Some of the nation’s largest airlines are cutting back their Sept. 11 flight schedules, bowing to Americans’ reluctance to fly on the anniversary of the terrorist attacks.

American and United, the two largest carriers, are making unspecified reductions for that day based on weak bookings. No. 3 Delta is trimming flights for the entire work week of Sept. 9-13.

Unease about another terrorist strike is behind the decline in bookings, but so are patriotism and remembrance, according to interviews with consumers, travel agents and industry experts.

While air travelers may be wary, Richard Rubenstein, a professor of public affairs at George Mason University in Virginia, said, the date may be one of the safest for travel.

“It’s highly unlikely anyone would do anything on the anniversary of the attack,” he said. “They are not sentimentalists.”