![]() We have become accustomed to flying point-to-point direct, often far from the nearest navigable VOR or airway. While we had experienced no immediate danger, the event opened my eyes to the perils of lost GPS. Clearing skies allowed us to land in visual conditions. For backup, I reverted to time-honored navigation techniques: triangulating our position using VOR radials, and peering between clouds for charted landmarks. The outage continued at least 30 more minutes while ATC vectored us to our destination. Losing those comfy moving maps was momentarily disorienting, and I’m glad I wasn’t shooting an instrument approach at the time. But even decades of navigating by VORs, pilotage, and dead reckoning couldn’t prepare me for the shock of my entire panel flipping out at once. Obviously the same GPS signal drives all the “failed” equipment, so it made sense they would drop guidance simultaneously. (Oddly, jamming was not listed in today’s notams.) Aha! To my limited relief the problem was military GPS jamming, not expensive avionics problems. Now other pilots began reporting lost GPS, and I noted that the position symbol on my tablet computer had stopped moving. After I reported the failure, the controller assigned radar vectors around the restricted areas. ![]() He then cleared me to an intersection to bypass nearby White Sands Missile Range restricted airspace, but the GPS died as I entered the fix into my navigator. My first hint of trouble was when our controller asked, “Are you ADS-B equipped?” That seemed odd, as he had long been tracking us. This route spans a huge swath of military airspace that, when active, cannot be crossed IFR, so I’d filed a circuitous route over Socorro, New Mexico. Today, however, layered clouds shrouded the mountainous central portion of the route, so I’d filed under instrument flight rules (IFR). Normally we make the two-and-a-half-hour journey straight-line VFR. I was flying Jean from Flagstaff to El Paso for tennis sectionals. Next came an “ADS-B (Out) inoperative” warning, meaning our transponder had stopped transmitting our GPS coordinates to air traffic control (ATC). My multifunction display restarted itself with a “maintenance required” alert. Seconds after that initial warning, my primary flight display announced, “GPS reversion mode: for emergency use only” (but displayed no position). Jean and I were bouncing through clouds on instruments at 12,000 feet, over trackless mountains along the remote Arizona-New Mexico border.
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