By John Crawley

WASHINGTON (Reuters) - American Airlines may need several more days to restore normal operations after renewed wiring inspections of its MD-80 fleet forced the cancellation of nearly 2,500 flights this week, the company's chief executive said on Thursday.

Gerard Arpey also said the carrier had unsuccessfully asked the Federal Aviation Administration for an alternative to grounding the planes, because it did not believe the problem posed an imminent safety threat.

The unit of AMR Corp (AMR.N: Quote, Profile, Research) grounded its entire stable of nearly 300 MD-80 medium-range airliners on Tuesday. The disruption has affected more than 100,000 passengers and wreaked havoc with its operations at big airports like Chicago and Dallas.

Arpey apologized to passengers and said he had no doubt American operates safely. "I put my kids on these airplanes all the time," he told a conference call with reporters.

Delta Air Lines Inc (DAL.N: Quote, Profile, Research) and Alaska Airlines Group (ALK.N: Quote, Profile, Research) canceled a few dozen flights combined over the same issue with their MD-80s.

Arpey said American is trying "to stay ahead" of the problem and it could take "several more days to get back up to speed."

The inspections relate to a 2006 FAA order to ensure that wiring in the MD-80's right wheel well is properly installed and secured to guard against electrical shorts and fire.

The FAA, under pressure from Congress and government watchdogs to step up oversight, demanded in March that American reinspect MD-80s to ensure wire bundles were properly secured.