North Star Restoration

North Star Restoration: a labour of love—and precision MRO work

The Canadair North Star was an unusual beast, borne out of a desperate need for Canadian long-range air transport following World War II . . .

BY JAMES CARELESS

The airframe was either a military Douglas C54 Skymaster or its DC-4 civilian cousin. The four propeller engines were Rolls-Royce Merlin 622s: together they gave the North Star a 35 mph faster cruise speed than the DC-4’s original Pratt & Whitney R2000 radial piston engines, but were much noisier due to the 622’s superchargers; the ones mounted on the inner engines discharged against the fuselage. The result was a tough, reliable transport that was long on capability, but short on silence.

71 North Stars were built: The civilian versions used by Trans Canada Airlines (now Air Canada) featured pressurization, luxury appointments and extensive noise insulation along with the TCA-designed MacLeod exhaust crossover system. The military versions had no pressurization, webbing-and-aluminum “troop seats” and such thin noise insulation that “getting a headache from the roar of the Merlins went with the job,” says Bill Tate.

Tate is vice president of the Project North Star Association of Canada, a volunteer group that aids the Canada Aviation and Space Museum (Ottawa) in the restoration of vintage aircraft like the North Star. For 10 years, these skilled volunteers have worked side-by-side with CASM conservators in the meticulous disassembly, component restoration/replacement, and refitting of RCAF 17515 — the last North Star in existence.

The level of care being shown in restoring 17515 to flightworthy display-only condition is akin to the restoration of a fine Swiss watch: every single element, whether seen or unseen, is being brought literally to a factory-fresh level.

18 Years of Service, 39 Years of Neglect

17515 joined the Royal Canadian Air Force in 1948, and served as a troop and equipment transport until 1965.
“This aircraft flew during the Korean War, supported United Nations operations worldwide, and worked with NATO,” Tate says. “When the RCAF retired its North Stars, 17515 was flown to the Canada Aviation and Space Museum in 1965, here at the former RCAF Rockland airbase. Due to a lack of storage space, it sat outside for the next 39 years, enduring the winter cold and snow, and the summer sun and thunderstorms.”

In 2003, local aviation enthusiasts formed The Project North Star Association of Canada, and persuaded the CASM to start restoring 17515. Since then, association volunteers have donated 60,000 hours working on the last North Star. In that time, they have restored the cockpit and three of the engines, and have also made substantial headway in cleaning and restoring/repairing parts of the airframe.

A look inside the cockpit, the galley and washroom, and the storage compartments reveals just how much they have done: “We’ve done everything that you don’t see as well behind the walls,” says Tate. “We want this restoration to create an aircraft where everything is up to standard.” However, the amount that remains to be done — the interior, the outer skin, and the landing gear — is substantial.

A Nuts-and-Bolts Challenge

From an AMT perspective, restoring the 17515 North Star is an exercise in extreme precision. Whatever the component — engine, electronics, or airframe — it has to be carefully removed then cleaned using varsol baths, glass bead blasting, and Scotch Brite plastic scouring pads. Given that the aircraft has been parked outside for 39 years, the amount of cleaning is substantial. (To help the CASM with the projec’s cost, the Project North Star volunteers raised the funds to buy one of the two bead-blasters being used in the restoration process.) Removing rivets by hand can also be mind-blogging, since even the smallest airframe section can contain hundreds of rivets of different types and thicknesses.

“After all this time, any oil remaining inside the engine has solidified to a kind of thick gunk,” says Tate. “Meanwhile, the birds that have set up nests inside the aircraft have caused us real problems because the acid in their waste products literally eats through the aluminum.”

Speaking of aluminum, the weathering on this North Star’s aluminum skin is so severe that any cloth used to clean it turns black within seconds. Unfortunately, not all parts can be cleaned. Many are just too damaged by time to be brought back to life. Further, since Canadair stopped making the North Star more than half a century ago, spares are often impossible to find.

This is where expert volunteers such as retired machinist Rolf Geiger come into play. Using skills gained through decades of professional work as a tool and die maker, Geiger and a handful of volunteers/CASM conservators scan through the original North Star manuals and original parts to make replacements by hand. That’s if they’re lucky. Sometimes, the North Star crew has nothing more than an old photograph to go on, perhaps aided by a similar part in some other still-existing aircraft. In making replacement troop seats for instance, Geiger has created his own dies to cast the seat brackets, and hand-curved the aluminum seat spars into the right shape.

“He can create anything out of virtually nothing,” says Tate. “Often times, we’ll be stuck trying to come up with a specific tool suited to working on the North Star. Rolf will listen to us, think a bit, and then ask what colour we’d like it in!”

Once the restored part is ready to go, it may have to be painted to an appropriate period finish, including stencilling warning labels with the right lettering. Then the tricky part comes: fitting the parts back together. The problem is that 17515 is 65 years old. With 18 years of hard military flying under its belt, followed by decades of settling, many parts have changed shape over time.

A High-Level View

In addition to the nuts-and-bolts challenges of restoring the 17515 North Star, there are also challenges on the macro level, namely, finding the money and facilities to do major system and airframe repairs. “One thing we really need is help overhauling the landing gear,” says Tate. “This is a massive job where a helpful MRO would make all the difference, just as Hope Aero of Mississauga did when they restored the North Star’s 12 propeller blades.” Restoring the rest of the cabin — (the cockpit, front galley and washroom are done, but the rest of the interior including the aft washroom needs work) — is another big undertaking. But again, the work has to be done to bring 17515 to flight display worthy condition.

That said, the goal is not to fly this aircraft again: “There is irreparable damage by corrosion to one each of the propeller hubs that makes it unsafe to start the engines,” Tate explains. “If we start the engines, the propeller could lose a blade. The imbalance would take the engine out of its mounts.”

Instead, the goal is to restore every single element of this North Star so that, 100 years from now, someone could ask, “how did they make this kind of airplane work?” and get the answer just by looking at its components, both visible and invisible. Think of this North Star as a physical prototype that could be duplicated and then the duplicate can be flown: that’s where 17515 will fit into the historical record.

“The Canadair North Star was an incredible aircraft that shaped our aviation history, and stands as a monument to the engineering skill and innovative imaginations of post-WW2 Canadian engineers,” says Tate. “That is why we want to preserve this last example in as close to perfect working order as we can — as a tribute to their genius, and as physical proof of what they achieved.”