Air India CEO Campbell Wilson said on Tuesday that the global aircraft shortage, which is limiting airline growth, will continue for four to five more years. This is because supply snags are affecting production at Boeing and Airbus. Wilson, speaking at an event organized by travel news website Skift said that he sees pinch-points in the supply of narrowbody engines, business and First Class seats, and certain elements of aircraft fuselages.

Air India is undergoing a major turnaround two years after Tata Group acquired control of the airline. However, delays in jet deliveries have complicated its restructuring efforts. These setbacks forced the airline to use older jets for longer than planned. This increased maintenance costs and slowed its modernization and growth drive.

Wilson responded to reporters when asked how Air India would handle delays: “There’s not much we can do. We are as much a victim of circumstance as any other airline.”

“If your capacity is limited, you have to be more ruthless about where you deploy aircraft in order to maximise the return,” said he. “It means that you can’t expand in places where you would like to expand.”

Wilson added that leasing aircraft can be challenging due to the competition among airlines for aircraft and the various configurations that are available.

Air India has ordered 470 aircraft from Airbus and Boeing for 2023. This includes 10 of Boeing’s 737 MAX jets and 190 of Airbus’s much-delayed 777X planes. The airline ordered 100 additional Airbus aircraft late last year.

Wilson responded “Who knows” when asked for an estimate of the delivery date for the 777X. Wilson’s comment highlighted the uncertainty among airlines that have ordered the jet, which is considered to be a successor of Boeing’s 777 – one of the most successful long-haul aircraft.

Wilson told Reuters that Air India has been holding off on buying additional Boeing jets pending the planemaker’s clearing its backlog.

Boeing is recovering after a crippling two-month strike by workers last year. A cap set by the US Federal Aviation Administration prevents Boeing from producing more than 38 737 MAX planes per month. Boeing did not respond immediately to a Reuters’ request for comment.