By Alwyn Scott

MIDDLETOWN, Conn. (Reuters) - The head of aircraft engine maker Pratt & Whitney countered criticism on Tuesday from Qatar Airways and Lufthansa about Pratt’s new Geared Turbofan engine, saying early teething issues that have delayed delivery of some Airbus <AIR.PA> planes have been fixed.

"I'm not going to debate the CEO of Lufthansa or the CEO of Qatar. I'm just going to state the facts to you as I know them,” Bob Leduc, president of Pratt & Whitney, said at a media event in Connecticut.

The chief executive of Qatar Airways, Akbar Al Baker, said last week he had canceled one Pratt-powered A320neo, part of a large Airbus order, over concern that the engine required extra time to start under certain conditions.

Some A320s are at Airbus' factory in Toulouse, France, awaiting engines, and Lufthansa <LHAG.DE> is not flying the plane into some airports because of the slow start issue.

Pratt, a unit of United Technologies Corp <UTX.N>, is one of the world's biggest aircraft engine makers, along with General Electric Co <GE.N> and Britain's Rolls-Royce Holdings Plc <RR.L>.

Leduc ticked off Pratt's numbers: three airlines flying seven A320s with the engine, known as the PW1100G, which is demonstrating a 16 percent cut in fuel burn and 75 percent noise reduction compared with prior engines. In more than 2,000 takeoffs and landings so far, it has shown no major in-flight or takeoff issues, Leduc said, and it has dispatch reliability of 99.75 percent, meaning it was able to leave the gate on time.

"This has been a phenomenal entry into service" second only to the Boeing <BA.N> 777 in 1995, he said.

The GTF’s performance is critical as Pratt speeds up production from about 200 engines this year to 1,200 annually by the end of the decade, working through a backlog of 7,100 firm orders and commitments, enough to keep its factories running for eight years and generate $750 billion in revenue over 25 years.

The GTF engine is being used on new commercial jetliners from Airbus, Brazil’s Embraer SA <EMBR3.SA>, Canada’s Bombardier Inc, Japan’s Mitsubishi and Russia’s Irkut.

To ensure the ramp-up goes smoothly, Pratt is buttoning down its network of 1,600 suppliers, which provide about 80 percent of the engine’s content. Pratt is holding them to such a high standard that many do not quite measure up.

“About 44 percent of that (1,600) is what we would consider to be underperforming,” said Gregory Hayes, chief executive of United Technologies Corp. “That is, they don’t deliver at 95 percent on time and they don’t deliver with (quality of) 500 parts per million or better."

If a supplier is not meeting standard, Pratt will send engineers to help fix the problem, part of a multibillion-dollar investment in the new engine.

The company is about halfway through investing $1.3 billion in new facilities. At a sparkling white plant here, workers were assembling five engines on Tuesday.

Each 7,000-pound (3,175 kg) machine hung in a cradle from an overhead track, allowing workers to maneuver them for easier assembly, a trick learned from auto plants.

Two engines stood near the door, wrapped in white plastic, ready to ship to Airbus. A similar line exists in West Palm Beach, Florida, part of Pratt's strategy of having no single point of failure on its lines.

The company also has doubled up on suppliers, trying to find second or third sources for parts to ensure it will always have what it needs on time, Leduc said.

Leduc said Pratt is looking more deeply into its supply chain. It is shifting to monitoring suppliers 100 weeks ahead of when parts are due to arrive, up from 20 weeks in January.

If suppliers are not ready "and you're six weeks out, you're dead in the water," he said.

(Editing by Matthew Lewis)