Air Canada (AC, Montréal Trudeau) has announced it revised its Boeing (BOE, Chicago O'Hare) order book during the first quarter of the year with the purchase now tilted towards the B737-8.

The carrier has firm orders for sixty-one B737 MAX aircraft which had consisted of thirty-three B737 MAX 8s and twenty-eight B737-9s. The order included substitution rights between them as well as for the B737 MAX 7 aircraft.

However, in a 1Q17 financial disclosure, Air Canada said it had now exercised its substitution rights and had rejigged the order substituting sixteen B737 MAX 9s for sixteen B737 MAX 8 aircraft. Consequently, the firm order now entails forty-nine B737 MAX 8 and twelve B737 MAX 9s.

The first two B737 MAX 8s are due for delivery by year-end with the remaining firm order MAX 8s and 9s due between 2018 and 2021, subject to deferral and substitution rights.

The MAX 8 will replace the carrier's A320-200s of which it currently has forty-two, while the MAX 9s will replace the A321-200s which number fifteen.