A recent ruling by the NTSB reminds all pilots that VFR only GPSs, no matter how current and sophisticated, may contain erroneous information and may not be relied upon by pilots to avoid airspace incursions.

At issue was an August 5, 2011 incursion into a presidential TFR in the Chicagoland area. The commercial pilot, with over 9000 hours of experience, was operating a C-172 RG with a deluxe, VFR-only GPS with a satellite link to NOTAMS, TFRs, METARS, TAFs, etc.

From the automated AOPA notification system the pilot had learned of the 30 nautical mile presidential TFR in Chicago which the pilot confirmed by reviewing a FAA NOTAM prior to his departure from LaCrosse, Wisconsin to Ashland, Ohio.

The pilot made an intermediary stop in Burlington Wisconsin. Before leaving Burlington the pilot updated his information on the TFR by looking only at the GPS display which depicted a much smaller, 10 mile TFR consistent with TFRs the pilot recognized from prior flights through Chicago.

After departing Burlington the pilot confirmed the satellite link was properly functioning and the TFR displayed was active. Nevertheless, the pilot entered into the presidential TFR. Upon notification from Chicago Approach that he was in the TFR, the pilot stated he was well out of the TFR and photographed his GPS display which showed him thirty miles “outside” the depicted TFR.

As it turned out the size of the TFR was incorrectly depicted on his GPS. The TFR had remained 30 nautical miles and never was reduced in size. The GPS manufacturer admitted, “It appears that the inflight presentation of the TFR that was in effect on that flight was depicted incorrectly.” The FAA initiated an enforcement action.

In finding for the Administrator the NTSB acknowledged the widespread use of GPS devices, but reiterated that VFR GPS displays, even with current and properly functioning FIS, can only be used as a secondary source of information. Sole reliance upon them to avoid airspace, including TFRs, is at the pilot’s peril if that information is erroneous.

The pilot was represented by Philip Prossnitz of Woodstock, Illinois and Charles Barnett of Crystal Lake, Illinois.