WASHINGTON, March 15 (Reuters) - The CEOs of major U.S.

airlines urged Congress on Sunday to move quickly to end a

29-day partial government shutdown that has forced 50,000

airport security officers to work without pay, warning it could

further disrupt U.S. air travel.

Absences by Transportation Security Administration officers

have ​already disrupted travel at some major airports over the

last week, raising alarm as the busy spring break travel season

continues.

"Too many travelers are having to wait in extraordinarily

long - and painfully slow - lines at checkpoints," the CEOs of

American Airlines ( AAL ), United Airlines, Delta Air

Lines ( DAL ), Southwest Airlines ( LUV ), JetBlue Airways ( JBLU )

, Alaska Air ( ALK ) and others wrote in an open letter

to Congress.

"First, leaders should immediately come together to reach an

agreement to fund the Department of Homeland Security. Then they

need to act so this problem never happens again," they added.

Last fall, a 43-day government shutdown led to widespread

flight disruptions and the FAA ordered a 10% flight cut at major

airports. "Once again air travel is the political football amid

another government shutdown," the CEOs wrote.

The group of airline executives - which also includes senior

executives at cargo carriers FedEx ( FDX ), UPS and

Atlas Air - called for legislation to ensure during future

government shutdowns all critical government aviation personnel

are paid.

Senators from both parties failed on Thursday in competing

efforts ​to fund the TSA, which said last week that ​more than

300 officers have quit since the ‌shutdown ⁠began.

The Homeland Security Department's funding lapsed on

February 13 after Congress failed to reach a deal ​on

immigration enforcement reforms demanded by Democrats.

Airlines are expecting a ​record-breaking spring ⁠travel

period, with 171 million passengers expected to fly, up 4% from

the same two-month period last year.

Last week, some airports like Houston Hobby and New Orleans

reported security lines exceeding two hours as ​TSA absences

rose, while on Saturday, Newark said it was experiencing

higher-than-normal delays.

"Americans - who live in your districts and home states -

are tired of long lines at airports, travel delays and flight

cancellations caused by shutdown after shutdown," the CEOs

wrote.

Some airports have closed some security checkpoints and

others are working to raise money to help TSA workers buy food

or other essentials as they go without pay.