September 17, 1963: Varese, Lombardy, Italy
Even before Canadair had begun pushing "Project Viper" and securing sales in South America, it had been decided that the first four prototypes of the CL-215 would be built and tested by Aermacchi at their facilities in Varese, Italy.
Priority had been put on getting one prototype each of the Rolls Royce Dart powered version and General Electric T64 powered version. The Dart powered version had been completed and taxi runs done with it by early September.
September 17 saw the first taxi runs of the T64 version completed and a small naming ceremony held for the two aircraft.
The Dart powered prototype was given the name "Dorothea" and the T64 prototype would be known as "Teresa".
A former Aermacchi executive:
"We surprised ourselves in getting the first two CL-215 prototypes finished less than a year after deciding to go ahead with the project. Mind you, Canadair had already done a lot of the design work. Mostly, we just had finer details to work out in the design by this point.
Given the situation with the MB-326 in Canada and what a priority it was to secure customers for it, we decided to take the pressure off Cartierville by starting the CL-215 prototyping and testing in Varese. We had the space available to do it and we had Lake Varese available when it was time to test the aircraft in the water.
Canadair sent their CL-215 design team to Italy to help form the Aermacchi part of the team and lead the team. The design was Canadian, so it was only fair that Canadians should be leading it."
By the end of September, both CL-215 prototypes had taken their first flights and were seen favourably by the test pilots.
A former Canadair test pilot:
"Testing the first CL-215 prototypes in Italy went quite smoothly for the most part; they both handled well and didn't hit us with any nasty little surprises.
I'd flown Dart powered aircraft before. It was a good engine and I knew what to expect from it, but aero engine technology was going ahead by leaps and bounds at the time and the Dart was an older engine as turpoprops went.
The T64 was also a good engine, nicely responsive and no particular bad habits.
The real advantage of the T64 was how much lighter it was than the Dart. The version of Dart we used was of higher horsepower than the T64 in order to offset the weight difference.
The difference in engines made "Teresa" a lighter aircraft on the controls and more fuel efficient than "Dorothea". I had a feeling "Dorothea" would be the only prototype fitted with the Dart, and I was right."
November 10, 1963: Lake Varese, Italy
Early in the morning, "Teresa" and "Dorothea" taxied into the waters of Lake Varese for the first time. Their landing gears were retracted and neither aircraft had any water leakage through the hull. The morning was occupied with taxi testing on the water and further tests for leakage. Both aircraft did very well in those tests.
After lunch, the crews returned to the aircraft and it was time to test their ability to take off and land on water.
The former Canadair test pilot continues:
"The advantages of the T64 over the Dart were made very clear when taking off from water. Even without taking on a load of water, "Dorothea" took longer to get airborne and used more fuel to do so than "Teresa". None of the test pilots were keen to try scooping water with "Dorothea" after taking off with her empty and we let the design team know that in our reports.
They still made us do water scooping tests, but it was all very academic by that point. Both aircraft could scoop and get back in the air, but "Dorothea" took a bit longer to get back up in the air and the fuel guages made clear to us that she wouldn't be able to stay in the fight as long as "Teresa" without going home for fuel.
Immediately after the scooping trials, all further testing with the Dart was cancelled and the T64 was settled on as the engine for the CL-215 from that point on.
It wasn't the end for "Dorothea" though. She was inspected and it was decided that it was worth keeping her and refitting her with T64s. In spring of 1964, she was back in the air with new engines and seemed much happier for the change."