By Howard Deevers
M O N stands for: Minimum Operating Network. Pilots will find this MON inside a shaded box, on the Low En Route Charts at airports that are considered Minimum Operating Network airports and VOR's. This system was instituted by the FAA in 2016. No big announcement was made about it that I can remember.
With more and more pilots going to GPS navigation, the FAA realized that the possibility of a GPS shutdown, or failure, could be a disaster. Imagine that you are flying IFR on a cross-country flight relying on your GPS equipment in your panel, or even on your lap, and suddenly it is not there, or at least not correct and giving you error messages.
I have been enjoying GPS navigation for many years. It gives me the ability to go “direct” to my destination, in most cases. Only once early on, did I experience a problem with GPS navigation. On a flight from Pittsburgh (AGC) to Charleston, WV (CHW), my GPS navigator went blank. I was in actual IFR conditions at the time, and very new to GPS navigation at that time. I was navigating by VOR to CHW, so when the GPS went away, I still knew where I was and where I was going. I tried to reset the GPS, but it took a while to get the signal back. By that time, I was already in VFR conditions and close to my destination. The iPad did not exist at that time.
When the FAA started to retire older VORs, and pilots started to rely on GPS more, it became apparent that a problem could develop. GPS is subject of interference from solar flares, jamming, and other technical problems. The MON became the backup for such problems. The AIM devotes almost 2 pages to explaining the MON, with several footnotes such as: IF you are VFR when a problem develops, stay VFR, and find a place to land.
You will not find MON airports or VORs on VFR charts, or on Hi altitude IFR charts. They only show up on the Low En Route charts. According to the AIM, you should be within 100 nautical miles of an MON airport. In order to find out more about the use of MON, I called several sources to find out what they know.
First of all, there are no questions on the Instrument Written about MON, that I can find. I called a DPE and asked if he asked questions about the MON during the Oral portion of the IFR flight exam. He said, no. I asked CFII friends if they were teaching anything about the MON. Many did not even know it existed. So, I checked the larger flight schools, such as Embry Riddle, and American Flyers, and yes, they are teaching this in IFR classes, but again, no testing is being done on the subject. What does Air Traffic Control know about MON and how are they trained to use it? I called my grandson, a Controller at Chicago Center, and asked if he knew about MON? He said yes, he did know about it. I asked if the FAA was giving any special training to ATC about MON in the event of a GPS outage. To this he said, No. They know about it, and where the MON airports are but are not given any special training for GPS outages at this time. His comment was that ATC would vector aircraft to an airport in such an event by radar.
Several things in the AIM give advice on how to use the MON in the event of a GPS outage. If you are on an IFR flight and in VFR conditions, stay in VFR flight conditions. Instrument pilots know that regulations require enough fuel to fly to the intended destination, complete an approach, do a missed approach and proceed to an alternate that you file, and hold for 45 minutes. There are no regulations about fuel requirements for IFR and the MON, but the AIM suggests that careful fuel planning should be a part of any IFR or cross-country flight planning. IF such an event as a GPS outage should occur, it would be the PIC responsibility to estimate how much fuel was on board, and if the plane could make that MON location and do an approach. I guess the bottom line is that we hope this never happens, but it is comforting to know that some plan is in place just in case that GPS goes dark.
Could this be considered an Emergency? I would think so, and ATC would vector you to a MON location where you could complete an instrument approach and make a safe landing. Of course, in such an event ATC is likely to be overloaded with Emergencies, and they would likely have some issues to deal with. The closest thing I can think of to this would be the terrorist attacks on 911 when all air traffic was ordered to land as soon as practical so the government could have more control over air traffic at that time. It was not just a one-day event. It took weeks and even months before GA was allowed back into the skies.
Want more information on this and other subjects? Come to a safety seminar sponsored by your ARIZONA PILOTS ASSOCIATION and the FAASTeam at a location near you. They are free and do count for the WINGS program. Don't forget to “Bring your Wingman!”