Cascade Locks airfield is busier than usual this month, and frequented by a large and distinctive helicopter, not the small airplanes typically seen parked on the grass along Forest Lane.
The helicopter is the workhorse K-Max, built by Kaman Aerospace of Connecticut, according to pilot Bruno Levi of Rotak Helicopter Services, of Anchorage, Alaska.
The tall, single-seat chopper weighs 5,000 pounds, and is purpose-built for carrying loads up to 6,000 pounds. Kaman built 38 K-Max craft and they’re used in logging, construction, firefighting and hurricane relief.
In this case, the construction project served by the K-Max is Bonneville Power Administration’s planned replacement of 100-foot towers along seven miles of transmission lines through the western Gorge.
Helicopters replace the pack animals used decades ago when the original towers were built.
Rotak is working with contractor Wilson Construction of Canby and drilling company Crux Subservice. Levi expects to be operating at Cascade Locks for about another week.
‘The project is going well,” he said.
Levi and other pilots based at the airfield and other area landing spots are carrying workers and equipment to the hills above Cascade Locks, where deep holes are drilled for tower anchors.
“The drill sites are not easily accessible so we have to fly in the drills and bags of crushed grout (concrete),” Levi said.
“This is purely external load, long-lining, no passengers, in a one-seat helicopter,” he explained. In long-lining, Levi drops a 100-foot synthetic cable to pick up and deliver cargo.
Via a smaller helicopter, workers are transported, and dropped by long-line and harness, to the work areas.
While the Forest Lane field is the operations base for the K-Max and support trailer and vehicles, the long-line cannot be attached at that site because it is illegal to cross the freeway with the line attached. So Levi flies to a quarry just east of town on the south side of Interstate 84, drops the long-line, and Wilson workers connect gear at that location.
“The linemen on the ground will be harnessed, and helicopter lowers them and they clip in like mountain climbers, and (the helicopter) drop them off on the towers or on the ground, wherever they need to be.”
He said about 20 people are working on the towers, two or three at each site.
“It can be dangerous work, especially with the winds, the winds make it tricky,” Levi said. “There are a lot of pinch points. With heavy loads up to 6,000 pounds, things can move.”
Levi joked that with its tall, thin design, “it’s like a piece of plywood, so you try to keep it headed into the wind.”
K-Max and operations
“When they need me, I fly to that site, put on the long-line on a hook, and they call me and let me know what they need,” said Levi, who was specially trained for K-Max using Husky helicopters with the same rotor system.
Levi explained the construction process this way:
“The workers drill holes 50-feet deep and install casing, and then when that’s done, pull the drill off, and I bring in a steel liner and have to thread that into the hole. Someone on ground guides it, and when (the liner) reaches the bottom, it’s been pre-measured and the grout hose goes all the way down, pours the grout, and forms the anchor.”
The K-Max based at Cascade Locks has logged around 400 working hours, according to Levi.
He called K-Max “a very unique and rare aircraft; the design is purpose-built for lifting. It does nothing else but lift. It affords great visibility, because just for lifting you don’t need a cabin and it has a small cargo cabinet.
“They’re very quiet compared to a conventional helicopter because they have no rear rotor, and the top rotor is designed so that downwash is minimal.”