Canadians share pride in a variety of symbols and heroes that make our nation what it is today. But very few things in our history have generated so much pride and controversy all at the same time. The Avro Arrow is certainly on top of it. When the Canadian Aviation and Space Museum contacted Creadditive to scan the nose section of the Avro Arrow for reconstruction, it felt like our company got engaged in nurturing the myth of one of the greatest airplanes ever designed and built in Canada.
History of the Avro Arrow
After WWII, the Soviet Union began developing a fleet of aircraft capable of launching nuclear weapons across North America and Europe. To counter this threat, Western countries developed interceptors that could destroy these weapons before reaching their targets. A.V. Roe Canada limited, a company involved in aircraft repair and maintenance activities at what was then the precursor to the Person International airport in Toronto, began working on the design of the first jet fighter for the Royal Canadian Air Force (RCAF), the Avro CF-100 Canuck, which entered into service in 1953.
Given the rapid advancements in the Soviets’ bomber aircraft development programs, the RCAF realized quickly that our country needed a supersonic, missile-armed replacement for the Canuck.
The Avro Arrow was a culmination of a series of studies that begun in 1953 to improve the design of the existing Avro Canada CF-100 Canuck. The production of the first aircraft began in 1955 was rolled out to the public in 1957, demonstrating a very robust aircraft, reaching Mach 1.9 in level flight while demonstrating superior handling and overall performance. A star was born.
Avro Arrow Unveiling Ceremony (1957)
Then on 20 February 1959 (known as the ‘Black Friday’) the Prime Minister of the time, John Diefenbaker, abruptly halted the development of the Canadian icon and its engine. Canada tried to sell the design to other nations, without success. A few months later, the assembly line, tooling, drawings as well as existing airframes and engines were ordered to be destroyed, causing a major political controversy that still fuels debate among historians and aerospace experts today.
This legend of Canadian aviation is still very much alive today through arts and culture. Numerous books, movies and paintings were produced honouring the aircraft. The Canadian Aviation and Space Museum in Ottawa possesses the largest surviving piece of an Avro Arrow: its nose section. When the aircraft was disassembled after 1959, this piece was saved for use as a pressure chamber at the Institute of Aviation Medicine in Toronto. The Institute donated the nose section to the Museum in 1965.
Avro Arrow Nose Section, Canadian Aviation and Space Museum
The 3D scanning and 3D modeling process: choosing the right tool for the right job
Choosing the right scanning methods can seem almost obvious. In many cases, the project’s scope and size determines which method is used: long-range scanning for buildings and short-range scanning for objects or artifacts. What happens when a project is in this overlapping region where short-range and long-range scanning are both possible? How do you determine which method and equipment to use?
The CF-105 was scanned using Creadditive’s Surphaser, a LIDAR-based long-range 3D scanning equipment, to accurately digitize the features of this aircraft. Although a manual scan using a short-range 3D scanner would also have been possible, the scale of this project and the level of detail required for the product did not justify the use of a hand-scan method. In cases such as these, it becomes an art to determine how best to approach the scan and digital reconstruction, as the cloud point produced using long-range 3D scanners is more difficult to process into CAD software than the pre-meshed short-range scanner’s deliverable, due to higher uncertainty in the model’s digital representation.
Using point cloud best-fit and meshing tools allowed our engineer to create a parametric CAD model from the point cloud, after being interpreted, cleaned and reduced. Once the parametric output was produced, it was then possible to overlay the raw data from the scan onto the modeled produced to verify its accuracy and where deviations might have occurred in the automated processes. Manual corrections and touch-ups could then be performed to ensure that the highest possible accuracy was reached using this workflow.
3D modeling of the Avro Arrow Nose Section
Working for the client’s best interest
The method we used for this job is vastly different from a hand-scan based workflow, which typically outputs a deliverable which is corrected and meshed using automated processes with minimal user input. Although the hand scan method is more automated on the back-end (digital processing), it is much more resource intensive in the front end (data acquisition by scanning) and thus ends up being less cost-effective than using its long-range counterpart. For each project, it is thus imperative to consider both front-end and back-end costs to deliver the solution that is right for each project, each deliverable type and every client’s budget. That is why Creadditive created its own proprietary workflow evaluation tools, to properly determine at the outset of a project how the two scanning methods compare in terms of front-end vs back-end time, so we can accurately direct our clients towards the solution that is right for them.
For this specific project, Creadditive’s experts concluded that long-range 3D scanning was the best tool for this job, reducing the time required for data acquisition by 77% and the total cost of the project by 43%.
Whether it is using only one or a combination of both techniques (to measure gross dimensions using long-range scanning and capture fine details using short-range scanning), Creadditive will find and use the right workflow for your project!