Boeing said on Thursday it expects Indian and South Asian airlines will add 2,835 commercial aircraft to their fleet over the next 20 years, a four-fold increase over current levels, as a rising middle class and healthy economic growth spur travel.

On the impact of the production slowdown on delivery timelines, Boeing officials did not provide an estimate of the delay, saying that they are being transparent with their customer airlines.

Air India and Akasa have ordered planes from Boeing and the deliveries have been delayed by several months due to slowdown in production and strike at the company’s manufacturing unit in the US last year.

Boeing said the Indian and South Asian region will need 2,835 new aircraft by 2043, continuing the fleet growth observed over the last decade

Boeing projects that South Asian carriers will need 2,835 new airplanes over the next 20 years, driven largely by demand from India. The aviation market in this region is expected to grow rapidly, with aircraft fleet set to quadruple by 2043.