July 2012
My column in the May issue of Piper Flyer had been prompted by a copy of a letter I’d received from a fellow who had flown with me as copilot on a great many of my international airline flights in the 1990s. Capt. Scott Reynolds (now retired) was a prince of an aviator to have sitting beside me in those days while I plied back and forth across the Atlantic in widebody jets. His recent letter reminded me of a particular flight from Rome, Italy to Philadelphia in a Boeing 767 when deteriorating weather, increasing ATC delays and lowering fuel reserves caused us some interesting moments.
The outcome was an approach and landing from which I had no intention of executing a missed approach; we were going to land this airplane on that runway, irrespective of what the ceiling and visibility might prove to be. In effect, we had mentally committed ourselves to a zero/zero landing. We would, if necessary, have made one—but it turned out that the actual weather remained at the legal minimums, so no zero/zero touchdown was necessary. Like I said, we were ready.
Let’s look again at the definition of what I’m talking about. A zero/zero landing would literally mean landing the airplane while the ceiling was absolutely zero and the visibility was absolutely zero, too—a condition we hardly ever encounter. In reality, zero/zero means “hardly any” ceiling or visibility to work with.
It’s interesting to note that modern jetliners can do autolands regardless of what the cloud ceiling and the forward visibility might be, but the rules still require that the captain and crew have a slight chance of verifying that there really is a runway beneath them at least a few heartbeats before the wheels actually touch. For that reason, most full autolands require a few hundred feet of forward visibility so that the glow from the runway and centerline lights can be briefly seen by the flight crew before the rubber meets the concrete. In the vernacular it’s called “decision height,” and the pilot has a fraction of a second to decide to either keep things going just as they are or to make an autopilot missed approach.
That’s the legal and technical stuff. But when you’re shrouded in far more clouds, rain and fog than you normally deal with and the inflight situation has gotten out of hand, sometimes you’ve got to make a choice between the lesser of two evils: violating a government rule about landing weather minimums, or finding yourself running the fuel tanks dry while you’re still between airports. Not much choice, right?
My initial bouts with zero/zero occurred long before I ever officially stepped into an airliner’s cockpit. When I was a new General Aviation commercial pilot and flight instructor, one of the things we practiced religiously was taking our singles and light twins all the way to touchdown on an ILS approach.
Why? Well, for the fun of it, mostly—but also to ready ourselves for that day when the whole world within fuel range suddenly went W0X0F (the old acronym for zero ceiling and zero visibility in fog) and we had no choice but to do a zero/zero landing or crash with dry tanks. While I actually never found myself doing one of these W0X0F approaches for real, let’s look back at how we practiced them and why.
Even 40 or 50 years ago, most ILS approaches provided a very stable signal down to 100 feet above the runway, or even less. (Nowadays, the electronics are even better and localizer/glideslope signals are usually rock-steady to nearly the runway surface.) The first thing we would do was to prep the airplane by selecting a flaps and engine power configuration that provided us with a steady descent in a landing attitude. In most of the General Aviation airplanes that I flew, it meant little or no flaps, a steady airspeed, and not much engine power.
We’d nail the localizer and glideslope early on the approach and hold it. Since what we were simulating was a bad day in fog, wind wouldn’t usually be a factor and once the pilot had the needles nicely centered, they would stay that way. The key ingredient was to make any necessary corrections small or hardly at all because once you got the approach set up, the airplane would literally be on rails that were pointed directly at the touchdown spot on the runway.
One advantage of being in a smaller airplane is that the safety margins were far greater. A runway with a full ILS approach is invariably much wider and longer than most General Aviation airplanes would ever need, so just holding onto whatever heading/rate of descent/engine power that had worked to get the airplane to 100 feet above the touchdown point would work another 100 feet further. We would just hold what we had, and wait until the main wheels (which were now slightly below the nose tire, what with the flaps up and the airspeed low) touched against the concrete. Then, chop the power and roll to a stop. There was no flinching allowed for any flareout, since we were simulating absolute zero/zero conditions. Sometimes the touchdown itself would be a little on the firmer side, but it was always reasonable.
It was great fun to practice these zero/zero approaches—and a great confidence builder, too. After you’d proven to yourself repeatedly that you could hand-fly the airplane to an absolute W0X0F touchdown, the prospect of having to make a normal ILS approach to the legal minimums of 200 feet would seem like a piece of cake.
Another reason we did these simulated zero/zero approaches is that General Aviation airplanes were legal to make takeoffs in any weather conditions; it was only the landings that we had legal limitsfor. It was good to know that on days when we launched with less-than-legal landing limits, we could retrace our steps and get the airplane back down if we had to.
I also did some of this years later at the airline because, for ferry and test flights, we could legally make a takeoff when the airport was still technically below landing limits by declaring that we were going “Part 91.” It was nice to know that, if push came to shove, we could get back on the ground.
And speaking of that, I do have one additional airline story from the annals of zero/zero. It was nearly 50 years ago, and I was in the right seat of a Convair 240 piston airliner, holding north of New York’s La Guardia (KLGA) waiting out an ever-creeping ATC delay while we watched the airport weather getting worse and worse.
The captain was a nervous sort of guy who, I guess, had every right to be—he had been fired by the airline a couple of years earlier for refusing to fly an airplane that management thought that he should. The union had managed to get him his job back, but that experience made him wary of doing anything contrary to what he suspected the managers might prefer. Hence, we continued to hold and hold, waiting our turn for the ILS approach to LGA.
It was a perfect setup for a nightmare. Approach Control kept promising us that we would get our approach clearance in another 15 minutes—which became 15 more, and then 15 more after that. While the weather at LGA was still (barely) above minimums, I pointed out that if we wanted to go to our alternate airport, we had to leave the holding area right now, or else we wouldn’t have enough fuel to get there. While the captain debated this fact with himself, La Guardia Approach Control chimed in that we would be getting our approach clearance in 10 more minutes at the most.
So the captain said, “We’ll be okay to stay right here.”
Ten minutes became 15, then it became 20. I pressed La Guardia Approach as much as the captain would allow me; they transmitted back that things had slowed up a little more than expected, but that we were next. The weather was at minimums.
Finally, they took us off the holding stack and gave us a heading toward the final approach course. I glanced down at the fuel gauges. I’d never seen the needles that low, and now we didn’t have enough fuel in the tanks to reach our alternate.
We turned onto the ILS a hefty distance from the outer marker and began tracking the localizer inbound. I glanced at the fuel gauges again, licked my lips, and then said to the captain, “We need to land out of this approach. No fuel for a go-around.”
“I know,” he answered tersely. He was hand-flying the Convair pretty well—we had no autopilot on board—but I could also see that he was pretty nervous. He understood all too well what our situation had become.
“I’ll read altitudes to touchdown,” I said. The legal minimums didn’t mean anything at that point, so there was no sense in my referencing them. Only field elevation—the runway surface—mattered to us.
“O.K.” The captain kept the needles centered. “No go-around,” he repeated.
“Right.” We passed the marker, gear down. We were cleared to land. We were absolutely committed to land. “Eight hundred feet,” I called out. “Four hundred feet…three hundred feet…”.
We broke out at 200 feet with the rain-swept runway dead ahead; La Guardia never looked sweeter.
Touchdown. Taxi in. The captain and I never spoke another word to each other about the incident. But the La Guardia mechanic told me later that they had to add fuel to the Convair’s tanks before they could get an accurate reading on the fuel sticks. We had, maybe, 20 minutes of fuel remaining on board when we shut down at the gate.
As Scott Reynolds had said about his own experience of coming across the North Atlantic and into Philadelphia with me many years later, you might say that I learned about flying from that.
Editor-at-large Thomas Block has flown nearly 30,000 hours since his first hour of dual in 1959. In addition to his 36-year career as a U.S. Airways pilot, he has been an aviation magazine writer since 1969, and a best-selling novelist. Over the past 30 years he has owned more than a dozen personal airplanes of varying types. Send questions or comments to editor@www.piperflyer.com.
