Riding the waves over the Rockies

Sometimes the impossible is possible. My husband Bruce's 1948 Cessna 140 aircraft is a case in point. With a darling little 85 hp engine, it can get him most places in about half the time of a car (and half the cost). But this plane wasn't designed to conquer the Rocky Mountains on a hot afternoon with full fuel tanks.

That is until this past September when he and his "little airplane that could" sailed over the Rocky Mountains at 15,500 MSL (Mean (above) Sea Level).

Bruce left from the Sisters Airport after work for a cross-country trip to Colorado. He put down at Malad, Idaho, at the end of the day and slept under the wing of his plane falling asleep gazing at the stars. Resuming his trip the next morning, he covered the rest of Idaho, Utah and parts of Wyoming.

By the time the Rockies were near, it was early afternoon and density altitude took over. Density altitude happens when the air temperature warms enough that the air molecules move farther apart from one another causing difficulty climbing or getting lift. The thinner air of higher altitudes negatively affects the performance of the engine, the lift of the wings and the pull of the propeller.

"Sort of feels like mush," pilots say.

Nine thousand feet MSL was all that could be achieved in that little plane that used to fly mail in Canada in its younger days, and Bruce needed a minimum of 11,000 feet to clear the mountain passes, the ones the highways follow up and over the Rockies. He was resigned to the fact that he'd have to turn back, try again the following day in the cool of the early morning or divert to a northerly route to avoid the Rockies altogether.

Then he thought of mountain waves...

Mountain waves were discovered quite by accident by Wolf Hirth while he was soaring in the lee of Germany's Riesengebirge Mountains in 1933. Due to the way moving air interacts with mountain terrain, unseen waves are created causing objects like birds and aircraft to ascend or decend at rates that can exceed 2,500 feet per minute.

So, after noting his fuel levels, the search for an unseen aerial elevator to sail upon was on! If you've ever flown in an airliner over the Rockies to land in Denver, you'll recall all the thermal effects around those peaks that can cause an aircraft to lurch all over.

In no time at all, Bruce found the wave he longed for and stayed there, flying in circles just like birds do, till he caught enough altitude to sail him and his little plane over the imposing Rocky Mountains. Bruce's rate of climb was 1,500 feet per minute, giving him all the lift he needed in less than five minutes. He took every inch of it, even though he didn't need it all, knowing the safety margin was great.

He followed Interstate 70 turning south at Highway 24 and flew over the highest airport in North America (and third highest in the world), the Leadville Airport, which sits at 9,927 feet MSL and has Mt. Elbert (14,433 feet), the Rockies' highest peak, as its majestic backdrop. After spying Denver from his aerial vantage point, he took the shortest visual path over to Centennial Airport where he was greeted by our two nieces and their families who helped him accomplish his surprise visit to our daughter and her husband.

Bruce says he felt like a cowboy riding his steed across the open plains viewing endless prairie and towering rock monuments. The little old Cessna is back, all snug in its stall... er...hangar at the Sisters Airport awaiting its next adventure into the wild blue yonder of America.