A Canada-wide aviation fuel shortage may ground some small planes and helicopters.

Last month, Imperial Oil warned Transport Canada that aviation gasoline shipped from its Edmonton-area refinery could interfere with aircraft fuel gauge sensors. The Calgary-headquartered company is Canada’s only supplier of “avgas” for small piston-based planes and some helicopters.

Pat Cunningham of the Springbank Airport Business and Pilots Association told CTV Calgary that supply is running low, and the company has not given any indication of when more fuel will be available.

“It’s very frustrating and very alarming for many of the owners,” he said on Tuesday. “People have on average anything between six and 20,000 litres in their tank here. That, on a good day, could mean anything between two and four, and five days of flying.”

It’s not just hobby pilots being impacted. Many of the aircraft based at Calgary/Springbank Airport are owned by survey companies, contractors and training schools.

Imperial Oil spokesperson Jon Harding said the “at-risk fuel” was predominantly sold in Western Canada. The company said the fuel warning does not extend to larger aircraft that use jet fuel, known in the industry as “Jet A.”

Imperial Oil said it halted shipments from its Strathcona refinery as soon as the company became aware of the issue on Feb. 13, and continues to investigate what caused the drop in fuel quality. Transport Canada instructed those who purchased the fuel to quarantine and test it.

Calgary/Springbank’s avgas passed the test, but its supply is quickly running out. Nearby Three Hills Airport received a bad batch, and is now on empty.

Hording said in a separate statement to CTV Calgary that Imperial Oil is exploring options for alternative supplies of avgas, and is working as quickly as possible to fulfill customer needs.

The fuel shortfall has boosted avgas sales at Okotoks Air Ranch Airport, about 70 kilometres south of Calgary/Springbank. However, the good times may be short-lived for Fueling Around President Trent Obrigewitsch. He worries he may have to resort to buying more expensive foreign fuel if Canadian supply remains out of reach.

“It’s more expensive to bring product in from other locations, including the U.S.,” he said. “So it will affect us even when we go to order more again.”

With a report from CTV Calgary