It’s going to take a lot of coordination between Northwest College staff, contractors, emergency responders and pilots of twin-rotor military helicopter to remove a couple HVAC units from the roof of the college’s Orendorff Building.
Later this month, a Boeing CH-47D Chinook helicopter will lift two rooftop units (RTU) off the Orendorff Building at NWC, set them down safely, and lift two new units back onto the roof.
The operation is planned for Tuesday, May 21, with an alternate date of Wednesday, May 22 in case of bad weather.
The new rooftop units (RTU) are over 6,000 pounds each. It’s unclear what the older units weigh, but they’re likely in the same three-ton neighborhood.
“They are pretty sizable,” said Dave Plute, NWC plant manager.
But the Chinook is up to the task. Not only can they carry more than four times as much weight as the RTUs, they can operate in winds of nearly 35 mph.
The obvious question is: why not just use a crane? However, not only would crews have to cut down trees to get into position a crane large enough to handle the weight of the RTUs, a crane that size would also break concrete. By the time they got done removing and replacing trees and concrete, college officials would spend more than using a helicopter.
There’s some danger to the operation, but the planners are making safety a priority.
Before the operation begins, NWC will evacuate Orendorff and all buildings in the flightpath of the helicopter. The streets around Orendorff will be blocked off, as will Cabre Gym parking lot just north of the Fagerberg Building. That lot will serve as an emergency landing zone, as will the field west of the Science and Math Building. The main landing zone, where they’ll stage the new units, is the field north of the Vehicle Maintenance building.
Police and volunteer firefighters will be standing by in case anything goes wrong.
Plute said the senior pilots of Billings Flying Service, which will be providing the copter service, were very interested in this assignment.
“We should have a guy who’s been in the seat for quite a while,” Plute said.
If the mission gets the green light on May 21, the streets will be blocked off at 6 a.m. At 9:30 a.m., police, fire, ground teams and rooftop teams will perform communication checks. They expect to establish communication with the helicopter coming down from Billings by 10 a.m. At 10:45 a.m., the helicopters will take off from the main landing zone and hook onto the existing units. Then, 15 minutes later, they will put both the units down. Another 15 minutes after that, the new units will be hoisted onto the roof. Before noon, the helicopter lands, and crews will remove the rigging used to hoist the RTUs. By 12:30 p.m., the Chinook will leave Powell.
Of course, there are contingencies built into the plan. But the college has carried out this operation for another RTU on Trapper Gym in 2017, and Billings Air Service was very punctual.
“The Billings Air schedule is aggressive,” Plute said.
There’s a lot of parts that have to fall into place, even if the weather cooperates. Last week, Plute was on the phone with the RTU manufacturer, who said the delivery of the new units would be delayed.
At a planning meeting last week with various contractors involved in the operation, Plute discussed the delay and said he went all the way to the company’s president to try to explain that if the units are not ready for the operation, it could cost the college over $20,000 to reschedule with the air service.
Beyond the expense, Plute said the air service company’s availability is so limited, they’d have a lot of trouble rescheduling. He took a deep breath and said, “I’m seeking my inner calm, my patience.”
College officials planned to execute this operation last summer, intending to remove just one of the units on Orendorff. However, the helicopters are used during the fire season to fight forest fires. When the woods started burning, the feds jumped NWC’s contract, leaving the college to wait another year.
Over that time, a second unit developed problems. With it having to be replaced soon, NWC decided to replace them both now to save some money down the road.
The operation might draw an audience to watch the copters move the RTUs. Plute is asking people to stay outside the barriers and protect their eyes. The copter’s airwash will kick up a lot of dust.
Once the Chinook is gone, there will still be work to do: Other contractors must disconnect the old units — which requires draining refrigerant according to EPA regulations — and hook up the new ones.