March 18 (Reuters) -

A Southwest Airlines ( LUV ) flight was less than 200 feet

behind a business jet when the Southwest ( LUV ) pilot aborted the

landing and made an emergency maneuver to narrowly avoid a

collision at Chicago Midway Airport on February 25, U.S. safety

officials said on Tuesday.

A FlexJet Challenger business jet entered the runway without

authorization, prompting the Southwest Boeing 737-800 to circle

and re-approach the landing, a maneuver called a go-around.

The Southwest ( LUV ) first officer saw the business jet and

realized it was not stopping, called for a go-around and the

captain executed it, the National Transportation Safety Board

said in a preliminary report.

The FlexJet crew said the instructions from controllers did

not make sense and said after they sought clarification they

were given a new taxi route. The flight crew initially read back

the instructions incorrectly but the ground controller

immediately reissued the instructions and received a correct

readback.

The FlexJet flight crew said the sun was impeding

visibility from the right side of the aircraft and crew members

did not recall seeing any hold short line or pavement markings.

The crew said it did not observe the Southwest ( LUV ) jet on final

approach.

A controller instructed the FlexJet to hold short as it

approached, but the transmission was not acknowledged, the NTSB

said.

This month, the Federal Aviation Administration said it was

taking steps to address safety issues involving general aviation

and business jets.

After the Chicago incident, the FAA said it was

initiating a safety-risk analysis of close encounters between

pilots flying visually and pilots flying under air traffic

control. The FAA said it had met with general and business

aviation groups.

Over the last two years, a series of near-miss incidents

has raised concerns about U.S. aviation safety and the strain on

understaffed air traffic control operations. Several incidents

have involved close calls with small planes.

The FAA said it would take a series of steps to remind

pilots to check notices for situations they can encounter during

flight, be familiar with their destination airport, avoid

complacency by paying attention to pre-flight checklists and pay

close attention to onboard collision warnings.