Ill let AA answer that. Although I can he can be more descriptive.
Didn't know you were a pilot Ryan. We are gonna have to Teamspeak some aviation war stories some time for fun!
For BV, I'll keep it simple:
Here is a NOTAM, Notice to Airman, a procedure the FAA uses as an advisory service for aviation matters, weather, war zones, etc. Very good intel source BTW:
A0369/15 (FDC 5/2817) - SPECIAL NOTICE...DUE TO MILITARY ACTIVITIES ON 1030/1090 MHZ, THE TRAFFIC ALERT AND COLLISION AVOIDANCE SYSTEM (TCAS) AND AUTOMATIC DEPENDENT SYSTEM BROADCAST (ADS- SURVEILLANCE MAY BE UNRELIABLE IN THE AIRSPACE OVER THE STATES OF VIRGINIA, NORTH CAROLINA, SOUTH CAROLINA, GEORGIA, AND FLORIDA, AND EXTENDING APPROXIMATELY 200NM OFFSHORE. PILOTS ARE ADVISED THAT THE TRAFFIC ALERT AND COLLISION AVOIDANCE SYSTEM (TCAS) MAY FAIL TO ESTABLISH TRACKS ON NEARBY AIRCRAFT AND MAY FAIL TO RECEIVE TRAFFIC ALERTS (TA) AND/OR RESOLUTION ADVISORIES (RA). FURTHER, PILOTS ARE ADVISED THAT TRACKS MAY FIRST APPEAR WITHIN CLOSE PROXIMITY TO THEIR AIRCRAFT AND MAY IMMEDIATELY GO INTO TA/RA STATUS. FALSE ALERTS ARE NOT EXPECTED TO BE GENERATED BY THIS MILITARY ACTIVITY AND ANY ALERTS SHALL BE TREATED AS REAL
The two systems referred to are TCAS (Trafffic Collision Avoidance System) and ADS-B (Automatic Dependent Surveillance Broadcast-BTW there are ADS-C,CPDLC, ATC COM, ACARS, AOC which have related functions which seem to be not affected).
Starting with ADS-B, which is for ATC to coordinate with transponder equipped A/C, which virtually all aircraft have, and is mandatory for commercial airliners. This system is diagrammed above and is ground-based integrated with avionics on the planes.
The NOTAM says will be unreliable because it operates on the referenced frequencies. The ADS-B system can be configured for aircraft-to aircraft collision avoidance as well as providing secondary radar targets (virtual, not primary). That's why any manipulation of these freqs can not only make aircraft appear and dissappear for nefarious or offensive purposes, they can be hijacked to display wrong positions of two approaching aircraft and even have rogue voice transmissions.
Now for TCAS. Here is a visual:
TAs are Traffic advisories
RAs are resolution advisories (the computer will interpret whatever input, real or imaginary and make an recommendation)
To save time, I will copy Wikipedia to expalin:
the following points receive emphasis during pilot training:
Do not manoeuver in a direction opposite to that indicated by the RA because this may result in a collision.
Inform the controller of the RA as soon as permitted by flight crew workload after responding to the RA. There is no requirement to make this notification prior to initiating the RA response.
Be alert for the removal of RAs or the weakening of RAs so that deviations from a cleared altitude are minimized.
If possible, comply with the controller's clearance, e.g. turn to intercept an airway or localizer, at the same time as responding to an RA.
When the RA event is completed, promptly return to the previous ATC clearance or instruction or comply with a revised ATC clearance or instruction
Type Text Meaning Required action
TA Traffic; traffic. Intruder near both horizontally and vertically. Attempt visual contact, and be prepared to manoeuvre if an RA occurs.
RA Climb; climb. Intruder will pass below Begin climbing at 1500–2000 ft/min
RA Descend. Descend. Intruder will pass above. Begin descending at 1500–2000 ft/min
RA Increase climb. Intruder will pass just below Climb at 2500 – 3000 ft/min.
RA Increase descent. Intruder will pass just above. Descend at 2500 – 3000 ft/min.
RA Reduce climb. Intruder is probably well below. Climb at a slower rate.
RA Reduce descent. Intruder is probably well above. Descend at a slower rate.
RA Climb; climb now. Intruder that was passing above, will now pass below. Change from a descent to a climb.
RA Descend; descend now. Intruder that was passing below, will now pass above. Change from a climb to a descent.
RA Maintain vertical speed; maintain. Intruder will be avoided if vertical rate is maintained. Maintain current vertical rate.
RA Level off, level off. Intruder considerably away, or weakening of initial RA. Begin to level off.
RA Monitor vertical speed. Intruder ahead in level flight, above or below. Remain in level flight.
RA Crossing. Passing through the intruder's level. Usually added to any other RA. Proceed according to the associated RA.
CC Clear of conflict. Intruder is no longer a threat. Return promptly to previous ATC clearance.
So any interference obviously affects aviation safety. If you plan on flying in the mentioned areas, well at least you know. My concern is for DOD to endanger aviation safety and announce it, this is serious. If it were some defense strategy against the RF, the positioning in the south east coast region and the reported range of only 200 nautical miles, means it will provide little or no protection from aircraft from the northern Atlantic.
So, while I understand training with new toys is required, a much smaller scale on a military range would be much safer. So this is truly unprecedented, and I have no idea why a decision was made to endanger thousands of flights with millions of people for an entire month in one of the busiest areas of the US. The risk of some sort must outweigh the safety somehow is all I can think.