One way to avoid mid-air surprises is to know where likely traffic is coming from. That’s easier said than done outside your local area. It’s really tough for new pilots still learning the ropes.
When I was a student in the mid-1960s, I already knew the FAA said to watch out around VORs, where traffic converges. But on a solo stint out to a “distant” VOR, the lesson came in spades.
Over the Modena VOR southwest of Philly International, I came face-to-face with a Navy R5D (Douglas DC-4) arriving for the transition to NAS Willow Grove. Nothing I would learn for years alerted me to transition routes and instrument approaches not on VFR sectionals, let alone arrival flows using gateway or “corner post” VORs.
In the new omni-range era, the VFR chart user now had less appreciation for the IFR route structure. Before then, the old low-frequency radio ranges had four (and just four) nicely depicted courses often associated with an instrument approach. Perhaps awareness later increased as more pilots earned an instrument rating.
And then FAA Terminal Area charts later adopted informative arrows depicting major arrival/departure flows. But in the 1960s and early 1970s, this young pilot was fat, dumb and happy.
This 1944 chart for LA (above), for instance, shows numerous four-course navigation ranges also used for airport approaches. How clearly they depict areas of heavy traffic! Even today, a young VFR pilot might gain this detailed insight only from IFR approach plates and/or instructor knowledge.
Admittedly, today’s Class B and Class C airspace moots this concern around our biggest hubs. Concentrated heavy/high-speed traffic descends or climbs within protected airspace. But non-hub airports and military bases can still have approaches and transitions unknown to the VFR pilot.
This 1942 radio navigation chart (below) shows how four-course ranges served instrument approaches into major Indiana airports (shown as small starbursts.) The A and N sectors of each range are indicated by letter and Morse Code notation.
The four courses were generated by directional radio signals emitted from a low-frequency AM range station. One signal radiated in one bi-directional pattern (for instance, the northwest and southeast quadrants for Lafayette, Indiana.) That signal would transmit a repetitive Morse Code “A” or dot-dash.
Another signal radiated into the opposite quadrants (like Lafayette’s southwest and northeast) and carried a Morse “N” or dash-dot.
The two directionally radiated patterns overlapped along four lines, creating the charted courses labeled as to compass heading.
If on a course line, pilots would hear a constant tone as the Morse “A” and Morse “N” combined. If off-course, either the “A” or “N” would re-emerge depending on right or left deviation into that respective quadrant.
There’s more to it, but that’s basically how pilots “flew the beam” pre-VOR.
In contrast, the new Visual Omni Range served up on/off-course indications visually (on the VOR instrument) and not as sounds in a pilot’s headphones.)
But as VORs and ILSs replaced four-course ranges and chart congestion increased, the VFR pilot lost insight into where approach traffic might be. And even in the mid-1980s, a now-more-experienced IFR pilot like me got caught in the trap!
It happened when I took my new mother-in-law up in the Bonanza. We flew over her house in Port Norris, a little New Jersey fishing village on the Delaware Bay. Then we flew south over the Bay to find my oysterman father-in-law aboard his 65-foot working schooner, the A.J. Meerwald. (The old ship captain was less than impressed. He had been buzzed many times before and paid us no mind.)
But what impressed us FAST — after a climbing turn back north to 2000 — was a windshield-full of Air Force C-5 at 12 o’clock. It was bigger than anything I’d seen! Luckily, we missed.
Why did it happen? Clearly, my head was in New Jersey, at the state’s remotest southern reaches at that! I didn’t grasp the big picture.
On the Delaware side of the bay was Dover AFB, the East Coast’s largest aerial port. Not on my sectional were Dover’s ILS 19 and TACAN 19 approaches, whose transition routes were from the north at 2,000 feet! One from New Jersey’s Cedar Lake VORTAC corresponded with our aerial joyride near Port Norris.
This chart segment gives you some idea of the geography involved. Delaware is in the extreme southwest corner. Lacking info on Dover AFB approaches, I assumed the operative guidance for the area was in the box advising, “Contact Atlantic City Approach on 124.6 within 20 miles.” But I wasn’t within 20 miles of ACY, so I didn’t.
Deceptively, it was another charted warning – placed farther south — that I should have heeded: “Caution: High-Speed and Transport-Category Aircraft Operating within 25 NM of Dover AFB. Dover Approach 132.425.” I was within 25 nm of DAFB but “my head” was in New Jersey. And hey, that warning box was farther south on the chart than I was flying. It didn’t click with me.
Operating anywhere near a major airport or military base, look out! Get familiar with their IFR approaches and transition routes.
Dover AFB has a special pamphlet on heavy/fast jet routes in the area. One illustration supposes head-to-head traffic closing at 360 knots (the Air Force at 250, you at 110.) If you’re unprepared, recognition and reaction time is a full 12 seconds. Yet at the distance you might notice the traffic (if not scanning,) impact occurs in just 10.
I believe most air bases now have similar guidance. Get a copy from a base or wing safety office. The one from the 436th Airlift Wing at Dover reveals that their airspace extends almost to Millville, New Jersey. That’s far inland and north of my VFR chart’s warning box advising Atlantic City (N.J.) radar services. Tricky!
Dover Approach when anywhere within 25 nm
of this remote but busy airbase.
One more thing: On that same Washington Sectional is a Military Training Route near the eastern edge of Delaware Bay. Not unusual. Low-level MTRs are often located in isolated or over-water areas that light GA usually avoids. If you’re going to be playing around near such areas, check your chart!
Also be “heads-up” for unique landmarks, like power plant cooling towers, that may be used as simulated targets or low-level navigation turn-points.
Now I know that Dover AFB recommends flying above 1,500 near this MTR since Air Guard A-10s from Baltimore are down low practicing tactical navigation. They have the ejection seats, survival gear and turbine engines to be ultra-low, fast and “feet wet.”
I found that out in the L-16 while put-putting the Bay coastline back from remote Cape May, New Jersey. Fortunately, I heeded the MTR, gave up my sightseeing and climbed to 1,000. Minutes later, an A-10 whizzed below at several hundred knots, likely too busy to spot a little antique two-seater doing just 70!
So whether you’re flying a glass cockpit or using paper charts, keep your eyes outside and actively scanning – not focused on a moving map or chart. That you should have done in pre-flight planning.
Map study and resulting “big picture” thinking can alert you to what’s not explicit on your VFR chart. And that’s a head start towards greater situational awareness.
© Drew Steketee 2014 All Rights Reserved
Freedom to know many thank sir
Being mindful of the MTRs is very important. GA on MTRs was always a concern to me when I flew B-52s. We flew at speeds 325 to 390 KIAS on low level training routes at altitudes of 400 to 1000 AGL. The time to see and avoid was down to 5 to 7 seconds. B-1s fly MTRs in excess of 500 KIAS with less time. The best advice I give fellow GA pilots is to climb and pass over 1500 to 2000 AGL within 4 miles of the depicted route on sectionals.
Excellent article!