Sometimes we feel like Chicken Little. "The sky is falling! The sky is falling!" Only in our case we worry about the helicopter falling. And we feel obligated to do our best to prevent this...
Not long ago, an F-16 straight-up ran-over a small aircraft between Charleston, SC and Shaw Air Force Base. It wasn't a mid-air collision, it was a smackdown in the sky. One can only hope that the folks in the Cessna were knocked immediately senseless and weren't awake for their final approach.
The folks in the Cessna never saw the jet coming, for good reason. "Fast-Movers" or military jet aircraft on "military training routes" are not subject to the national aviation speed limit of 250 knots (below 10,000 feet above mean sea level), which is still fast in our eyes, and can be screaming across the tree-tops at speeds up to 420 knots.
Consider that speed for a second. 420 knots equates to 7 miles a minute, or a full nautical mile traveled in 8.5 seconds. So you glance out the window and see a distant speck which might easily be a bird, look inside to check on your patient or your position...and then...
Now we don't want to sound alarmist, or be overly dramatic, or create a solution looking for a problem; but we also didn't know that freezing rain dropping through the engine inlet barrier filter on an Astar could create invisible icicles that could drop into the engine and cause it to quit - until it happened. We like to consider hazards before the crash vice after.
So, what about these "military training routes?"
Military Training Routes are divided into Instrument Routes (IR), and Visual Routes (VR). Each route is identified by either of these two letters, followed by either four digits for routes below 1,500 feet above ground level, or three digits for routes extending for at least one leg above 1,500 ft AGL. (ei: VR-1056). The difference between the IR and VR routes is that IR routes are flown under Air Traffic Control, while VR routes are not.(Wikipedia)
Are there any in our vicinity? Probably.
Do military aircraft fly on these routes at night? Yes. If they are flying in formation, at least the trail aircraft should have lit position lights and anti-collision strobes on. The leading aircraft(s) may be flying "dark" to avoid shutting down trail's goggles.
Are they active while we are flying? Maybe. They call into and out of routes on ATC or flight service station frequencies 122.2 is the universal/common flight service station frequency. We have heard fast-movers call into a route on this.. Flight-following with and being on some ATC radar will help. Even an air-route-traffic-control-center controller will flight-follow with you if she isn't too busy and you are high enough for her radar to see you.
How far from the line on the chart might a jet be cooking with kerosene? 5 miles either side. Think Russian Roulette with a barrel 10 miles wide.
Is a military jet pilot on a "IR" or instrument training route even looking outside? Maybe not, he or she may be "heads down." And by-the-way, C-17s use these route too.
Can we deconflict by altitude? Maybe, MTRs with a 4 digit ID are supposed to be flown at less than 1500 feet above the ground. 3 digit routes have at least one segment above 1500 feet. Visual routes can only be used when the ceiling is greater than 3000 feet above the ground.
A good technique might be to pull out a sectional aviation chart at your next briefing and discuss how the routes conflict with the routes YOU routinely fly. And remember, "heads on a swivel when flying."