By Richard N. Velotta

Published Thursday, April 10, 2008 | 3:36 p.m.

Updated Thursday, Oct. 30, 2008 | 2:14 p.m.

You’ve heard all about the American Airlines flight cancellations that stranded thousands of passengers across the country, including McCarran International Airport.

The aircraft groundings involve the company’s 300 twin-engine MD-80 jets, which comprise nearly half of American’s jet fleet.

So how is Las Vegas-based Allegiant Air – whose entire fleet is comprised of MD-80 jets – coping and are Allegiant’s jets safe?

The grounding of the American jets was based on an audit conducted by the Federal Aviation Administration, which issued an “airworthiness directive” about the bundling of wires for an auxiliary hydraulic pump system in one of the wheelwells of the jet. The FAA directive was issued about two months ago.

The wiring bundle was required to be enclosed in a plastic harness that the FAA directive said had to be about four inches long. When American mechanics first addressed the problem, some of the harnesses were 3.7 or 3.8 inches long – not four inches. But when FAA auditors checked them, they said since they weren’t four inches long, they didn’t comply with the directive.

In addition, some of the spacing of the ties on the wiring bundle and the direction in which the lacing cords were facing weren’t consistent.

That’s why American has said the problems are not “safety-of-flight” issues.

Allegiant flies 36 MD-80s and will add one more by the end of the month. Today, the company announced that it had purchased six more from Finnair that will be introduced into the fleet by 2010.

Airline spokeswoman Tyri Squyres said Allegiant checked its fleet as soon as the FAA issued its directive. The airline was not among those audited by the FAA when the agency checked compliance with the directive.

Allegiant averages 17 flights a day in and out of McCarran with its MD-80 fleet, but far the biggest operator of that model plane at McCarran.

In addition to American’s average nine flights a day with MD-80s at McCarran, Midwest Airlines averages 3½ a day, Alaska Airlines averages three a day and Delta Air Lines, one a day.

American Airlines has canceled about 2,500 flights since it began reinspecting its planes. The airline expects its schedule to be back to normal by Saturday.