Grounding the aircraft led to delays on most of the 121 flights Allegiant had scheduled Friday, company spokesman Brian Davis told reporters, and 16 flights were rescheduled for Saturday. Two Friday flights between Oakland, Calif., and Reno were canceled.
"We want our customers to know we take disruption of their travel plans very seriously," said Davis, spokesman for the airline and its parent company, Allegiant Travel Co. But he said safety of passengers and crew members was the company's top priority.
Davis said he didn't immediately know how many passengers were affected, but most would be compensated with discounts on future travel. Allegiant would also make hotel arrangements for travelers stranded overnight, he said.
Disruptions could continue through the end of the month, Davis added.
No injuries were reported among the 144 passengers and six crew members on the plane that was evacuated Monday before takeoff for Peoria, Ill.
By late Thursday, all 52 MD-80 aircraft in Allegiant's fleet were grounded until they could be brought into compliance with a McDonnell Douglas recommendation — updated in 2007 — that calls for an annual overhaul of all four inflatable chutes on aircraft older than 15 years, Davis said.
Allegiant had been maintaining the MD-80 slides according to an original three-year maintenance interval, the spokesman said.
The FAA learned about the maintenance issue while investigating the evacuation of Flight 436 and directed Allegiant to immediately inspect slides on its MD-80 fleet, said agency official Ian Gregor in Hawthorne, Calif.
Gregor said the FAA doesn't comment on pending investigations and he couldn't discuss possible sanctions against the airline.
Davis said that by Friday morning, 15 aircraft were returned to service and Allegiant also had six Boeing 757s and two Airbus A320s aircraft in the air. The company also sought to charter aircraft to fill scheduled routes.
Davis said passengers affected by the slide problem would be compensated on a sliding scale ranging from a $100 voucher for future travel for a two-hour delay, to a ticket refund and a $200 credit for future travel if a flight was canceled.
He promised updates on the company website, http://www.allegiantair.com , and a telephone information line, 702-505-8888.
Allegiant serves about 100 mostly small cities and vacation destinations including Orlando, Fla., Las Vegas and the Phoenix area. It carried nearly 2.3 passengers in and out of McCarran airport in 2012.
The company's shares fell $4.89 to $98.10 in afternoon trading Friday.