Horizon Air’s head of flight operations recently warned of a a lax safety culture among the airline’s pilots and called for urgent action to prevent a serious air accident. John Hornibrook, the Seattle-based airline’s president of flight operations, wrote in an internal Nov. 27 email message: “If we sit back and do nothing, we will have an accident. Nothing good can come of the trajectory we are currently on.”

The Seattle Times reported that the email was sent to top airline managers and pilot leaders.

The incidents Hornibrook listed ranged from pilots going over airspeed limits to aircraft approaching stalls, and also included weather-induced threats that perhaps could have been avoided.

In an interview with the newspaper, Hornibrook and Horizon president Joe Sprague said the distribution of the email should be seen as an example of Horizon’s high safety standards.

“The memo was meant to respond to the spike we saw in irregular events,” Hornibrook said. “I’m not sitting back and waiting for something bigger.”

Horizon Air’s pilots fly Bombardier Q400 turboprops and Embraer E175 jets on routes that link smaller cities into a feeder network for Alaska Airlines.

The only serious accident in the airline’s passenger service history happened in 1988, when a Q400 crash-landed at Seattle-Tacoma International Airport after an engine fire. Four passengers suffered serious injuries.

In 2017, a major pilot shortage at Horizon caused hundreds of flight cancellations. In response, Horizon raised pilot pay, added signing bonuses and boosted recruitment.