DUBAI, May 7 (Reuters) - The chairman of Dubai carrier

Emirates said on Tuesday he was not happy with Boeing ( BA ), which he

said had promised him that it would fix issues plaguing the U.S.

planemaker, including its 777X program.

Emirates is the biggest customer of Boeing's ( BA ) 777X, which

will be the industry's largest twin-engined jet with around 400

seats. But its entry into service has been delayed by about five

years due to problems including certification delays.

Sheikh Ahmed bin Saeed Al Maktoum, a key member of Dubai's

ruling family and member of government, said he believed the

certification would now happen in the first quarter of 2025.

But he said the uncertainty over when it would be delivered

was putting pressure on Emirates, by far the Middle East's

biggest airline and which only uses large twin-engined jets.

Sheikh Ahmed said the airline would keep using existing jets

for longer than expected as a result of the 777X delays.

"I'm not happy," he told reporters at the Arabian Travel

Market tourism trade exhibition in Dubai.

"They promised they would do their best to fix it," he said

of Boeing's ( BA ) new management when asked about the issues it faces.

Boeing ( BA ) is overhauling its management amid mounting pressure

from airlines, regulators and investors as it grapples with a

growing crisis following a January mid-air panel blowout on a

737 MAX plane.