The morning in early May dawned bright and clear. My wife, Jeri, and I would fly that day from Baker, Montana, to McMinnville, Oregon. Our plan called for my sister to meet us and then the three of us would drive to Seattle for my daughter's college graduation.
The briefing consisted of the usual airmets for afternoon rain showers and occasional light to moderate turbulence associated with the typical spring weather. I was surprised, however, when the briefer shared an airmet calling for occasional mountain obscuration and restricted visibility of five to eight miles along the eastern slopes of the Rocky Mountains because of dust. Dust! It seemed preposterous this early in the spring that visibility would be reduced by dust.
I made note of the forecast along my route of flight as well as current conditions at some of the en route airports. As the briefing concluded I requested a clarification of the airmet for mountain obscuration. Apparently a significant windstorm had lifted dust into the jet stream from some desert region in China. After being carried into the United States the dust was drifting along the eastern ranges of the Continental Divide as high as 16,000 feet msl.
An uneventful preflight of our early model Piper Comanche followed our quick trip to the airport. Soon we were in the clear early morning air and cruising at 10,500 feet on the first leg of our trip. I planned a refueling stop in Helena, Montana, before resuming the next portion of the trip to Pendleton, Oregon. Here we would refuel and eat lunch, then engage the final leg of our flight over the Cascade Mountain range into the Willamette Valley and McMinnville.
A half-hour into our flight the familiar landscape of Miles City and the Yellowstone River valley was passing off our left wing tip. I asked Jeri to have the Great Falls Sectional chart folded and spread out on her lap for ready access. Once we passed the town of Roundup my route to Helena would be over terrain that I had never seen from the air before.
Two hours had elapsed and the jack pine-dotted hills near Roundup were behind us. I glimpsed a brown haze ahead instead of the tall mountain ridges flanking the peaks that dominated the horizon westward from central Montana. After I gave flight service a pirep they asked if I had the airmet for mountain obscuration. I replied that I did. Just off the Comanche's nose I could see a distant small town with the outline of a body of water lying a few miles beyond. A quick glance at the sectional identified the town as Harlowtown and Martinsdale as the reservoir. Upon nearing the reservoir, we found our visibility deteriorating. With five miles of visibility at best and cruising at 175 mph, I reduced manifold pressure two inches and commenced a gentle descending turn back to the east to see if the visibility would improve at a lower altitude. By now we had been in the air approximately two and one-half hours and I wished to refuel no later than three. In descending to the minimum altitude where I felt I was safe, the visibility did not improve. Consulting the sectional I saw that some 30 miles directly to the west of Harlowtown lay Elk Peak with its surrounding mountains. Also, a few miles to the southwest of our position the Crazy Mountains reared up out of the plains to an elevation of more than 11,000 feet. I began to catch occasional glimpses of this range ghosting beyond the veil of dust, which had engulfed our route. A furtive glance at my wife revealed nervousness that she was trying hard to disguise. She was concentrating hard on the sectional chart in front of her, trying to find something on it that corresponded with what she was seeing on the ground.
I had to make a decision. I mentally began to sort out what options I felt I had. Trying to reach Helena over unfamiliar mountainous terrain in lowering visibility was foolhardy and therefore out of the question. I could return to Roundup, which probably remained clear of the dust but would crowd my fuel reserves. As I was going through these mental gymnastics, I realized that I was becoming disoriented relative to my position to the terrain. Nothing on the sectional now seemed to correspond with what was visible below. I reached for the loran and pushed the nav button to display the nearest airport. To my relief it displayed that I was only 28 nm from Livingston. Armed with this new information I proceeded to fly the displayed bearing, making sure that I maintained a safe distance east of the Crazy Mountains, which tracked south parallel to our new route.
Minutes later I faintly began to make out the valley where I knew we would find Livingston and the airport. Soon thereafter I announced our position over the common traffic advisory frequency (CTAF), acquired the current surface conditions from unicom, and entered the downwind leg to Runway 22 at Mission Field. After refueling, another briefing, and flight-plan modifications with Great Falls radio, we were airborne once more. With the information I had just gained I expected the visibility to gradually improve on our route to the west. We decided to continue our trip, but now we would remain above Interstate 90, which was visible through the haze.
Once beyond Bozeman Pass and approaching Bozeman, I announced our position over Gallatin Field's CTAF. No response. After another transmission with no response I felt a little uneasy, since I expected busy airspace. In the absence of any radio contact I(decided that I would fly well south of the airfield, still keeping I-90 in sight.
Suddenly, in the haze directly in front of us and no more than a few miles away appeared a Northwest Airlines Boeing 727 bound for Gallatin Field. I quickly banked to the south to increase separation. I would later discover that the CTAF had recently changed with the commissioning of a tower frequency and my outdated chart did not reflect any of these changes.
By keeping the interstate in sight we reached Missoula. As predicted, the visibility continued to improve and by the time we reached the Continental Divide west of Missoula we were experiencing 15 to 20 miles of visibility.
I now alter my route so that I am flying over familiar terrain that has highly recognizable features if I think the possibility of encountering reduced visibility exists. Also, I carefully check notams and carry current copies of charts and the airport/facility directory to better ensure that I am transmitting on the proper radio frequencies. Flight following would have been an invaluable resource had I enlisted the service. The controllers undoubtedly would have alerted me to the presence of the 727 and perhaps other traffic that may have been near my route of flight.
I also will be cautious of those weather briefing details that sound "a little too preposterous" to be taken seriously.
Tim L. Tromble, AOPA 1273914, is a minister and a private pilot with more than 500 hours in seven years of flying. He owns a Piper Comanche.
An original "Never Again" story is published each month on AOPA Online ( www.aopa.org/pilot/never_again/).
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