WASHINGTON, Oct 21 (Reuters) - The chair of the National

Transportation Safety Board said on Tuesday that a weather

balloon may be responsible for cracking the windshield of a

United Airlines jet at 36,000 feet, prompting an

emergency landing.

WindBorne Systems said in a statement late on Monday that it

believes one of its balloons struck United Flight 1093, a Boeing

737 MAX, on Thursday over Utah.

NTSB Chair Jennifer Homendy said the board had received the

report from the company and is reviewing it as part of the

investigation. She said the incident "in the wrong situation

could have been really devastating for the aircraft and those on

board."

The incident had raised concerns the damage could have been

caused by space debris. Prior government studies have suggested

a very small risk of debris striking jets in flight.

Airplane windshields are multi-layered to prevent a loss of

cabin pressure if damaged in flight.

United said last week the flight that had left Denver with

134 passengers and six crew declared an emergency and diverted

safely in Salt Lake City. Passengers were transported on another

aircraft to Los Angeles later that day.

Homendy said the NTSB is reviewing technology that tells

aircraft where objects are in the air.

WindBorne said it has conducted more than 4,000 launches and

files notice for every balloon launched with the Federal

Aviation Administration.

"We are working closely with the FAA on this matter," the

company said. "We immediately rolled out changes to minimize

time spent between 30,000 and 40,000 feet."

The balloon company plans to use "live flight data to

autonomously avoid planes, even if the planes are at a

non-standard altitude. We are also actively working on new

hardware designs to further reduce impact force magnitude and

concentration."