April 17 (Reuters) - Boeing's ( BA ) safety culture and

production quality, both at the center of a full-blown crisis

following a Jan mid-air panel blowout, are facing scrutiny on

Wednesday in two U.S. Senate hearings.

Boeing ( BA ) has been grappling with a crisis that has undermined

its reputation following the Jan. 5 mid-air panel blowout on a

737 MAX single-aisle plane. It has undergone a management

shakeup, U.S. regulators have put curbs on its production, and

deliveries fell by half in March.

Members of the U.S. Senate Commerce Committee said in a

morning hearing that Boeing ( BA ) needs to do more to improve its

safety culture. Panel members released a report in February

criticizing some of the planemaker's safety practices following

two crashes involving the 737 MAX which killed a combined 346

people.

U.S. Senate Commerce Committee Chair Maria Cantwell said she

expects Boeing ( BA ) to submit a serious plan in response to a

deadline from regulator the Federal Aviation Administration

(FAA). In late February, the FAA said Boeing ( BA ) must develop a

comprehensive plan to address "systemic quality-control issues"

within 90 days.

"I personally think that Boeing's ( BA ) recent manufacturing

problems are merely a symptom of a much deeper problem, the

destruction of a proper safety culture by, you know, share price

obsessed executives," U.S. senator Tammy Duckworth said.

A second is expected to feature testimony and documents

from Boeing ( BA ) whistleblower Sam Salehpour, a current engineer at

the company, his lawyers said.

Salehpour has claimed that Boeing ( BA ) failed to adequately shim,

or use a thin piece of material to fill tiny gaps in a

manufactured product, an omission that could cause premature

fatigue failure over time in some areas of the Boeing 787

Dreamliner.

Boeing ( BA ) has challenged Salehpour's claims against two of its

widebody jets, the 787 and 777, which fly internationally.

Boeing ( BA ) said on Monday it has not found fatigue cracks on

in-service 787 jets that have gone through heavy maintenance.

In a statement on Wednesday, Boeing ( BA ) defended the safety of

the twin-aisle jets, arguing that the global 787 fleet has

safely transported more than 850 million passengers, while the

777 has safely flown more than 3.9 billion travelers.

The FAA said in a statement that every aircraft flying

is in compliance with the regulator's airworthiness directives.