July 31: Global Positioning System (GPS Jamming)

If your flying this could make things interesting

While web surfing the other day I came across an article dated June of 2016 that was interesting because it brought to mind an occurrence that happened to me several years ago when flying a cross country flight from Michigan thru Indian and Illinois.

Now this was quite a few years ago and I was flying Visual Flight Rules (VFR) using compass and landmarks but had my GPS on as a backup. During the flight as I flew thru a Military Operations Area (MOA) my GPS lost all signal reference and was totally out of service.  At that time this was an unexpected occurrence but now days it may not be that unusual for that to happen.

The article I read about stated that “FAA Warns of GPS Outages This Month During Mysterious Tests on the West Coast”.  Very interesting I thought!

 Starting today, it appears the US military will be testing a device or devices that will potentially jam GPS signals for six hours each day.  

 The FAA issued an advisory warning pilots on Saturday that global positioning systems (GPS) could be unreliable during six different days this month, primarily in the Southwestern United States. The testing will be centered on China Lake, California—home to the Navy’s 1.1 million- acre Naval Air Weapons Center in the Mojave Desert.

It stated that the testing would be on June 7, 9, 21, 23, 28, and 30th with the GPS interference testing taking place between 9:30 am and 3:30 pm Pacific time. But it noted that if you’re on the ground, you probably won’t notice interference.

Now last month as I was checking out Notice to Airmen (NOTAMS) & Temporary Flight Restriction (TFR’s) prior to flying I came across the following “NOTC7933 – Flight Advisory GPS Interference Testing, August 02-15, 2018 Camp Grayling, MI.”

Now this month (August) Military Training is a routine part of the flying season in Alaska.  Sporting the largest contiguous complex of special use airspace in the country , military planners announced the dates of four Red Flag exercises over the coming months.  The thing that is a little different is that each of these 10 day exercises this year will include “GPS testing” where military forces on the ground will jam the GPS signal from participating aircraft, to test this real-world threat now faced by our armed forces.  The challenge is, it may also impact civil aircraft, outside the boundaries of the MOA’s and Restricted Areas used by the military aircraft. On the dates within these ranges that GPS testing is planned, NOTAM’s will be issued at least 72 hours in advance, with defined date and time ranges that will limit the testing.

Bottom line is If you are operating IFR, remembering to tune in the VOR and ILS frequencies from our “legacy” equipment.  For those of us that fly VFR, it might be a good idea to make a long flight flight or two this summer just navigating with a good old paper chart and compass, if your addicted to using your GPS, and re-discovering the joys of pilotage.

Definitions:

Military Operations Area (MOA) is airspace designated to separate or segregate military activities from Instrument Flight Rules (IFR) traffic and to identify for Visual Flight Rules (VFR) traffic where these activities are conducted.

During active times,  MOA’s often have different types of aircraft performing maneuvers at different air speeds and have  active and inactive hours, also known as “hot” and “cold” times. Check with a flight service specialist before you fly to find out whether the MOA is active or not.  Note that aircraft in MOA’s are sometimes granted permission to fly “lights out” training missions. Military aircraft do not have airspeed restrictions within MOA limits and the  250-knot limit for commercial aircraft, for example, does not apply to military aircraft in MOAs.

Notice to Airmen (NOTAM) is a notice filed with an aviation authority to alert aircraft pilots of potential hazards along a flight route or at a location that could affect the safety of the flight. NOTAM’s are unclassified notices or advisories concerning the establishment, conditions or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel and systems concerned with flight operations.

Temporary Flight Restriction (TFR) is a type of Notices to Airmen (NOTAM).  A TFR defines an area restricted to air travel due to a hazardous condition, a special event, or a general warning for the entire FAA airspace. The text of the actual TFR contains the fine points of the restriction.