The bad news came through my earphones as I cruised over southeastern Newfoundland: "Gander’s reporting indefinite ceiling, zero; visibility zero." The only suitable alternate airports within range, Goose Bay and St. John’s, were similarly shrouded. Although fog had been in the forecast, it wasn’t supposed to have been so dense and extensive. I cursed myself for not having been more patient about beginning what was to be my third single-engine crossing of the North Atlantic. This was in 1963.
I reduced power to economize fuel and give me time to formulate a plan of action and pray for an improvement in the weather. But it soon became obvious that my only option was to execute an ILS approach and attempt a zero-zero landing. It was an emergency procedure I had heard discussed in hangar flying sessions, but I never thought that I would be confronted by such a challenge.
Fortunately, dense ground fog usually means smooth air and little or no wind, so tracking the ILS was to be relatively easy (except for the distraction caused by tickling rivulets of perspiration).
A little voice told me that I had to do this; I had no choice. It also reminded me that safety is proportional to the number of available options, and I had allowed mine to dwindle to one.
I passed over the outer marker under a clear sky. A setting sun had painted the rumpled and stratified undercast that spread beneath my wings as far as the eye could see, a reminder that nature’s gifts of beauty also can be the most hazardous.
The wings sliced acutely into the stratus at 500 feet agl, an altitude by which most instrument approaches come to an end. But instead of being greeted by approach and runway lights, my surroundings became darker and increasingly somber as the hands of my altimeter slowly unwound. I would have paid a princely price for a radio altimeter (and even more not to have been there in the first place).
"Concentrate! Concentrate!" I said these commands aloud as if to ensure that I would hear and heed my own advice. I had to keep the needles centered. I had to make only the smallest corrections. I had to avoid overcontrolling.
The perspiration found the small of my back. As Tennessee Ernie Ford once said, "I was as nervous as a long-tailed cat in a room full of rocking chairs." I even tried to instill confidence in myself by whistling the way John Wayne did in The High and the Mighty, but my lips were too dry despite how wet the rest of me was.
I began to wonder if I would see enough of the ground to flare for landing. I had to assume that I would not. Consequently, I made the approach with the flaps fully retracted, because this results in a nose-high attitude that would improve the odds of touching down on the main gear instead of on the nosewheel. And what if I bounced? I thought. How would I recover without visual references? Would I even recognize a bounce in time to execute a safe go-around? This was frightening, I thought—much easier in theory than in practice.
Until reaching the decision height (DH) at 200 feet agl, an ILS approach in zero-zero conditions obviously is the same as any other ILS approach. The big difference occurs when descending below DH without visual reference to the ground. To warrant descent below DH at such a time, the airplane must be stabilized on the glideslope and localizer; cross-tracking and needle chasing cannot be tolerated. Otherwise, a missed approach is mandatory.
Things really get dicey below 100 feet. With respect to staying on the localizer, a pilot should make only the tiniest heading changes. Some might prefer to pressure the rudder pedals left or right, as necessary, instead of using ailerons.
Forget about glideslope guidance below 100 feet. Contrary to popular belief, the glideslope does not lead to touchdown. It flares at 25 to 30 feet agl, and a pilot following it will sail high over the runway and eventually climb. This is why a pilot might not want to use the autopilot or flight director for a coupled approach when below 100 feet. (Aircraft with autoland systems utilize a programmed landing flare based on sink rate versus radio altitude.)
At 100 feet, nothing was visible outside the aircraft, nor could I afford to spend time looking for anything when so low. Too few cues can be confusing and do more harm than good. It was more important to focus all my attention on flying the airplane. I concentrated on holding a slight nose-high attitude while ignoring the glideslope and cutting the sink rate in half. (I found it difficult to hold a specific sink rate, and I did my best to keep the VSI needle roughly halfway between 0 and 500 fpm.)
The most frightening aspect of the approach was anticipating touchdown and not knowing when it would occur. The altimeter indicated that I had already descended below the published runway elevation.
The Beech Bonanza plunked onto the runway. It wasn’t a pretty landing but was better than some I had made visually. "Ruddering" the localizer kept me near the centerline, but the fog was so thick that I had to shut down on the runway and wait 30 minutes for a "follow-me" truck to find me.
The zero-zero approach and landing is an unapproved, emergency procedure used only when there is no other option. Next month, we’ll discuss the zero-zero takeoff, which can be equally hazardous but is approved.
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