WASHINGTON, April 3 (Reuters) -

U.S. regulators should require airlines to inspect, and if

necessary, replace latches on Boeing 757 airplane doors,

the National Transportation Safety Board said on Thursday,

citing a 2023 emergency evacuation of a FedEx ( FDX ) flight in

Tennessee.

The NTSB also urged the Federal Aviation Administration

to require Boeing 727 and 737 operators that use the same latch

design to inspect and replace them if warranted. The agency said

defective latches "could lead to delayed evacuation during an

emergency should the slide become jammed." It also called on

Boeing ( BA ) to issue new service bulletins for operators.

Boeing ( BA ) and FedEx ( FDX ) did not immediately respond to requests for

comment. The FAA said it takes NTSB recommendations seriously

and will respond within an appropriate timeframe.

The October 2023 FedEx ( FDX ) flight -- a 757 built in 1988 --

received an engine indication and crew alerting system message

indicating a failure of the left hydraulic system shortly after

takeoff from Chattanooga and returned to the airport but was

unable to lower the landing gear.

After multiple unsuccessful attempts to extend the gear,

the crew performed an emergency gear up landing. After landing,

a jumpseat occupant attempted to open the left door, which

rotated halfway open but would not open fully, and the slide did

not deploy.

The occupant then attempted to open the right door but

it lodged on the slide pack, which prompted the occupant to use

force to open the door and the slide deployed normally.

There were no injuries to flight crew members or the

jumpseat occupant.

The NTSB found one door latch that releases the slide

pack when the door opened did not conform to the configuration

of the release cable assembly.

The NTSB said FedEx ( FDX ) inspected the doors on the 97 other

airplanes in its Boeing 757 fleet after the accident,

finding 46 doors -- about 24% -- that were not compliant with

airworthiness directives issued in 1986 and 2001.

After the findings, Boeing ( BA ) issued an April 2024 message

to operators about the issue and a non-U.S. carrier said its

inspection of four 757 doors found three doors with latches not

in compliance, the NTSB said.