Such grounding of aircraft is wreaking havoc on Biman's flight schedule chipping away at its market share.

No other international airline uses such antiquated aircraft which end up incurring a very high operating cost, Biman insiders said. They also identified the high operating cost as one of the main reasons for the national flag carrier's turning into a losing concern.

Usually reputed international airlines use only new aircraft for six to seven years before replacing them with the latest ones, according to Biman sources.

Biman presently owns three types of aircraft -- four DC10-30s, four F-28s, and three A310-300s. Production of DC10-30s and F-28s has been discontinued because of their lack of viability in business.

Biman's current market share of passengers plummeted to approximately 32 percent from 57 percent in 1991, the planning department of Biman disclosed to The Daily Star.

Due to a pre-eminence of bureaucratic red tape and for a vested interest group, Biman could not buy new generation aircraft so far, the airline sources said.

In 2005-06, Biman carried only about 14 lakh passengers out of the 30 lakh that boarded different airliners at Zia International Airport, the sources added.

Out of a total of 11 aircraft of the Biman fleet, only six are operating now while the rest are grounded due to technical malfunctions.

Out of the four DC10-30s three are 29 years old while the other is 17 years old, the four F-28s are 31 years old, and two of the A310-300s are 11 years old while the other is 7 years old.

On Saturday, some 200 Abudhabi bound passengers of Biman got stuck at Zia for 39 hours because the flight was delayed due to a technical glitch on the antiquated aircraft, the sources said.

In another incident on Sunday, a DC10-30 of Biman had to hover over Zia for half an hour before it could make a landing, due to a trouble with its wheels. The aircraft is yet to be ready for flying, the sources said.

"Antiquated aircraft of Biman impose high operating cost because they are fuel guzzlers," said a high official of Biman wishing anonymity.

“Parts of those old aircraft are also not available as the manufacturing company discontinued them making it difficult to repair those antiquated planes," the official added.

"Everyday Biman's aircraft face technical delays, as they are very old," Mamdud Khan, general manager of the central control of Biman, told The Daily Star yesterday.

"Biman ends up incurring additional cost due to hotel accommodations and feeding of passengers when it cannot maintain flight schedules," Belayet Hossain, general manager of the planning department of Biman, told The Daily Star last night.

"Biman has to spend additional amount of money to buy extra fuel for its antiquated fleet of aircraft, which makes 40 percent of its total cost while a standard airline's fuel cost is usually about 25 percent of its total cost," he said.

"Due to an aging fleet, Biman's maintenance cost is also very high," he said.

"Currently grounding of aircraft for technical reasons occurs almost everyday making Biman's schedule go awry," he added.

Biman's Managing Director Dr MA Momen said, "Replacing the antiquated aircraft with new generation ones is imperative for remaining competitive in the aviation business."

Biman now has air service agreement (ASA) with 42 countries, but it can use only 18, he added.

"Biman's competitors like Emirates, Singapore Airlines, Qatar Airways, and Kuwait Airways use new generation aircraft while Biman uses antiquated ones," Belayet Hossain quipped.

In 2005, Biman sent a proposal to the erstwhile government for purchasing four Boeing 777s, six A-330 airbuses, and three A-319 aircraft, but due to bureaucratic red tape the proposal bore no result, said a Biman high official.

"Boeing proposed to arrange finances for buying those aircraft, seeking a guarantee from the Bangladesh government," the official said adding, but the government did not provide any guarantee, so Boeing lost its interest.