Paul's Down-Home Page

Sometimes one word can speak volumes. This is especially true when there’s a well-defined and mutually understood vocabulary that all parties in a conversation are using– which is exactly what happens when you talk on the radio with an air traffic controller. Although it often sounds bizarre to outsiders, the back-and-forth between pilot and controller can be incredibly information-rich. The FAA has a standard glossary that pilots and controllers are supposed to use, and you can’t go far wrong by sticking with it. Many of the terms in the glossary compress a great deal of meaning into a few syllables, which is important when you’re busy– which, as either a pilot or controller, you will be!

For example, the controller at a busy training airport such as Palo Alto (which usually has between 500-700 takeoffs/landings per day, a lot for a small airport with a 2500′ runway) could say “One Tango Golf, there’s a 172 on final. If you go right now, then you can take off on runway 31”, or he can say “One Tango Golf, landing traffic, expedite, cleared for take off, 31”. Now consider the workload of a pilot flying into an airport like Atlanta or Dallas, or a controller in the tower cab at Chicago-O’Hare or Newark, and you see why brevity is so important.

My favorite of all these expressions is simple: “unable”. The glossary defines it thus:

Indicates inability to comply with a specific instruction, request, or clearance.

Depending on how you use it, it can mean “I won’t do that” or “I can’t do that.” Rather than provide a long explanation, all you have to say is “unable.” Suppose I’ve filed a route from point A to point B and the controller wants to have me deviate to point C, and I happen to be low on fuel? “Unable.” Want me to turn towards an area of built-up clouds? “Unable.” Because the pilot in command has ultimate responsibility for the safety of flight, as PIC you have unlimited authority to accept, or reject, controller requests or instructions– with the very significant caveat that you may be required to account for doing so. If the controller tells me to sidestep to a parallel runway on approach, and I don’t, and I cause an accident, having said “unable” isn’t going to get me out of trouble.

The magic word works both ways, of course: when you ask a controller for something (“Niner Eight Mike, request lower” to get a lower altitude, for example) the controller can merely say “Unable” and that’s it. Of course, whoever receives the U-word can always ask for something different, or explain why they want whatever it is.

Now I just need to brief the people I talk to most frequently so they know what the word means to. “Dad, can you take me to the mall?” “Unable.”

Recently I had the opportunity to fly down to Louisiana to see my mom, grandmother, and uncles. This was an easy trip: straight-line, it’s 411 miles from airport to airport. It took me 3:12 to get down there and 3:00 to get back. Why the difference? In a word, wind. In the northern hemisphere (and, more particularly, in the US, since that’s where I’m flying), prevailing winds tend to follow predictable patterns: west-to-east for much of the country, and (in general) onshore in coastal areas. The strength and direction of winds aloft vary, of course. For example, the definition of a frontal boundary (the line demarcating where a cold or warm front actually starts or ends) is an area where the wind suddenly changes direction and speed. It’s generally true that you’ll face headwinds when flying from east to west and tailwinds when flying from west to east, but the strength and direction of the winds can change quite a bit as you move across different types of terrain, through different weather systems, and so on.

astute readers can figure out exactly where I was when this picture was taken

In the picture above, the “GS” number in the lower right shows that I had a groundspeed of 148 knots. Since one knot is 1.14 statute miles/hour, that’s just over 170mph. That seems pretty good, considering that it’s more than double the speed limit on any of the roads that link Huntsville and Alexandria (and triple, or more, the speed limit for the West Monroe-Alexandria leg). The 128kts average groundspeed I had going westbound still equates to 147mph. Although a 20-knot difference is nothing to sneeze at, the practical impact is that it saved me… exactly 12 minutes, mostly because the winds kept changing.

That brings up the question of fuel usage. Every powered airplane has a set of performance charts that show you, for a given altitude and power setting, how fast you can go in still air (and remember, airspeed isn’t the same as groundspeed; that’s a topic for another post) and how much fuel you’ll burn while doing so. Book fuel burn for the Cessna 182P is between 12 and 14 gallons per hour, depending on your altitude and power setting. Most rental aircraft are rented “wet”; that is, the hourly rental rate includes gas and oil. In a rental, you therefore have an incentive to configure the engine for best speed even if you burn a couple more gph. When it’s your airplane (or when it’s a “dry” rental) you’re paying for the fuel, so you get to choose: would you rather burn more gph or get there a little later?

The correct answer is “it depends.” Aviation gasoline costs anywhere from $5 to $7/gallon in the US. (Why so much? Why the variance? Those are topics for another post too.) Suppose I can cruise at 130kts for 12gph, or 150kts for 15gph. That extra speed is going to cost me, let’s say, $18/hour. For a 411nm trip, that means I can get there in about 3 hours 9 minutes for just under 38 gallons (so, call it $228). On the other hand, at 150kts I could get there in only 2 hours 44 minutes, but it would cost me 41 gallons of fuel, or $246. In my case, since I was renting a plane, I went pedal to the metal, adjusting the engine for max speed rather than best fuel efficiency.

Now, this is an oversimplification, of course. It ignores the time spent climbing and descending (you burn more fuel in the climb, and less in a descent, but not enough to equal what you burned climbing), it assumes that ATC doesn’t reroute you anyplace inconvenient, and so on; it’s a good enough estimate for our purposes.

Let’s compare, now, the cost/mile of flying versus driving. I drive a 2005 Nissan Altima that gets 30mpg on the highway. Bing Maps says the fastest road route is 514 statute miles. So, that’ll cost me about $60 in gas, as opposed to $384 for the airplane rental. I’m leaving out all the other fixed and variable costs of the car; if I wanted this to be more precise I’d compare the cost of driving a rental car from here to there, but who would do that if they didn’t have to? Anyway, flying is considerably more expensive until you figure the time savings. Bing calls this an 8-hour trip, assuming no stops for fuel, food, or bathroom breaks. I can make it in a hair over 3 in the plane, though I have to take my own food. As with the car, that price stays the same whether I fly solo or with passengers (or cargo, such as the excellent banana pudding I brought back– thanks, Mom!)

Clearly I could come up with a business rationale that values my time at what Dell bills customers for it, or what I bill for it on standalone projects, but the right way to think about it, I think, is that the time I gain is priceless: being able to get to see family and friends, or attend important events, or just get out of town for a trip, is important, and the airplane gives me the flexibility to go farther, faster, more often than I could in a car, for considerably less money (usually) than it would take to fly commercial.

For another time: does it make sense to spend more money to rent or buy a faster airplane? It depends.

The boys and I had been discussing where we should go on vacation. As usual, they wanted to go someplace exotic, like on a cruise. I counteroffered with a trip to our former home in Perrysburg, reasoning that it was an easy flight and that they’d like to visit friends. It turned out to be a great trip and a good example of the utility of personal aviation. The plan was for David, Tom, and I to fly to Ohio, where Matt would join us, then we’d all fly back together.

We left on a Sunday mid afternoon, loaded up our rental 182 with full fuel and our bags, and departed HUA for Bowling Green, Kentucky, 158nm to the north. There were some rainstorms moving from west to east near Nashville, so we had to dodge them a bit, but between guidance from ATC and the onboard weather data provided by my Stratus/Foreflight combination, that was no problem. It’s worth pointing out that the value of datalink weather in the cockpit is not for real-time storm avoidance. It’s to see where storms were the last time the weather data was updated and to plan routes so that you stay well away from potential trouble spots.

Anyway, the flight to KBWG was uneventful; when we landed, we called a taxi to take us to the National Corvette Museum, which I hadn’t previously visited. I think it’s fair to say that my jaw was at least partially agape the entire time. There are some spectacular cars there, and their memorabilia collection is excellent. Our lunch at the museum cafe wasn’t bad either. In fact, my only gripe with the entire stop was the taxi service; if you plan a trip through the Bowling Green airport be forewarned that taxis there are hard to come by and (at least for the two we had) decrepit nearly to the point of unsafeness.

From Bowling Green, our route of flight took us another 340nm to the northeast to the Wood County airport (1G0), coincidentally located in Bowling Green. As with many other county-owned airports, the Wood County airport is clean, modern, small, and lightly used, although Bowling Green State University has a flying club there and there’s a small FBO on the field. By the time we arrived, the building had closed but thankfully the vending and restroom areas are open so we could clean up a bit. Our friends Matt and Anita were kind enough to come get us, since there’s no good way to get a rental car in Bowling Green, Ohio on a Sunday evening; we had a great visit on the way to the hotel, the first of several.

The trip itself was marvelous. We went to a Mud Hens game, ate at all our favorite restaurants (yay for Mr. Freeze!), and saw many of our friends. I was shocked to see how much the “little” kids I used to teach in Sunday school had grown, and likewise I could tell that my adult friend were surprised to see David, Tom, and Matt in their 2013 editions. Perrysburg and the surrounding area didn’t seem to have changed that much. In fact, when we visited Imagination Station, the former COSI, it was surprising how little it had changed.

take me out to the ball game… (not shown: chili dogs, scoreboard showing Mud Hens’ loss)

just because I love sunflowers– this was taken next to the parking garage across the street from the science museum

On the trip back, we had too much stuff– Matt had brought 2 weeks worth of luggage with him back from Vermont, and we were already close to the weight limit on the 182, so we shipped some bags back via UPS. The 182 is a forgiving airplane but that’s no excuse for overloading it or loading it outside its acceptable center of gravity (CG) range, as difficult as that might be to do. For trips with all four of us, it looks like we’ll need a bigger plane, or to pack lighter.

On our return flight we planned a fuel step at the Springfield-Lebanon airport in Kentucky. As with 1G0, this airport seemed scarcely used. The very friendly attendant gave us the keys to a crew car and said “oh, I’ll be gone by the time y’all get back from dinner, so just leave the keys here on the counter”. True to her word, when we returned from an excellent lunch at Mordecai’s, she was gone, so we parked the car, fueled the plane, and departed again for the 220nm leg back to Redstone. Here’s how the flight went on the way back:

see, naps do make the trip go faster

As a pilot and a father, that’s exactly what I’m aiming for: to make flights with my family so routine and uneventful that the kids fall asleep, get bored, and even quarrel a bit, just as they would in the car.. with the added bonus that a trip that would have taken 8+ hours each way in the car took less than half that. That’s one of the best parts of personal aviation: it’s a time machine, enabling you to go places in less time and thus making trips feasible that would otherwise be impossible. What’s not to love?