Nov 7 (Reuters) -

UPS on Friday said it has grounded its fleet of

McDonnell Douglas MD-11s, the type of plane involved in

Tuesday's crash in Louisville, Kentucky, which killed at least

13 people.

"Out of an abundance of caution and in the interest of

safety, we have made the decision to temporarily ground our

MD-11 fleet," a UPS spokesperson said in an emailed statement to

Reuters. MD-11s account for about 9% of the company's fleet, the

spokesperson added. The grounding is effective immediately.

The news was first reported by NBC News.

On Tuesday night, a UPS cargo plane bound for Honolulu

crashed just after takeoff

at Louisville International Airport. On Friday, U.S. safety

investigators said as a bell sounded in the cockpit, three UPS

pilots were trying to control the cargo flight.

While UPS flight 2976 started uneventfully, a repeating

bell was heard on the aircraft's cockpit voice recorder just 37

seconds after the crew called for takeoff thrust, National

Transportation Safety Board member Todd Inman

told reporters.

Boeing ( BA ), which owns the MD-11 program since its

1997 merger with McDonnell Douglas, and FedEx ( FDX ), which

also operates MD-11 planes for cargo operations, did not

immediately respond to Reuters requests for comment.