator that should have listed it as 110.50 MHz. This is called a source anomaly, and it must be resolved with the source provider.

This doesn’t happen that often, right?

Actually, source anomaly happens about 2,500 times every year . That’s almost 200 source anomalies to resolve every 28-day cycle.

Data experts translate, analyze, validate and verify source data.

 

Data specialists also review the new change to determine how it will impact other components in the database. Our localizer frequency change example could potentially affect airport records, terminal procedure records and enroute records to name a few. It’s not just one frequency change entry and done. All the database records linked to that frequency must be checked and verified.

Finally, the new data is added or ‘coded’ into the master database. After all that work, it’s done, right? No, not yet. Edits are reviewed and any errors are corrected with the new data entries. This step is performed with workflow tools and a huge library of Quality Check (QC) business rules. Jeppesen has over 10,000 business rules as part of the QC process.

At this point in the process, our example piece of source data has been translated, analyzed, validated and verified multiple times. Surely, this new localizer frequency data has been through enough. But what if, as a final verification step, it was entered again by a different person using the original source document? Not a cross check, not a visual comparison, not just another review, but rather repeating the action of entering the new data as it was initially entered from the source publication. This is exactly part of the final verification process performed by Jeppesen data experts depending on the criticality of the data. It’s a very effective process to avoid any potential data entry errors.

After what seems like an eternally long production process, the data is finally committed to the master aviation database. The data maintenance team can now take a quick breather and get a good night’s sleep before it starts all over again.

4. Distribute the data

The final phase is all that aeronautical data, over 2 million records, must now be extracted and distributed to aviation operations and users around the world. This happens every 28 days per the regulatory Aeronautical Information Regulation and Control (AIRAC) cycle calendar. Depending on the year, there are typically 13 AIRAC cycle updates annually.

The process starts with a snapshot of the master database that is taken and run through additional QC evaluations to resolve any errors before it’s formatted to the final ARINC-424 standard (Aeronautical Radio Incorporated). This international standard is defined by the International Civil Aviation Organization (ICAO), headquartered in Montreal, Canada. All that source data from hundreds of different providers using different standards and formats is now compiled into one industry-wide standard format.

 

 

However, each avionics OEM also requires the data sets to be formatted through their proprietary processing software. This is called packing the data and it can be performed by data providers such as Jeppesen (in agreement with some OEMs), by the OEM itself, or by a third-party data packing company. The data packing process takes into consideration avionics and aircraft specific requirements which allow the ARINC 424 data to be packaged in a way that supports the aircraft mission needs.  Once the data is packed, then it is finally distributed to end users (you) and loaded into the avionics panel, typically a Flight Management System box, Multi-Function Display or other devices such as Electronic Flight Bags (EFB). There are several companies that provide database products in different regions of the world. Jeppesen stands out as the leader with over 50-years of producing the largest and most accurate global data products. In fact, the first ever FMS database was created by Jeppesen in 1973 through an effort lead by a former employee, Jim Terpstra. Check out this video about the beginning of Jeppesen NavData.
New frequency appears on the primary flight display.

 

It really does take a village

Our story’s example of a localizer frequency change to 110.50 MHz is now loaded in your flight deck avionics and ready to be your lifeline when you need it most. A simple keystroke change in a database took a village of nearly 1,000 people to ensure the correct data reached your panel. The finished database product has earned the stamp of quality by all those people who helped make it possible so you can trust the data in the box.