The other week, we Florida east coast residents enjoyed a strong, refreshing breeze — welcome tonic after a long summer. The weatherman said it was out of the north, but flags on the beach weren’t parallel to the surf. Reminds me of a grim story from my flying career. Stay tuned. I’m fessing up!
For my kind of flying, I considered myself a better-than-average GA pilot. And that was important, flying as I did for the manufacturers and for AOPA. But that attitude should have been a red flag. Just as all the kids in Lake Wobegon are above average and every driver thinks he or she is better than most, you know statistically that can’t be true.
Despite later opportunities for more flying time and training than most, I have to admit my early learning had weak spots. Not having money to buy modern training materials, some early knowledge came from old Air Force manuals. I was essentially “self-taught” in some things due to scrimping and saving and a couple of substandard instructors.
This gap in knowledge is like an intermittent mechanical fault. You never know when it’s going to crop up. For me, it happened during a 1980s flight from D.C. along Florida’s northeast coast. The problem? I was never terribly sharp on the hemispherical rule; I don’t know why. Perhaps it was the poet in me, thinking flying was just a great freedom. The fewer rules, the better.
Turns out, the hemispherical rule can ruin a fun day. As you know, those cruising westbound (heading 180°-359°) should be at even altitudes (plus 500 for VFR.) Those flying eastbound (000-179) should be at odd alts. My memory aid from a New Jersey point-of-view: All the “even” people were leaving New York; the “odd” people were going there. That works great unless you’re flying close to north and south, the hemispherical rule’s dividing line.
Back to those flags on our Florida beach. It was natural to think, coming out of Washington, that the Florida peninsula runs north-south. And you’re lulled on your way south by coastal courses that can run southwest through the Carolinas. The tricky part starts at Jacksonville. There, the Florida coast bends slightly southeast. That’s why the beach flags display that north wind as slightly off-shore. That’s where north is. And that’s why the major coastal north-south Victor airway is aligned ever-so-slightly southeast. Subtle.
Got it yet? Yep, “Mr. Above Average” left the Georgia coast to follow coast-hugging Victor 3 off-shore of Jacksonville en route to Ormond Beach and Daytona. From the Brunswick (GA) VOR, Victor 3 is aligned just a few degrees east of the dividing line, demanding that I be “odd” at 3,500.
Proof-positive came straight at me in the form of a Mooney at 4,500 feet, 12 O’clock Level. We didn’t miss by much! At least it was fast. But it didn’t go unnoticed. I was flying my boss, General Aviation Manufacturers Association President Ed Stimpson. He would be speaking that evening at Embry Riddle Aeronautical University, where he also served as ERAU chairman. Nice moment to make a mistake.
Stimpson said nothing in the plane. Nothing was said heading to the hotel either or driving to the event. Had I gotten away with it? No. Stimpson began his speech to ERAU flight students with a nice anecdote about how his pilot had just nearly killed him on the way in, courtesy of a windshield-full of Mooney. Ugh! Guilty as charged.
Sure, those course lines off VORs are sometimes hard to read on a congested VFR chart. And beware, one’s mental conception of geography is first learned at ground level and on roads, not in the air.
Civilization along the East Coast, for instance, runs “on a 45” (northeast-southwest) from the mid-Atlantic to New York, not north and south. Heading south along the Carolinas, the coastline runs southwest.And south of Jacksonville, watch out! Interstate 95 (and Victor 3) head ever-so-slightly southeast.
I also must have been holding some right correction along the airway southbound for winds out of the west or to sneak a little closer to shore. Thus, I was further reassured (deceived) that the airway was aligned on the “even” (west) side of 180°. Tricky, eh? A lazy assumption? Yes.
Lesson learned! It was time to update my appreciation for some of the finer points of the hemispherical rule. Remember what they taught us? On airways close to 000-180, watch out!
This frankly wasn’t my last stupid mistake, but I was lucky enough to survive them all and tell you about it. And that was dumb luck, I assure you.
Makes you think….
© 2013 Drew Steketee All Rights Reserved
Years back as I was working on my CFI I was quizzed by my instructor as to why I felt like I had to climb to an even + 500 altitude as I turned my course from 090 to 270 degrees. I simply stated the hemispherical rule as written and told him because we were more than 3K AGL that the rule certainly applied to us at this time. I was quite sure this was his way of checking to see if I understood the rule. Not quite. He suprised me completely by telling me that he had been flying for more than 30 years and had never heard of any ‘Hemispherical Rule’. He also stated that if that were a real rule that it wouldn’t be applied unless we crossed into the southern hemisphere as we were flying in the northern hemisphere. I thought he was joking. When we got back to the airport I decided that we should look it up. He was very suprised by what he found. Later I also found out that he had never heard of a ‘demonstration stall’ either. The best rule is to always question everything and then verify. A lot of lives might depend upon it.
I remember it as ONE (odd-north-east). For what it’s worth, it isn’t heading that’s significant; it’s ground track. On a magnetic course of 000 through 179, the thousands digit is odd; 180-359, it’s even. VOR radials are magnetic, so those work. But the HI and compass do not, unless you’re flying on the one day a year there’s no wind. ;-}
It’s one of those details that great for a flight review “gotcha” question, along with the *pressure* (not indicated) altitude restrictions for use of O2.
When flying in mountainous regions I never use the hemispherical rule. I live and fly in the Pyrenees (the high mountain range between Spain and France) and I do a lot of flying in the glacier area of the Mont Blanc in the Alps, where the basic rule of looking out and listen to other traffic is used. You may find three or four aircraft flying over the glaciers around Mont Blanc at more or less the same altitude. Normally the flights are done from east to west but it is not mandatory so separation is kept by listening to the air-to-air frequency and by watching out. By the way, it is a great experience to fly there!
Of course, while you’re changing course and altitude (assuming you realize that you should do that), you’re still in some danger. At 8500′ over Denver last night, slightly west of southbound on vectors from Denver Approach, I wanted to climb only to 9500′ to go over Monument Hill to Colorado Springs. If I climbed too soon, however, I’d be nudging into the hemispheric rule problem. So I waited until my vectors were changed to slightly southeast. But would oncoming traffic be that careful? Fortunately at night, other traffic is easy to see, and while in the Bravo, I’m being watched like a hawk by ATC. But for certain, flying very close to north or south increases the likelihood of encountering oncoming traffic above 3000′ AGL.
On the other hand, below 3000′ AGL, often people follow no rules at all. The hemispheric rule doesn’t apply (although following it to the extent possible might reduce risk somewhat), but there seems to be very little attempt by many to stick with any particular altitude at all.
See and avoid–if possible, right?
The sky seems empty here in Colorado away from Denver. In the mountains there are not much traffic to be seen. So flying a C206 and hugging the side of a smaller mountain for the fun of it and following the curve eastbound I was startled by a Navy A-4 skyhawk doing the same thing only going westbound. There was about 200 to 300 feet difference in altitude and maybe the same in distance as we passed. Probably both shocked. It happened so quickly there was no time to be frightened. How two planes can arrive at the same point in space at the same time is difficult to imagine, but it does seem to happen all to frequently.