Estimated reading time 4 minutes, 26 seconds.
Towards the end of December 2017, the main gearbox of an Erickson S-64F Aircrane, “Bubba,” timed out prior to the aircraft being needed for the Bipole III Transmission Line Project in Manitoba in the new year.
The S-64F Aircrane is a large aircraft — 88 feet in total length — and suitable hangar space was not available within a 300-nautical-mile radius of Winnipeg, Manitoba, until Dec. 30. In order for Bubba to be ready to go back to work, crews had to begin preparing the main gearbox on Dec. 28 on the apron at Winnipeg’s James Armstrong Richardson International Airport.
The task became problematic when Environment Canada issued multiple extreme cold weather alerts beginning on Dec. 28 that called for daily highs between -20 C and -30 C (-4 F and -22 F), with wind chills threatening -40 C.
“The timing of this couldn’t have been at a colder period of the year,” said Bryan Dudas, one of the aircraft maintenance technicians who worked on the project. Dudas described the challenges he and his team faced in an account accompanying his video of the gearbox change, which he shared with Vertical.
With temperatures reportedly colder than Antarctica at the time, the frigid weather caused dangers of frostbite for the crew, who had to ensure they were properly dressed. As Dudas recalled, “It was almost unavoidable to take a gasp of cold air without feeling a burning sensation in the lungs.”
Considering the working conditions, the maintenance crew decided on a strategy to get everything ready for the removal of the rotorhead assembly; the placement of the swashplate and main servo units; and the reinstallation of the new main gearbox/rotorhead assemblies.
However, the extreme cold caused numerous unforeseen setbacks. According to Dudas, the low temperatures caused the main gearbox output shaft to freeze to the rubber padding on the shipping can. The crew also had to use a heat gun to remove each lower pitch control bolt.
“As we hand-packed grease on the inside diameter pocket of the spherical bearing of the swashplate, the back side of [our] hands burned from the wind chill through the industrial nitrile gloves,” Dudas recounted. “As we wiped the excess grease with a rag, the grease began to crumble and turn into a dusty paste, something that we have never seen before.”
When a hangar finally became available in Winnipeg, the rubber of Bubba’s outboard right-side tire was cold enough to pull away from the wheel rim as it taxied in temperatures of -31 C (-24 F), causing further delays.
The maintenance task was untimely and cold, but nonetheless necessary for the sake of the transmission line project.
“If it wasn’t for the work experience, the great team of crew, and the joy of photography and filming in these locations, what other reason would we be here?” said Dudas.