Air India (AI, Delhi International) is once again in talks with Boeing (BOE, Washington National) regarding compensation for what it claims is the failure of its B787-8s to live up to their pre-determined fuel efficiency performance guarantees.

“Boeing has agreed that the weight is higher than what was previously indicated leading to lower fuel efficiency. They have agreed that they could not give the plane as promised. There is a commitment that they will discuss in good faith and will have a positive outlook to our demands for compensation,” an Air India official told India's Express.

As part of the investigation into the poor fuel burn, Air India had collected data for the past 24 months with the results now collated and presented to the US manufacturer.

Sources in the airline claim the aircraft, which had promised a 17% improvement in fuel efficiency over the A330, had only delivered 13-14%. In addition, it had claimed to be 37% more efficient than the B777 but had only shown an improvement of 28-30%.

"As far as the fuel efficiency is concerned, when Air India received these planes, even at that time, we knew that the planes were heavier than what they were originally promised to be," Rohit Nandan, chairman of India's state-run carrier, said. Air India was among the first operators to receive the revolutionary new aircraft though its initial batch was sourced from the "Terrible Teen" B787s - so-called for their operational problems and technical shortfalls.

Having already sought and received compensation for the late delivery of the aircraft in 2012, Air India now expects to reach an agreement with the manufacturer by year-end.

However, despite the difficulties experienced with the aircraft, Air India last week reaffirmed its commitment to the type by raising a bridge loan of USD410million for the purchase of four more Dreamliner jets. The aircraft form the crux of Air India's ambitious turnaround plan, aimed at improving the carrier's operational efficiency while driving down fuel costs.

Of the twenty-seven B787-8s Air India ordered in 2007, fourteen have so far been delivered with a two more expected in June and July. A further two are scheduled for delivery before the year end.