Have You Checked Your Data?

H. Dean Chamberlain
Reprinted with permission from FAA Aviation News

As flying evolves, we constantly add items to our list of things to do before we can go flying. We have to check weather. We have to check our paperwork——current medical, current flight review, required number of takeoff and landings if we want to be pilot in command and carry passengers, instrument currency, and the list goes on. With the advent of global positioning (GPS), we now have to add other piece of information to our list of things to check. We now have to ask Flight Service for GPS Notices to Airmen (NOTAMs) if we plan on using GPS in flight. Please note: Flight Service does not provide GPS NOTAMs without being asked. Add Receiver Autonomous Integrity Monitoring (RAIM) availability along your route and destination to your required list of information if you are planning on flying a GPS approach, for example.

But if you are using an FAA-approved, installed instrument flight rules (IFR) capable GPS in your aircraft, when was the last time you reviewed your data service provider’s notification process to verify the accuracy of the service provider’s data? Have you ever checked with your data service provider to verify the accuracy of the data you are trusting for your flight’s safety?

This question recently came up in a discussion, when an aviation safety inspector in the General Aviation and Commercial Division commented on a recent change to the Aeronautical Information Manual (AIM). The change, AIM Chap.1, Para. 1-1-19(f) (1) (c) (1), referred to the need for IFR pilots to review important safety information before a flight using an IFR GPS unit. Then AIM Chap.1, Para. 1-1-19(f) (1) (c) (1) (b) says to “Verify that the database provider has not published a notice limiting the use of the specific waypoint or procedure.”

The point of the discussion was how many IFR pilots check all available information required for a safe flight while using GPS. Checking for any FAA GPS NOTAMS is one check. The RAIM check is another. Having Wide Area Augmentation System (WAAS) at the time of an approach is a third. In our discussion, we noted the most common check was for the current data cycle dates. Maybe the reason the cycle check is always done is because it is one of the automatic checks the GPS unit makes when turned on. Pilots are then asked to confirm that currency by manually pushing the enter button or its functional equivalent. But no one was willing to say how many IFR pilots routinely check the accuracy of the IFR data base installed in their GPS units. Data accuracy is not the same as cycle currency.

The regulatory basis for requiring a pilot to check all available information before a flight is Title 14 Code of Federal Regulation (CFR) section 91.103, Preflight action. The AIM then reminds pilots of that requirement. But the AIM does not tell how or where a pilot can find the information regarding data accuracy.

The short answer is to check with your data source provider. Having said that, if your data source provider is Jeppesen®, your search is easy. Jeppesen®, one of the major data and chart providers in the world, provides its own alerting service to warn those who use its services of problems. One of its services, NavData® Alert, is one of the means used to warn users. As noted on the NavData® Alert, the service is provided to avionics companies and other raw data users, and airlines receiving data direct from Jeppesen®. The information is not provided to individual pilots.

The good news is Jeppesen® provides NavData® Alert information on its Internet site at <www.jeppesen.com>. Anyone can review the Jeppesen® information. A review of the site included an “URGENT” NavData® Alert about incorrect coordinates for a waypoint. In addition to its NavData® Alert, Jeppesen® publishes its own weekly NavData® NOTAMs service. It also produces Jeppesen® NavData® Notices. If your data source provider is Jeppesen ®, you now know how to find its data related pages.

If your data source is not Jeppesen ®, you should review the information provided by your GPS equipment manufacturer about how to find updated information about your data source provider and how to determine if in fact you have “…all available information concerning that flight.”