Partek Ski Lifts, based in Pine Island, New York, advised ski resort operators using Borvig and Partek chairlifts to perform safety checks and to pay close attention to an electrical switch believed to have played a role in the accident at Sugarloaf.

The National Ski Areas Association believes about 170 Borvig and Partek lifts could be affected. There are 3,500 ski lifts in the U.S.

The bulletin issued Thursday called for daily checks but stopped shy of recommending that chairlifts be taken out of service.

A mechanical failure caused a 27-year-old Borvig chairlift to begin moving in reverse last weekend in Carrabassett Valley. Engineers believe a design flaw that utilized the wrong type of electrical switch prevented a safety system from locking the lift when it began going backward. Some of the panicked skiers were hurt when they jumped.

The National Ski Areas Association said the industry was moving swiftly by issuing a bulletin a day after Sugarloaf disclosed the flaw.

“The manufacturer, the state regulators and the ski area operators are taking a serious look at this and the public should be reassured about the safety and operation of chairlifts,” said Dave Byrd from NSAA.

Borvig went out of business in the 1990s. Partek provides parts and support for both Partek and Borvig lifts.

The Sugarloaf accident — the second in five years that injured skiers — began with a fractured drive shaft in a gearbox. That led to the failure of the lift’s primary brakes. An emergency brake eventually brought the King Pine quad lift to a stop after it moved more than 400 feet in reverse.

The system with the faulty switch is designed to deploy automatically and to bring the lift to an immediate stop; officials likened it to putting a stick in the spokes of a spinning bicycle wheel.

The accident is being investigated by engineers from Sugarloaf and its operator, Boyne Resorts, along with other industry officials and a state inspector.

Sugarloaf replaced the faulty component on six similar chairlifts on Wednesday and Thursday. The King Pine lift will remain offline while the investigation continues.