Britain's Royal Air Force Red Arrows perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

Britain's Royal Air Force Red Arrows perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

Britain's Royal Air Force Red Arrows perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

The Royal Canadian Air Force Snowbirds perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

The Royal Canadian Air Force Snowbirds perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

Britain's Royal Air Force Red Arrows perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

A CF-18 Hornet of the Royal Canadian Air Force performs during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

Britain's Royal Air Force Red Arrows perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)

Britain's Royal Air Force Red Arrows perform during the 2019 Canadian International Air Show in Toronto, Canada, Sept. 1, 2019. The annual event is held here from Aug. 31 to Sept. 2. (Photo: Zou Zheng/Xinhua)